Multivascular network and functional intravascular topology within biocompatible hydrogel

Abstract

To provide a device made from a hydrogel matrix.SOLUTION: A hydrogel matrix includes a photoabsorber with a void architecture in the matrix, having a first vessel architecture and a second vessel architecture that are each tubular and branching, wherein the first and second vessel architectures are fluidically independent from each other. A pre-polymerization solution for forming the device, and a method of fabricating such devices are described. A method of fabricating a 3D hydrogel construct is provided. The method includes using a computer-implemented process to create a 3D model of the construct on the basis of a tessellation of polyhedra having a number of faces connected by edges and vertices, generate a first vascular component of the model, generate a second vascular component of the model, and combine the first and second vascular components of the model.SELECTED DRAWING: Figure 22

Description

[Technical field]

[0001] The present disclosure relates to the formation of multiple vascular networks and functional endovascular topologies within biocompatible hydrogels. [Background technology]

[0002] background Solid organs transport fluids through distinct vascular networks that are biophysically and biochemically intertwined to create complex three-dimensional (3D) transport regimes that are difficult to manufacture and study. Tissues of the circulatory and pulmonary systems are physically and evolutionarily intertwined. In air-breathing vertebrates, these limited and conserved vascular topologies interact to enable oxygen-dependent respiration throughout the organism. Summary of the Invention

[0003] overview The detailed description below describes the preparation of monolithic, transparent hydrogels by stereolithographic fabrication. The cytocompatible hydrogels contain complex and functional vascular architectures with functional vascular topologies for the study of fluid mixers, valves, intervascular transport, nutrient delivery and host engraftment. These endovascular and multi-vascular designs are created with photopolymerizable hydrogels by using food dye additives as biocompatible photoabsorbers for projection stereolithography. The stereolithography process allows for simultaneous orthogonal control of tissue architecture and biomaterials for the design of regenerative tissues. Intertwined vascular networks formed from space-filling mathematical topologies allow for the creation of complex geometries.

[0004] In some embodiments, the device comprises a photopolymerizable hydrogel matrix comprising a light absorber and a void architecture in the matrix having a first vascular architecture and a second vascular architecture that are tubular and branched, respectively, wherein the first and second vascular architectures are fluidically independent from each other.

[0005] Embodiments may include one or more of the following: The device allows at least 90% of visible light incident on the device to be transmitted through the device for imaging the device; The light absorbing agent has been at least partially washed off the device; The light absorbing agent is degradable independent of any degradation of the remaining hydrogel matrix; The light absorbing agent is degradable by chemical or physical processes; The light absorbing agent is photobleachable or removable by boiling; The multi-vascular void architecture is a torus entangled torus knot; One or both of the first vascular architecture and the second vascular architecture are formed from a model based on a tessellation of polyhedrons; The model is based on a tessellation of polyhedrons representing blood vessels; The model is based on a tessellation of polyhedrons representing airways; In various aspects, the multi-vascular void architecture has features of a functional valve; In various aspects, the valve is a bicuspid valve, a tricuspid valve, a monocuspid valve, or a Tesla valve; In various aspects, the multi-vascular void architecture has features of a fluidic static mixer; In various aspects, the fluidic static mixer has between 2 and 50 fin elements. The feature is positionable at any location in the multi-vascular void architecture. The device is monolithic. The hydrogel matrix is ​​biodegradable. The device is fabricated by additive manufacturing. The first vascular architecture and the second vascular architecture are intertwined. The first vascular architecture is covered by the second vascular architecture. The hydrogel matrix is ​​porous. The device is implantable. The light absorber is hydrophilic.The light absorber is one of the following: food color, tartrazine, Sunset Yellow FCF (Yellow No. 6), Brilliant Blue FCF (FD&C Blue No. 1), Indigo Carmine (FD&C Blue No. 2), Fast Green FCF (FD&C Green No. 3), anthocyanin, anthocyanidin, erythrosine (FD&C Red No. 3), Allura Red AC (FD&C Red No. 40), riboflavin (vitamin B2, E101, E101a, E106), ascorbic acid (vitamin C), quinoline yellow WS, carmoisine (azorubine), Ponceau 4R (E124), patent blue V (E131), green S (E142), yellow 2G (E107), orange GGN (E111), red 2G (E128), caramel color, phenol red, methyl orange, 4-nitrophenol, and NADH disodium salt. The light absorber is hydrophobic. The light absorber is one of curcumin (E100), turmeric, alpha carotene, beta carotene, canthaxanthin (ketocarotenoid), cochineal extract, paprika, saffron, ergocalciferol (vitamin D2), cholecalciferol (vitamin D3), citrus red 2, annatto extract and lycopene. The three or more vascular architectures are fluidly independent from each other and from the first and second vascular architectures.

[0006] In some embodiments, the prepolymerized solution comprises a photopolymer and a biocompatible light absorbing additive suitable for controlling the transmission of light, the additive being at least partially removable from a solid formed from the prepolymerized solution, the solution comprising plant cells, bacterial cells, or mammalian cells.

