Ceramic compositions and methods of use

Abstract

The present disclosure provides devices that include a therapeutic agent bound to a printed three-dimensional structure. Ink formulations for three-dimensional printing are further disclosed. Additionally, methods for manufacturing the devices and methods of their use in treating diseases, for example, in a subject in need thereof, are provided herein.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Application No. 63 / 153,279, filed February 24, 2021, the entirety of which is incorporated herein by reference.

[0002] Government Rights This invention was made with government support under W81XWH-18-C-0182 awarded by the USAArmy Medical Material Command and W81XWH-20-C-0069 awarded by the USAArmy Medical Research Acquisition Activity. The government has certain rights in this invention.

[0003] Sequence Listing This application contains a Sequence Listing, which has been submitted in ASCII format via EFS-Web and is incorporated by reference in its entirety. The ASCII copy created on December 3, 2020 has the filename 50222-709_601_SL.txt and is 285,147 bytes in size. [Background technology]

[0004] Three-dimensional (3D) printing is a manufacturing process that creates three-dimensional solid objects from digital files. In additive methods of 3D printing, objects are created by depositing successive layers of material until the desired object is created, with up to micrometer precision. Combined with computer-aided design (CAD) software, 3D printing allows for the generation of complex functional shapes that can be easily customized compared to traditional manufacturing methods.

[0005] Surgical implantation of scaffolds and / or other forms of graft materials to promote tissue regeneration is a useful technique when the implant can match the mechanical properties of natural tissue. A variety of materials can be used as inks in the fabrication of porous 3D printed structures for implantation, including materials that mimic tissue and allow tissue regrowth. Inks with effective bioactivity and mechanical properties are required for the regeneration of natural tissue, and when used in 3D printing, can be customized and employed in the repair of large tissue defects. Summary of the Invention

[0006] The present disclosure provides ink formulations and methods for 3D printing scaffolds. Additionally, scaffolds that can be produced using such ink formulations and methods are provided. The scaffolds may be coated with therapeutic agents, such as those that promote bone growth, and / or seeded with cells to produce devices for use in tissue replacement and implantation. For some devices, the therapeutic agents may be tethered to the scaffold via targeting moieties that interact with the scaffold components, such as ceramic materials. Advantages of the materials and methods described herein include providing 3D printed customizable implants, as well as more universal objects, such as pieces, chunks, or cylindrical objects. When the implant is 3D printed, precise control of the implant geometry is possible. Thus, implants printed with these inks are suitable for a number of different treatments, including long bone repair, spinal fusion, maxillofacial structures, and the like. Different formulations of the inks produce materials that result in implantable devices with different properties, including different porosity and flexibility.

[0007] Various inks and scaffolds of the present disclosure are designed to enhance the accessibility of therapeutic agents and / or targeting moieties to scaffold components, such as ceramic materials like β-tricalcium phosphate, e.g., the ink formulations described in Examples 1-2.

[0008] The various inks and methods of the present disclosure are designed to improve the manufacturability of 3D printed scaffolds by converting the ink into 1.75 mm diameter filaments. In filament form (rather than syringe-based bioprinting inks), larger quantities of material (e.g., 1 kg of filament wound on a spool) can be prepared, stored, and used continuously before the material needs to be reloaded in the 3D printer. In addition, Fused Filament Fabrication (FFF) 3D printers generally have a larger available build volume than syringe-based bioprinters and can print at faster nozzle speeds, both of which improve manufacturing throughput. Furthermore, there is a very wide variety of FFF printers on the market compared to the relatively small classification of syringe-based bioprinters. For example, both ink formulations #5 and #6 were fabricated into 1.75 mm diameter filament material and were demonstrated in an FFF 3D printer, as further described in Examples 1-2.

[0009] The various inks and scaffolds of the present disclosure are designed to optimize the bioabsorption of the scaffold. For example, the copolymers used in ink formulation #2 (caprolactone / glycolide copolymer (95:5)), ink formulation #3 (caprolactone / glycolide copolymer (90:10)), and ink formulation #4 (poly(D,L-lactide-co-glycolide) copolymer (50:50)) have faster absorption rates than polycaprolactone. Absorption rates vary from slowest to fastest, such as polycaprolactone, polycaprolactone / polyglycolide copolymer (95:5), polycaprolactone / glycolide copolymer (90:10), polydioxanone / L-lactide copolymer (90:10), poly(D,L-lactide-co-glycolide) copolymer (50:50).

[0010] In one aspect, provided herein is a three-dimensional structure comprising about 50% to about 90% by weight ceramic and about 10% to about 50% by weight polymer having a plurality of micropores. In some embodiments, the micropores have an average pore size of about 1 micron to about 500 microns in diameter, or about 50 microns to about 250 microns, or about 150 microns. In some embodiments, the micropores provide the structure with additional surface area for contact with a therapeutic agent. In some embodiments, the micropores are formed after removing one or more pore-forming agents from the structure. In some embodiments, the pore-forming agent comprises a second polymer, a sugar, or a salt, or a combination thereof. In some embodiments, the micropores are formed by the release of carbon dioxide from a blowing agent present during the manufacture of the structure. In some embodiments, the blowing agent comprises sodium bicarbonate.

[0011] In another aspect, provided herein is a three-dimensional structure comprising about 50% to about 90% by weight ceramic and about 10% to about 50% by weight polymer, having an open porosity of about 15% to about 50%.

[0012] In other aspects, provided herein is a composition having a viscosity of about 1 g / cm 3 ~About 2g / cm 3 The ceramic ceramic material is a three-dimensional structure having a density of about 50% to about 90% by weight and about 10% to about 50% by weight of a polymer.

[0013] In another aspect, provided herein is a three-dimensional structure comprising about 50% to about 90% by weight ceramic and about 10% to about 600% by weight polymer, having a strut diameter of about 300 micrometers to about 600 micrometers.

[0014] In some embodiments of the structures provided herein, the ceramic comprises calcium phosphate, hydroxyapatite, fluorapatite, bone, silicate, or vanadate, or a combination thereof. In some embodiments of the structures provided herein, the polymer comprises polycaprolactone, caprolactone / glycolide copolymer, poly(D,L-lactide-co-glycolide) copolymer, or dioxanone / L-lactide copolymer, or a combination thereof. In some embodiments of the structures provided herein, the ceramic comprises calcium phosphate, hydroxyapatite, fluorapatite, bone, silicate, or vanadate, or a combination thereof, and the polymer comprises polycaprolactone, caprolactone / glycolide copolymer, poly(D,L-lactide-co-glycolide) copolymer, or dioxanone / L-lactide copolymer, or a combination thereof.

[0015] In some embodiments of the structures provided herein, the polymer comprises polycaprolactone and the ceramic comprises calcium phosphate. In some embodiments, the structure comprises about 65% to about 85% by weight calcium phosphate and about 15% to about 35% by weight polycaprolactone. In some embodiments, provided herein are structures comprising about 65% to about 85% by weight calcium phosphate and about 15% to about 35% by weight polycaprolactone.

[0016] In some embodiments of the structures provided herein, the polymer comprises a caprolactone / glycolide copolymer and the ceramic comprises calcium phosphate. In some embodiments, the structure comprises about 65% to about 85% by weight calcium phosphate and about 15% to about 35% by weight caprolactone / glycolide copolymer. In some embodiments, provided herein are structures comprising about 65% to about 85% by weight calcium phosphate and about 15% to about 35% by weight caprolactone / glycolide copolymer. In some embodiments of the structures provided herein, the polymer comprises a poly(D,L-lactide-co-glycolide) copolymer or a dioxanone / L-lactide copolymer and the ceramic comprises calcium phosphate. In some embodiments, the structure comprises about 65% to about 85% by weight calcium phosphate, and about 15% to about 35% by weight poly(D,L-lactide-co-glycolide) copolymer, or dioxanone / L-lactide copolymer. In some embodiments, provided herein are structures comprising about 65% to about 85% by weight calcium phosphate, and about 15% to about 35% by weight poly(D,L-lactide-co-glycolide) copolymer, or dioxanone / L-lactide copolymer.

[0017] In some embodiments of the structures provided herein, the structures are formed from an ink comprising a ceramic, a polymer, and a sacrificial pore former. In some embodiments of the structures provided herein, the structures are formed from filaments using an extrusion-based three-dimensional printing method.

[0018] Further provided is a device comprising the structure provided herein and a therapeutic agent. In some embodiments, the therapeutic agent comprises a bone morphogenetic protein (BMP). In some embodiments, the therapeutic agent comprises a targeting moiety, and the targeting moiety is non-covalently attached to the three-dimensional structure. In some embodiments, the targeting moiety comprises a polypeptide at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to any one of the sequences in Tables 2-3. In some embodiments, the therapeutic agent comprises a chimeric polypeptide comprising a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to any one of SEQ ID NOs: 433-441.

[0019] In one aspect, a device is provided herein, the device comprising a therapeutic agent and a printed three-dimensional structure, the printed three-dimensional structure comprising about 50% to about 90% by weight of a ceramic and about 10% to about 50% by weight of a polymer. In some embodiments, the therapeutic agent is non-covalently bound to the printed three-dimensional structure. In some embodiments, the ceramic comprises calcium phosphate, hydroxyapatite, fluorapatite, bone, silicate, or vanadate, or a combination thereof. In some embodiments, the ceramic comprises β-tricalcium phosphate (β-TCP). In some embodiments, the structure comprises about 70% to about 80% by weight of a ceramic. In some embodiments, the structure comprises about 75% by weight of a ceramic. In some embodiments, the polymer comprises a polyester. In some embodiments, the polymer comprises polycaprolactone (PCL), polyglycolide, lactide, or polydioxanone (PDS), or a combination thereof. In some embodiments, the polymer comprises polycaprolactone (PCL). In some embodiments, the polymer comprises polyglycolide. In some embodiments, the polymer comprises polydioxanone (PDS). In some embodiments, the polymer comprises lactide. In some embodiments, the lactide comprises L-lactide. In some embodiments, the lactide comprises poly(D,L-lactide). In some embodiments, the polymer comprises a copolymer. In some embodiments, the copolymer comprises polycaprolactone (PCL) and polyglycolide. In some embodiments, the copolymer comprises about 90-95 mol % PCL and about 10 mol % polyglycolide. In some embodiments, the copolymer comprises poly(D,L-lactide-co-glycolide) copolymer. In some embodiments, the copolymer comprises about 40-60 mol % poly(D,L-lactide) and about 40-60 mol % polyglycolide. In some embodiments, the copolymer comprises PDS-glycolide copolymer. In some embodiments, the copolymer comprises about 90-95 mol % PDS and about 5-10 mol % glycolide.In some embodiments, the copolymer comprises a PDS-L-lactide copolymer. In some embodiments, the copolymer comprises about 90-95 mol % PDS and about 5-10 mol % L-lactide. In some embodiments, the structure comprises about 15% to about 25% by weight polymer. In some embodiments, the structure comprises about 25% by weight polymer. In some embodiments, the printed three-dimensional structure is formed from an ink comprising about 30% to about 70% by weight ceramic, about 10% to about 30% by weight polymer, and optionally one or more additional agents. In some embodiments, the ink comprises about 50% to about 70% by weight ceramic. In some embodiments, the ink comprises about 60% by weight ceramic. In some embodiments, the ink comprises about 15% to about 25% by weight ceramic. In some embodiments, the ink comprises about 20% by weight ceramic. In some embodiments, the ink comprises one or more additional agents. In some embodiments, the ink comprises one or more additional agents at about 1% to about 30% by weight. In some embodiments, the one or more additional agents comprise an additional polymer, a particulate, or a foaming agent, or a combination thereof. In some embodiments, the one or more additional agents comprise an additional polymer. In some embodiments, the additional polymer comprises polyethylene glycol. In some embodiments, the additional polymer is present in the ink at about 10% to about 30% by weight. In some embodiments, the one or more additional agents comprise a particulate. In some embodiments, the particulate comprises sodium chloride, calcium chloride, sucrose, trehalose (e.g., α,α trehalose dihydrate), or mannitol (e.g., D-mannitol), or a combination thereof. In some embodiments, the particulate is present in the ink at about 1% to about 10% by weight. In some embodiments, the one or more additional agents comprise a foaming agent. In some embodiments, the foaming agent comprises baking powder (e.g., monocalcium phosphate, sodium bicarbonate, cornstarch) and / or azodicarbonamide. In some embodiments, the particulates are present in the ink at about 5% to about 20% by weight.In some embodiments, the therapeutic agent comprises a mammalian growth factor or functional portion thereof. In some embodiments, the therapeutic agent comprises one or more polypeptides selected from Table 1, or functional portions thereof. In some embodiments, the therapeutic agent comprises a bone morphogenetic protein (BMP). In some embodiments, the therapeutic agent comprises a targeting moiety, and the targeting moiety is non-covalently attached to the printed three-dimensional structure. In some embodiments, the targeting moiety is attached to the printed three-dimensional structure with an affinity of about 1 pM to about 100 μM. In some embodiments, the targeting moiety comprises a polypeptide at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to any one of the sequences in Tables 2-3. In some embodiments, the targeting moiety comprises about 2, 3, 4, 5, 6, 7, 8, 9, or 10 sequences selected from the sequences in Tables 2-3. In some embodiments, the therapeutic agent comprises a chimeric polypeptide comprising a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to any one of SEQ ID NOs: 433-441.

[0020] Also provided is a method of treating a condition in a subject in need thereof, comprising administering a device to the subject. In some embodiments, the condition comprises bone defect, cartilage defect, soft tissue defect, tendon defect, fascial defect, ligament defect, organ defect, osteotendinous tissue defect, skin defect, osteochondral defect, osteoporosis, avascular necrosis, or congenital skeletal deformity, or a combination thereof. In some embodiments, the method comprises spinal fusion. In some embodiments, the spinal fusion comprises posterior lumbar fusion (PLF) and / or interbody fusion. In some embodiments, the method comprises bone repair, dental repair, craniomaxillofacial repair, ankle fusion, vertebroplasty, osteoplasty, navicular fracture repair, tendon-bone repair, rib reconstruction, subchondral bone repair, cartilage repair, or surgical implantation of a three-dimensional structure or device, or a combination thereof.

[0021] Further provided is a formulation comprising about 30% to about 70% by weight of a ceramic, about 10% to about 30% by weight of a polymer, and optionally one or more additional agents. In some embodiments, the ceramic comprises calcium phosphate, hydroxyapatite, fluorapatite, bone, silicate, or vanadate, or a combination thereof. In some embodiments, the ceramic comprises β-tricalcium phosphate (β-TCP). In some embodiments, the ink comprises about 50% to about 70% by weight of a ceramic. In some embodiments, the ink comprises about 60% by weight of a ceramic. In some embodiments, the polymer comprises a polyester. In some embodiments, the polymer comprises polycaprolactone (PCL), polyglycolide, lactide, or polydioxanone (PDS), or a combination thereof. In some embodiments, the polymer comprises polycaprolactone (PCL). In some embodiments, the polymer comprises polyglycolide. In some embodiments, the polymer comprises polydioxanone (PDS). In some embodiments, the polymer comprises lactide. In some embodiments, the lactide comprises L-lactide. In some embodiments, the lactide comprises poly(D,L-lactide). In some embodiments, the polymer comprises a copolymer. In some embodiments, the copolymer comprises polycaprolactone (PCL) and polyglycolide. In some embodiments, the copolymer comprises about 90-95 mol % PCL and about 5-10 mol % polyglycolide. In some embodiments, the copolymer comprises poly(D,L-lactide-co-glycolide) copolymer. In some embodiments, the copolymer comprises about 40-60 mol % poly(D,L-lactide) and about 40-60 mol % polyglycolide. In some embodiments, the copolymer comprises PDS-glycolide copolymer. In some embodiments, the copolymer comprises about 90-95 mol % PDS and about 5-10 mol % glycolide. In some embodiments, the copolymer comprises PDS-L-lactide copolymer. In some embodiments, the copolymer comprises about 90-95 mol % PDS and about 5-10 mol % L-lactide.In some embodiments, the ink comprises one or more additional agents. In some embodiments, the ink comprises from about 1% to about 30% by weight of one or more additional agents. In some embodiments, the one or more additional agents comprise an additional polymer, a particulate, or a foaming agent, or a combination thereof. In some embodiments, the one or more additional agents comprise an additional polymer. In some embodiments, the additional polymer comprises polyethylene glycol. In some embodiments, the additional polymer is present in the ink at about 10% to about 30% by weight. In some embodiments, the one or more additional agents comprise a particulate. In some embodiments, the particulate comprises sodium chloride, calcium chloride, sucrose, trehalose (e.g., α,α trehalose dihydrate), or mannitol (e.g., D-mannitol), or a combination thereof. In some embodiments, the particulate is present in the ink at about 1% to about 10% by weight. In some embodiments, the one or more additional agents comprise a foaming agent. In some embodiments, the foaming agent comprises baking powder (e.g., monocalcium phosphate, sodium bicarbonate, cornstarch) and / or azodicarbonamide. In some embodiments, the particulates are present in the ink at about 5% to about 20% by weight.

[0022] Also provided is a filament comprising the formulation, in some embodiments, the filament has a diameter of about 1.5 mm to about 2 mm.

[0023] Also provided is a method of preparing a three-dimensional structure, the method comprising using the former in a three-dimensional printing process.

[0024] Also provided are three-dimensional structures prepared using the ink formulations. In some embodiments, the structures include about 50% to about 90% by weight ceramic. In some embodiments, the structures include about 50% to about 90% by weight tricalcium phosphate. In some embodiments, the structures include about 10% to about 50% by weight polymer. In some embodiments, the polymer includes polyester. In some embodiments, the polymer includes polycaprolactone (PCL), polyglycolide, lactide, or polydioxanone (PDS), or combinations thereof. In some embodiments, the polymer includes polycaprolactone (PCL). In some embodiments, the polymer includes polyglycolide. In some embodiments, the polymer includes polydioxanone (PDS). In some embodiments, the polymer includes lactide. In some embodiments, the lactide includes L-lactide. In some embodiments, the lactide includes poly(D,L-lactide). In some embodiments, the polymer includes a copolymer. In some embodiments, the copolymer comprises polycaprolactone (PCL) and polyglycolide. In some embodiments, the copolymer comprises about 90-95 mol% PCL and about 5-10 mol% polyglycolide. In some embodiments, the copolymer comprises poly(D,L-lactide-co-glycolide) copolymer. In some embodiments, the copolymer comprises about 40-60 mol% poly(D,L-lactide) and about 40-60 mol% polyglycolide. In some embodiments, the copolymer comprises PDS-glycolide copolymer. In some embodiments, the copolymer comprises about 90-95 mol% PDS and about 5-10 mol% glycolide. In some embodiments, the copolymer comprises PDS-L-lactide copolymer. In some embodiments, the copolymer comprises about 90-95 mol% PDS and about 5-10 mol% L-lactide. In some embodiments, the structure comprises about 15% to about 25% by weight of polymer, hi some embodiments, the structure comprises about 25% by weight of polymer.

[0025] Also provided is a three-dimensional structure comprising about 50% to about 90% by weight of a ceramic and about 10% to about 30% of a polymer. In some embodiments, the ceramic comprises calcium phosphate, hydroxyapatite, fluorapatite, bone, silicate, or vanadate, or a combination thereof. In some embodiments, the ceramic comprises β-tricalcium phosphate (β-TCP). In some embodiments, the structure comprises about 65% to about 85% by weight of a ceramic. In some embodiments, the structure comprises about 70% to about 80% by weight of a ceramic. In some embodiments, the structure comprises about 75% by weight of a ceramic. In some embodiments, the polymer comprises a polyester. In some embodiments, the polymer comprises polycaprolactone (PCL), polyglycolide, lactide, or polydioxanone (PDS), or a combination thereof. In some embodiments, the polymer comprises polycaprolactone (PCL). In some embodiments, the polymer comprises polyglycolide. In some embodiments, the polymer comprises polydioxanone (PDS). In some embodiments, the polymer comprises lactide. In some embodiments, the lactide comprises L-lactide. In some embodiments, the lactide comprises poly(D,L-lactide). In some embodiments, the polymer comprises a copolymer. In some embodiments, the copolymer comprises polycaprolactone (PCL) and polyglycolide. In some embodiments, the copolymer comprises about 90-95 mol % PCL and about 5-10 mol % polyglycolide. In some embodiments, the copolymer comprises poly(D,L-lactide-co-glycolide) copolymer. In some embodiments, the copolymer comprises about 40-60 mol % poly(D,L-lactide) and about 40-60 mol % polyglycolide. In some embodiments, the copolymer comprises PDS-glycolide copolymer. In some embodiments, the copolymer comprises about 90-95 mol % PDS and about 5-10 mol % glycolide. In some embodiments, the copolymer comprises a PDS-L-lactide copolymer.In some embodiments, the copolymer comprises about 90-95 mol% PDS and about 5-10 mol% L-lactide. In some embodiments, the structure comprises about 15% to about 25% by weight polymer. In some embodiments, the structure comprises about 25% by weight polymer. In some embodiments, the structure is prepared by a three-dimensional printing method.

[0026] Also provided is a method of producing a three-dimensional structure, the method comprising depositing an ink formulation onto a three-dimensional form, in some embodiments, the ink formulation comprises the ink formulation herein.

[0027] Further provided is a method of treating a disease in a subject in need thereof, the method comprising delivering a structure to an organ or tissue of the subject.

[0028] Further provided is a method of treating a disease in a subject in need thereof, the method comprising delivering to an organ or tissue of the subject a structure produced by the methods herein.

[0029] In some embodiments, the disease comprises bone defect, cartilage defect, soft tissue defect, tendon defect, fascial defect, ligament defect, organ defect, osteotendinous tissue defect, skin defect, osteochondral defect, osteoporosis, avascular necrosis, or congenital skeletal deformity, or a combination thereof. In some embodiments, the method comprises spinal fusion. In some embodiments, the spinal fusion comprises posterior lumbar fusion (PLF) and / or interbody fusion. In some embodiments, the method comprises bone repair, dental repair, craniomaxillofacial repair, ankle fusion, vertebroplasty, osteoplasty, navicular fracture repair, tendon-bone repair, rib reconstruction, subchondral bone repair, cartilage repair, or surgical implantation of a three-dimensional structure or device, or a combination thereof. In some embodiments, the method further comprises treating the subject with a therapeutic agent.

[0030] Further provided is a method of delivering a therapeutic agent to a subject in need thereof, comprising delivering a device comprising the therapeutic agent and a structure to an organ or tissue of the subject.

[0031] In some embodiments, the therapeutic agent comprises a mammalian growth factor or functional portion thereof. In some embodiments, the therapeutic agent comprises one or more polypeptides selected from Table 1, or functional portions thereof. In some embodiments, the therapeutic agent comprises a bone morphogenetic protein (BMP). In some embodiments, the therapeutic agent comprises a targeting moiety that non-covalently binds to the structure. In some embodiments, the targeting moiety binds to the printed three-dimensional structure with an affinity of about 1 pM to about 100 μM. In some embodiments, the targeting moiety comprises a polypeptide that is at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to any one of the sequences in Tables 5-6. In some embodiments, the targeting moiety comprises about 2, 3, 4, 5, 6, 7, 8, 9, or 10 sequences selected from the sequences in Tables 5-6. In some embodiments, the therapeutic agent comprises or is part of a chimeric polypeptide comprising a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to any one of SEQ ID NOs:433-441.

[0032] In some embodiments of the devices and / or structures herein, the structure has a density of about 1 g / cm 3 ~About 2g / cm 3 In some embodiments of the devices and / or structures herein, the structure has an open porosity of about 15% to about 50%. In some embodiments of the devices and / or structures herein, the structure of any one of claims 91 to 139 has a strut diameter of about 300 micrometers to about 600 micrometers.

[0033] The details of one or more embodiments of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the disclosure will be apparent from the description, drawings, and claims. [Brief description of the drawings]

[0034] [Figure 1A] 1A-1D are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #1 as outlined in Example 2. FIG 1A is an SEM image of the surface of the object at magnification. [Figure 1B] 1A-1C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #1 as outlined in Example 2. FIG IB is an SEM image of the side of the object. [Figure 1C] 1A-1C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #1 as outlined in Example 2. FIG 1C is an SEM image of the surface of the object at magnification. [Figure 2A] 2A-2D are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #2 as outlined in Example 2. FIG 2A is an SEM image of the surface of the object at magnification. [Figure 2B] 2A-2C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #2 as outlined in Example 2. FIG 2B is an SEM image of the side of the object. [Figure 2C] 2A-2C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #2 as outlined in Example 2. FIG 2C is an SEM image of the surface of the object at magnification. [Figure 3A] 3A-3D are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #3 as outlined in Example 2. FIG 3A is an SEM image of the surface of the object at magnification. [Figure 3B] 3A-3C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #3 as outlined in Example 2. FIG 3B is an SEM image of the side of the object. [Figure 3C]3A-3C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #3 as outlined in Example 2. FIG 3C is an SEM image of the surface of the object at magnification. [Figure 4A] 4A-4D are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #4 as outlined in Example 2. FIG 4A is an SEM image of the surface of the object at magnification. [Figure 4B] 4A-4C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #4 as outlined in Example 2. FIG 4B is an SEM image of the side of the object. [Figure 4C] 4A-4C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #4 as outlined in Example 2. FIG 4C is an SEM image of the surface of the object at magnification. [Figure 5A] 5A-5C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #5 as outlined in Example 2. FIG 5A is an SEM image of the surface of the object at magnification. [Figure 5B] 5A-5C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #5 as outlined in Example 2. FIG 5B is an SEM image of the side of the object. [Figure 5C] 5A-5C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #5 as outlined in Example 2. FIG 5C is an SEM image of the surface of the object at magnification. [Figure 6A] 6A-6C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #6 as outlined in Example 2. FIG 6A is an SEM image of the surface of the object at magnification. [Figure 6B] 6A-6C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #6 as outlined in Example 2. FIG 6B is an SEM image of the side of the object. [Figure 6C]6A-6C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #6 as outlined in Example 2. FIG 6C is an SEM image of the surface of the object at magnification. [Figure 7A] 7A-7C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #7 as outlined in Example 2. Figure 7A is an SEM image of the surface of the object at magnification. [Figure 7B] 7A-7C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #7 as outlined in Example 2. FIG 7B is an SEM image of the side of the object. [Figure 7C] 7A-7C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #7 as outlined in Example 2. FIG 7C is an SEM image of the surface of the object at magnification. [Figure 8A] 8A-8C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #8 as outlined in Example 2. FIG 8A is an SEM image of the surface of the object at magnification. [Figure 8B] 8A-8C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #8 as outlined in Example 2. FIG 8B is an SEM image of the side of the object. [Figure 8C] 8A-8C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #8 as outlined in Example 2. FIG 8C is an SEM image of the surface of the object at magnification. [Figure 9A] 9A-9C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #9 as outlined in Example 2. FIG 9A is an SEM image of the surface of the object at magnification. [Figure 9B] 9A-9C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #9 as outlined in Example 2. FIG 9B is an SEM image of the side of the object. [Figure 9C]9A-9C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #9 as outlined in Example 2. FIG 9C is an SEM image of the surface of the object at magnification. [Figure 10A] 10A-10C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #10 as outlined in Example 2. FIG 10A is an SEM image of the surface of the object at magnification. [Figure 10B] 10A-10C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #10 as outlined in Example 2. FIG 10B is an SEM image of the side of the object. [Figure 10C] 10A-10C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #10 as outlined in Example 2. FIG 10C is an SEM image of the surface of the object at magnification. [Figure 11A] 11A-11C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #11 as outlined in Example 2. FIG 11A is an SEM image of the surface of the object at magnification. [Figure 11B] 11A-11C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #11 as outlined in Example 2. FIG 11B is an SEM image of the side of the object. [Figure 11C] 11A-11C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #11 as outlined in Example 2. FIG 11C is an SEM image of the surface of the object at magnification. [Figure 12A] 12A-12C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #12 as outlined in Example 2. FIG 12A is an SEM image of the surface of the object at magnification. [Figure 12B] 12A and 12B are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #12 as outlined in Example 2. FIG 12B is an SEM image of the side of the object. [Figure 12C]12A-12C are images from a scanning electron microscope (SEM image) of an exemplary 3D printed object made with ink formulation #12 as outlined in Example 2. FIG 12C is an SEM image of the surface of the object at magnification. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Various formulations and structures are provided herein. The structures may be coated with anchorable proteins (e.g., growth factors) for a desired therapeutic effect, such as promoting bone growth after implantation of the anchored structure.

[0036] formulation In one aspect, a formulation for fabricating 3D printed structures is provided herein.As non-limiting examples, the formulation includes ceramic materials, such as calcium phosphates (e.g., tricalcium phosphate, beta tricalcium phosphate, alpha tricalcium phosphate), hydroxyapatite, fluorapatite, bone (e.g., demineralized bone), glass (bioglass), such as silicates, vanadates, and related ceramic minerals, or chelated divalent metal ions, or combinations thereof.In some embodiments, the ceramic material includes beta tricalcium phosphate (β-TCP). In some embodiments, the formulation is about 30-70, 30-65, 30-60, 30-55, 30-50, 30-45, 30-40, 30-35, 35-70, 35-65, 35-60, 35-55, 35-50, 35-45, 35-40, 40-70, 40-65, 40-60, 40-55, 40-50, 40-45, 45-70, 45-65, 45-60, 45-55, 45-50, 50-70, 50-65, 50-55, 55-70, 55-65, 55-60, 60-70, 60-65, or 65-70 weight percent ceramic of the formulation. For example, the formulation is about 30% by weight, 31% by weight, 32% by weight, 33% by weight, 34% by weight, 35% by weight, 36% by weight, 37% by weight, 38% by weight, 39% by weight, 40% by weight, 41% by weight, 42% by weight, 43% by weight, 44% by weight, 45% by weight, 46% by weight, 47% by weight, 48% by weight, 49% by weight, 50% by weight, 51% by weight, 52% by weight, 53% by weight, 54% by weight, 55% by weight, 56% by weight, 57% by weight, 58% by weight, 59% by weight, 60% by weight, 61% by weight, 62% by weight, 63% by weight, 64% by weight, 65% by weight, 66% by weight, 67% by weight, 68% by weight, 69% by weight, or 70% by weight ceramic. In some embodiments, the ceramic is β-TCP. In some embodiments, β-TCP is introduced into the formulation as a powder. In some embodiments, the formulation comprises one or more additional components, non-limiting examples of which include water, polymers (including copolymers), antifoaming agents, dispersants, solvents, particulates, blowing agents, and plasticizers.

[0037] In some embodiments, the formulation comprises one or more polymers, for example, about 1, 2, 3, 4, or 5 polymers. Non-limiting examples of polymers include poly(ethylene oxide), poly(propylene oxide), polyethylene glycol (PEG), and polyester. In some embodiments, the formulation comprises polymers that are about 5-30 weight percent of the formulation. In some embodiments, the formulation is about 20-60 weight percent total polymer. For example, the total polymer comprises two or more polymers in the formulation, and the total percentage of polymers in the formulation is about 20-60 weight percent of the formulation. In some embodiments, the formulation is about 30-50 weight percent total polymer. As a non-limiting example, the formulation is about 35-45 weight percent total polymer. In one example, the polymer comprises a poloxamer. Poloxamers are block copolymers of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO). A non-limiting example of a poloxamer is poloxamer 407, such as Pluronic® F-127. In some cases, the formulation includes about 5-20, 5-15, 5-10, 10-20, 10-15, or 15-20 weight percent of poloxamer 407. As another example, the polymer includes polyethylene glycol (PEG). In some cases, the formulation includes about 5-30, 5-25, 5-20, 5-15, 5-10, 10-30, 10-25, 10-20, 10-15, 15-30, 15-25, 15-20, 20-30, 20-25, or 25-30 weight percent of PEG. For example, the formulation comprises about 5-30, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 weight percent PEG. In some embodiments, there is a first PEG having a first molecular weight and a second PEG having a second molecular weight. In some embodiments, the PEG can have a molecular weight of 500 g / mol to 25,000 g / mol.In some cases, the molecular weight of the PEG is about 500 g / mol, about 1,000 g / mol, about 1,500 g / mol, 20,000 g / mol, about 2,500 g / mol, about 3,000 g / mol, about 3,500 g / mol, about 4,000 g / mol, about 4,500 g / mol, about 5,000 g / mol, about 5,500 g / mol, about 6,000 g / mol, about 6,5 00g / mol, approx. 7,000g / mol, approx. 7,500g / mol, approx. 8,000g / mol, approx. 8,500g / mol, approx. 9,000g / mol, approx. 9,500g / mol, approx. 10,000g / mol, approx. 10,500g / mol, approx. 11,000g / mol, approx. 11,500g / mol, approx. 12,000g / mol, approx. 12,500g / mol, approx. 13,0 00g / mol, approx. 13,500g / mol, approx. 14,000g / mol, approx. 14,500g / mol, approx. 15,000g / mol, approx. 15,500g / mol, approx. 16,000g / mol, about 16,500g / mol, about 17,000g / mol, about 17,500g / mol, about 18,000g / mol, about 18,500g / mol, about 19,000g / mol , about 19,500 g / mol, about 20,000 g / mol, about 20,500 g / mol, about 21,000 g / mol, about 21,500 g / mol, about 22,000 g / mol, about 22,500 g / mol, about 23,000 g / mol, about 23,500 g / mol, about 24,000 g / mol, about 24,500 g / mol, or about 25,000 g / mol. In a non-limiting exemplary embodiment, the formulation comprises a PEG having a molecular weight of 1,500 g / mol. In a further non-limiting exemplary embodiment, the formulation comprises a PEG having a molecular weight of 8,000 g / mol. In a further non-limiting exemplary embodiment, the formulation comprises a PEG having a molecular weight of 20,000 g / mol. In a non-limiting exemplary embodiment, the formulation comprises about 15 weight percent of the first PEG and about 15 weight percent of the second PEG. As another example, the polymer comprises polydioxanone (PDS). In some cases, the formulation comprises about 10-30, 10-25, 10-20, 10-15, 15-30, 15-25, 15-20, 20-30, 20-25, or 25-30 weight percent of PDS.For example, the formulation comprises about 15-25, or 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 weight percent PDS. As another example, the polymer comprises a polyester. In some embodiments, the polyester comprises a biodegradable polyester, such as polycaprolactone (PCL). In some cases, the formulation comprises about 10-30, 10-25, 10-20, 10-15, 15-30, 15-25, 15-20, 20-30, 20-25, or 25-30 weight percent PCL. For example, the formulation comprises about 15-25, or 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 weight percent PCL. In some cases, the formulation comprises a PCL having a molecular weight of 50,000 g / mol. In some embodiments, the polyester comprises polyglycolide or poly(glycolic acid) (PGA). In some embodiments, the formulation comprises about 0.5-20, 0.5-18, 0.5-16, 0.5-14, 0.5-12, 0.5-10, 0.5-8, 0.5-6, 0.5-4, 0.5-2, 1-20, 1-18, 1-16, 1-14, 1-12, 1-10, 1-8, 1-6, 1-4, 1-2, 2-20, 2-18, 2-16, 2-14, 2-12, 2-10, 2-8, 2-6, 2-4 , 3-20, 3-18, 3-16, 3-14, 3-12, 3-10, 3-8, 3-6, 3-4, 4-20, 4-18, 4-16, 4-14, 4-12, 4-10, 4-8, 4-6, 5-20, 5-18, 5-16, 5-14, 5-12, 5-10, 5-8, 5-6, 8-20, 8-18, 8-16, 8-14, 8-12, or 8-10 weight percent PGA. For example, the formulation comprises about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 weight percent PGA. In some cases, the PGA has a molecular weight of about 38,000 to 54,000. In some embodiments, the polyester comprises a polylactide, such as poly(D,L-lactide).In some cases, the formulation may comprise about 0.5-20, 0.5-18, 0.5-16, 0.5-14, 0.5-12, 0.5-10, 0.5-8, 0.5-6, 0.5-4, 0.5-2, 1-20, 1-18, 1-16, 1-14, 1-12, 1-10, 1-8, 1-6, 1-4, 1-2, 2-20, 2-18, 2-16, 2-14, 2-12, 2-10, 2-8, 2-6, 2-4, The formulation may comprise 3-20, 3-18, 3-16, 3-14, 3-12, 3-10, 3-8, 3-6, 3-4, 4-20, 4-18, 4-16, 4-14, 4-12, 4-10, 4-8, 4-6, 5-20, 5-18, 5-16, 5-14, 5-12, 5-10, 5-8, 5-6, 8-20, 8-18, 8-16, 8-14, 8-12, or 8-10 weight percent polylactide. For example, the formulation may comprise about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 weight percent polylactide.

[0038] In some embodiments, the polymer comprises a copolymer. In some cases, the copolymer comprises polyglycolide. In some cases, the copolymer comprises PCL and polyglycolide. For example, the copolymer may be comprised of about 80-99, 80-98, 80-97, 80-96, 80-95, 80-94, 80-93, 80-92, 80-91, 80-90, 80-89, 80-88, 80-87, 80-86, 80-85, 85-99, 85-98, 85-97, 85-96, 85-95, 85-94, 85-93, 85-92, 85-91, 85-90, 90-99, 90-98, 90-97, 90-96, 90-95, 90-94, 90-93, 90-92, 90-91, 95-99, 95-98, 95-97, or 95-96 mole percent PCL, and Approximately 1~20, 1~18, 1~16, 1~14, 1~12, 1~10, 1~8, 1~6, 1~4, 1~2, 2~20, 2~18, 2~16, 2~ 14, 2~12, 2~10, 2~8, 2~6, 2~4, 3~20, 3~18, 3~16, 3~14, 3~12, 3~10, 3~8, 3~6, ​​3~ and 4, 4-20, 4-18, 4-16, 4-14, 4-12, 4-10, 4-8, 4-6, 5-20, 5-18, 5-16, 5-14, 5-12, 5-10, 5-8, 5-6, 8-20, 8-18, 8-16, 8-14, 8-12, or 8-10 mole percent of polyglycolide. In some cases, the copolymer includes about 90-95 mole percent PCL and about 5-10 mole percent polyglycolide. In some cases, the copolymer includes PDS and polyglycolide. For example, the copolymer may be about 80-99, 80-98, 80-97, 80-96, 80-95, 80-94, 80-93, 80-92, 80-91, 80-90, 80-89, 80-88, 80-87, 80-86, 80-85, 85-99, 85-98, 85-97, 85-96, 85-95, 85-94, 85-93, 85-92, 85-91, 85-90, 90-99, 90-98, 90-97, 90-96, 90-95, 90-94, 90-93, 90-92, 90-91, 95-99, 95-98, 95-97, or 95-96 mole percent PDS, and Approximately 1~20, 1~18, 1~16, 1~14, 1~12, 1~10, 1~8, 1~6, 1~4, 1~2, 2~20, 2~18, 2~16, 2~ 14, 2~12, 2~10, 2~8, 2~6, 2~4, 3~20, 3~18, 3~16, 3~14, 3~12, 3~10, 3~8, 3~6, ​​3~ 4, 4-20, 4-18, 4-16, 4-14, 4-12, 4-10, 4-8, 4-6, 5-20, 5-18, 5-16, 5-14, 5-12, 5-10, 5-8, 5-6, 8-20, 8-18, 8-16, 8-14, 8-12, or 8-10 mole percent polyglycolide. In some cases, the copolymer comprises about 90-95 mole percent PDS and about 5-10 mole percent polyglycolide. In some cases, the copolymer comprises a PDS-glycolide copolymer. For example, the formulation comprises about 10-30, 10-25, 10-20, 10-15, 15-30, 15-25, 15-20, 20-30, 20-25, 25-30, or 20 weight percent of PDS-glycolide copolymer. In some cases, the copolymer comprises poly(D,L-lactide-co-glycolide) copolymer. For example, the formulation comprises about 10-30, 10-25, 10-20, 10-15, 15-30, 15-25, 15-20, 20-30, 20-25, 25-30, or 20 weight percent of poly(D,L-lactide-co-glycolide) copolymer. In some cases, the copolymer comprises lactide (e.g., poly(D,L-lactide)) and polyglycolide.For example, the copolymer may be about 35-65, 35-60, 35-55, 35-50, 35-45, 35-40, 40-65, 40-60, 40-55, 40-50, 40-45, 45-65, 45-60, 45-55, 45-50, 50-65, 50-60, 50-55, 55-65, 55-60, 60-65 mole percent lactide (e.g., poly (D,L-lactide)) and about 35-65, 35-60, 35-55, 35-50, 35-45, 35-40, 40-65, 40-60, 40-55, 40-50, 40-45, 45-65, 45-60, 45-55, 45-50, 50-65, 50-60, 50-55, 55-65, 55-60, 60-65 mole percent glycolide. In some cases, the copolymer comprises a poly(D,L-lactide-co-glycolide) copolymer. For example, the formulation includes about 10-30, 10-25, 10-20, 10-15, 15-30, 15-25, 15-20, 20-30, 20-25, 25-30, or 20 weight percent of poly(D,L-lactide-co-glycolide) copolymer. In some cases, the copolymer includes lactide (e.g., L-lactide) and PDS. For example, the copolymers may comprise about 35-65, 35-60, 35-55, 35-50, 35-45, 35-40, 40-65, 40-60, 40-55, 40-50, 40-45, 45-65, 45-60, 45-55, 45-50, 50-65, 50-60, 50-55, 55-65, 55-60, 60-65 mole percent PDS, and about 35-65, 35-60, 35-55, 35-50, 35-45, 35-40, 40-65, 40-60, 40-55, 40-50, 40-45, 45-65, 45-60, 45-55, 45-50, 50-65, 50-60, 50-55, 55-65, 55-60, 60-65 mole percent lactide (e.g., L-lactide). In some cases, the copolymer comprises a PDS-L-lactide copolymer. For example, the formulation includes about 10-30, 10-25, 10-20, 10-15, 15-30, 15-25, 15-20, 20-30, 20-25, 25-30, or 20 weight percent of the PDS-L-lactide copolymer. In some cases, the copolymer includes dioxanone.In some cases, the copolymer includes dioxanone and lactide (eg, L-lactide). For example, the copolymer may be from about 80-99, 80-98, 80-97, 80-96, 80-95, 80-94, 80-93, 80-92, 80-91, 80-90, 80-89, 80-88, 80-87, 80-86, 80-85, 85-99, 85-98, 85-97, 85-96, 85-95, 85-94, 85-93, 85-92, 85-91, 85-90, 90-99, 90-98, 90-97, 90-96, 90-95, 90-94, 90-93, 90-92, 90-91, 95-99, 95-98, 95-97, or 95-96 mole percent dioxanone, and Approximately 1~20, 1~18, 1~16, 1~14, 1~12, 1~10, 1~8, 1~6, 1~4, 1~2, 2~20, 2~18, 2~16, 2~14 , 2~12, 2~10, 2~8, 2~6, 2~4, 3~20, 3~18, 3~16, 3~14, 3~12, 3~10, 3~8, 3~6, ​​3~4, 4~ In some cases, the copolymer comprises about 85 to 95 mole percent dioxanone and about 5 to 15 mole percent lactide (e.g., L-lactide).

[0039] In some instances, copolymers have faster absorption rates than single polymers. For example, the copolymers used in the exemplary embodiments of Ink Formulation #2 (polycaprolactone / polyglycolide copolymer (95:5)), Ink Formulation #3 (polycaprolactone / polyglycolide copolymer (90:10)), and Ink Formulation #4 (poly(D,L-lactide-co-glycolide) copolymer (50:50)) have faster absorption rates than polycaprolactone. Absorption rates vary from slowest to fastest, such as polycaprolactone, polycaprolactone / polyglycolide copolymer (95:5), polycaprolactone / glycolide copolymer (90:10), polydioxanone / L-lactide copolymer (90:10), poly(D,L-lactide-co-glycolide) copolymer (50:50).

[0040] In some embodiments, the formulation comprises two or more polymers, hi some embodiments, the formulation is about 5-30, 5-25, 5-20, 5-15, 5-10, 10-30, 10-25, 10-20, 10-15, 15-30, 15-25, 15-20, 20-30, 20-25, or 25-30 weight percent of a first polymer and about 5-30, 5-25, 5-20, 5-15, 5-10, 10-30, 10-25, 10-20, 10-15, 15-30, 15-25, 15-20, 20-30, 20-25, or 25-30 weight percent of a second polymer. In a non-limiting example, the formulation is about 10-30 weight percent of the first polymer and about 10-30 weight percent of the second polymer, or about 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 weight percent of the first polymer and about 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 weight percent of the second polymer. In some cases, the first and / or second polymer comprises PEG. In some cases, the first polymer comprises PCL and the second polymer comprises PEG. In some cases, the first polymer comprises PDS and the second polymer comprises PEG. In some cases, the first polymer comprises a copolymer and the second polymer comprises PEG. The copolymer may comprise PCL and polyglycolide (e.g., 95 mol% polycaprolactone, 5 mol% polyglycolide; 90 mol% polycaprolactone, 10 mol% polyglycolide). The copolymer may comprise polylactide (e.g., poly(D,L-lactide) and polyglycolide (e.g., 50 mol% poly(D,L-lactide)), 50 mol% polyglycolide). The copolymer may comprise PDS-glycolide copolymer (e.g., 90 mol% PDS, 10 mol% polyglycolide). The copolymer may comprise PDS-L-lactide copolymer (e.g., 90 mol% PDS, 10 mol% L-lactide).

[0041] In some embodiments, the formulation comprises one or more microparticles. The microparticles may be pore-forming agents. The microparticles may be water-soluble. The microparticles may comprise salts and / or sugars. Non-limiting examples of microparticles include sodium chloride, calcium chloride, sucrose, trehalose (e.g., α,α trehalose dihydrate), and mannitol (e.g., D-mannitol). In some cases, the microparticles comprise sucrose. In some embodiments, the formulation comprises 1-10, 1-9, 1-8, 1-7, 1-6, 1-5, 2-10, 2-9, 2-8, 2-7, 2-6, 2-5, 3-10, 3-9, 3-8, 3-7, 3-6, 3-5, 4-10, 4-9, 4-8, 4-7, 4-6, 4-5, 5-10, 5-9, 5-8, 5-7, or 5-6 weight percent of microparticles. In some cases, the formulation comprises about 1-10%, or alternatively about 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10% microparticles. In some embodiments, the microparticles, or pore-forming agents, have an average pore size of about 1 micron to about 500 microns in diameter. For example, the average pore size may be about 1 micron to about 450 microns, about 1 micron to about 400 microns, about 1 micron to about 350 microns, about 1 micron to about 300 microns, about 1 micron to about 250 microns, about 1 micron to about 200 microns, about 1 micron to about 150 microns, about 50 microns to about 500 microns, about 50 microns to about 450 microns, about 50 microns to about 400 microns, about 50 microns to about 350 microns, about 50 microns to about 300 microns, about 50 microns to about 250 microns, about 50 microns to about 200 microns, about 50 microns to about 150 microns, about 100 microns to about 5 00 microns, about 100 microns to about 450 microns, about 100 microns to about 400 microns, about 100 microns to about 350 microns, about 100 microns to about 300 microns, about 100 microns to about 250 microns, about 100 microns to about 200 microns, about 100 microns to about 150 microns, about 150 microns to about 500 microns, about 150 microns to about 450 microns, about 150 microns to about 400 microns, about 150 microns to about 350 microns, about 150 microns to about 300 microns, about 150 microns to about 250 microns, or about 150 microns to about 200 microns.In some cases, the microparticles or pore formers have an average pore size of about 50 microns to about 250 microns in diameter, about 60 microns to about 240 microns, about 70 microns to about 230 microns, about 80 microns to about 220 microns, or about 90 microns to about 210 microns in diameter. In some embodiments, the microparticles or pore formers have an average pore size of about 100 microns to about 200 microns in diameter, e.g., about 110 microns to about 190 microns, about 120 microns to about 180 microns, about 130 microns to about 170 microns, about 140 microns to about 160 microns, or about 100 microns, about 110 microns, about 120 microns, about 130 microns, about 140 microns, about 150 microns, about 160 microns, about 170 microns, about 180 microns, about 190 microns, or about 200 microns. In some embodiments, the microparticles or pore formers have an average pore size of about 150 microns in diameter. In some embodiments, upon removal of the particulates or pore-forming agent, the structure formed from the formulation has micropores that provide the structure with additional surface area for contact with a therapeutic agent compared to structures formed with a formulation lacking the particulates or pore-forming agent, In some embodiments, the micropores of the structure have an average pore size of about 1 micron to about 500 microns, or about 50 microns to about 250 microns, or about 150 microns in diameter.

[0042] In some embodiments, the formulation comprises one or more foaming agents. In some embodiments, the foaming agent comprises 5-20, 5-18, 5-16, 5-14, 5-12, 5-10, 5-8, 5-6, 6-20, 6-18, 6-16, 6-14, 6-12, 6-10, 6-8, 8-20, 8-18, 8-16, 8-14, 8-12, 8-10, 10-20, 10-18, 10-16, 10-14, 10-12, 5-15, or about 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 weight percent of the foaming agent. In some cases, the foaming agent releases carbon dioxide base during printing to produce a foam structure that can increase the porosity of the 3D printed structure. Non-limiting examples of foaming agents include baking powder (e.g., monocalcium phosphate, sodium bicarbonate, cornstarch) and azodicarbonamide. In some cases, the foaming agent includes sodium bicarbonate. In some cases, the formulation includes about 5 to 15, or 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 weight percent sodium bicarbonate. In some embodiments, the foaming agent provides micropores in the structure having an average diameter of about 1 micron to about 500 microns, or about 50 microns to about 250 microns, or about 150 microns.

[0043] In some embodiments, the formulation comprises a ceramic material (e.g., β-TCP) and a polymer. The polymer comprises PEO, PPO, PDS, PEG, polyester, copolymer, or combinations thereof. In some embodiments, the formulation comprises about 30-70, 30-65, 30-60, 30-55, 30-50, 30-45, 30-40, 30-35, 35-70, 35-65, 35-60, 35-55, 35-50, 35-45, 35-40, 40-70, 40-65, 40-60, 40-55, 40-50, 40-45, 45-70, 45-65, 45-60, 45-55, 45-50, 50-70, 50-65, 50-60, 50-55, 55-70, 55-65, 55-60, 60-70, 60-65, or 65-70 weight percent ceramic material (e.g., β-TCP), e.g., about 30 %, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, or 70% by weight of a ceramic material (e.g., β-TCP). In some cases, the formulation includes about 5-20, 5-15, 5-10, 10-20, 10-15, or 15-20 weight percent poloxamer 407. In some cases, the formulation includes about 10-30, 10-25, 10-20, 10-15, 15-30, 15-25, 15-20, 20-30, 20-25, or 25-30 weight percent PEG. In some cases, the formulation includes about 10-30, 10-25, 10-20, 10-15, 15-30, 15-25, 15-20, 20-30, 20-25, or 25-30 weight percent PCL. In some cases, the formulation comprises about 10-30, 10-25, 10-20, 10-15, 15-30, 15-25, 15-20, 20-30, 20-25, or 25-30 weight percent PDS. In some embodiments, the formulation further comprises an antifoaming agent.In some embodiments, the formulation further comprises a dispersing agent. In some embodiments, the formulation further comprises a solvent. In some embodiments, the formulation further comprises a plasticizer. In some embodiments, the formulation further comprises microparticles. In some embodiments, the formulation further comprises a foaming agent.

[0044] In some embodiments, the formulation comprises a ceramic material (e.g., β-TCP) and a microparticle. The microparticle may be water-soluble. Non-limiting examples of microparticles include salts and sugars, such as sodium chloride, calcium chloride, sucrose, trehalose (e.g., α,α trehalose dihydrate), and mannitol (e.g., D-mannitol). In some embodiments, the formulation comprises about 30-70, 30-65, 30-60, 30-55, 30-50, 30-45, 30-40, 30-35, 35-70, 35-65, 35-60, 35-55, 35-50, 35-45, 35-40, 40-70, 40-65, 40-60, 40-55, 40-50, 40-45, 45-70, 45-65, 45-60, 45-55, 45-50, 50-70, 50-65, 50-60, 50-55, 55-70, 55-65, 55-60, 60-70, 60-65, or 65-70 weight percent ceramic material (e.g., β-TCP), e.g., about 30 %, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, or 70% by weight of a ceramic material (e.g., β-TCP). In some embodiments, the formulation comprises 1-10, 1-9, 1-8, 1-7, 1-6, 1-5, 2-10, 2-9, 2-8, 2-7, 2-6, 2-5, 3-10, 3-9, 3-8, 3-7, 3-6, 3-5, 4-10, 4-9, 4-8, 4-7, 4-6, 4-5, 5-10, 5-9, 5-8, 5-7, or 5-6 weight percent of particulates. In some embodiments, the formulation further comprises water. In some embodiments, the formulation further comprises a polymer. In some embodiments, the formulation further comprises an antifoaming agent. In some embodiments, the formulation further comprises a dispersing agent. In some embodiments, the formulation further comprises a solvent. In some embodiments, the formulation further comprises a plasticizer.In some embodiments, the formulation further comprises a foaming agent.

[0045] In some embodiments, the formulation includes a ceramic material (e.g., β-TCP) and a foaming agent. Non-limiting examples of foaming agents include baking powder (e.g., monocalcium phosphate, sodium bicarbonate, cornstarch) and azodicarbonamide. The foaming agent may include sodium bicarbonate. In some embodiments, the formulation comprises about 30-70, 30-65, 30-60, 30-55, 30-50, 30-45, 30-40, 30-35, 35-70, 35-65, 35-60, 35-55, 35-50, 35-45, 35-40, 40-70, 40-65, 40-60, 40-55, 40-50, 40-45, 45-70, 45-65, 45-60, 45-55, 45-50, 50-70, 50-65, 50-60, 50-55, 55-70, 55-65, 55-60, 60-70, 60-65, or 65-70 weight percent ceramic material (e.g., β-TCP), e.g., about 30 %, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, or 70% by weight of a ceramic material (e.g., β-TCP). In some embodiments, the effervescent agent comprises 5-20, 5-18, 5-16, 5-15, 5-14, 5-12, 5-10, 5-8, 5-6, 6-20, 6-18, 6-16, 6-14, 6-12, 6-10, 6-8, 8-20, 8-18, 8-16, 8-14, 8-12, 8-10, 10-20, 10-18, 10-16, 10-14, 10-12, 5-15, or about 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 percent by weight of effervescent agent. In some embodiments, the formulation comprises about 5-15, or about 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 percent by weight of sodium bicarbonate. In some embodiments, the formulation further comprises water.In some embodiments, the formulation further comprises a polymer. In some embodiments, the formulation further comprises an antifoaming agent. In some embodiments, the formulation further comprises a dispersing agent. In some embodiments, the formulation further comprises a solvent. In some embodiments, the formulation further comprises a plasticizer. In some embodiments, the formulation further comprises a microparticle.

[0046] In other aspects, the formulation comprises a ceramic material and one or more polymers. In some embodiments, the formulation comprises about 30% to about 70% ceramic material (e.g., β-TCP). For example, the formulation comprises about 30-70, 30-65, 30-60, 30-55, 30-50, 30-45, 30-40, 30-35, 35-70, 35-65, 35-60, 35-55, 35-50, 35-45, 35-40, 40-70, 40-65, 40-60, 40-55, 40-50, 40-45, 45-70, 45-65, 45-60, 45-55, 45-50, 50-70, 50-65, 50-6 In some embodiments, the formulation comprises 0, 50-55, 60-70, 60-65, 65-70, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, or 70 percent by weight of a ceramic material (e.g., β-TCP). In some embodiments, the formulation comprises a first polymer, e.g., about 10-30, 10-25, 10-20, 10-15, 15-30, 15-25, 15-20, 20-30, 20-25, or 25-30 percent by weight of a first polymer. The first polymer can be polycaprolactone (PCL). The first polymer can be polydioxanone (PDS). In some embodiments, the formulation includes a second polymer, for example, about 10-30, 10-25, 10-20, 10-15, 15-30, 15-25, 15-20, 20-30, 20-25, or 25-30 weight percent of the second polymer. The second polymer can be polyethylene glycol (PEG). In a non-limiting embodiment, the formulation includes about 30-70 weight percent ceramic, about 10-30 weight percent first polymer, and about 10-30 weight percent second polymer. For example, the formulation can include about 30-70 weight percent β-TCP, about 10-30 weight percent PCL, and about 10-30 weight percent PEG. As another example, the formulation may include about 30-70% by weight β-TCP, about 10-30% by weight PDS, and about 10-30% by weight PEG.

[0047] In some further embodiments, the formulation comprises microparticles. The microparticles may be water-soluble. In some cases, the microparticles comprise sucrose. In some embodiments, the formulation comprises 1-10, 1-9, 1-8, 1-7, 1-6, 1-5, 2-10, 2-9, 2-8, 2-7, 2-6, 2-5, 3-10, 3-9, 3-8, 3-7, 3-6, 3-5, 4-10, 4-9, 4-8, 4-7, 4-6, 4-5, 5-10, 5-9, 5-8, 5-7, or 5-6 weight percent of microparticles. For example, the formulation may comprise about 30-70 weight percent β-TCP, about 10-30 weight percent PCL, about 10-30 weight percent PEG, and about 1-10 weight percent microparticles.

[0048] In some further embodiments, the formulation comprises an effervescent agent. In some cases, the effervescent agent comprises sodium bicarbonate. In some embodiments, the formulation comprises 5-20, 5-18, 5-16, 5-14, 5-12, 5-10, 5-8, 5-6, 6-20, 6-18, 6-16, 6-14, 6-12, 6-10, 6-8, 8-20, 8-18, 8-16, 8-14, 8-12, 8-10, 10-20, 10-18, 10-16, 10-14, 10-12, 5-15, or about 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 weight percent of the effervescent agent. For example, the formulation may include about 30-70% by weight β-TCP, about 10-30% by weight PCL, about 10-30% by weight PEG, and about 5-20% by weight foaming agent.

[0049] In some further embodiments, the polymer of the formulation is a copolymer, such as a PCL and polyglycolide copolymer. For example, the copolymer may be about 80-99, 80-90, 80-98, 80-97, 80-96, 80-95, 80-94, 80-93, 80-92, 80-91, 80-90, 80-89, 80-88, 80-87, 80-86, 80-85, 85-99, 85-98, 85-97, 85-9 6, 85-95, 85-94, 85-93, 85-92, 85-91, 85-90, 90-99, 90-98, 90-97, 90-96, 90-95, 90-94, 90-93, 90-92, 90-91, 95-99, 95-98, 95-97, or 95-96 mole percent PCL; and about 1-20, 1-18, 1-16, 1-14, 1-12, 1-10, 1-8, 1-6, 1-4, 1-2, 2-20, 2-18, 2-16, 2-14, 2-12, 2-10, 2-8, 2-6, 2-4, 3-20, 3-18, 3-16, 3-14, 3-12, 3-10, 3-8, 3-6, The copolymer may comprise 3-4, 4-20, 4-18, 4-16, 4-14, 4-12, 4-10, 4-8, 4-6, 5-20, 5-18, 5-16, 5-14, 5-12, 5-10, 5-8, 5-6, 8-20, 8-18, 8-16, 8-14, 8-12, or 8-10 mole percent polyglycolide. In some cases, the copolymer comprises about 90-95 mole percent PCL and about 5-10 mole percent glycolide. In one example, the formulation may comprise about 30-70% β-TCP, about 10-30 weight percent PCL and polyglycolide copolymer (e.g., 95 mole percent polycaprolactone, 5 mole percent polyglycolide), and about 10-30 weight percent PEG. In one example, a formulation may include about 30-70% β-TCP, about 10-30% by weight of a PCL and polyglycolide copolymer (e.g., 90 mol% polycaprolactone, 10 mol% polyglycolide), and about 10-30% by weight of PEG.

[0050] In some further embodiments, the polymer of the formulation is a copolymer, such as a PDS and polyglycolide copolymer. For example, the copolymer may be about 80-99, 80-90, 80-98, 80-97, 80-96, 80-95, 80-94, 80-93, 80-92, 80-91, 80-90, 80-89, 80-88, 80-87, 80-86, 80-85, 85-99, 85-98, 85-97, 85- 96, 85–95, 85–94, 85–93, 85–92, 85–91, 85–90, 90–99, 90–98, 90–97, 90–96, 90–95, 90–94, 90–93, 90–92, 90–91, 95–99, 95–98, 95–97, or 95–96 mole percent PDS , and about 1-20, 1-18, 1-16, 1-14, 1-12, 1-10, 1-8, 1-6, 1-4, 1-2, 2-20, 2-18, 2-16, 2-14, 2-12, 2-10, 2-8, 2-6, 2-4, 3-20, 3-18, 3-16, 3-14, 3-12, 3-10, 3-8, 3- 6, 3-4, 4-20, 4-18, 4-16, 4-14, 4-12, 4-10, 4-8, 4-6, 5-20, 5-18, 5-16, 5-14, 5-12, 5-10, 5-8, 5-6, 8-20, 8-18, 8-16, 8-14, 8-12, 8-10 mole percent polyglycolide. In some cases, the copolymer comprises about 90-95 mole percent PDS, and about 5-10 mole percent glycolide. In one example, the formulation may comprise about 30-70% β-TCP, about 10-30 weight percent PDS and polyglycolide copolymer (e.g., 90 mole percent PDS, 10 mole percent polyglycolide), and about 10-30 weight percent PEG.

[0051] In some further embodiments, the polymer of the formulation is a copolymer, such as a PDS and lactide copolymer. For example, the copolymer may be about 80-99, 80-98, 80-97, 80-96, 80-95, 80-94, 80-93, 80-92, 80-91, 80-90, 80-89, 80-88, 80-87, 80-86, 80-85, 85-99, 85-98, 85-97, 85-96, 85-95, 85-94, 85-93, 85-92, 85-91, 85-90, 90-99, 90-98, 90-97, 90-96, 90-95, 90-94, 90-93, 90-92, 90-91, 95-99, 95-98, 95-97, or 95-96 mole percent PDS, and and about 1-20, 1-18, 1-16, 1-14, 1-12, 1-10, 1-8, 1-6, 1-4, 1-2, 2-20, 2-18, 2-16, 2-14, 2-12, 2-10, 2-8, 2-6, 2-4, 3-20, 3-18, 3-16, 3-14, 3-12, 3-10, 3-8, 3-6, The copolymer may comprise 3-4, 4-20, 4-18, 4-16, 4-14, 4-12, 4-10, 4-8, 4-6, 5-20, 5-18, 5-16, 5-14, 5-12, 5-10, 5-8, 5-6, 8-20, 8-18, 8-16, 8-14, 8-12, or 8-10 mole percent lactide. In some cases, the copolymer comprises about 90-95 mole percent PDS and about 5-10 mole percent lactide. In one example, the formulation may comprise about 30-70% β-TCP, about 10-30 weight percent PDS and lactide copolymer (e.g., 90 mole percent PDS, 10 mole percent lactide), and about 10-30 weight percent PEG.

[0052] In other aspects, the formulation comprises a ceramic material and one or more polymers. In some embodiments, the formulation comprises about 30% to about 70% ceramic material (e.g., β-TCP). For example, the formulation comprises about 30-70, 30-65, 30-60, 30-55, 30-50, 30-45, 30-40, 30-35, 35-70, 35-65, 35-60, 35-55, 35-50, 35-45, 35-40, 40-70, 40-65, 40-60, 40-55, 40-50, 40-45, 45-70, 45-65, 45-60, 45-55, 45-50, 50-70, 50-65, 50-6 In some embodiments, the formulation comprises 0, 50-55, 60-70, 60-65, 65-70, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, or 70 percent by weight of a ceramic material (e.g., β-TCP). In some embodiments, the formulation comprises a first polymer, e.g., about 10-30, 10-25, 10-20, 10-15, 15-30, 15-25, 15-20, 20-30, 20-25, or 25-30 percent by weight of a first polymer. The first polymer may be a copolymer. In some embodiments, the copolymer comprises a lactide (e.g., poly(D,L-lactide)) and a polyglycolide. In some embodiments, the copolymer comprises a poly(D,L-lactide-co-glycolide) copolymer. In some embodiments, the copolymer comprises about 50 mol% poly(D,L-lactide) and about 50 mol% polyglycolide. In some embodiments, the formulation comprises a second polymer, e.g., about 10-30, 10-25, 10-20, 10-15, 15-30, 15-25, 15-20, 20-30, 20-25, or 25-30 weight percent of the second polymer. The second polymer may be a polyethylene glycol (PEG). In a non-limiting embodiment, the formulation comprises about 30-70 wt% ceramic, about 10-30 wt% first polymer, and about 10-30 wt% second polymer.For example, the formulation may contain about 30-70% by weight β-TCP, about 10-30% by weight copolymer, and about 10-30% by weight PEG.

[0053] In some further embodiments, the formulation comprises a ceramic material and one or more polymers. In some embodiments, the formulation comprises about 30% to about 70% ceramic material (e.g., β-TCP). For example, the formulation comprises about 30-70, 30-65, 30-60, 30-55, 30-50, 30-45, 30-40, 30-35, 35-70, 35-65, 35-60, 35-55, 35-50, 35-45, 35-40, 40-70, 40-65, 40-60, 40-55, 40-50, 40-45, 45-70, 45-65, 45-60, 45-55, 45-50, 50-70, 50-65, 50-6 In some embodiments, the formulation comprises 0, 50-55, 60-70, 60-65, 65-70, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, or 70 percent by weight of a ceramic material (e.g., β-TCP). In some embodiments, the formulation comprises a first polymer, e.g., about 10-30, 10-25, 10-20, 10-15, 15-30, 15-25, 15-20, 20-30, 20-25, or 25-30 percent by weight of a first polymer. The first polymer may be a copolymer, such as a dioxanone and lactide (eg, L-lactide) copolymer.For example, the copolymer may be from about 80-99, 80-98, 80-97, 80-96, 80-95, 80-94, 80-93, 80-92, 80-91, 80-90, 80-89, 80-88, 80-87, 80-86, 80-85, 85-99, 85-98, 85-97, 85-96, 85-95, 85-94, 85-93, 85-92, 85-91, 85-90, 90-99, 90-98, 90-97, 90-96, 90-95, 90-94, 90-93, 90-92, 90-91, 95-99, 95-98, 95-97, or 95-96 mole percent dioxanone, and about 1-20, 1-18, 1-16, 1-14, 1-12, 1-10, 1-8, 1-6, 1-4, 1-2, 2-20, 2-18, 2-16, 2-14, 2-12, 2-10, 2-8, 2-6, 2-4, 3-20, 3-18, 3-16, 3-14, 3-12, 3-10, 3-8, 3-6 , 3-4, 4-20, 4-18, 4-16, 4-14, 4-12, 4-10, 4-8, 4-6, 5-20, 5-18, 5-16, 5-14, 5-12, 5-10, 5-8, 5-6, 8-20, 8-18, 8-16, 8-14, 8-12, or 8-10 mole percent lactide. In some embodiments, the copolymer comprises about 90-95 mole percent dioxanone and about 5-10 mole percent lactide. In some embodiments, the formulation comprises a second polymer, e.g., about 10-30, 10-25, 10-20, 10-15, 15-30, 15-25, 15-20, 20-30, 20-25, or 25-30 weight percent of the second polymer. The second polymer can be polyethylene glycol (PEG). In a non-limiting embodiment, the formulation comprises about 30-70% by weight ceramic, about 10-30% by weight first polymer, and about 10-30% by weight second polymer. For example, the formulation can comprise about 30-70% by weight β-TCP, about 10-30% by weight copolymer, and about 10-30% by weight PEG. In one example, the formulation can comprise about 30-70% by weight β-TCP, about 10-30% by weight PDS and lactide copolymer (e.g., 90 mol % dioxanone, 10 mol % L-lactide), and about 10-30% by weight PEG.

[0054] In one aspect, the formulation has a low viscosity that may be useful during manufacturing for extrusion through a small diameter nozzle. The nozzle diameter may be about 240 μm to about 500 μm, or about 280 to about 450 μm, e.g., about 240, 260, 280, 300, 320, 340, 360, 380, 400, 420, 440, 460, 480, or 500 μm. In a non-limiting exemplary embodiment, the formulation is melt mixed in a double asymmetric centrifugal mixer to create a homogenous liquid ink.

[0055] In one aspect, the formulation has a higher viscosity that may be useful during manufacturing by forming the formulation into filaments, which may then be used in molten filament manufacturing.

[0056] In one aspect, the formulation is in the form of a filament. For example, as further described in Example 2, the ink formulation was prepared into a filament for use in 3D printing structures on a fused filament fabrication (FFF) 3D printer. In some embodiments, the diameter of the filament formulation is about 1 to about 3 mm, alternatively about 1 to about 2.75 mm, about 1 to about 2.5 mm, about 1 to about 2.25 mm, about 1 to about 2 mm, about 1 to about 1.75 mm, about 1 to about 1.5 mm, about 1.25 to about 3 mm, about 1.25 to about 2.75 mm, about 1.25 to about 2.5 mm, about 1.25 to about 2.25 mm, about 1.25 to about 2 mm, about 1.25 to about 1.75 mm, about 1.25 to about 1. 5mm, about 1.5 to about 3mm, about 1.5 to about 2.75mm, about 1.5 to about 2.5mm, about 1.5 to about 2.25mm, about 1.5 to about 2mm, about 1.5 to about 1.75mm, about 1.75 to about 3mm, about 1.75 to about 2.75mm, about 1.75 to about 2.5mm, about 1.75 to about 2.25mm, about 1.75 to about 2mm, about 2 to about 3mm, about 2 to about 2.75mm, about 2 to about 2.5mm, or about 2 to about 2.25mm. As a non-limiting example, the diameter of the filament preparation is about 1.5mm to about 2mm, or about 1.5mm, about 1.75mm, or about 2mm.

[0057] In one embodiment, the formulation is in the form of a pellet. For example, as further described in Example 2, the ink formulation is prepared into a pellet for use in a 3D structure. In some embodiments, the pellet can be made into a filament. In some embodiments, the pellet can be made into a powder. In some embodiments, the length of the pellet is about 1 to about 6 mm, or about 1 to about 5.5 mm, about 1 to about 5 mm, about 1 to about 4.5 mm, about 1 to about 4 mm, about 1 to about 3.5 mm, about 1 to about 3 mm, about 1 to about 2.5 mm, about 1 to about 2 mm, about 1 to about 1.5 mm, about 1.5 to about 6 mm, about 1.5 to about 5.5 mm, about 1.5 to about 5 mm, about 1.5 to about 4.5 mm, about 1.5 to about 4 mm, about 1.5 to about 3.5 mm, about 1.5 to about 3 mm, about 1.5 to about 2.5 mm, about 2 to about 6 mm, about 2 to about 5.5 mm, about 2 to about 5 mm, about 2 to about 4.5 mm, about 2 to about 4 mm, about 2 to about 3.5 mm, about 2 to about 3 mm, about 2 to about 2.5 mm, about 2.5 ~6mm, ~2.5~5.5mm, ~2.5~5mm, ~2.5~4.5mm, ~2.5~4mm, ~2.5~3.5mm, ~2.5~3mm, ~3~6mm, ~3~5.5mm, ~3~5mm, ~3~4.5mm, ~3~4mm, ~3~3.5mm, ~3.5~6mm, ~ The pellets may be about 5.5 mm, about 3.5 to about 5 mm, 3.5 to about 4.5 mm, about 3.5 to about 4 mm, about 4 to about 6 mm, about 4 to about 5.5 mm, about 4 to about 5 mm, about 4 to about 4.5 mm, about 4.5 to about 6 mm, about 4.5 to about 5.5 mm, about 4.5 to about 5 mm, about 5 to about 6 mm, about 5 to about 5.5 mm, or 5.5 to about 6 mm. As non-limiting example embodiments, the pellets may be about 2.5 mm to about 4.5 mm long, or about 2.5 mm, about 3 mm, about 3.5 mm, about 4 mm, or about 4.5 mm long. In some embodiments, the pellets include a variety of different shapes, including spears, rods, granules, blocks, particles, and particles of any suitable shape.

[0058] In one aspect, the formulation is in the form of a powder. In some embodiments, the powder can be produced from pellets. In a non-limiting exemplary embodiment, the components of the formulation are melt mixed into a homogenous ink and freeze-milled to form a powder. In a non-limiting exemplary embodiment, the components of the formulation are dissolved in a solvent-based slurry and spray-dried to form a powder. In some embodiments, the powder is used for selective laser sintering.

[0059] 3D printed structure In other aspects, 3D printed structures are provided herein. The structures can be prepared using the formulations and / or manufacturing methods described herein.

[0060] In some embodiments, the three-dimensional structure comprises micropores. The micropores may be formed after removal of particulates or pore-forming agents. The micropores may be formed by the use of foaming agents during formulation. In some embodiments, the micropores provide additional surface area to the structure for contact with the therapeutic agent compared to a structure lacking micropores. In a non-limiting example, the therapeutic agent comprises a targeting moiety that is non-covalently bound to the ceramic material of the structure. In some embodiments, the average diameter of the micropores is from about 1 micron to about 500 microns. For example, the diameter may be about 1 micron to about 450 microns, about 1 micron to about 400 microns, about 1 micron to about 350 microns, about 1 micron to about 300 microns, about 1 micron to about 250 microns, about 1 micron to about 200 microns, about 1 micron to about 150 microns, about 50 microns to about 500 microns, about 50 microns to about 450 microns, about 50 microns to about 400 microns, about 50 microns to about 350 microns, about 50 microns to about 300 microns, about 50 microns to about 250 microns, about 50 microns to about 200 microns, about 50 microns to about 150 microns, about 100 microns to about 5 In some cases, the average diameter of the micropores is about 50 microns to about 250 microns, about 60 microns to about 240 microns, about 70 microns to about 230 microns, about 80 microns to about 220 microns, or about 90 microns to about 210 microns.In some embodiments, the average diameter of the micropores is about 100 microns to about 200 microns, e.g., about 110 microns to about 190 microns, about 120 microns to about 180 microns, about 130 microns to about 170 microns, about 140 microns to about 160 microns, or about 100 microns, about 110 microns, about 120 microns, about 130 microns, about 140 microns, about 150 microns, about 160 microns, about 170 microns, about 180 microns, about 190 microns, or about 200 microns. In some embodiments, the average diameter of the micropores is about 150 microns.

[0061] In some embodiments, the three-dimensional structure has a density of about 1 g / cm 3 ~About 3g / cm 3 In some embodiments, the three-dimensional structure has a density of about 1 g / cm 3 ~About 2g / cm 3 (e.g., about 1, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.5, 1.55, 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, 1.9, 1.95, or 2 g / cm 3 , or any value in between).

[0062] In some embodiments, the three-dimensional structure has an open porosity of about 15% to about 50%, about 15% to about 45%, about 15% to about 40%, about 20% to about 50%, about 20% to about 45%, about 25% to about 40%, about 25% to about 50%, about 25% to about 45%, or about 25% to about 40%. In some embodiments, the open porosity is about 25% to about 40%, such as about 25%, 30%, 35%, or 40%, or any value therebetween.

[0063] In some embodiments, the three-dimensional structure has a diameter of about 300 μm to about 600 μm, about 325 μm to about 600 μm, about 350 μm to about 600 μm, 375 μm to about 600 μm, 400 μm to about 600 μm, about 425 μm to about 600 μm, about 450 μm to about 600 μm, about 475 μm to about 600 μm, about 500 μm to about 600 μm, about 525 μm to about 600 μm, about 550 μm to about 600 μm, about 300 μm to about 575 μm, about 325 μm to about 575 μm, about 350 μm to about 575 μm, about 375 μm to about 575 μm, about 400 μm to about 575 μm, or about 575 μm. 5μm, about 425μm to about 575μm, about 450μm to about 575μm, about 475μm to about 575μm, about 500μm to about 575μm, Approximately 525μm to approximately 575μm, approximately 550μm to approximately 575μm, approximately 300μm to approximately 550μm, approximately 325μm to approximately 550μm, approximately 350 μm ~ approx. 550 μm, approx. 375 μm ~ approx. 550 μm, approx. 400 μm ~ approx. 550 μm, approx. 425 μm ~ approx. 550 μm, approx. 450 μm ~ approx. 550μm, about 475μm to about 550μm, about 500μm to about 550μm, about 525μm to about 550μm, about 300μm to about 525μm m, approximately 325 μm to approximately 525 μm, approximately 350 μm to approximately 525 μm, approximately 375 μm to approximately 525 μm, approximately 400 μm to approximately 525 μm, approximately 425μm~approx. 525μm, approx. 450μm~approx. 525μm, approx. 475μm~approx. 525μm, approx. 500μm~approx. 525μm, approx. 300μm m ~ approx. 500 μm, approx. 325 μm ~ approx. 500 μm, approx. 350 μm ~ approx. 500 μm, approx. 375 μm ~ approx. 500 μm, approx. 400 μm ~ approx. 5 00μm, about 425μm to about 500μm, about 450μm to about 500μm, about 475μm to about 500μm, about 300μm to about 475μm , about 325 μm to about 475 μm, about 350 μm to about 475 μm, about 375 μm to about 475 μm, about 400 μm to about 475 μm, about 425 μm to about 475 μm, about 450 μm to about 475 μm, about 300 μm to about 450 μm, about 325 μm to about 450 μm, about 350 μm to about 450 μm, about 375 μm to about 450 μm, about 400 μm to about 450 μm, about 425 μm to about 450 μm, about 300 μm to about 400 μm, about 325 μm to about 400 μm, about 350 μm to about 400 μm, or about 375 μm to about 400 μm.

[0064] In some embodiments, the structure comprises a ceramic material such as calcium phosphate. In some embodiments, the structure comprises a ceramic material such as calcium phosphate. 0, 60~100, 60~95, 60~90, 60~85, 60~80, 60~75, 60~70, 60~65, 65~100, 65~95, 65~90, 65~85, 65~80, 65~75, 65~70, 70~100, 70~95, 70~90, 70~85, 70~80, 70~75, 75 ~100, 75~95, 75~90, 75~85, 75~80, 80~100, 80~95, 80~90, 80~85, 85~100, 85~95, 85~90, 90~100, 90~95, 95~100, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 6 3, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100 percent ceramic material. In some cases, the ceramic material is a calcium phosphate, such as beta-tricalcium phosphate (β-TCP).

[0065] In a non-limiting example, the structure has about 50-90% ceramic material, such as β-TCP. In some cases, the structure has about 50, 55, 60, 65, 70, 75, 80, 85, or 90% ceramic material, such as β-TCP. In some embodiments, the structure has about 10-50% polymer, such as polycaprolactone (PCL) or polydioxanone (PDS). In some cases, the structure has about 10, 15, 20, 25, 30, 35, 40, 45, or 50% polymer, such as PCL or PDS. Exemplary structures include about 85-90% by weight ceramic (e.g., β-TCP) and about 10-15% by weight polymer (e.g., PCL or PDS), about 80-85% by weight ceramic (e.g., β-TCP) and about 15-20% by weight polymer (e.g., PCL or PDS), about 75-80% by weight ceramic (e.g., β-TCP) and about 20-25% by weight polymer (e.g., PCL or PDS), about 70-75% by weight ceramic (e.g., β-TCP) and about 25-30% by weight polymer (e.g., PCL or PDS), about 65-70% by weight ceramic (e.g., β-TCP) and about 30-35% by weight polymer (e.g., PCL or PDS), about 60-65% by weight ceramic (e.g., β-TCP) and about 35-40% by weight polymer (e.g., PCL or PDS), about 55-60% by weight about 50-55% by weight of ceramic (e.g., β-TCP) and about 45-50% by weight of polymer (e.g., PCL or PDS); about 90% by weight of ceramic (e.g., β-TCP) and about 10% by weight of polymer (e.g., PCL or PDS); about 89% by weight of ceramic (e.g., β-TCP) and about 11% by weight of polymer (e.g., PCL or PDS); about 88% by weight of ceramic (e.g., β-TCP) and about 12% by weight of polymer (e.g., PCL or PDS); about 87% by weight of ceramic (e.g., β-TCP) and about 13% by weight of polymer (e.g., PCL or PDS); about 86% by weight of ceramic (e.g., β-TCP) and about 14% by weight of polymer (e.g., PCL or PDS);about 85% by weight ceramic (e.g., β-TCP) and about 15% by weight polymer (e.g., PCL or PDS), about 84% by weight ceramic (e.g., β-TCP) and about 16% by weight polymer (e.g., PCL or PDS), about 83% by weight ceramic (e.g., β-TCP) and about 17% by weight polymer (e.g., PCL or PDS), about 82% by weight ceramic (e.g., β-TCP) and about 18% by weight polymer (e.g., PCL or PDS), about 81% by weight ceramic (e.g., β-TCP) and about 19% by weight polymer - (e.g., PCL or PDS), about 80% by weight ceramic (e.g., β-TCP) and about 20% by weight polymer (e.g., PCL or PDS), about 79% by weight ceramic (e.g., β-TCP) and about 21% by weight polymer (e.g., PCL or PDS), about 78% by weight ceramic (e.g., β-TCP) and about 22% by weight polymer (e.g., PCL or PDS), about 77% by weight ceramic (e.g., β-TCP) and about 23% by weight polymer (e.g., PCL or PDS), about 76% by weight ceramic (e.g., β-TCP) and about 23 ...6% by weight ceramic (e.g., β-TCP) and about 23% by weight polymer (e.g., PCL or PDS), about 76% by weight ceramic (e.g., β-TCP % of a ceramic (e.g., β-TCP) and about 24% by weight of a polymer (e.g., PCL or PDS), about 75% by weight of a ceramic (e.g., β-TCP) and about 25% by weight of a polymer (e.g., PCL or PDS), about 74% by weight of a ceramic (e.g., β-TCP) and about 26% by weight of a polymer (e.g., PCL or PDS), about 73% by weight of a ceramic (e.g., β-TCP) and about 27% by weight of a polymer (e.g., PCL or PDS), about 72% by weight of a ceramic (e.g., β-TCP) and about 28% by weight of a polymer (e.g., PCL or PDS), about 71% by weight of a ceramic (e.g., β-TCP) and about 28% by weight of a polymer (e.g., PCL or PDS), about 72% by weight of a ceramic (e.g., β-TCP) and about 28 ...2% by weight of a ceramic (e.g., β-TCP) and about 28% by weight of a polymer % ceramic (e.g., β-TCP) and about 29% by weight polymer (e.g., PCL or PDS), about 70% by weight ceramic (e.g., β-TCP) and about 30% by weight polymer (e.g., PCL or PDS), about 69% by weight ceramic (e.g., β-TCP) and about 31% by weight polymer (e.g., PCL or PDS), about 68% by weight ceramic (e.g., β-TCP) and about 32% by weight polymer (e.g., PCL or PDS), about 67% by weight ceramic (e.g., β-TCP) and about 33% by weight polymer (e.g.,about 66% by weight ceramic (e.g., β-TCP) and about 34% by weight polymer (e.g., PCL or PDS), about 65% by weight ceramic (e.g., β-TCP) and about 35% by weight polymer (e.g., PCL or PDS), about 64% by weight ceramic (e.g., β-TCP) and about 36% by weight polymer (e.g., PCL or PDS), about 63% by weight ceramic (e.g., β-TCP) and about 37% by weight polymer (e.g., PCL or PDS), about 62% by weight ceramic % of a ceramic (e.g., β-TCP) and about 38% by weight of a polymer (e.g., PCL or PDS), about 61% by weight of a ceramic (e.g., β-TCP) and about 39% by weight of a polymer (e.g., PCL or PDS), about 60% by weight of a ceramic (e.g., β-TCP) and about 40% by weight of a polymer (e.g., PCL or PDS), about 59% by weight of a ceramic (e.g., β-TCP) and about 41% by weight of a polymer (e.g., PCL or PDS), about 58% by weight of a ceramic (e.g., β-TCP) and about 42% by weight of a polymer (e.g., PCL or PDS), % ceramic (e.g., β-TCP) and about 45% polymer (e.g., PCL or PDS), about 57% by weight ceramic (e.g., β-TCP) and about 43% by weight polymer (e.g., PCL or PDS), about 56% by weight ceramic (e.g., β-TCP) and about 44% by weight polymer (e.g., PCL or PDS), about 55% by weight ceramic (e.g., β-TCP) and about 45% by weight polymer (e.g., PCL or PDS), about 54% by weight ceramic (e.g., β-TCP) and about 46% by weight polymer (e.g., For example, about 53% by weight ceramic (e.g., β-TCP) and about 47% by weight polymer (e.g., PCL or PDS), about 52% by weight ceramic (e.g., β-TCP) and about 48% by weight polymer (e.g., PCL or PDS), about 51% by weight ceramic (e.g., β-TCP) and about 49% by weight polymer (e.g., PCL or PDS), about 50% by weight ceramic (e.g., β-TCP) and about 50% by weight polymer (e.g., PCL or PDS).

[0066] The structures may be fabricated using 3D printing from an ink comprising about 30-70% by weight β-TCP powder, about 10-30% by weight of a first polymer, and about 10-30% by weight of a second polymer. In some cases, the first polymer comprises PCL. In some cases, the first polymer comprises PDS. In some cases, the second polymer comprises PEG. In some cases, the ink further comprises about 1-10% by weight of a particulate (e.g., sucrose). In some cases, the ink further comprises about 5-20% of a foaming agent (e.g., sodium bicarbonate).

[0067] In some embodiments, the three-dimensional structure has a density of about 1 g / cm 3 ~About 2g / cm 3 , or about 1.25 g / cm 3 ~Approx. 1.75g / cm 3 In some embodiments, the three-dimensional structure has an open porosity of about 20% to about 40%, about 25% to about 35%, e.g., about 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, or 35%. In some embodiments, the three-dimensional structure has a strut diameter of about 400 μm to about 500 μm, about 400 μm to about 450 μm, or about 425 μm to about 450 μm.

[0068] In some embodiments, the three-dimensional structure has a density of about 1 g / cm 3 ~About 2g / cm 3 , or about 1 g / cm 3 ~Approx. 1.5g / cm 3 In some embodiments, the three-dimensional structure has an open porosity of about 30% to about 50%, about 35% to about 45%, e.g., about 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, or 45%. In some embodiments, the three-dimensional structure has a strut diameter of about 325 μm to about 425 μm, about 350 μm to about 400 μm, or about 360 μm to about 390 μm.

[0069] In some embodiments, the three-dimensional structure has a density of about 1 g / cm 3 ~About 2g / cm3 , or about 1 g / cm 3 ~Approx. 1.5g / cm 3 In some embodiments, the three-dimensional structure has an open porosity of about 30% to about 50%, about 35% to about 45%, e.g., about 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, or 45%. In some embodiments, the three-dimensional structure has a strut diameter of about 350 μm to about 450 μm, about 350 μm to about 400 μm, or about 380 μm to about 405 μm.

[0070] In a non-limiting example, the structure has about 50-90% ceramic material, such as β-TCP. In some cases, the structure has about 50, 55, 60, 65, 70, 75, 80, 85, or 90% ceramic material, such as β-TCP. In some embodiments, the structure has about 10-50% copolymer, such as polycaprolactone / polyglycolide copolymer (PCL / PGA, e.g., 90:10, 95:5), poly(D,L-lactide-co-glycolide copolymer (PLGA, e.g., 50:50), PDS-glycolide copolymer (PDS / PGA, e.g., 90:10), PDS-L-lactide copolymer (PDS / PLA, e.g., 90:10), or dioxanone / L-lactide copolymer (e.g., 90:10). In some cases, the structure has about 10, 15, 20, 25, 30, 35, 40, 45, or 50% polymer, such as PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide. Exemplary structures include about 85-90% by weight ceramic (e.g., β-TCP) and about 10-15% by weight polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 80-85% by weight ceramic. % by weight of a ceramic (e.g., β-TCP) and about 15-20% by weight of a polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 75-80% by weight of a ceramic (e.g., β-TCP) and about 20-25% by weight of a polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 70-75% by weight of a ceramic (e.g., β-TCP) and about 25-30% by weight of a polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), For example, PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 65-70% by weight ceramic (e.g., β-TCP) and about 30-35% by weight polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 60-65% by weight ceramic (e.g., β-TCP) and about 35-40% by weight polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA,or dioxanone / L-lactide), about 55-60% by weight ceramic (e.g., β-TCP) and about 40-45% by weight polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 50-55% by weight ceramic (e.g., β-TCP) and about 45-50% by weight polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 90% by weight ceramic (e.g., β-TCP) and about 10% by weight polymer (e.g., For example, about 89% by weight ceramic (e.g., β-TCP) and about 11% by weight polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 88% by weight ceramic (e.g., β-TCP) and about 12% by weight polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 87% by weight ceramic (e.g., β-TCP) and about 13% by weight polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), ...7% by weight ceramic (e.g., β-TCP) and about 13% by weight polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 87% by weight ceramic (e.g., β-TCP) and about 13% by weight polymer (e.g., PCL / PGA % by weight of a ceramic (e.g., β-TCP) and about 13% by weight of a polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 86% by weight of a ceramic (e.g., β-TCP) and about 14% by weight of a polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 87% by weight of a ceramic (e.g., β-TCP) and about 13% by weight of a polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 86% by weight ceramic (e.g., β-TCP) and about 14% by weight polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 85% by weight ceramic (e.g., β-TCP) and about 15% by weight polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 84% by weight ceramic (e.g., β-TCP) and about 16% by weight polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA,or dioxanone / L-lactide), about 83% by weight ceramic (e.g., β-TCP) and about 17% by weight polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 82% by weight ceramic (e.g., β-TCP) and about 18% by weight polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 81% by weight ceramic (e.g., β-TCP) and about 19% by weight polymer (e.g., PCL / PGA, PDS about 80% by weight ceramic (e.g., β-TCP) and about 20% by weight polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 79% by weight ceramic (e.g., β-TCP) and about 21% by weight polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 78% by weight ceramic (e.g., β-TCP) and about 22% by weight polymer % by weight of a polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 77% by weight of a ceramic (e.g., β-TCP) and about 23% by weight of a polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 76% by weight of a ceramic (e.g., β-TCP) and about 24% by weight of a polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 75% by weight of a ceramic (e.g., β-TCP) and about 25% by weight of a polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 74% by weight of a ceramic (e.g., β-TCP) and about 26% by weight of a polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 73% by weight of a ceramic (e.g., β-TCP) and about 27% by weight of a polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide),about 72% by weight ceramic (e.g., β-TCP) and about 28% by weight polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 71% by weight ceramic (e.g., β-TCP) and about 29% by weight polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 70% by weight ceramic (e.g., β-TCP) and about 30% by weight polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 69% by weight ceramic (e.g., β-TCP) and about 31% by weight polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 68% by weight ceramic (e.g., β-TCP) and about 32% by weight polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 67% by weight ceramic (e.g., β-TCP) and about 33% by weight polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide). S / PGA, PDS / PGA, PLGA, or dioxanone / L-lactide), about 66% by weight ceramic (e.g., β-TCP) and about 34% by weight polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 65% by weight ceramic (e.g., β-TCP) and about 35% by weight polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 64% by weight ceramic (e.g., β-TCP) and about 36% by weight polymer % by weight of a polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 63% by weight of a ceramic (e.g., β-TCP) and about 37% by weight of a polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 62% by weight of a ceramic (e.g., β-TCP) and about 38% by weight of a polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 61% by weight of a ceramic (e.g.,β-TCP) and about 39% by weight of a polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 60% by weight of a ceramic (e.g., β-TCP) and about 40% by weight of a polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 59% by weight of a ceramic (e.g., β-TCP) and about 41% by weight of a polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), % by weight of ceramic (e.g., β-TCP) and about 42% by weight of polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 57% by weight of ceramic (e.g., β-TCP) and about 43% by weight of polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 56% by weight of ceramic (e.g., β-TCP) and about 44% by weight of polymer (e.g., PCL / PGA, PDS / PGA, PDS % by weight of ceramic (e.g., β-TCP) and about 45% by weight of polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 54% by weight of ceramic (e.g., β-TCP) and about 46% by weight of polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 53% by weight of ceramic (e.g., β-TCP) and about 47% by weight of polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 5 ...5% by weight of ceramic (e.g., β-TCP) and about 45% by weight of polymer ( For example, about 52% by weight ceramic (e.g., β-TCP) and about 48% by weight polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 51% by weight ceramic (e.g., β-TCP) and about 49% by weight polymer (e.g., PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide), about 50% by weight ceramic (e.g.,The structures include those having about 30-70% by weight of β-TCP powder, about 10-30% by weight of a first polymer, and about 10-30% by weight of a second polymer, In some embodiments, the three-dimensional structure may be fabricated using 3D printing from an ink comprising: In some cases, the first polymer comprises PCL / PGA, PDS / PGA, PDS / PLA, PLGA, or dioxanone / L-lactide. In some cases, the second polymer comprises PEG. In some embodiments, the three-dimensional structure may have a mass of about 1 g / cm. 3 ~About 2g / cm 3 , or about 1.25 g / cm 3 ~Approx. 1.75g / cm 3 In some embodiments, the three-dimensional structure has an open porosity of about 15% to about 35%, about 20% to about 30%, e.g., about 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, or 30%. In some embodiments, the three-dimensional structure has a strut diameter of about 350 μm to about 450 μm, about 375 μm to about 425 μm, or about 385 μm to about 415 μm.

[0071] In some embodiments, the three-dimensional structure has a density of about 1 g / cm 3 ~About 2g / cm 3 , or about 1.5 g / cm 3 ~About 2g / cm 3 In some embodiments, the three-dimensional structure has an open porosity of about 15% to about 35%, about 20% to about 30%, e.g., about 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, or 30%. In some embodiments, the three-dimensional structure has a strut diameter of about 500 μm to about 600 μm, about 550 μm to about 600 μm, or about 555 μm to about 585 μm.

[0072] In some embodiments, the three-dimensional structure has a density of about 1 g / cm 3 ~About 2g / cm 3, or about 1.25 g / cm 3 ~Approx. 1.75g / cm 3 In some embodiments, the three-dimensional structure has an open porosity of about 20% to about 40%, about 25% to about 35%, e.g., about 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, or 35%. In some embodiments, the three-dimensional structure has a strut diameter of about 400 μm to about 500 μm, about 450 μm to about 500 μm, or about 450 μm to about 475 μm.

[0073] In some embodiments, the composition of the ink formulations herein is altered to optimize the specific surface area. The surface area may be optimized for combination with a therapeutic agent. For example, the structures may be designed to have a specific surface area of ​​approximately 0.2-2 m for combination with a BMP protein (e.g., tBMP-2). 2 In some embodiments, the surface area of ​​the structures herein is about 0.2-2, 0.2-1.8, 0.2-1.6, 0.2-1.4, 0.2-1.2, 0.2-1, 0.2-0.8, 0.2-0.6, 0.2-0.4, 0.4-2, 0.4-1.8, 0.4-1.6, 0.4-1.4, 0.4-1.2, 0.4-1, 0.4-0.8, 0.4-0.6, 0.6-2, 0.6-1.8, 0.6-1. 6, 0.6~1.4, 0.6~1.2, 0.6~1, 0.6~0.8, 0.8~2, 0.8~1.8, 0.8~1.6, 0.8~1.4, 0.8~1.2, 0.8~1, 1~2, 1~1.8, 1~1.6, 1~1.4, 1~1.2, 1.2~2, 1.2~1.8, 1.2~1.6, 1.2~1.4, 1.4~2, 1.4~1.8, 1.4~1.6, 1.6~2, 1.6~1.8, or 1.8~2m 2 / g. In some embodiments, the surface area is calculated by Brunauer-Emmett-Teller (BET) by gas physisorption.

[0074] In some embodiments, the composition of the ink formulations herein is modified to optimize the absorption rate of one or more materials of the scaffold. For example, polymers are selected based on absorption rate. Absorption rates range from slowest to fastest for polycaprolactone, polycaprolactone / polyglycolide copolymer (95:5), polycaprolactone / glycolide copolymer (90:10), polydioxanone / L-lactide copolymer (90:10), poly(D,L-lactide-co-glycolide) copolymer (50:50).

[0075] Manufacturing method In another aspect, a method of manufacturing a structure using 3D printing techniques is provided.

[0076] In some embodiments, the method includes syringe-based melt extrusion bioprinting. Exemplary inks in this method may have low viscosity to extrude the ink through a narrow nozzle. Non-limiting examples of manufacturing methods using this method are described in Example 2, for example, for printing ink formulations #1, #2, #3, #4.

[0077] In one embodiment, the method is an extrusion method, including a 3D printing method in which material is extruded from a nozzle.

[0078] In some embodiments, extrusion methods include bioprinting (syringe-based pneumatic printing) or fused granulation (FGF), where pellets of feedstock are fed from a hopper into a mini-screw extrusion head that melts the material and extrudes it through fine nozzles. In some embodiments, the ink is formed into small (e.g., 2-5 mm) pellets or granules.

[0079] In some embodiments, the method includes fused filament fabrication (FFF). The exemplary ink in this method can be formed into a filament for printing on an FFF 3D printer. A non-limiting example of a manufacturing method using this method is described in Example 2, for example, for printing ink formulations #5 and #6.

[0080] In some embodiments, the method includes pelletized fused deposition modeling. Fused deposition modeling (FDM) is an additive manufacturing process. Three-dimensional objects are formed by extrusion and deposition of individual layers of thermoplastic material. FDM involves the melt extrusion of filamentary material through a heated nozzle and deposition as a thin solid layer on a platform. Thermoplastic polymer material is fed into a temperature-controlled FDM extrusion head and heated to a semi-liquid state. The FDM extrusion head then extrudes the material in ultra-thin layers to precisely deposit it on a base. The material solidifies, stacking onto the previous layer. In this way, parts are manufactured in layers, where each layer is built by extruding small beads of material, called "loads," in a specific pattern such that the layer is covered by the adjacent loads. After each layer is completed, the extrusion head is raised to build subsequent layers to make up the part. Typically, FDM is used to fabricate solid models. To fabricate porous structures, a raster fill gap has a positive value that is applied to impart channels within the build layer. The channels are regularly arranged and interconnected in three dimensions as well, and layer-by-layer fabrication allows for the design of varying pore morphologies across the scaffold structure.

[0081] In some embodiments, the method includes selective laser sintering (SLS), which is a process in which a dispenser deposits layers of powdered material onto a target area. There is a laser control mechanism, typically comprising a computer on which the article design is stored. The laser control mechanism modulates and moves the laser beam to selectively irradiate the powder layers within the defined boundaries of the design, melting the powder as it falls. This is done to selectively sinter successive powder layers. The method produces a finished product comprised of multiple layers sintered together.

[0082] In some embodiments, after 3D printing, the resulting object is immersed in water to dissolve certain components of the ink, such as PEG, particulates (e.g., pore formers, sucrose), foaming agents (e.g., sodium bicarbonate), or combinations thereof. The structure may then be dried, sterilized, treated with therapeutic agents as described elsewhere herein, or combinations thereof.

[0083] Any of the 3D printed structures described herein can be coated with an anchorable protein (e.g., tBMP2). After completing the structure using any of the methods discussed herein, the structure can be washed with an acidic sodium acetate buffer. This can be one, two, or more washes. After washing, the structure can be incubated for 2 hours in sodium acetate buffer containing tBMP2 protein at a concentration of 1 mg / mL. The anchorable tBMP2 binds to the β-TCP surface of the monolayer embedded structure.

[0084] In further embodiments, the ink formulations discussed herein can include a photosensitive resin that is mixed with ceramic powder for digital light processing (DLP), an additional manufacturing technique that is faster than robocasting or melt extrusion. The components in a photosensitive ceramic-filled resin for DLP 3D printing of bone implants typically include ceramic powder (e.g., β-TCP, hydroxyapatite, bioglass, typically particle size 10 μm or less), one or more crosslinked acrylates or methacrylates (e.g., polyethylene glycol diacrylate, polycaprolactone methacrylate), a plasticizer (e.g., water) that reduces resin viscosity, a dispersant (e.g., Darvan® 821-A) that promotes the breakup of powder aggregates, a photoinitiator (e.g., lithium phenyl-2,4,6-trimethylbenzoylphosphinate) that starts the photocrosslinking reaction, and a photoabsorber (e.g., tartrazine) that maintains high xy resolution. Once the resin formulation is prepared by asymmetric centrifugal mixing of the components, the ink is exposed layer by layer to a DLP image, which selectively solidifies the illuminated pixels when the resin is exposed to light. Once the implantable structure is built up layer by layer, it is heat treated to sinter the included polymer and either densify the ceramic (e.g., polyethylene glycol diacrylate-containing resins) or leave it to yield a flexible ceramic / polymer composite implant (e.g., polycaprolactone methacrylate-containing resins).

[0085] device In other aspects, devices and kits are provided that include the 3D printed structures described herein and therapeutic agents.In some embodiments, the devices include therapeutic agents that are connected to, dispersed within, or otherwise combined with the 3D printed structures.As used herein, therapeutic agents include multiple therapeutic agents, such as 2, 3, 4, or 5 therapeutic agents.

[0086] Therapeutic Agents In some embodiments, the therapeutic agent comprises a mammalian growth factor or a functional portion thereof. The mammalian growth factor may be an osteoinductive molecule capable of initiating or enhancing bone repair processes. The functional portion of the mammalian growth factor is a region having a therapeutic effect. For example, the functional portion of the mammalian growth factor is osteoinductive. As another example, the functional portion of the mammalian growth factor can initiate and / or enhance bone repair. The functional portion of the mammalian growth factor may have osteogenic activity.

[0087] Non-limiting examples of mammalian growth factors are described herein. In some examples, the mammalian growth factor is selected from the group consisting of epidermal growth factor (EGF), platelet derived growth factor (PDGF), insulin-like growth factor (IGF-1), fibroblast growth factor (FGF), fibroblast growth factor 2 (FGF2), fibroblast growth factor 18 (FGF18), transforming growth factor alpha (TGF-α), transforming growth factor beta (TGF-β), transforming growth factor beta-1 (TGF-β1), transforming growth factor beta 3 (TGF-β3), osteogenic protein 1 (OP-1), osteogenic protein 1 (OP-2), osteogenic protein 3 (OP-3), osteogenic protein 4 (OP-4), osteogenic protein 5 (OP-5), osteogenic protein 6 (OP-6), osteogenic protein 7 (OP-7), osteogenic protein 8 (OP-8), osteogenic protein 9 (OP-9), osteogenic protein 10 (OP-10), osteogenic protein 11 (OP-11), osteogenic protein 12 (OP-12), osteogenic protein 13 (OP-14), osteogenic protein 14 (OP-15), osteogenic protein 15 (OP-16), osteogenic protein 16 (OP-17), osteogenic protein 17 (OP-18), osteogenic protein 18 (OP-19), osteogenic protein 19 ... Bone morphogenetic protein 2 (BMP-2), bone morphogenetic protein 3 (BMP-3), bone morphogenetic protein 4 (BMP-4), bone morphogenetic protein 5 (BMP-5), bone morphogenetic protein 6 (BMP-6), bone morphogenetic protein 7 (BMP-7), bone morphogenetic protein 9 (BMP-9), bone morphogenetic protein 10 (BMP-10), bone morphogenetic protein 11 (BMP-11), bone morphogenetic protein 12 (BMP-12), bone morphogenetic protein 13 (BMP-13), bone morphogenetic protein 15 (BMP-15), dentin phosphoprotein (DPP), plant-related growth factor ( Vgr), growth differentiation factor 1 (GDF-1), growth differentiation factor 3 (GDF-3), growth differentiation factor 5 (GDF-5), growth differentiation factor 6 (GDF-6), growth differentiation factor 7 (GDF-7), growth differentiation factor 8 (GDF8), growth differentiation factor 11 (GDF11), growth differentiation factor 15 (GDF15), vascular endothelial growth factor (VEGF), hyaluronic acid binding protein (HABP), and collagen binding protein (CBP), fibroblast growth factor 18 (FGF-18), keratinocyte growth factor (KGF), tumor necrosis factor alpha (TNFα), tumor necrosis factor tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), wnt family member 1 (WNT1), wnt family member 2 (WNT2), wnt family member 2B (WNT2B), wnt family member 3 (WNT3), wnt family member 3A (WNT3A), wnt family member 4 (WNT4), wnt family member 5A (WNT5A), wnt family member 5B (WNT5B), wnt family member 6 (WNT6), wnt family member 7A (WNT7A),wnt family member 7B (WNT7B), wnt family member 8A (WNT8A), wnt family member 8B (WNT8B), wnt family member 9A (WNT9A), wnt family member 9B (WNT9B), wnt family member 10A (WNT10A), wnt family member 10B (WNT10B), wnt family member 11 (WNT11), or wnt family member 16 (WNT16), or a mature peptide or functional portion thereof.

[0088] In some embodiments, the mammalian growth factor is a human growth factor. Non-limiting examples of human growth factors and mature peptides and / or functional portions thereof are provided in Table 1. In some embodiments, the mammalian growth factor comprises a sequence that is at least 70% identical (e.g., at least 75% identical, at least 80% identical, at least 85% identical, at least 90% identical, at least 95% identical, at least 99% identical) to any of the sequences in Table 1 or any secreted human growth factor and has osteogenic activity. In some embodiments, amino acids in mammalian growth factors that are conserved among various species may be important for osteogenic activity and may not be mutated, while amino acids in mammalian growth factors that are not conserved among various species may be important for osteogenic activity and may be mutated.

[0089] In some embodiments, the mammalian growth factor comprises BMP-2. In some embodiments, the mammalian growth factor is a mature peptide of BMP-2 (e.g., does not include a signal sequence). In some embodiments, the mammalian growth factor comprises a functional portion of BMP-2. In some embodiments, the functional portion of BMP-2 comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to QAKHKQRKRLKSSCKRHPLYVDFSDVGWNDWIVAPPGYHAFYCHGECPFPLADHLNSTNHAIVQTLVNSVNSKIPKACCVPTELSAISMLYLDENEKVVLKNYQDMVVEGCGCR (SEQ ID NO: 454). In some embodiments, the mammalian growth factor comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 454. In some embodiments, the mammalian growth factor comprises a sequence at least about 90% identical to SEQ ID NO: 454. In some embodiments, the mammalian growth factor comprises SEQ ID NO:454.

[0090] In some embodiments, the mammalian growth factor is a non-human mammalian growth factor. The non-human mammalian growth factor may be homologous to a human growth factor, such as one or more of the human growth factors in Table 1. In some embodiments, the non-human mammalian growth factor is homologous to a human growth factor if the non-human mammalian growth factor is at least about 80% identical to the human mammalian growth factor as determined using the NCBI Blast alignment algorithm as of the date of this application. In some examples, the coverage is at least about 90%. In some embodiments, the non-human mammalian growth factor is homologous to a human growth factor if the non-human mammalian growth factor is at least about 80% positive compared to the human mammalian growth factor as determined using the NCBI Blast alignment algorithm as of the date of this application. In some examples, the coverage is at least about 90%. In some embodiments, a non-human mammalian growth factor is homologous to a human growth factor if, as of the filing date of this application, the non-human mammalian growth factor aligns to the human growth factor using NCBI Blast has an E-value of about 1E-40, at least about 1E-50, 1E-60, 1E-70, or less than 1E-10, with a query coverage of at least about 90%.

[0091] [Table 1-1]

[0092] [Table 1-2]

[0093] [Table 1-3]

[0094] [Table 1-4]

[0095] [Table 1-5]

[0096] [Table 1-6]

[0097] targeting part In some embodiments, the device or kit includes a targeting moiety that tethers the therapeutic agent to the structure. In some embodiments, the targeting moiety is connected to the therapeutic agent and the moiety is non-covalently bound to the structure. As a non-limiting example, the targeting moiety is covalently bound to the therapeutic agent by a peptide bond. For example, the targeting moiety includes a targeting peptide, and the targeting peptide is linked to the therapeutic agent by a peptide bond.

[0098] In some embodiments, the targeting moiety has an affinity for the structure, or a component of the structure, for example, the ceramic material of the structure, such as calcium phosphate. In some embodiments, the dissociation constant (KD) for binding between the targeting moiety and the structure or a component thereof is (i) at least about 1 fM, at least about 10 fM, at least about 100 fM, or at least about 1 pM; and (ii) less than about 100 μM, less than about 90 μM, less than about 80 μM, less than about 70 μM, less than about 60 μM, less than about 50 μM, less than about 40 μM, less than about 30 μM, less than about 20 μM, less than about 10 μM, less than about 5 μM, less than about 1 μM, or less than about 100 pM. For example, the targeting moiety can bind to β-tricalcium phosphate with an affinity of about 100 fM to about 100 μM, about 1 pM to about 100 μM, about 10 pM to about 100 μM, about 100 pM to about 100 μM, or about 1 μM to about 100 μM.

[0099] In some embodiments, the targeting moiety comprises one or more targeting peptides, each of which binds to the structure. In some embodiments, the targeting peptide binds to the ceramic material of the structure. For example, the targeting peptide binds to calcium phosphate (e.g., tricalcium phosphate, beta tricalcium phosphate, alpha tricalcium phosphate), hydroxyapatite, fluorapatite, bone (e.g., demineralized bone), glass (bioglass), such as silicate, vanadate, and related ceramic minerals, or chelated divalent metal ions, or combinations thereof. In some embodiments, the targeting peptide comprises two or more targeting peptides. In some embodiments, the two or more targeting peptides are about 50, 45, 40, 35, 30, 25, 20, 15, or 10 or less targeting peptides. In some embodiments, the two or more targeting peptides are about 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, or 30 targeting peptides. In some embodiments, the two or more targeting peptides are about 2 to about 10 targeting peptides. In some embodiments, the two or more targeting peptides are about 5 targeting peptides.

[0100] In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO:1. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO:2. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO:3. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO:4. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO:5. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO:6. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO:7. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO:8. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO:9. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO:10. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 11. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 12. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 13.In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 14. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 15. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 16. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 17. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 18. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 19. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 20. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 21. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 22. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 23. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 24. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 25. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 26.In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 27. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 28. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 29. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 30. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 31. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO:32. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO:33. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO:34. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO:35. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO:36. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 37. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 38. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 39.In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 40. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 41. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 42. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 43. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 44. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 45. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 46. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 47. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 48. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 49. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 50. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 51. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 52.In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO:53. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO:54. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO:55. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO:56. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO:57. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 58. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 59. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 60. In some embodiments, the targeting peptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 61.

[0101] [Table 2-1]

[0102] [Table 2-2]

[0103] In some embodiments, the targeting peptide comprises one or more sequences in Table 2. In some embodiments, the targeting peptide comprises a sequence that is at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to a sequence in Table 2.

[0104] [Table 3-1]

[0105] [Table 3-2]

[0106] [Table 3-3]

[0107] [Table 3-4]

[0108] [Table 3-5]

[0109] In some embodiments, the targeting peptide comprises one or more sequences in Table 3. In some embodiments, the targeting peptide comprises a sequence that is at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to a sequence in Table 3.

[0110] Additional targeting peptides useful in the present disclosure include any one of SEQ ID NOs: 1-558 of U.S. Patent No. 7,572,766. In some embodiments, the targeting peptide comprises a sequence that is at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to any one of SEQ ID NOs: 1-558 of U.S. Patent No. 7,572,766.

[0111] In some embodiments, the device or kit comprises a chimeric polypeptide comprising a targeting peptide and a targeting moiety. In some cases, the chimeric polypeptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 433 (ASGAGGSEGGGSEGGTSGATGAGTSTSGGGASTGGGTGQAKHKQRKRLKSSCKRHPLYVDFSDVGWNDWIVAPPGYHAFYCHGECPFPLADHLNSTNHAIVQTLVNSVNSKIPKACCVPTELSAISMLYLDENEKVVLKNYQDMVVEGCGCR). In some cases, the chimeric polypeptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 434 (MPIGSLLADTTHHRPWTVIGESTHHRPWSIIGESSHHKPFTGLGDTTHHRPWGILAESTHHKPWTASGAGGSEGGGSEGGTSGATGAGTSTSGGGASTGGGTGQAKHKQRKRLKSSCKRHPLYVDFSDVGWNDWIVAPPGYHAFYCHGECPFPLADHLNSTNHAIVQTLVNSVNSKIPKACCVPTELSAISMLYLDENEKVVLKNYQDMVVEGCGCR). In some cases, the chimeric polypeptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 435 (LLADTTHHRPWTVIGESTHHRPWSIIGESSHHKPFTGLGDTTHHRPWGILAESTHHKPWTASGAGGSEGGGSEGGTSGATGAGTSTSGGGASTGGGTGQAKHKQRKRLKSSCKRHPLYVDFSDVGWNDWIVAPPGYHAFYCHGECPFPLADHLNSTNHAIVQTLVNSVNSKIPKACCVPTELSAISMLYLDENEKVVLKNYQDMVVEGCGCR).In some cases, the chimeric polypeptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 436 (VIGESTHHRPWSIIGESSHHKPFTGLGDTTHHRPWGILAESTHHKPWTASGAGGSEGGGSEGGTSGATGAGTSTSGGGASTGGGTGQAKHKQRKRLKSSCKRHPLYVDFSDVGWNDWIVAPPGYHAFYCHGECPFPLADHLNSTNHAIVQTLVNSVNSKIPKACCVPTELSAISMLYLDENEKVVLKNYQDMVVEGCGCR). In some cases, the chimeric polypeptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 437 (IIGESSHHKPFTGLGDTTHHRPWGILAESTHHKPWTASGAGGSEGGGSEGGTSGATGAGTSTSGGGASTGGGTGQAKHKQRKRLKSSCKRHPLYVDFSDVGWNDWIVAPPGYHAFYCHGECPFPLADHLNSTNHAIVQTLVNSVNSKIPKACCVPTELSAISMLYLDENEKVVLKNYQDMVVEGCGCR). In some cases, the chimeric polypeptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 438 (GLGDTTHHRPWGILAESTHHKPWTASGAGGSEGGGSEGGTSGATGAGTSTSGGGASTGGGTGQAKHKQRKRLKSSCKRHPLYVDFSDVGWNDWIVAPPGYHAFYCHGECPFPLADHLNSTNHAIVQTLVNSVNSKIPKACCVPTELSAISMLYLDENEKVVLKNYQDMVVEGCGCR).In some cases, the chimeric polypeptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 439 (ILAESTHHKPWTASGAGGSEGGGSEGGTSGATGAGTSTSGGGASTGGGTGQAKHKQRKRLKSSCKRHPLYVDFSDVGWNDWIVAPPGYHAFYCHGECPFPLADHLNSTNHAIVQTLVNSVNSKIPKACCVPTELSAISMLYLDENEKVVLKNYQDMVVEGCGCR). In some cases, the chimeric polypeptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 440 ((X)QAKHKQRKRLKSSCKRHPLYVDFSDVGWNDWIVAPPGYHAFYCHGECPFPLADHLNSTNHAIVQTLVNSVNSKIPKACCVPTELSAISMLYLDENEKVVLKNYQDMVVEGCGCR), where X comprises a targeting peptide and optionally a linker. For example, the targeting peptide comprises one or more of SEQ ID NOs: 1-41. In some cases, the chimeric polypeptide comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 441 ((X)ASGAGGSEGGGSEGGTSGATGAGTSTSGGGASTGGGTGQAKHKQRKRLKSSCKRHPLYVDFSDVGWNDWIVAPPGYHAFYCHGECPFPLADHLNSTNHAIVQTLVNSVNSKIPKACCVPTELSAISMLYLDENEKVVLKNYQDMVVEGCGCR), where X comprises a targeting peptide and optionally a linker. For example, the targeting peptide comprises one or more of SEQ ID NOs: 1-41.

[0112] In some embodiments, the therapeutic agent is not connected to the structure using a targeting moiety. For example, the therapeutic agent may interact with the structure by non-covalent bonds. The therapeutic agent may be connected to the structure by hydrogen bonds, ionic bonds, hydrophobic interactions, or van der Waals forces. The therapeutic agent may also be connected to the structure using covalent bonds. Examples of methods for connecting using covalent bonds include chemical linkers and spacers used to modify active groups in proteins, such as amines, thiols, and carbohydrates.

[0113] In some embodiments, a device is provided that includes a cell-seeded structure. Non-limiting examples of cells include osteocytes and other bone cells, chondrocytes, and meniscal cells. In some examples, the cells may be added to the completed implantable structure.

[0114] Device fabrication Further provided herein are methods of manufacturing a device comprising a structure and a therapeutic agent. Some methods include: (a) providing a first solution of a therapeutic agent (e.g., a chimeric polypeptide comprising a therapeutic agent and a targeting moiety), (b) providing a 3D structure, and (c) combining (a) and (b). In some embodiments, the therapeutic agent is present in the first solution at a concentration of about 0.25-1.5, 0.25-1.25, 0.25-1, 0.25-0.75, 0.25-0.5, 0.5-1.5, 0.5-1.25, 0.5-1, 0.5-0.75, 0.75-1.5, 0.75-1.25, 0.75-1, 1-1.5, 1-1.25, 1.25-1.5, 0.25, 0.5, 1, 1.25, or 1.5 mg / mL. In some methods, step (c) is performed at about 10-240, 10-180, 10-120, 20-240, 20-180, 20-120, 30-240, 30-180, 30-120, 40-240, 40-180, 40-120, 50-240, 50-180, 50-120, 60-240, 60-180, 60-120, 70-240, 70-180, 70-120, 80-240, 80-180, 80-120, The method includes incubating the first solution and the structure for 90-240, 90-180, 90-120, 100-240, 100-180, 100-120, 110-240, 110-180, 110-120, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, or 240 minutes. In some methods, step (c) includes incubating the first solution and the structure by circulation and / or agitation (e.g., using a plate shaker) or the like. In some cases, the first solution includes a buffer. For example, the buffer includes sodium acetate and acetic acid. In some cases, the first solution has a pH of about 4 to about 5, or about 4, 4.1, 4.15, 4.2, 4.25, 4.3, 4.35, 4.4, 4.45, 4.5, 4.45, 4.6, 4.65, 4.7, 4.75, 4.8, 4.85, 4.9, 4.95, or 5. In some cases, the first solution comprises a salt.For example, the first solution may be 50-150, 50-140, 50-130, 50-120, 50-110, 50-100, 50-90, 50-80, 50-70, 50-60, 60-150, 60-140, 60-130, 60-120, 60-110, 60-100, 60-90, 60-80, 60-70, 70-150, 70-140, 70-130, 70-120, 70-110, 70-100, 70-90, 70-80, 80-150, 80-140, 80- The first solution may include sodium chloride such as 130, 80-120, 80-110, 80-100, 80-90, 90-150, 90-140, 90-130, 90-120, 90-110, 90-100, 100-150, 100-140, 100-130, 100-120, 100-110, 110-150, 110-140, 110-130, 110-120, 120-150, 120-140, 120-130, 130-150, 130-140, or 140-150. In some embodiments, the first solution includes 10 mM sodium acetate, 7 mM acetic acid, 100 mM NaCl, pH=4.75. In some embodiments, the method further comprises (d) washing the 3D structure of step (c) with a second solution, such as phosphate buffered saline (PBS). In some embodiments, the method further comprises drying the 3D structure of step (c) or step (d).

[0115] In some embodiments, the mass of therapeutic agent (e.g., therapeutic agent alone or therapeutic agent attached to a targeting moiety) per cubic centimeter of structure in the device is between about 0.05-50 (mg / cc) (e.g., about 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 15, 20, 25, 30, 35, 40, 45, or 50 mg / cc), or any number therebetween. For example, the therapeutic agent is about 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2 mg per cubic centimeter of device. One method for measuring the amount of therapeutic peptide bound to the structure includes (1) measuring the mass of the therapeutic peptide input in a first solution, (2) measuring the mass of the therapeutic agent remaining in the first solution after combination with the structure and removal from the structure, (3) if a wash step is included, measuring the mass of the therapeutic agent in the second solution, and (4) summing (2) and (3) and subtracting the sum of (4) from (1).

[0116] Treatment Method In other aspects, methods of treating a subject with the structures herein are provided. In some methods, a subject is treated with a device comprising a therapeutic peptide and a structure. In some examples, the subject has a bone fracture or bone defect. In some examples, the subject requires vertebral fusion of the spine. In some examples, the subject has a cartilage tear or cartilage defect. In some examples, the subject has cartilage loss.

[0117] In some embodiments, the subject suffers from a defect of bone, cartilage, soft tissue, tendon, fascia, ligament, organ, bone-tendon tissue, skin, osteochondral, or a combination of one or more of the aforementioned defects. In some embodiments, the defect is a lack of bone, cartilage, soft tissue, tendon, fascia, ligament, organ, bone-tendon tissue, skin, or osteochondral, or a combination of one or more of the aforementioned defects. In some embodiments, the defect in the subject results from trauma. In some embodiments, the defect in the subject results from a congenital disease. In some embodiments, the defect in the subject results from an acquired disease. In some embodiments, the defect refers to the absence, loss, and / or damage of a body tissue and / or organ. In some embodiments, "bone defect" refers to the absence or loss (e.g., partial loss) of bone at a subject's anatomical location that would be present in a control healthy subject. The bone defect may be the result of an infection (e.g., osteomyelitis), a tumor, trauma, or an adverse event of a procedure. The bone defect may further affect and cause damage to the muscles, soft tissues, tendons, or joints surrounding the bone defect. In some embodiments, bone defect comprises damage to soft tissue. In some embodiments, "cartilage defect" refers to the absence or loss (e.g., partial loss) of cartilage at a target anatomical location that would be present in a control healthy subject. Cartilage defect may be the result of disease, osteochondritis, osteonecrosis, or trauma. For example, cartilage defect may affect the knee joint.

[0118] Non-limiting examples of diseases suitable for treatment with the structures or devices described herein include osteoarthritis, disc degeneration, congenital defects, spinal stenosis, spondylolisthesis, spondylosis, fractures, scoliosis, kyphosis, spinal fusion (PLF and interbody fusion), bone trauma repair, dental repair, craniomaxillofacial repair, ankle fusion, vertebroplasty, balloon osteoplasty, navicular fracture repair, tendon-bone repair, osteoporosis, avascular necrosis, congenital skeletal deformity, rib reconstruction, subchondral bone repair, cartilage repair (e.g., at low doses), or trauma, or combinations thereof. BMP2 is also involved in the development of hair follicles, and thus the method may include treatment of hair follicles. The trauma is to bone, cartilage, soft tissue, tendon, fascia, ligament, organ, bone-tendon tissue, or skin tissue, or osteochondral tissue. In some embodiments, the method is for treating osteochondral damage.

[0119] The treatment method may include spinal fusion. In some embodiments, spinal fusion is a surgical procedure to join two or more vertebrae. In some embodiments, spinal fusion includes PLF. In some embodiments, spinal fusion includes interbody fusion.

[0120] Provided herein are methods of promoting bone or cartilage formation in a subject, comprising administering to the subject a therapeutically effective amount of any of the structures or devices described herein. Some embodiments of these methods can further comprise first selecting a subject in need of bone or cartilage formation. In some embodiments, the structure or device is administered to the subject proximal to a desired site of bone or cartilage formation in the subject.

[0121] Further provided herein are methods of replacing and / or repairing bone or cartilage in a subject, comprising administering to the subject a therapeutically effective amount of any of the structures or devices described herein. Some embodiments of these methods can further comprise first selecting a subject in need of bone replacement, bone repair, cartilage replacement, or cartilage repair. In some embodiments, the structure or device is administered to the subject proximate to the desired site of bone or cartilage replacement or repair in the subject.

[0122] Also provided herein are methods of treating a fracture or bone loss in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of a structure or device described herein. Some embodiments of these methods may further comprise first selecting a subject suffering from a fracture or bone loss. In some embodiments, the structure or device is administered to the subject proximal to a fracture or bone loss site in the subject.

[0123] Also provided herein are methods of repairing soft tissue in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of any of the structures or devices described herein. Some embodiments of these methods may further comprise first selecting a subject suffering from a fracture or bone loss. In some embodiments, the composition is administered to the subject proximal to the site of the fracture or bone loss in the subject.

[0124] Further provided herein are methods for locally delivering a therapeutic agent to a subject in need thereof, comprising administering to the subject a therapeutically effective amount of any of the structures or devices described herein. Some embodiments of these methods may further comprise first selecting a subject suffering from a fracture or bone loss. In some embodiments, the structure or device is administered to the subject proximal to a site of fracture or bone loss in the subject.

[0125] Methods for determining the effectiveness of treating a fracture or bone loss in a subject are known in the art and include, for example, imaging techniques (eg, magnetic resonance imaging, x-ray, or computed tomography).

[0126] Methods for detecting bone or cartilage formation, or bone or cartilage replacement or repair in a subject are also known in the art and include, for example, imaging techniques (e.g., magnetic resonance imaging, X-ray, or computed tomography).

[0127] Animal models suitable for treating fracture or bone loss, forming bone or cartilage, or replacing or repairing bone or cartilage are known in the art.Non-limiting examples of such animal models are described in Examples and, for example, Drosse et al., Tissue Engineering Part C 14(1):79-88,2008; Histing et al., Bone 49:591-599,2011; and Poser et al., Hindawi Publishing Corporation, BioMed Research International; Article ID 348635,2014.

[0128] As used herein, a method of treatment includes administering a structure or device of the present invention to a subject. In some embodiments, the administration includes implanting a polypeptide or composition of the present invention.

[0129] In some embodiments, the polypeptides and / or compositions herein comprising BMP-2 are administered to a subject. In some embodiments, the BMP2 comprises a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to SEQ ID NO: 454. In some embodiments, the BMP-2 is administered to induce bone formation in a subject. In some embodiments, the BMP-2 is administered to induce cartilage formation. In some embodiments, the BMP-2 is administered in a spinal fusion procedure.

[0130] The terms used herein are intended to describe particular cases only and are not intended to limit the invention. The singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. To the extent that the terms "including," "includes," "having," "has," "with," or variations thereof are used in either the detailed description and / or claims, such terms are intended to be included in a manner similar to the term "comprising."

[0131] In some embodiments, as used herein, the term "about" or "approximately" means within an acceptable error range of a particular value as determined by one of ordinary skill in the art, which depends in part on how the value is measured or determined, e.g., the limitations of the measurement system. For example, "about" can mean within 1 or more than 1 standard deviation, according to convention for any value.

[0132] As used herein, the term "subject" refers to any mammal. Thus, a subject may refer to, for example, a mouse, a rat, a dog, a cat, a horse, a cow, a pig, a guinea pig, a rat, a human, a monkey, etc. If the subject is a human, the subject may be referred to herein as a patient. In some embodiments, a subject or "subject in need of treatment" may be a canine (e.g., a dog), a feline (e.g., a cat), an equine (e.g., a horse), a sheep, a cow, a pig, a goat, a primate, for example, a monkey (e.g., a marmoset, a baboon), or an ape (e.g., a gorilla, a chimpanzee, an orangutan, or a gibbon), a human, or a rodent (e.g., a mouse, a guinea pig, a hamster, or a rat). In some embodiments, the subject or "subject in need of treatment" may be a mammal other than a human, particularly a mammal traditionally used as a model to demonstrate therapeutic efficacy in humans (e.g., a murine, lagomorph, porcine, canine, or primate).

[0133] In some embodiments, the term "therapeutically effective amount" refers to an amount of a polypeptide or composition effective to "treat" a disease, condition, or disorder in a subject. In some cases, a therapeutically effective amount of a polypeptide or composition reduces the severity of a symptom of the disease, condition, or disorder. In some examples, the disease, condition, or disorder involves an organ or tissue defect.

[0134] In some embodiments, "affinity" refers to the strength of the sum of non-covalent interactions between a β-TCP binding sequence (or a chimeric or polypeptide containing a β-TCP binding sequence) and its binding partner (e.g., β-TCP). Affinity can be measured by common methods known in the art, including those described herein. Affinity can be determined, for example, using surface plasmon resonance (SPR) technology (e.g., BIACORE®) or biolayer interferometry (e.g., FORTEBIO®).

[0135] Percent (%) sequence identity to a reference polypeptide sequence is the percentage of amino acid residues in a candidate sequence that are identical to those in a reference polypeptide sequence, after aligning sequences and introducing gaps, if necessary, to achieve the maximum percent sequence identity, and does not consider any conservative substitutions as part of sequence identity. Alignment for the purpose of determining percent amino acid sequence identity can be achieved in a variety of known ways, for example, using publicly available computer software such as BLAST, BLAST-2, ALIGN, or Megalign (DNASTAR) software. Suitable parameters for aligning sequences can be determined, including the algorithm required to achieve maximum alignment over the entire length of the sequences being compared. However, for the purposes herein, % amino acid sequence identity values ​​are generated using the sequence comparison computer program ALIGN-2. The ALIGN-2 sequence comparison computer program was created by Genentech, Inc., and the source code has been submitted to the U.S. Copyright Office (Washington DC, 20559) together with user documentation, and is registered under U.S. Copyright Registration No. TXU510087. The ALIGN-2 program is publicly available from Genentech, Inc. (South San Francisco, Calif.) or can be compiled from the source code. The ALIGN-2 program must be compiled for use on UNIX operating systems, including Digital UNIX V4.0D. All sequence comparison parameters are set by the ALIGN-2 program and do not vary.

[0136] In situations where ALIGN-2 is used for amino acid sequence comparison, the % amino acid sequence identity of a given amino acid sequence A to a given amino acid sequence B (which may alternatively be expressed as a given amino acid sequence A having or containing a % amino acid sequence identity to the given amino acid sequence B) is calculated as follows: multiply the fraction X / Y by 100, where X is the number of amino acid residues scored as identical matches by the sequence alignment program ALIGN-2 in the sequences A and B of that program, and where Y is the total number of amino acid residues in B. It should be understood that if the length of amino acid sequence A is not equal to the length of amino acid sequence B, then the % amino acid sequence identity of A to B is not equal to the % amino acid sequence identity of B to A. Unless otherwise specified, all % amino acid sequence identity values ​​used herein are obtained as described in the immediately preceding paragraph using the ALIGN-2 computer program.

[0137] Each of the embodiments described and illustrated herein has distinct components and features which may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the invention. Any recited method may be carried out in the order of events recited or in any other order which is logically possible.

[0138] A number of embodiments of the present disclosure have been described. However, it is understood that various modifications may be made without departing from the spirit and scope of the present disclosure. Furthermore, although specific formulations for the inks have been described, variations in the specific amounts of each ink component are possible. Accordingly, other embodiments are within the scope of the following claims.

[0139] Exemplary embodiments 1. A device comprising a therapeutic agent and a printed three-dimensional structure, the printed three-dimensional structure comprising about 50% to about 90% by weight ceramic and about 10% to about 50% by weight polymer. 2. The device of embodiment 1, wherein the therapeutic agent is non-covalently attached to the printed three-dimensional structure. 3. The device of embodiment 1 or embodiment 2, wherein the ceramic comprises calcium phosphate, hydroxyapatite, fluoroapatite, bone, silicate, or vanadate, or a combination thereof. 4. The device of any one of embodiments 1 to 3, wherein the ceramic comprises beta-tricalcium phosphate (β-TCP). 5. The device of any one of embodiments 1 to 4, wherein the structure comprises about 70% to about 80% by weight ceramic. 6. The device of embodiment 5, wherein the structure comprises about 75% by weight ceramic. 7. The device of any one of the preceding embodiments, wherein the polymer comprises a polyester. 8. The device of any one of embodiments 1-7, wherein the polymer comprises polycaprolactone (PCL), polyglycolide, lactide, or polydioxanone (PDS), or a combination thereof. 9. The device of any one of embodiments 1 to 8, wherein the polymer comprises polycaprolactone (PCL). 10. The device of any one of the preceding embodiments, wherein the polymer comprises polyglycolide. 11. The device of any one of the preceding embodiments, wherein the polymer comprises polydioxanone (PDS). 12. The device of any one of the preceding embodiments, wherein the polymer comprises lactide. 13. The device of embodiment 12, wherein the lactide comprises L-lactide. 14. The device of embodiment 12 or embodiment 13, wherein the lactide comprises poly(D,L-lactide). 15. The device of any one of the preceding embodiments, wherein the polymer comprises a copolymer. 16. The device of embodiment 15, wherein the copolymer comprises polycaprolactone (PCL) and polyglycolide. 17. The device of embodiment 16, wherein the copolymer comprises about 90-95 mol % PCL and about 5-10 mol % polyglycolide. 18. The device of any one of embodiments 15 to 17, wherein the copolymer comprises poly(D,L-lactide-co-glycolide) copolymer. 19. The device of embodiment 18, wherein the copolymer comprises about 40-60 mol % poly(D,L-lactide) and about 40-60 mol % polyglycolide. 20. The device of any one of embodiments 15 to 19, wherein the copolymer comprises a PDS-glycolide copolymer. 21. The device of embodiment 20, wherein the copolymer comprises about 90-95 mol % PDS and about 5-10 mol % glycolide. 22. The device of any one of embodiments 15 to 21, wherein the copolymer comprises a PDS-L-lactide copolymer. 23. The device of embodiment 20, wherein the copolymer comprises about 90-95 mol % PDS and about 5-10 mol % L-lactide. 24. A device according to any one of the preceding embodiments, wherein the structure comprises from about 15% to about 25% by weight of polymer. 25. The device of embodiment 24, wherein the structure comprises about 25% by weight of polymer. 26. A device described in any one of embodiments 1 to 25, wherein the printed three-dimensional structure is formed from an ink comprising about 30% by weight to about 70% by weight of ceramic, about 10% by weight to about 30% by weight of polymer, and optionally one or more additional agents. 27. The device of embodiment 26, wherein the ink comprises about 50% to about 70% by weight of ceramic. 28. The device of embodiment 27, wherein the ink comprises about 60% by weight of ceramic. 29. The device of any one of embodiments 26 to 28, wherein the ink comprises about 15% to about 25% by weight of ceramic. 30. The device of embodiment 29, wherein the ink comprises about 20% by weight of ceramic. 31. A device according to any one of embodiments 26 to 30, wherein the ink comprises one or more additional agents. 32. A device according to any one of embodiments 26 to 31, wherein the ink comprises from about 1% by weight to about 30% by weight of one or more additional agents. 33. A device according to any one of embodiments 26 to 32, wherein the one or more additional agents include additional polymers, microparticles, or foaming agents, or combinations thereof. 34. The device of embodiment 33, wherein the one or more additional agents comprise an additional polymer. 35. The device of embodiment 33 or embodiment 34, wherein the additional polymer comprises a first polyethylene glycol and optionally a second polyethylene glycol, where the second polyethylene glycol, if present, has a different molecular weight than the first polyethylene glycol. 36. The device of any one of embodiments 33 to 35, wherein the additional polymer is present in the ink at about 10% by weight to about 30% by weight. 37. A device according to any one of embodiments 33 to 36, wherein the one or more additional agents comprise microparticles. 38. A device according to any one of embodiments 33 to 37, wherein the microparticles comprise sodium chloride, calcium chloride, sucrose, trehalose (e.g., α,α trehalose dihydrate), or mannitol (e.g., D-mannitol), or a combination thereof. 39. The device of any one of embodiments 33 to 38, wherein the microparticles are present in the ink at about 1% by weight to about 10% by weight. 40. A device according to any one of embodiments 33 to 39, wherein the one or more additional agents include an effervescent agent. 41. A device according to any one of embodiments 33 to 40, wherein the foaming agent comprises baking powder (e.g., monocalcium phosphate, sodium bicarbonate, cornstarch) and / or azodicarbonamide. 42. The device of any one of embodiments 33 to 41, wherein the microparticles are present in the ink at about 5% by weight to about 20% by weight. 43. A device according to any one of embodiments 1 to 42, wherein the therapeutic agent comprises a mammalian growth factor or a functional portion thereof. 44. A device according to any one of embodiments 1 to 43, wherein the therapeutic agent comprises one or more polypeptides selected from Table 1, or functional portions thereof. 45. A device according to any one of embodiments 1 to 44, wherein the therapeutic agent comprises a bone morphogenetic protein (BMP). 46. ​​A device described in any one of embodiments 1 to 45, wherein the therapeutic agent comprises a targeting moiety, which is non-covalently attached to the printed three-dimensional structure. 47. The device of embodiment 46, wherein the targeting moiety is bound to the printed three-dimensional structure with an affinity of about 1 pM to about 100 μm. 48. The device of embodiment 46 or embodiment 47, wherein the targeting moiety comprises a polypeptide that is at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to any one of the sequences in Tables 2-3. 49. The device of embodiment 46 or embodiment 47, wherein the targeting moiety comprises about 2, 3, 4, 5, 6, 7, 8, 9, or 10 sequences selected from the sequences of Tables 2-3. 50. The device of any one of embodiments 1 to 49, wherein the therapeutic agent comprises a chimeric polypeptide comprising a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to any one of SEQ ID NOs: 433 to 441. 51. A method for treating a disease in a subject in need thereof, the method comprising administering to the subject a device described in any one of embodiments 1 to 50. 52. The method of embodiment 51, wherein the disease comprises a bone defect, a cartilage defect, a soft tissue defect, a tendon defect, a fascial defect, a ligament defect, an organ defect, an osteotendinous tissue defect, a skin defect, an osteochondral defect, osteoporosis, avascular necrosis, or a congenital skeletal deformity, or a combination thereof. 53. The method of embodiment 51 or embodiment 52, wherein the method comprises spinal fixation. 54. The method of embodiment 53, wherein the spinal fixation includes posterolateral fixation (PLF) and / or interbody fusion. 55. The method of embodiment 51 or embodiment 52, wherein the method comprises bone repair, dental repair, craniomaxillofacial repair, ankle fusion, vertebroplasty, osteoplasty, navicular fracture repair, tendon-bone repair, rib reconstruction, subchondral bone repair, cartilage repair, or surgical implantation of a three-dimensional structure or device, or a combination thereof. 56. A formulation comprising about 30% to about 70% by weight of a ceramic, about 10% to about 30% by weight of a polymer, and optionally one or more additional pharmaceutical agents. 57. The formulation of embodiment 56, wherein the ceramic comprises calcium phosphate, hydroxyapatite, fluoroapatite, bone, silicate, or vanadate, or a combination thereof. 58. The formulation of embodiment 56 or embodiment 57, wherein the ceramic comprises beta-tricalcium phosphate (β-TCP). 59. A formulation according to any one of embodiments 56 to 58, wherein the ink comprises from about 50% to about 70% by weight of ceramic. 60. The formulation of embodiment 59, wherein the ink comprises about 60% by weight of ceramic. 61. A formulation according to any one of embodiments 56 to 60, wherein the polymer comprises a polyester. 62. A formulation according to any one of embodiments 56-61, wherein the polymer comprises polycaprolactone (PCL), polyglycolide, lactide, or polydioxanone (PDS), or a combination thereof. 63. A formulation according to any one of embodiments 56-62, wherein the polymer comprises polycaprolactone (PCL). 64. A formulation according to any one of embodiments 56 to 63, wherein the polymer comprises polyglycolide. 65. A formulation according to any one of embodiments 56-64, wherein the polymer comprises polydioxanone (PDS). 66. A formulation according to any one of embodiments 56-65, wherein the polymer comprises lactide. 67. A formulation according to any one of embodiments 56-66, wherein the lactide comprises L-lactide. 68. A formulation according to any one of embodiments 56-67, wherein the lactide comprises poly(D,L-lactide). 69. A formulation according to any one of embodiments 56 to 68, wherein the polymer comprises a copolymer. 70. The formulation of embodiment 69, wherein the copolymer comprises polycaprolactone (PCL) and polyglycolide. 71. The formulation of embodiment 70, wherein the copolymer comprises about 90-95 mol % PCL and about 5-10 mol % polyglycolide. 72. A formulation according to any one of embodiments 69-71, wherein the copolymer comprises poly(D,L-lactide-co-glycolide) copolymer. 73. A formulation according to any one of embodiments 69-72, wherein the copolymer comprises about 40-60 mol% poly(D,L-lactide) and about 40-60 mol% polyglycolide. 74. A formulation according to any one of embodiments 69-73, wherein the copolymer comprises a PDS-glycolide copolymer. 75. The formulation of embodiment 74, wherein the copolymer comprises about 90-95 mol % PDS and about 5-10 mol % glycolide. 76. A formulation according to any one of embodiments 69 to 75, wherein the copolymer comprises a PDS-L-lactide copolymer. 77. The formulation of embodiment 76, wherein the copolymer comprises about 90-95 mol % PDS and about 5-10 mol % L-lactide. 78. A formulation according to any one of embodiments 56 to 77, wherein the ink comprises one or more additional agents. 79. A formulation according to any one of embodiments 56 to 78, wherein the ink comprises from about 1% by weight to about 30% by weight of one or more additional agents. 80. The formulation of any one of embodiments 56-79, wherein the one or more additional agents include additional polymers, microparticles, or foaming agents, or combinations thereof. 81. The formulation of embodiment 80, wherein the one or more additional agents comprises an additional polymer. 82. The formulation of embodiment 80 or embodiment 81, wherein the additional polymer comprises a first polyethylene glycol and optionally a second polyethylene glycol, where the second polyethylene glycol, if present, has a different molecular weight than the first polyethylene glycol. 83. The formulation of any one of embodiments 80-82, wherein the additional polymer is present in the ink at about 10% by weight to about 30% by weight. 84. The formulation of any one of embodiments 80-83, wherein the one or more additional agents comprise microparticles. 85. A formulation according to any one of embodiments 80-84, wherein the microparticles comprise sodium chloride, calcium chloride, sucrose, trehalose (e.g., α,α trehalose dihydrate), or mannitol (e.g., D-mannitol), or a combination thereof. 86. A formulation according to any one of embodiments 80 to 85, wherein the microparticles are present in the ink at about 1% by weight to about 10% by weight. 87. The formulation of any one of embodiments 80-86, wherein the one or more additional agents comprises an effervescent agent. 88. A formulation according to any one of embodiments 80 to 87, wherein the foaming agent comprises baking powder (e.g., monocalcium phosphate, sodium bicarbonate, cornstarch) and / or azodicarbonamide. 89. A formulation according to any one of embodiments 80 to 88, wherein the microparticles are present in the ink at about 5% by weight to about 20% by weight. 90. A method for preparing a three-dimensional structure, the method comprising using a formulation described in any one of embodiments 56 to 89 in a three-dimensional printing method. 91. A three-dimensional structure prepared using an ink formulation according to any one of embodiments 56 to 89. 92. The structure of embodiment 91, comprising about 50% to about 90% by weight ceramic. 93. The structure of embodiment 91, comprising about 50% to about 90% by weight of tricalcium phosphate. 94. The structure of any one of embodiments 91-93, comprising about 10% to about 50% by weight of polymer. 95. The structure of embodiment 94, wherein the polymer comprises a polyester. 96. The structure of embodiment 94 or embodiment 95, wherein the polymer comprises polycaprolactone (PCL), polyglycolide, lactide, or polydioxanone (PDS), or a combination thereof. 97. The structure of any one of embodiments 94-96, wherein the polymer comprises polycaprolactone (PCL). 98. The structure of any one of embodiments 94-97, wherein the polymer comprises polyglycolide. 99. The structure of any one of embodiments 94-98, wherein the polymer comprises polydioxanone (PDS). 100. The structure of any one of embodiments 94-99, wherein the polymer comprises lactide. 101. The structure of embodiment 100, wherein the lactide comprises L-lactide. 102. The structure of embodiment 100 or embodiment 101, wherein the lactide comprises poly(D,L-lactide). 103. The structure of any one of embodiments 94-102, wherein the polymer comprises a copolymer. 104. The structure of embodiment 103, wherein the copolymer comprises polycaprolactone (PCL) and polyglycolide. 105. The structure of embodiment 104, wherein the copolymer comprises about 90-95 mol % PCL and about 5-10 mol % polyglycolide. 106. The structure of any one of embodiments 103-105, wherein the copolymer comprises poly(D,L-lactide-co-glycolide) copolymer. 107. The structure of any one of embodiments 103-106, wherein the copolymer comprises about 40-60 mol % poly(D,L-lactide) and about 40-60 mol % polyglycolide. 108. The structure of any one of embodiments 103-107, wherein the copolymer comprises a PDS-glycolide copolymer. 109. The structure of embodiment 108, wherein the copolymer comprises about 90-95 mol % PDS and about 5-10 mol % glycolide. 110. The structure of any one of embodiments 103 to 109, wherein the copolymer comprises a PDS-L-lactide copolymer. 111. The structure of embodiment 110, wherein the copolymer comprises about 90-95 mol % PDS and about 5-10 mol % L-lactide. 112. The structure of any one of embodiments 94 to 111, wherein the structure comprises about 15% to about 25% by weight of polymer. 113. The structure of embodiment 112, wherein the structure comprises about 25% by weight of polymer. 114. A three-dimensional structure comprising about 50% to about 90% by weight ceramic and about 10% to about 30% polymer. 115. The structure of embodiment 114, wherein the ceramic comprises calcium phosphate, hydroxyapatite, fluorapatite, bone, silicate, or vanadate, or a combination thereof. 116. The structure of embodiment 114 or embodiment 115, wherein the ceramic comprises beta-tricalcium phosphate (β-TCP). 117. The structure of any one of embodiments 114-116, comprising about 65% to about 85% by weight ceramic. 118. The structure of embodiment 117, comprising about 70% to about 80% by weight ceramic. 119. The structure of embodiment 118, comprising about 75% by weight ceramic. 120. The structure of any one of embodiments 114-119, wherein the polymer comprises a polyester. 121. The structure of any one of embodiments 114-120, wherein the polymer comprises polycaprolactone (PCL), polyglycolide, lactide, or polydioxanone (PDS), or a combination thereof. 122. The structure of any one of embodiments 114-121, wherein the polymer comprises polycaprolactone (PCL). 123. The structure of any one of embodiments 114-122, wherein the polymer comprises polyglycolide. 124. The structure of any one of embodiments 114-123, wherein the polymer comprises polydioxanone (PDS). 125. The structure of any one of embodiments 114-124, wherein the polymer comprises lactide. 126. The structure of embodiment 125, wherein the lactide comprises L-lactide. 127. The structure of embodiment 125 or embodiment 126, wherein the lactide comprises poly(D,L-lactide). 128. The structure of any one of embodiments 114-127, wherein the polymer comprises a copolymer. 129. The structure of embodiment 128, wherein the copolymer comprises polycaprolactone (PCL) and polyglycolide. 130. The structure of embodiment 129, wherein the copolymer comprises about 90-95 mol % PCL and about 5-10 mol % polyglycolide. 131. The structure of any one of embodiments 128-130, wherein the copolymer comprises poly(D,L-lactide-co-glycolide) copolymer. 132. The structure of embodiment 131, wherein the copolymer comprises about 40-60 mol % poly(D,L-lactide) and about 40-60 mol % polyglycolide. 133. The structure of any one of embodiments 128-132, wherein the copolymer comprises a PDS-glycolide copolymer. 134. The structure of embodiment 133, wherein the copolymer comprises about 90-95 mol % PDS and about 5-10 mol % glycolide. 135. The structure of any one of embodiments 128-134, wherein the copolymer comprises a PDS-L-lactide copolymer. 136. The structure of embodiment 135, wherein the copolymer comprises about 90-95 mol % PDS and about 5-10 mol % L-lactide. 137. The structure of any one of embodiments 114 to 136, wherein the structure comprises about 15% to about 25% by weight of polymer. 138. The structure of embodiment 137, wherein the structure comprises about 25% by weight of polymer. 139. The structure of any one of embodiments 91 to 138, prepared by a three-dimensional printing method. 140. A method for producing a three-dimensional structure according to any one of embodiments 91 to 139, the method comprising depositing an ink formulation on a three-dimensional form. 141. The method of embodiment 140, wherein the ink formulation comprises an ink formulation according to any one of embodiments 56 to 89. 142. A method for treating a disease in a subject in need thereof, the method comprising delivering a structure according to any one of embodiments 91 to 139 to an organ or tissue of the subject. 143. A method for treating a disease in a subject in need thereof, the method comprising delivering a structure produced by a method according to any one of embodiments 90, 140, or 141 to an organ or tissue of the subject. 144. The method of embodiment 142 or embodiment 143, wherein the disease comprises a bone defect, a cartilage defect, a soft tissue defect, a tendon defect, a fascial defect, a ligament defect, an organ defect, an osteotendon tissue defect, a skin defect, an osteochondral defect, osteoporosis, avascular necrosis, or a congenital skeletal deformity, or a combination thereof. 145. The method according to any one of embodiments 142 to 144, wherein the method comprises spinal fixation. 146. The method of embodiment 145, wherein the spinal fixation includes posterolateral fixation (PLF) and / or interbody fusion. 147. The method of embodiment 142 or embodiment 143, wherein the method comprises bone repair, dental repair, craniomaxillofacial repair, ankle fusion, vertebroplasty, osteoplasty, navicular fracture repair, tendon-bone repair, rib reconstruction, subchondral bone repair, cartilage repair, or surgical implantation of a three-dimensional structure or device, or a combination thereof. 148. The method of any one of embodiments 142-147, further comprising treating the subject with a therapeutic agent. 149. A method for delivering a therapeutic agent to a subject in need thereof, the method comprising the step of delivering a device comprising the therapeutic agent and a structure described in any one of embodiments 91 to 139 to an organ or tissue of the subject. 150. The method of embodiment 148 or embodiment 149, wherein the therapeutic agent comprises a mammalian growth factor or a functional portion thereof. 151. The method of any one of embodiments 148-150, wherein the therapeutic agent comprises one or more polypeptides selected from Table 1, or functional portions thereof. 152. The method of any one of embodiments 148-151, wherein the therapeutic agent comprises a bone morphogenetic protein (BMP). 153. The method of any one of embodiments 148-152, wherein the therapeutic agent comprises a targeting moiety that is non-covalently bound to the structure. 154. The method of embodiment 153, wherein the targeting moiety binds to the printed three-dimensional structure with an affinity of about 1 pM to about 100 μm. 155. The method of embodiment 153 or embodiment 154, wherein the targeting moiety comprises a polypeptide at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to any one of the sequences in Tables 5-6. 156. The method of embodiment 153 or embodiment 154, wherein the targeting moiety comprises about 2, 3, 4, 5, 6, 7, 8, 9, or 10 sequences selected from the sequences of Tables 5-6. 157. The method of any one of embodiments 148-156, wherein the therapeutic agent comprises a chimeric polypeptide comprising a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to any one of SEQ ID NOs: 433-441. 158. The structure is approximately 1g / cm 3 ~About 2g / cm 3 The device of any one of embodiments 1 to 50, the method of any one of embodiments 51 to 55, 90, 140 to 157, or the structure of any one of embodiments 91 to 139, having a density of 159. The device according to any one of embodiments 1 to 50, the method according to any one of embodiments 51 to 55, 90, 140 to 157, or the structure according to any one of embodiments 91 to 139, wherein the structure has an open porosity of about 15% to about 50%. 160. The device according to any one of embodiments 1 to 50, the method according to any one of embodiments 51 to 55, 90, 140 to 157, or the structure according to any one of embodiments 91 to 139, wherein the structure has a strut diameter of about 300 μm to about 600 μm. 161. A filament comprising a formulation according to any one of embodiments 56 to 89. 162. The filament of embodiment 161, having a diameter of about 1.5 mm to about 2 mm. 163. A pellet comprising a formulation according to any one of embodiments 56 to 89. 164. The pellet of embodiment 163, having a length of about 3 mm to about 4 mm. EXAMPLES

[0140] Example 1: Ink formulation and 3D printed scaffolds Ink formulation and scaffold #1: The 3D printing ink material is a flexible polymer-ceramic composite containing β-TCP that can be tethered to a therapeutic agent, such as tBMP2. The formulation contains two sacrificial pore formers (water-soluble polyethylene glycol and water-soluble sucrose) to expose more β-TCP surface area for tBMP2 binding. The ink is a low-viscosity formulation extruded through a 400 μm diameter nozzle on an Allevi3 pneumatic bioprinter. After 3D printing was completed, the resulting scaffold was immersed in water to dissolve the sacrificial polyethylene glycol and sucrose pore formers. The resulting scaffold #1 contains 75% by weight β-TCP powder, and 25% by weight polycaprolactone.

[0141] This ink is further converted into filament form and utilized to prepare 3D printed scaffolds using a fused filament fabrication (FFF or FDM) 3D printer. After 3D printing is completed, the resulting scaffold is immersed in water to dissolve the sacrificial polyethylene glycol and sucrose pore formers. The resulting scaffold contains 75% by weight of β-TCP powder, and 25% by weight of polycaprolactone.

[0142] This ink is further converted into pellets (i.e. the filaments are formed into small pellets) and fed from a hopper into a mini-screw extrusion head which melts the material and extrudes it through fine nozzles.

[0143] The ink is also freeze-milled into a fine powder, and a laser is used to heat the powder into the desired shape using the selective laser cutting process.

[0144] [Table 4]

[0145] Ink Formulation #2 The 3D printing ink material is a flexible polymer-ceramic composite containing β-TCP that can be tethered to a therapeutic agent, such as tBMP2. The formulation contains a sacrificial pore former (water-soluble polyethylene glycol) to expose more β-TCP surface area for drug binding. The formulation uses 95 mol% caprolactone 5 mol% glycolide copolymer for faster bioabsorption properties compared to polycaprolactone. The ink is a low viscosity formulation extruded through a 320 μm diameter nozzle on an Allevi3 pneumatic bioprinter. After 3D printing was completed, the resulting scaffold was immersed in water to dissolve the sacrificial polyethylene glycol pore former. The resulting scaffold #2 contains 75 wt% β-TCP powder, and 25 wt% caprolactone / glycolide copolymer (95:5).

[0146] This ink is further converted into the form of filaments and utilized to prepare 3D printed scaffolds using a fused filament fabrication (FFF or FDM) 3D printer. After 3D printing is completed, the resulting scaffold is immersed in water to dissolve the sacrificial polyethylene glycol pore former. The resulting scaffold contains 75% by weight of β-TCP powder, and 25% by weight of caprolactone / glycolide copolymer (95:5).

[0147] This ink is further converted into pellets (i.e. the filaments are formed into small pellets) and fed from a hopper into a mini-screw extrusion head which melts the material and extrudes it through fine nozzles.

[0148] The ink is also freeze-milled into a fine powder, and a laser is used to heat the powder into the desired shape using the selective laser cutting process.

[0149] [Table 5]

[0150] Ink Formulation #3 The 3D printing ink material is a flexible polymer-ceramic composite containing β-TCP that can be tethered to a therapeutic agent, such as tBMP2. The formulation contains a sacrificial pore former (water-soluble polyethylene glycol) to expose more β-TCP surface area for drug binding. The formulation uses 90 mol% caprolactone 10 mol% glycolide copolymer for fast bioabsorption properties compared to polycaprolactone. The ink is a low viscosity formulation extruded through a 320 μm diameter nozzle on an Allevi3 pneumatic bioprinter. After 3D printing was completed, the resulting scaffold was immersed in water to dissolve the sacrificial polyethylene glycol pore former. The resulting scaffold #3 contains 75 wt% β-TCP powder, and 25 wt% caprolactone / glycolide copolymer (90:10).

[0151] This ink is further converted into the form of filaments and utilized to prepare 3D printed scaffolds using a fused filament fabrication (FFF or FDM) 3D printer. After 3D printing is completed, the resulting scaffold is immersed in water to dissolve the sacrificial polyethylene glycol pore former. The resulting scaffold contains 75 wt% β-TCP powder, and 25 wt% caprolactone / glycolide copolymer (90:10).

[0152] This ink is further converted into pellets (i.e. the filaments are formed into small pellets) and fed from a hopper into a mini-screw extrusion head which melts the material and extrudes it through fine nozzles.

[0153] The ink is also freeze-milled into a fine powder, and a laser is used to heat the powder into the desired shape using the selective laser cutting process.

[0154] [Table 6]

[0155] Ink Formulation #4 The 3D printing ink material is a flexible polymer-ceramic composite containing β-TCP that can be tethered to a therapeutic agent, such as tBMP2. The formulation contains a sacrificial pore former (water-soluble polyethylene glycol) to expose more β-TCP surface area for drug binding. The formulation uses 50 mol%:50 mol% poly(D,L-lactide-co-glycolide) copolymer for fast bioabsorption properties compared to polycaprolactone. The ink is a low viscosity formulation extruded through a 400 μm diameter nozzle on an Allevi3 pneumatic bioprinter. After 3D printing was completed, the resulting scaffold was immersed in water to dissolve the sacrificial polyethylene glycol pore former. The resulting scaffold #4 contains 75 wt% β-TCP powder, and 25 wt% poly(D,L-lactide-co-glycolide) copolymer (50:50).

[0156] This ink is further converted into the form of filaments and utilized to prepare 3D printed scaffolds using a fused filament fabrication (FFF or FDM) 3D printer. After 3D printing is completed, the resulting scaffold is immersed in water to dissolve the sacrificial polyethylene glycol pore former. The resulting scaffold contains 75% by weight of β-TCP powder, and 25% by weight of poly(D,L-lactide-co-glycolide) copolymer (50:50).

[0157] This ink is further converted into pellets (i.e. the filaments are formed into small pellets) and fed from a hopper into a mini-screw extrusion head which melts the material and extrudes it through fine nozzles.

[0158] The ink is also freeze-milled into a fine powder, and a laser is used to heat the powder into the desired shape using the selective laser cutting process.

[0159] [Table 7]

[0160] Ink Formulation #5 The 3D printing ink material is a flexible polymer-ceramic composite containing β-TCP that can be tethered to a therapeutic agent, such as tBMP2. The formulation contains a sacrificial pore former (water-soluble polyethylene glycol) to expose more β-TCP surface area for drug binding. The ink is a medium viscosity formulation formed into 1.75 mm filaments for 3D printing on a RepRap style FFF 3D printer (e.g., Prusa i3 MK3S 3D printer) with a 400 μm diameter nozzle. The higher molecular weight polyethylene glycol (8000 MW for FFF 3D printing vs. 1500 MW for syringe-based bioprinting) results in a higher viscosity material that aids in the extrusion of 1.75 mm diameter filaments. After 3D printing was completed, the resulting scaffold was immersed in water to dissolve the sacrificial polyethylene glycol pore former. The resulting scaffold #5 contains 75% by weight β-TCP powder and 25% by weight polycaprolactone.

[0161] This ink is further converted into pellets (i.e. the filaments are formed into small pellets) and fed from a hopper into a mini-screw extrusion head which melts the material and extrudes it through fine nozzles.

[0162] The ink is also freeze-milled into a fine powder, and a laser is used to heat the powder into the desired shape using the selective laser cutting process.

[0163] [Table 8]

[0164] Ink Formulation #6 The 3D printing ink material is a flexible polymer-ceramic composite containing β-TCP that can be tethered to a therapeutic agent, such as tBMP2. The formulation contains a sacrificial pore former (water-soluble polyethylene glycol) to expose more β-TCP surface area for drug binding. The ink further contains a foaming agent (sodium bicarbonate), which pyrolyzes and releases CO2 gas during 3D printing to generate a foam structure, thus increasing the porosity of the 3D printed scaffold. The ink is a medium viscosity formulation formed into a 1.75 mm filament for 3D printing on a RepRap style FFF 3D printer (e.g., Prusa i3 MK3S 3D printer) with a 400 μm diameter nozzle. The higher molecular weight polyethylene glycol (8000 MW for FFF 3D printing vs. 1500 MW for syringe-based bioprinting) results in a higher viscosity material that aids in the extrusion of 1.75 mm diameter filaments. After 3D printing was completed, the resulting scaffold was immersed in water to dissolve the sacrificial polyethylene glycol pore former and the sodium carbonate by-product from sodium bicarbonate pyrolysis. The resulting scaffold #6 contains 75% by weight β-TCP powder and 25% by weight polycaprolactone.

[0165] This ink is further converted into pellets (i.e. the filaments are formed into small pellets) and fed from a hopper into a mini-screw extrusion head which melts the material and extrudes it through fine nozzles.

[0166] The ink is also freeze-milled into a fine powder, and a laser is used to heat the powder into the desired shape using the selective laser cutting process.

[0167] [Table 9]

[0168] Ink Formulation #7 The 3D printing ink material is a flexible polymer-ceramic composite containing β-TCP that can be tethered to a therapeutic agent, such as tBMP2. The formulation contains a sacrificial pore former (water-soluble polyethylene glycol) to expose more β-TCP surface area for drug binding. The formulation uses 90 mol%:10 mol% poly(dioxanone-co-L-lactide) copolymer for faster bioabsorption properties compared to polycaprolactone. The ink is a low viscosity formulation that can be extruded through a 400 μm diameter nozzle on an Allevi3 pneumatic bioprinter. After 3D printing is completed, the resulting scaffold is immersed in water to dissolve the sacrificial polyethylene glycol pore former. The resulting scaffold contains 75 wt% β-TCP powder, and 25 wt% dioxanone / L-lactide copolymer (90:10).

[0169] This ink is further converted into filament form and utilized to prepare 3D printed scaffolds using a fused filament fabrication (FFF or FDM) 3D printer. After 3D printing is completed, the resulting scaffold is immersed in water to dissolve the sacrificial polyethylene glycol pore former. The resulting scaffold contains 75 wt% β-TCP powder, and 25 wt% dioxanone / L-lactide copolymer (90:10).

[0170] This ink is further converted into pellets (i.e. the filaments are formed into small pellets) and fed from a hopper into a mini-screw extrusion head which melts the material and extrudes it through fine nozzles.

[0171] The ink is also freeze-milled into a fine powder, and a laser is used to heat the powder into the desired shape using the selective laser cutting process.

[0172] [Table 10]

[0173] Ink Formulation #8 The 3D printing ink material is a flexible polymer-ceramic composite containing β-TCP that can be tethered to a therapeutic agent, such as tBMP2. The formulation contains a sacrificial pore former (water-soluble polyethylene glycol) to expose more β-TCP surface area for drug binding. The ink is a medium viscosity formulation that can be formed into 1.75 mm filaments for 3D printing on a RepRap style FFF 3D printer (e.g., Prusa i3 MK3S 3D printer) with a 400 μm diameter nozzle. A higher molecular weight polyethylene glycol mixture (8000 MW and 20000 MW for FFF 3D printing vs. 1500 MW for syringe-based bioprinting) results in a higher viscosity material that aids in the extrusion of 1.75 mm diameter filaments. After 3D printing is completed, the resulting scaffold is immersed in water to dissolve the sacrificial polyethylene glycol pore former. The resulting scaffold contains 75% by weight β-TCP powder and 25% by weight polycaprolactone.

[0174] This ink is further converted into pellets (i.e. the filaments are formed into small pellets) and fed from a hopper into a mini-screw extrusion head which melts the material and extrudes it through fine nozzles.

[0175] The ink is also freeze-milled into a fine powder, and a laser is used to heat the powder into the desired shape using the selective laser cutting process.

[0176] [Table 11]

[0177] Ink Formulation #9 The 3D printing ink material is a flexible polymer-ceramic composite containing β-TCP that can be tethered to a therapeutic agent, such as tBMP2. The formulation contains two sacrificial pore formers (water-soluble polyethylene glycol and water-soluble glucose) to expose more β-TCP surface area for drug binding. The ink is a medium viscosity formulation that can be formed into 1.75 mm filaments for 3D printing on a RepRap style FFF 3D printer (e.g., Prusa i3 MK3S 3D printer) with a 400 μm diameter nozzle. The higher molecular weight polyethylene glycol mixture (8000 MW and 20000 MW for FFF 3D printing vs. 1500 MW for syringe-based bioprinting) results in a higher viscosity material that aids in the extrusion of 1.75 mm diameter filaments. After 3D printing is completed, the resulting scaffold is immersed in water to dissolve the sacrificial polyethylene glycol and sucrose pore formers. The resulting scaffold contains 75% by weight β-TCP powder and 25% by weight polycaprolactone.

[0178] This ink is further converted into pellets (i.e. the filaments are formed into small pellets) and fed from a hopper into a mini-screw extrusion head which melts the material and extrudes it through fine nozzles.

[0179] The ink is also freeze-milled into a fine powder, and a laser is used to heat the powder into the desired shape using the selective laser cutting process.

[0180] [Table 12]

[0181] Ink Formulation #10 The 3D printing ink material is a flexible polymer-ceramic composite containing β-TCP that can be tethered to a therapeutic agent, such as tBMP2. The formulation contains a sacrificial pore former (water-soluble polyethylene glycol) to expose more β-TCP surface area for drug binding. The formulation uses 95 mol% caprolactone 5 mol% glycolide copolymer for faster bioabsorption properties compared to polycaprolactone. The ink is a medium viscosity formulation that can be formed into 1.75 mm filaments for 3D printing on a RepRap style FFF 3D printer (e.g., Prusa i3 MK3S 3D printer) with a 400 μm diameter nozzle. A higher molecular weight polyethylene glycol mixture (8000 MW and 20000 MW for FFF 3D printing vs. 1500 MW for syringe-based bioprinting) results in a higher viscosity material that aids in the extrusion of 1.75 mm diameter filaments. After 3D printing is completed, the resulting scaffold is immersed in water to dissolve the sacrificial polyethylene glycol pore former. The resulting scaffold contains 75% by weight of β-TCP powder and 25% by weight of caprolactone / glycolide copolymer (95:5).

[0182] This ink is further converted into pellets (i.e. the filaments are formed into small pellets) and fed from a hopper into a mini-screw extrusion head which melts the material and extrudes it through fine nozzles.

[0183] The ink is also freeze-milled into a fine powder, and a laser is used to heat the powder into the desired shape using the selective laser cutting process.

[0184] [Table 13]

[0185] Ink Formulation #11 The 3D printing ink material is a flexible polymer-ceramic composite containing β-TCP that can be tethered to a therapeutic agent, such as tBMP2. The formulation contains a sacrificial pore former (water-soluble polyethylene glycol) to expose more β-TCP surface area for drug binding. The formulation uses 90 mol% caprolactone 10 mol% glycolide copolymer for fast bioabsorption properties compared to polycaprolactone. The ink is a medium viscosity formulation that can be formed into 1.75 mm filaments for 3D printing on a RepRap style FFF 3D printer (e.g., Prusa i3 MK3S 3D printer) with a 400 μm diameter nozzle. A higher molecular weight polyethylene glycol mixture (8000 MW and 20000 MW for FFF 3D printing vs. 1500 MW for syringe-based bioprinting) results in a higher viscosity material that aids in the extrusion of 1.75 mm diameter filaments. After 3D printing is completed, the resulting scaffold is immersed in water to dissolve the sacrificial polyethylene glycol pore former. The resulting scaffold contains 75% by weight of β-TCP powder and 25% by weight of caprolactone / glycolide copolymer (90:10).

[0186] This ink is further converted into pellets (i.e. the filaments are formed into small pellets) and fed from a hopper into a mini-screw extrusion head which melts the material and extrudes it through fine nozzles.

[0187] The ink is also freeze-milled into a fine powder, and a laser is used to heat the powder into the desired shape using the selective laser cutting process.

[0188] [Table 14]

[0189] Ink Formulation #12 The 3D printing ink material is a flexible polymer-ceramic composite containing β-TCP that can be tethered to a therapeutic agent, such as tBMP2. The formulation contains a sacrificial pore former (water-soluble polyethylene glycol) to expose more β-TCP surface area for drug binding. The formulation uses 50 mol%:50 mol% poly(D,L-lactide-co-glycolide) copolymer for fast bioabsorption properties compared to polycaprolactone. The ink is a medium viscosity formulation that can be formed into 1.75 mm filaments for 3D printing on a RepRap style FFF 3D printer (e.g., Prusa i3 MK3S 3D printer) with a 400 μm diameter nozzle. A higher molecular weight polyethylene glycol mixture (8000 MW and 20000 MW for FFF 3D printing vs. 1500 MW for syringe-based bioprinting) results in a higher viscosity material that aids in the extrusion of 1.75 mm diameter filaments. After 3D printing is completed, the resulting scaffold is immersed in water to dissolve the sacrificial polyethylene glycol pore former. The resulting scaffold contains 75% by weight of β-TCP powder and 25% by weight of poly(D,L-lactide-co-glycolide) copolymer (50:50).

[0190] This ink is further converted into pellets (i.e. the filaments are formed into small pellets) and fed from a hopper into a mini-screw extrusion head which melts the material and extrudes it through fine nozzles.

[0191] The ink is also freeze-milled into a fine powder, and a laser is used to heat the powder into the desired shape using the selective laser cutting process.

[0192] [Table 15]

[0193] Ink Formulation #13 The 3D printing ink material is a flexible polymer-ceramic composite containing β-TCP that can be tethered to a therapeutic agent, such as tBMP2. The formulation contains a sacrificial pore former (water-soluble polyethylene glycol) to expose more β-TCP surface area for drug binding. 3D printing is performed using a syringe ink and a formulation in filament form. After 3D printing is completed, the resulting scaffold is immersed in water to dissolve the sacrificial polyethylene glycol pore former. The resulting scaffold contains β-TCP and PDS.

[0194] This ink is further converted into pellets (i.e. the filaments are formed into small pellets) and fed from a hopper into a mini-screw extrusion head which melts the material and extrudes it through fine nozzles.

[0195] The ink is also freeze-milled into a fine powder, and a laser is used to heat the powder into the desired shape using the selective laser cutting process.

[0196] [Table 16]

[0197] Ink Formulation #14 The 3D printing ink material is a flexible polymer-ceramic composite containing β-TCP that can be tethered to a therapeutic agent, such as tBMP2. The formulation contains a sacrificial pore former (water-soluble polyethylene glycol) to expose more β-TCP surface area for drug binding. 3D printing is performed using the formulation in syringe ink and filament form. After 3D printing is completed, the resulting scaffold is immersed in water to dissolve the sacrificial polyethylene glycol pore former. The resulting scaffold contains β-TCP and PDS-glycolide copolymer (90:10).

[0198] This ink is further converted into pellets (i.e. the filaments are formed into small pellets) and fed from a hopper into a mini-screw extrusion head which melts the material and extrudes it through fine nozzles.

[0199] The ink is also freeze-milled into a fine powder, and a laser is used to heat the powder into the desired shape using the selective laser cutting process.

[0200] [Table 17]

[0201] Ink Formulation #15 The 3D printing ink material is a flexible polymer-ceramic composite containing β-TCP that can be tethered to a therapeutic agent, such as tBMP2. The formulation contains a sacrificial pore former (water-soluble polyethylene glycol) to expose more β-TCP surface area for drug binding. 3D printing is performed using the formulation in syringe ink and filament form. After 3D printing is completed, the resulting scaffold is immersed in water to dissolve the sacrificial polyethylene glycol pore former. The resulting scaffold contains β-TCP and L-lactide copolymer (90:10).

[0202] This ink is further converted into pellets (i.e. the filaments are formed into small pellets) and fed from a hopper into a mini-screw extrusion head which melts the material and extrudes it through fine nozzles.

[0203] The ink is also freeze-milled into a fine powder, and a laser is used to heat the powder into the desired shape using the selective laser cutting process.

[0204] [Table 18]

[0205] Example 2: Ink preparation and scaffold fabrication by 3D printing Ink formulation and scaffold #1 Methods: To make a 5.3 cc batch of ink, 5.6 g β-TCP powder, 1.87 g polycaprolactone powder, 1.87 g polyethylene glycol flakes, and 0.49 g sucrose were added to a glass mixing vessel. The glass vessel was placed in a dual asymmetric centrifugal mixer (FlackTek Speedmixer) and mixed at low intensity (300 rpm) for 2 minutes to homogenize the powder blend before mixing at high speed. The mixer was mixed at high intensity (3500 rpm) for 5 minutes. During mixing, internal friction melts the polycaprolactone and polyethylene glycol, turning the ink into a viscous molten liquid. This liquid phase mixing promotes homogenous dispersion of the β-TCP and sucrose powders into the molten polymer blend. The blended ink was cooled for 10-15 minutes and then mixed at 3500 rpm for an additional 5 minutes. The mixing / cooling process was repeated a total of four times with 5 minutes of mixing at 3500 rpm. After the fourth mix at 3500 rpm, the ink charge was poured onto a glass plate and, using two spatulas, formed into a cylinder approximately 1 cm in diameter by 6 cm in length. While the ink was still semi-molten, it was cut into 1-2 cm lengths with a straight razor.

[0206] 3D Printing: Solid polymer / β-TCP pieces were transferred to a 5cc stainless steel syringe (for use in an Allevi3 Bioprinter). The extruder CORE print head was heated to 135°C and allowed to dwell for approximately 30 minutes to ensure melting of the ink. The ink was printed with a 400 micron inner diameter conical metal luer lock tip using 70 psi pressure and a nozzle speed of 7 mm / sec. Scaffolds were 3D printed onto painter's tape applied to a smooth glass or polymer surface such as a glass microscope slide, a larger glass plate, or the lid of a 96-well plate.

[0207] Post-treatment: The 3D printed constructs were immersed overnight in distilled water to dissolve the polyethylene glycol and sucrose from the prints, thus creating a porous and flexible β-TCP / polycaprolactone composite. The scaffolds were dried for at least 12 hours to ensure that any residual moisture had evaporated from the porous scaffolds before conjugating with therapeutic agents such as tBMP2 protein. The scaffolds were sterilized by immersion in a 70% ethanol solution for 2-4 hours and dried in a biosafety cabinet for approximately 12 hours. Images of the scaffolds are shown in Figure 1A-C.

[0208] 3D printing is further performed using a FFF 3D printer. Ink #1 is extruded into a filament and the filament is fed into the FFF 3D printer to produce a 3D printed scaffold. The scaffold is processed using the post-processing methods outlined above.

[0209] Ink formulation and scaffold #2 Methods: To make a 5 cc batch of ink, 5.6 g of β-TCP powder, 1.87 g of 95:5 caprolactone / glycolide copolymer pellets, and 1.87 g of polyethylene glycol flakes were added to a glass mixing vessel. The glass vessel was placed in a dual asymmetric centrifugal mixer (FlackTek Speedmixer) and mixed at low intensity (300 rpm) for 2 minutes to homogenize the powder blend before mixing at high speed. The mixture was mixed at high intensity (3500 rpm) for 5 minutes. During mixing, internal friction melts the 95:5 caprolactone / glycolide copolymer and polyethylene glycol, turning the ink into a viscous molten liquid. This liquid phase mixing promotes homogenous dispersion of the β-TCP powder into the molten polymer blend. The blended ink was cooled for 10-15 minutes and then mixed at 3500 rpm for an additional 5 minutes. The mixing / cooling process was repeated a total of four times with 5 minutes of mixing at 3500 rpm. After the fourth mix at 3500 rpm, the ink charge was poured onto a glass plate and, using two spatulas, formed into a cylinder approximately 1 cm in diameter by 6 cm in length. While the ink was still semi-molten, it was cut into 1-2 cm lengths with a straight razor.

[0210] 3D Printing: The solid polymer / β-TCP pieces were transferred to a 5cc stainless steel syringe (for use in an Allevi3 Bioprinter). The extruder CORE print head was heated to 130°C and allowed to dwell for approximately 30 minutes to ensure melting of the ink. The ink was printed with a 320 micron inner diameter conical metal luer lock tip using 80 psi pressure and a nozzle speed of 6 mm / sec. Scaffolds were 3D printed onto painter's tape applied to a smooth glass or polymer surface such as a glass microscope slide, a larger glass plate, or the lid of a 96-well plate.

[0211] Post-processing: The 3D printed constructs were soaked overnight in distilled water to dissolve the polyethylene glycol and cellulose from the prints, thereby creating a porous and flexible β-TCP / 95:5 caprolactone / glycolide copolymer composite. The scaffolds were allowed to dry for at least 12 hours to ensure that any residual moisture had evaporated from the porous scaffolds before coupling with therapeutic agents such as tBMP2. The scaffolds were sterilized by immersion in a 70% ethanol solution for 2-4 hours and allowed to dry for approximately 12 hours in a biosafety cabinet. Images of the scaffolds are shown in Figure 2A-C.

[0212] 3D printing is further performed using a FFF 3D printer. Ink #2 is extruded into a filament and the filament is fed into the FFF 3D printer to produce a 3D printed scaffold. The scaffold is processed using the post-processing methods outlined above.

[0213] Ink formulation and scaffold #3 Methods: To make a 5 cc batch of ink, 5.6 g of β-TCP powder, 1.87 g of 90:10 caprolactone / glycolide copolymer chips, and 1.87 g of polyethylene glycol flakes were added to a glass mixing vessel. The mixture was placed in a dual asymmetric centrifugal mixer (FlackTek Speedmixer) in a glass bottle and mixed at low intensity (300 rpm) for 2 minutes to homogenize the powder blend before mixing at high speed. It was then mixed at high intensity (3500 rpm) for 5 minutes. During mixing, internal friction melts the 90:10 caprolactone / glycolide copolymer and polyethylene glycol, turning the ink into a viscous molten liquid. This liquid phase mixing promotes homogenous dispersion of the β-TCP powder into the molten polymer blend. The blended ink was cooled for 10-15 minutes and then mixed at 3500 rpm for an additional 5 minutes. The mixing / cooling process was repeated a total of four times with 5 minutes of mixing at 3500 rpm. After the fourth mix at 3500 rpm, the ink charge was poured onto a glass plate and, using two spatulas, formed into a cylinder approximately 1 cm in diameter by 6 cm in length. While the ink was still semi-molten, it was cut into 1-2 cm lengths with a straight razor.

[0214] 3D Printing: The solid polymer / β-TCP pieces were transferred to a 5cc stainless steel syringe (for use in an Allevi3 Bioprinter). The extruder CORE print head was heated to 130°C and allowed to dwell for approximately 30 minutes to ensure melting of the ink. The ink was printed with a 320 micron inner diameter conical metal luer lock tip using 45 psi pressure and a nozzle speed of 7 mm / sec. Scaffolds were 3D printed onto painter's tape applied to a smooth glass or polymer surface such as a glass microscope slide, a larger glass plate, or the lid of a 96-well plate.

[0215] Post-processing: The 3D printed constructs were soaked overnight in distilled water to dissolve the polyethylene glycol and cellulose from the prints, thereby creating a porous and flexible β-TCP / 90:10 caprolactone / glycolide copolymer composite. The scaffolds were allowed to dry for at least 12 hours to ensure that any residual moisture had evaporated from the porous scaffolds before coupling with therapeutic agents such as tBMP2. The scaffolds were sterilized by immersion in a 70% ethanol solution for 2-4 hours and allowed to dry in a biosafety cabinet for approximately 12 hours. Images of the scaffolds are shown in Figure 3A-C.

[0216] 3D printing is further performed using a FFF 3D printer. Ink #3 is extruded into a filament and the filament is fed into the FFF 3D printer to produce a 3D printed scaffold. The scaffold is processed using the post-processing methods outlined above.

[0217] Ink formulation and scaffold #4 Methods: To make a 2.5cc batch of ink, 2.8g of β-TCP powder, 0.94g of 50:50 poly(D,L-lactide-co-glycolide) copolymer chunks and 0.94g of polyethylene glycol flakes were added to a glass mixing vessel. The glass vessel was placed in a dual asymmetric centrifugal mixer (FlackTek Speedmixer) and mixed at low intensity (300 rpm) for 2 minutes to homogenize the powder blend before mixing at high speed. It was mixed at high intensity (3500 rpm) for 5 minutes. During mixing, internal friction causes the 50:50 poly(D,L-lactide-co-glycolide) copolymer and polyethylene glycol to flow, turning the ink into a viscous molten liquid. This liquid phase mixing promotes homogenous dispersion of the β-TCP powder into the molten polymer blend. The blended ink was cooled for 10-15 minutes and then mixed at 3500 rpm for an additional 5 minutes. The mixing / cooling process was repeated a total of four times with 5 minutes of mixing at 3500 rpm. After the fourth mixing at 3500 rpm, the ink charge was poured onto a glass plate and two spatulas were used to form cylinders approximately 1 cm in diameter by 3 cm in length. While the ink was still in a semi-molten state, it was cut into 1-2 cm lengths with a straight razor.

[0218] 3D Printing: The solid polymer / β-TCP pieces were transferred to a 5cc stainless steel syringe (for use in an Allevi3 Bioprinter). The extruder CORE print head was heated to 85°C and allowed to dwell for approximately 30 minutes to ensure melting of the ink. The ink was printed with a 400 micron inner diameter conical metal luer lock tip using 60 psi pressure and a nozzle speed of 7 mm / sec. Scaffolds were 3D printed onto painter's tape applied to a smooth glass or polymer surface such as a glass microscope slide, a larger glass plate, or the lid of a 96-well plate.

[0219] Post-processing: The 3D printed constructs were soaked overnight in distilled water to dissolve the polyethylene glycol from the prints, thereby creating a porous and flexible β-TCP / 50:50 poly(D,L-lactide-co-glycolide) copolymer composite. The scaffolds were allowed to dry for at least 12 hours to ensure that any residual moisture had evaporated from the porous scaffolds before coupling with a therapeutic agent such as tBMP2. The scaffolds were sterilized by immersion in a 70% ethanol solution for 2-4 hours and allowed to dry for approximately 12 hours in a biosafety cabinet. Images of the scaffolds are shown in Figure 4A-C.

[0220] 3D printing is further performed using a FFF 3D printer. Ink #4 is extruded into a filament and the filament is loaded into the FFF 3D printer to produce a 3D printed scaffold. The scaffold is processed using the post-processing methods outlined above.

[0221] Ink formulation and scaffold #5 Methods: To make a 5 cc batch of ink, 5.6 g of β-TCP powder, 1.87 g of polycaprolactone powder, and 1.87 g of polyethylene glycol flakes were added to a glass mixing vessel. The glass vessel was placed in a dual asymmetric centrifugal mixer (FlackTek Speedmixer) and mixed at low intensity (300 rpm) for 2 minutes to homogenize the powder blend before mixing at high RPM. It was then mixed at high intensity (3500 rpm) for 5 minutes. During mixing, internal friction melts the polycaprolactone and polyethylene glycol, turning the ink into a sticky molten liquid. This liquid phase mixing promotes homogenous dispersion of the β-TCP powder into the molten polymer blend. The molten ink was poured onto a glass plate and flattened with a spatula into a layer approximately 3 mm thick for cooling. After cooling, it was cut into pellets of approximately 3-4 mm using shear. This was repeated twice for additional 5 cc batches to make a total of 15 cc of pellets for filament extrusion.

[0222] Filament Production: 15cc of 3-4mm pellets were loaded into the hopper of a filament extruder (Filabot EX2 Filament Extruder). A 3x length drawn melt filter nozzle (filter screen removed) with a hole size of 1.75mm diameter was used. A cooling fan was placed near the extrusion nozzle to accelerate the solidification of the extruded filament. Filaments with a diameter of 1.75mm were extruded at an extrusion temperature of 62°C and an extrusion speed analog dial of 1 / 2 (approximately 1cm / sec extrusion speed).

[0223] 3D Printing: 1.75mm of filament was loaded into a Prusa i3 MK3S 3D printer. The filament material was printed using a 400 micron brass nozzle, 105°C extruder temperature, and a print speed of 15mm / s.

[0224] Post-treatment: The 3D printed constructs were immersed in distilled water overnight to dissolve the polyethylene glycol from the prints, thus creating a porous and flexible β-TCP / polycaprolactone composite. The scaffolds were allowed to dry for at least 12 hours to ensure that any residual moisture had evaporated from the porous scaffolds before coupling with therapeutic agents such as tBMP2. The scaffolds were sterilized by immersion in a 70% ethanol solution for 2-4 hours and allowed to dry for approximately 12 hours in a biosafety cabinet. Images of the scaffolds are shown in Figure 5A-C.

[0225] Ink formulation and scaffold #6 Methods: To make a 5.5 cc batch of ink, 5.6 g β-TCP powder, 1.87 g polycaprolactone powder, 1.87 g polyethylene glycol flakes, and 1.04 g sodium bicarbonate were added to a glass mixing vessel. The glass vessel was placed in a dual asymmetric centrifugal mixer (FlackTek Speedmixer) and mixed at low intensity (300 rpm) for 2 minutes to homogenize the powder blend before mixing at high RPM. It was then mixed at high intensity (3500 rpm) for 2 minutes. During mixing, internal friction melts the polycaprolactone and polyethylene glycol, turning the ink into a sticky molten liquid. This liquid phase mixing promotes homogenous dispersion of the β-TCP and sodium bicarbonate powders into the molten polymer blend. The molten ink was poured onto a glass plate and flattened with a spatula into a layer about 3 mm thick for cooling. After cooling, it was cut into pellets of about 3-4 mm using shear. This was repeated two additional 5.5 cc batches to produce a total of 16.5 cc pellets for filament extrusion.

[0226] Filament Production: 16.5cc of 3-4mm pellets were loaded into the hopper of a filament extruder (Filabot EX2 Filament Extruder). A 3x length drawn melt filter nozzle (with the filter screen removed) with a hole size of 1.75mm diameter was used. A cooling fan was placed near the extrusion nozzle to accelerate the solidification of the extruded filament. Filaments with a diameter of 1.75mm were extruded at an extrusion temperature of 62°C and an extrusion speed analog dial of 1 / 2 (approximately 1cm / sec extrusion speed).

[0227] 3D Printing: 1.75mm of filament was loaded into a Prusa i3 MK3S 3D printer. The filament material was printed using a 400 micron brass nozzle, 155°C extruder temperature, and a print speed of 15mm / s.

[0228] Post-processing: The 3D printed constructs were soaked overnight in distilled water to dissolve the polyethylene glycol and sodium carbonate (a by-product of sodium bicarbonate pyrolysis) from the foam print, thereby creating a porous and flexible β-TCP / polycaprolactone composite. The scaffolds were allowed to dry for at least 12 hours to ensure that any residual moisture had evaporated from the porous scaffold before coupling with a therapeutic agent such as tBMP2. The scaffolds were sterilized by immersion in a 70% ethanol solution for 2-4 hours and allowed to dry for approximately 12 hours in a biosafety cabinet. Images of the scaffolds are shown in Figure 6A-C.

[0229] Ink formulation and scaffold #7 Methods: To make a 10 cc batch of ink, 11.2 g of β-TCP powder, 3.74 g of dioxanone / L-lactide (90:10) copolymer chips, and 3.74 g of polyethylene glycol flakes were added to a glass mixing vessel. The vial was placed in a dual asymmetric centrifugal mixer (FlackTek Speedmixer) and mixed at low intensity (300 rpm) for 2 minutes to homogenize the powder blend before mixing at higher RPM. The vial was transferred to a hot plate and heated until it reached 185°C (measured with an IR thermometer). The vial was then immediately placed back into the dual asymmetric centrifugal mixer and mixed at high intensity (3500 rpm) for 5 minutes. The liquid phase mixing promotes homogenous dispersion of the β-TCP powder into the molten polymer blend. The vial was then immediately placed back on the hot plate and the temperature was increased to 185°C. Once at temperature, the glass bottle was immediately placed back into the dual asymmetric centrifugal mixer and mixed at 3500 rpm for an additional 5 minutes. The mixing / heating process was repeated a total of four times with 5 minutes of 3500 rpm mixing. After the fourth 3500 rpm mixing, the ink charge was poured onto a glass plate and, using two spatulas, formed into a cylinder approximately 1 cm in diameter by 6 cm in length. While the ink was still in a semi-molten state, it was cut into 1-2 cm lengths with a straight razor.

[0230] 3D Printing: The solid polymer / β-TCP pieces were transferred to a 5cc stainless steel syringe (for use in an Allevi3 Bioprinter). The extruder CORE print head was heated to 110°C and allowed to dwell for approximately 30 minutes to ensure melting of the ink. The ink was printed with a 400 micron inner diameter conical metal luer lock tip using 15 psi pressure and a nozzle speed of 10 mm / sec. Scaffolds were 3D printed onto painter's tape applied to a smooth glass or polymer surface such as a glass microscope slide, a larger glass plate, or the lid of a 96-well plate.

[0231] Post-processing: The 3D printed constructs were soaked in distilled water overnight to dissolve the polyethylene glycol from the prints. The process produced a porous and flexible β-TCP / 90:10 dioxanone-L-lactide copolymer composite. The scaffolds were allowed to dry for at least 12 hours to ensure that any residual moisture had evaporated from the porous scaffolds before coupling with therapeutic agents such as tBMP2 protein. The scaffolds were sterilized by immersion in a 70% ethanol solution for 2-4 hours and allowed to dry in a biosafety cabinet for approximately 12 hours. Images of the scaffolds are shown in Figures 7A-C.

[0232] 3D printing is further performed using a FFF 3D printer. Ink #7 is extruded into a filament and the filament is fed into the FFF 3D printer to produce a 3D printed scaffold. The scaffold is processed using the post-processing methods outlined above.

[0233] Ink formulation and scaffold #8 Methods: To make a 16 cc batch of ink, 18 g of β-TCP powder, 6 g of polycaprolactone powder, 3 g of polyethylene glycol (8,000 MW) flakes, and 3 g of polyethylene glycol (20,000 MW) flakes were added to a Teflon mixing vessel. The Teflon vessel was placed in a dual asymmetric centrifugal mixer (FlackTek Speedmixer) and mixed at low intensity (300 rpm) for 2 minutes to homogenize the powder blend before mixing at high speed. The Teflon vessel was then mixed at high intensity (3500 rpm) for 2.5 minutes. During mixing, internal friction melts the polycaprolactone and polyethylene glycol, turning the ink into a viscous molten liquid. This liquid-phase mixing promotes homogenous dispersion of the β-TCP powder into the molten polymer blend. The molten ink was poured onto a glass plate and flattened with a spatula into a layer approximately 3 mm thick for cooling. It was allowed to cool for 10-15 minutes. The mixture was returned to the Teflon container and mixed at high intensity (3500 rpm) for an additional 2.5 minutes. The mixing / cooling process was repeated a total of four times with 2.5 minutes of mixing at 3500 rpm. After the fourth and final mix, the ink was cooled and then sheared into approximately 3-4 mm pellets.

[0234] Filament Production: 16cc of 3-4mm pellets were loaded into the hopper of a filament extruder (Filabot EX2 Filament Extruder). A 3x length drawn melt filter nozzle (filter screen removed) with a hole size of 1.75mm diameter was used. A cooling fan was placed near the extrusion nozzle to accelerate the solidification of the extruded filament. Filaments with a diameter of 1.75mm were extruded at an extrusion temperature of 62°C and an extrusion speed analog dial of 1 / 2 (approximately 1cm / sec extrusion speed).

[0235] 3D Printing: 1.75mm of filament was loaded into a Prusa i3 MK3S 3D printer. The filament material was printed using a 400 micron brass nozzle, 105°C extruder temperature, and a print speed of 15mm / s.

[0236] Post-treatment: The 3D printed constructs were immersed in distilled water overnight to dissolve the polyethylene glycol from the prints, thus creating a porous and flexible β-TCP / polycaprolactone composite. The scaffolds were allowed to dry for at least 12 hours to ensure that any residual moisture had evaporated from the porous scaffolds before coupling with therapeutic agents such as tBMP2. The scaffolds were sterilized by immersion in a 70% ethanol solution for 2-4 hours and allowed to dry for approximately 12 hours in a biosafety cabinet. Images of the scaffolds are shown in Figure 8A-C.

[0237] Ink formulation and scaffold #9 Methods: To make a 16.3 cc batch of ink, 17.1 g β-TCP powder, 5.7 g polycaprolactone powder, 2.85 g polyethylene glycol (8,000 MW) flakes, and 2.85 g polyethylene glycol (20,000 MW) flakes were added to a Teflon mixing vessel. The Teflon vessel was placed in a dual asymmetric centrifugal mixer (FlackTek Speedmixer) and mixed at low intensity (300 rpm) for 2 minutes to homogenize the powder blend before mixing at high speed. The Teflon vessel was then mixed at high intensity (3500 rpm) for 2 minutes. During mixing, internal friction melts the polycaprolactone and polyethylene glycol, turning the ink into a viscous molten liquid. This liquid-phase mixing promotes homogenous dispersion of the β-TCP powder into the molten polymer blend. The molten ink was poured onto a glass plate and flattened with a spatula into a layer approximately 3 mm thick for cooling. It was allowed to cool for 10-15 minutes. The mixture was returned to the Teflon container and mixed at high intensity (3500 rpm) for an additional 2 minutes. The mixing / cooling process was repeated a total of four times with 2 minutes of mixing at 3500 rpm. After the fourth and final mix, the ink was allowed to cool and then cut into approximately 3-4 mm pellets using a shear.

[0238] Filament Production: 16.3cc of 3-4mm pellets were loaded into the hopper of a filament extruder (Filabot EX2 Filament Extruder). A 3x length drawn melt filter nozzle (with the filter screen removed) with a hole size of 1.75mm diameter was used. A cooling fan was placed near the extrusion nozzle to accelerate the solidification of the extruded filament. Filaments with a diameter of 1.75mm were extruded at an extrusion temperature of 62°C and an extrusion speed analog dial of 1 / 2 (approximately 1cm / sec extrusion speed).

[0239] 3D Printing: 1.75mm of filament was loaded into a Prusa i3 MK3S 3D printer. The filament material was printed using a 400 micron brass nozzle, 140°C extruder temperature, and a print speed of 10mm / s.

[0240] Post-treatment: The 3D printed constructs were immersed in distilled water overnight to dissolve the polyethylene glycol and sucrose from the prints, thus creating a porous and flexible β-TCP / polycaprolactone composite. The scaffolds were dried for at least 12 hours to ensure that any residual moisture had evaporated from the porous scaffolds before coupling with therapeutic agents such as tBMP2. The scaffolds were sterilized by immersion in a 70% ethanol solution for 2-4 hours and dried in a biosafety cabinet for approximately 12 hours. Images of the scaffolds are shown in Figure 9A-C.

[0241] Ink formulation and scaffold #10 Methods: To make a 16 cc batch of ink, 18 g of β-TCP powder, 6 g of caprolactone / glycolide copolymer (95:5) pellets, 3 g of polyethylene glycol (8,000 MW) flakes, and 3 g of polyethylene glycol (20,000 MW) flakes were added to a Teflon mixing vessel. The Teflon vessel was placed in a dual asymmetric centrifugal mixer (FlackTek Speedmixer) and mixed at low intensity (300 rpm) for 2 minutes to homogenize the powder blend before mixing at high speed. The Teflon vessel was then mixed at high intensity (3500 rpm) for 2.5 minutes. During mixing, internal friction melts the caprolactone / glycolide copolymer (95:5) and polyethylene glycol, turning the ink into a viscous molten liquid. This liquid-phase mixing promotes homogenous dispersion of the β-TCP powder into the molten polymer blend. The molten ink was poured onto a glass plate and flattened with a spatula into a layer approximately 3 mm thick for cooling. It was allowed to cool for 10-15 minutes. The mixture was returned to the Teflon container and mixed at high intensity (3500 rpm) for an additional 4 minutes. The mixing / cooling process was repeated once for a total of 2.5 minutes of mixing at 3500 rpm and three times for 4 minutes of mixing. After the fourth and final mix the ink was cooled and then cut into approximately 3-4 mm pellets using a shear.

[0242] Filament Production: 16cc of 3-4mm pellets were loaded into the hopper of a filament extruder (Filabot EX2 Filament Extruder). A 3x length drawn melt filter nozzle (filter screen removed) with a hole size of 1.75mm diameter was used. A cooling fan was placed near the extrusion nozzle to accelerate the solidification of the extruded filament. Filaments with a diameter of 1.75mm were extruded at an extrusion temperature of 62°C and an extrusion speed analog dial of 1 / 2 (approximately 1cm / sec extrusion speed).

[0243] 3D Printing: 1.75mm of filament was loaded into a Prusa i3 MK3S 3D printer. The filament material was printed using a 400 micron brass nozzle, 150°C extruder temperature, and a print speed of 10mm / s.

[0244] Post-treatment: The 3D printed constructs were immersed in distilled water overnight to dissolve the polyethylene glycol from the prints, thus creating a porous and flexible β-TCP / caprolactone / glycolide copolymer (95:5) composite. The scaffolds were dried for at least 12 hours to ensure that any residual moisture had evaporated from the porous scaffolds before coupling with therapeutic agents such as tBMP2. The scaffolds were sterilized by immersion in a 70% ethanol solution for 2-4 hours and dried in a biosafety cabinet for approximately 12 hours. Images of the scaffolds are shown in Figure 10A-C.

[0245] Ink formulation and scaffold #11 Methods: To make a 16 cc batch of ink, 18 g of β-TCP powder, 6 g of caprolactone / glycolide copolymer (90:10) chips, 3 g of polyethylene glycol (8,000 MW) flakes, and 3 g of polyethylene glycol (20,000 MW) flakes were added to a Teflon mixing vessel. The Teflon vessel was placed in a dual asymmetric centrifugal mixer (FlackTek Speedmixer) and mixed at low intensity (300 rpm) for 2 minutes to homogenize the powder blend before mixing at high speed. The Teflon vessel was then mixed at high intensity (3500 rpm) for 2 minutes. During mixing, internal friction melts the caprolactone / glycolide copolymer (90:10) and polyethylene glycol, turning the ink into a viscous molten liquid. This liquid-phase mixing promotes homogenous dispersion of the β-TCP powder into the molten polymer blend. The molten ink was poured onto a glass plate and flattened with a spatula into a layer approximately 3 mm thick for cooling. It was allowed to cool for 10-15 minutes. The mixture was returned to the Teflon container and mixed at high intensity (3500 rpm) for an additional 5 minutes. The mixing / cooling process was repeated once for a total of 2 minutes of mixing at 3500 rpm and three times for 5 minutes of mixing. After the fourth and final mix the ink was allowed to cool and then cut into pellets of approximately 3-4 mm using a shear.

[0246] Filament Production: 16cc of 3-4mm pellets were loaded into the hopper of a filament extruder (Filabot EX2 Filament Extruder). A 3x length drawn melt filter nozzle (filter screen removed) with a hole size of 1.75mm diameter was used. A cooling fan was placed near the extrusion nozzle to accelerate the solidification of the extruded filament. Filaments with a diameter of 1.75mm were extruded at an extrusion temperature of 62°C and an extrusion speed analog dial of 1 / 2 (approximately 1cm / sec extrusion speed).

[0247] 3D Printing: 1.75mm of filament was loaded into a Prusa i3 MK3S 3D printer. The filament material was printed using a 400 micron brass nozzle, 150°C extruder temperature, 40°C print bed temperature, and a print speed of 10mm / s.

[0248] Post-treatment: The 3D printed constructs were immersed in distilled water overnight to dissolve the polyethylene glycol from the prints, thus creating a porous and flexible β-TCP / caprolactone / glycolide copolymer (90:10) composite. The scaffolds were allowed to dry for at least 12 hours to ensure that any residual moisture had evaporated from the porous scaffolds before coupling with therapeutic agents such as tBMP2. The scaffolds were sterilized by immersion in a 70% ethanol solution for 2-4 hours and allowed to dry in a biosafety cabinet for approximately 12 hours. Images of the scaffolds are shown in Figures 11A-C.

[0249] Ink formulation and scaffold #12 Methods: To make an 8 cc batch of ink, 9 g of β-TCP powder, 3 g of poly(D,L-lactide-co-glycolide) copolymer (50:50) chunks, 1.5 g of polyethylene glycol (8,000 MW) flakes, and 1.5 g of polyethylene glycol (20,000 MW) flakes were added to a Teflon mixing vessel. The Teflon vessel was placed in a dual asymmetric centrifugal mixer (FlackTek Speedmixer) and mixed at low intensity (300 rpm) for 2 minutes to homogenize the powder blend before mixing at high speed. The Teflon vessel was then mixed at high intensity (3500 rpm) for 2 minutes. During mixing, internal friction dissolves the poly(D,L-lactide-co-glycolide) copolymer (50:50) and polyethylene glycol, turning the ink into a viscous molten liquid. This liquid-phase mixing promotes homogenous dispersion of the β-TCP powder into the molten polymer blend. The molten ink was poured onto a glass plate and flattened with a spatula into a layer approximately 3 mm thick for cooling. It was allowed to cool for 10-15 minutes. The mixture was returned to the Teflon container and mixed at high intensity (3500 rpm) for an additional 2.5 minutes. The mixing / cooling process was repeated once for a total of 2 minutes of mixing at 3500 rpm and twice for 2.5 minutes of mixing. After the third and final mix the ink was allowed to cool and then cut into pellets of approximately 3-4 mm using a shear.

[0250] Filament Production: 8cc of 3-4mm pellets were loaded into the hopper of a filament extruder (Filabot EX2 Filament Extruder). A 3x length drawn melt filter nozzle (with the filter screen removed) with a hole size of 1.75mm diameter was used. A cooling fan was placed near the extrusion nozzle to accelerate the solidification of the extruded filament. Filaments with a diameter of 1.75mm were extruded at an extrusion temperature of 62°C and an extrusion speed analog dial of 1 / 2 (approximately 1cm / sec extrusion speed).

[0251] 3D Printing: 1.75mm of filament was loaded into a Prusa i3 MK3S 3D printer. The filament material was printed using a 400 micron brass nozzle, 140°C extruder temperature, and a print speed of 10mm / s.

[0252] Post-processing: The 3D printed constructs were soaked overnight in distilled water to dissolve the polyethylene glycol from the prints, thereby creating a porous and flexible β-TCP / poly(D,L-lactide-co-glycolide) copolymer (50:50) composite. The scaffolds were allowed to dry for at least 12 hours to ensure that any residual moisture had evaporated from the porous scaffolds before coupling with therapeutic agents such as tBMP2. The scaffolds were sterilized by immersion in a 70% ethanol solution for 2-4 hours and allowed to dry in a biosafety cabinet for approximately 12 hours. Images of the scaffolds are shown in Figures 12A-C.

[0253] Ink formulation and scaffold #13 Ink #13 is printed using a syringe-based melt extrusion printing method, for example, using the methods described for printing Inks #1 through #4. Ink #13 is printed using fused filament fabrication 3D printing, for example, using the methods described for printing Ink #5 and Ink #6.

[0254] Ink formulation and scaffold #14 Ink #14 is printed using a syringe-based melt extrusion printing method, for example, using the methods described for printing Inks #1 through #4. Ink #14 is printed using fused filament fabrication 3D printing, for example, using the methods described for printing Ink #5 and Ink #6.

[0255] Ink formulation and scaffold #15 Ink #9 is printed using a syringe-based melt extrusion printing method, for example, using the methods described for printing Inks #1 through #4. Ink #15 is printed using fused filament fabrication 3D printing, for example, using the methods described for printing Ink #5 and Ink #6.

[0256] Structure Characteristics The physical properties of scaffolds #1-#6 were determined and are outlined in Table 19.

[0257] [Table 19]

[0258] The structures of this example were examined by gas physisorption using Brunauer-Emmett-Teller (BET) surface area analysis.

[0259] Compression tests are also performed on the structures.

[0260] Example 3: Therapeutic Agents A chimeric polypeptide comprising a BMP therapeutic peptide linked to five beta-tricalcium phosphate binding peptides was expressed and purified using standard expression and purification methods. The chimeric polypeptide was designated tBMP-2 and has the following sequence: MPIGSLLADTTHHRPWTVIGESTHHRPWSIIGESSHHKPFTGLGDTTHHRPWGILAESTHHKPWTASGAGGSEGGGSEGGTSGATGAGTSTSGGGASTGGGTGQAKHKQRKRLKSSCKRHPLYVDFSDVGWNDWIVAPPGYHAFYCHGECPFPLADHLNSTNHAIVQTLVNSVNSKIPKACCVPTELSAISMLYLDENEKVVLKNYQDMVVEGCGCR (sequence number 434).

[0261] Example 4: Device Fabrication The 3D printed constructs are combined with tBMP-2 therapeutic agent to create devices. A 0.75 mg / mL tBMP-2 binding solution (10 mM sodium acetate, 7 mM acetic acid, 100 mM NaCl, pH=4.75) is prepared and sterilized using a 0.22 μm filter. In a biosafety cabinet, the tBMP-2 binding solution is added to a sterile polypropylene tube using a sterile pipette to achieve a ratio of 15 mg tBMP-2 per g of 3D printed scaffold. The sterile scaffold is added to the binding solution using sterile tweezers, after which the polypropylene tube is closed and wrapped in parafilm. The tube is placed in a LabLine Instruments Titer Plate Shaker, speed set to 6, and shaken for 2 hours. In a biosafety cabinet, the scaffold+tBMP-2 is removed with sterile tweezers and placed into a different sterile polypropylene tube containing sterile PBS (same volume as the tBMP-2 binding solution). The lid was closed, wrapped in parafilm, and placed back on the Titer Plate Shaker and shaken for 5 minutes at speed 6. The tube was opened in a biosafety cabinet and the scaffold+tBMP-2 was removed using sterile forceps and placed in a sterile petri dish. The scaffold+tBMP-2 was allowed to dry overnight in a biosafety cabinet, resulting in the tBMP-2 device.

[0262] The mass of tBMP-2 remaining in the binding solution and the mass of tBMP-2 in the PBS wash solution are measured using A280 absorbance measurements. The sum of these masses is calculated and then subtracted from the initial mass of tBMP-2 in the binding solution to obtain the mass of tBMP-2 that remains bound to the 3D printed scaffold.

[0263] Example 5: Animal Model Demonstration of the utility of the embodiments described herein is performed by demonstrating bone regeneration in animal models (e.g., rats, rabbits, goats, pigs, dogs, sheep) and evaluating through μCT imaging and histological analysis. Indications may include lumbar fusion (3D printed inserts in spinal fusion cages), posterolateral (PLF) spinal fusion (3D printed scaffold spanning the transverse process), tibial segmental defects (3D printed scaffold based on patient CT data), and / or alveolar ridge augmentation (3D printed thin barrier membrane), etc.

Claims

1. A three-dimensional structure comprising about 50% to about 90% by weight ceramic and about 10% to about 50% by weight polymer, said structure having a plurality of micropores, said micropores having an average pore size of about 1 micron to about 500 microns in diameter, or about 50 microns to about 250 microns, or about 150 microns.

2. The structure described in claim 1, wherein the micropores provide the structure with additional surface area for contact with a therapeutic agent.

3. The structure described in claim 1 or claim 2, wherein the micropores are formed after removing one or more pore-forming agents from the structure.

4. The structure described in claim 3, wherein the pore-forming agent comprises a second polymer, a sugar, or a salt, or a combination thereof.

5. A structure as described in claim 1 or claim 2, wherein the micropores are formed by the release of carbon dioxide from a blowing agent present during the manufacture of the structure.

6. The structure of claim 5, wherein the foaming agent comprises sodium bicarbonate.

7. A three-dimensional structure comprising about 50% to about 90% by weight ceramic and about 10% to about 50% by weight polymer, and having about 15% to about 50% open porosity.

8. A three-dimensional structure comprising about 50% to about 90% by weight ceramic and about 10% to about 50% by weight polymer, the three-dimensional structure having a density of about 1 g / cm 3 to about 2 g / cm 3 .

9. A three-dimensional structure comprising about 50% to about 90% by weight ceramic and about 10% to about 50% by weight polymer, and having a strut diameter of about 300 micrometers to about 600 micrometers.

10. The structure of any one of claims 1, 7, 8, or 9, wherein the ceramic comprises calcium phosphate, hydroxyapatite, fluorapatite, bone, silicate, or vanadate, or a combination thereof.

11. The structure of any one of claims 1, 7, 8, or 9, wherein the polymer comprises caprolactone / glycolide copolymer, polycaprolactone, poly(D,L-lactide-co-glycolide) copolymer, or dioxanone / L-lactide copolymer, or a combination thereof.

12. The structure of any one of claims 1, 7, 8, or 9, wherein the ceramic comprises calcium phosphate, hydroxyapatite, fluorapatite, bone, silicate, or vanadate, or a combination thereof, and the polymer comprises polycaprolactone, caprolactone / glycolide copolymer, poly(D,L-lactide-co-glycolide) copolymer, or dioxanone / L-lactide copolymer, or a combination thereof.

13. The structure of any one of claims 1, 7, 8, or 9, wherein the polymer comprises caprolactone / glycolide copolymer and the ceramic comprises calcium phosphate.

14. The structure of claim 13, comprising about 65% to about 85% by weight calcium phosphate and about 15% to about 35% by weight caprolactone / glycolide copolymer.

15. A structure comprising about 65% to about 85% by weight calcium phosphate, and about 15% to about 35% by weight caprolactone / glycolide copolymer.

16. The structure of any one of claims 1, 7, 8, or 9, wherein the polymer comprises polycaprolactone and the ceramic comprises calcium phosphate.

17. The structure of claim 16, comprising about 65% to about 85% by weight calcium phosphate and about 15% to about 35% by weight polycaprolactone.

18. A structure comprising about 65% to about 85% by weight calcium phosphate and about 15% to about 35% by weight polycaprolactone.

19. The structure of claim 1, 7, 8, or 9, wherein the polymer comprises poly(D,L-lactide-co-glycolide) copolymer or dioxanone / L-lactide copolymer, and the ceramic comprises calcium phosphate.

20. The structure of claim 19, comprising about 65% to about 85% by weight calcium phosphate and about 15% to about 35% by weight poly(D,L-lactide-co-glycolide) copolymer or dioxanone / L-lactide copolymer.

21. A structure comprising about 65% to about 85% by weight calcium phosphate, and about 15% to about 35% by weight poly(D,L-lactide-co-glycolide) copolymer or dioxanone / L-lactide copolymer.

22. A structure as described in any one of claims 1, 7, 8, 9, 15, 18, or 21, formed from an ink and comprising a ceramic, a polymer, and a sacrificial pore former.

23. A structure described in any one of claims 1, 7, 8, 9, 15, 18, or 21, formed from filaments using an extrusion-based three-dimensional printing method.

24. A device comprising a structure described in any one of claims 1, 7, 8, 9, 15, 18, or 21 and a therapeutic agent.

25. The device of claim 24, wherein the therapeutic agent comprises a bone morphogenetic protein (BMP).

26. The device described in claim 24 or claim 25, wherein the therapeutic agent comprises a targeting moiety, and the targeting moiety is non-covalently bound to the structure.

27. The device of claim 26, wherein the targeting portion comprises a polypeptide that is at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to any one of the sequences in Tables 2-3.

28. The device of claim 24, wherein the therapeutic agent comprises a chimeric polypeptide comprising a sequence at least about 70%, 75%, 80%, 85%, 90%, 95%, or 100% identical to any one of SEQ ID NOs:433-441.

29. Use of a structure described in any one of claims 1, 7, 8, 9, 15, 18, or 21 for treating a disease in a subject in need of such treatment.

30. Use of the device described in claim 24 for treating a disease in a subject in need of such treatment.

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