[0007] In some embodiments, a method for fabricating a 3D hydrogel construct is provided by creating a 3D model of the construct based on a tessellation of a polyhedron with several faces connected by edges and vertices. The vascular component of the model is then generated by removing the faces and optionally vertices of the polyhedron, using the remaining topology as a vascular skeleton, and skinning the skeleton with a polygon mesh, then smoothing the result to create cylindrical channels along the edges of the model with intervascular junctions located at each vertex position. The airway component of the model is then generated by scaling the faces of the 3D model along local surface normals to fit the airways within the vasculature (blood vessel) component, forming independent fluid connections to the vasculature and airways, performing a Boolean subtraction from the solid volume, and combining the vascular and airway components of the model.

[0008] In some embodiments, fabricating the hydrogel alveolar construct includes radially symmetrically fusing a plurality of spheres to create an airway topology, offsetting the airway topology to generate a vascular surface topology, tessellating, skeletonizing, and skinning the vascular surface topology to create a Voronoi vascular topology (wherein the tessellation includes performing a tessellation of a polyhedron), and performing a Boolean subtraction of the original airway and tessellated Voronoi vascular topology from a solid volume to generate a final 3D model for additive manufacturing. The tessellation of the polyhedron is a Weir-Phelan space-filling foam model of two dodecahedral cells and six tetradecahedral cells.

[0009] In some embodiments, the method for manufacturing a hydrogel matrix construct comprises using a design software to create a 3D model of the hydrogel matrix construct, the 3D model of the hydrogel matrix construct comprises a first computational algorithm that generates a first tubular channel network in the hydrogel matrix construct, and a second computational algorithm that is different from the first computational algorithm that generates a second tubular channel network in the hydrogel matrix, the first and second tubular channel networks being two independent intertwined vascular networks.The 3D model is then converted into a format suitable for use in a 3D additive manufacturing software to generate a formatted 3D model that is generated using a 3D additive manufacturing machine, and the additive manufacturing machine is instructed to generate the model.

[0010] The embodiment may include one or more of the following: the first computational algorithm is a tessellation of a polyhedron; the first computational algorithm is a torus and the second algorithm is a torus knot; a pre-polymerized solution including a light absorber is provided to the 3D additive manufacturing machine; the pre-polymerized solution includes one or more of bacterial cells, mammalian cells and plant cells; the first tubular channel network or the second tubular channel network is lined with cells; the cells are embedded in a hydrogel matrix; the cells are one or more of liver, lung, bone, endothelial, cardiac, pancreatic, renal, epithelial, muscle, cartilage, stem cells, skin or eye cells; heat is provided as the 3D additive manufacturing machine generates the 3D model; heat is applied via a silicone heater, a heat lamp or an infrared LED; the 3D model is enclosed in a heated enclosure during generation of the 3D model.

[0011] Embodiments include a method of treating a subject in need of treatment comprising implanting any of the devices into the subject, and a device comprising a plurality of joined subunits, each subunit being any of the devices.

[0012] Advantages of the methods and materials herein include the use of stereolithography to efficiently convert photoactive liquid resins into structured plastic parts by localized photopolymerization. Compared to extrusion 3D printing, which deposits voxels sequentially, photocrosslinking can be highly parallelized by image projection to simultaneously and independently address millions of voxels per time step. In stereolithography, the xy resolution is determined by the light path, and the z resolution is dictated by light-attenuating additives that absorb excess light and limit polymerization to a desired layer thickness, thereby improving pattern fidelity. In the absence of suitable light-absorbing additives, 3D photopatterning of soft hydrogels can be limited in the types of patterns that can be generated or implement complex, expensive, low-throughput microscopy methods. Common light-blocking chemicals utilized in photoresist patterning or plastic part fabrication are not suitable for biomanufacturing due to known genotoxicity and carcinogenicity. The use of non-toxic light-blocking materials for projection stereolithography provides a major advance in the wealth of architectures available for the design and generation of biocompatible hydrogels. [Brief description of the drawings]

[0013] The accompanying drawings are not intended to be drawn to scale. Like reference numbers in the various drawings indicate like elements. For clarity, not every component is labeled in every drawing.

[0014] [Figure 1-1] 1A-H show a monolithic hydrogel with a functional intravascular topology in the form of a static mixer. [Figure 1-2] See description of Figure 1-1. [Figure 1-3] See description of Figure 1-1. [Diagram 2]Figure 2A shows a monolithic hydrogel with a functional intravascular topology in the form of a bicuspid valve, and Figure 2B shows compliance measurements of a monolithic hydrogel with a functional intravascular topology in the form of a horizontal channel. [Figure 3-1] Figures 3A-G show the mathematical space-filling curve fits to the intertwined vascular topology within the hydrogel, and Figures 3H-J show the results showing the perfusion of deoxygenated RBCs through the vascular network as in Figure 3E. [Figure 3-2] See description of Figure 3-1. [Figure 4-1] 4A-G show the implantation of functional liver hydrogel carriers in an animal model. [Figure 4-2] See description of Figure 4-1. [Figure 5-1] Figure 5A-G show details of the tessellation of polyhedra to generate 3D models for additive manufacturing of bioinspired alveolar hydrogels. [Figure 5-2] See description of Figure 5-1. [Figure 6-1] Figure 6A-H demonstrate the use of 3D space-filling tessellation to recreate overlying vasculature that mimics airway topography. Figure 6A-I show a bioinspired alveolar model with overlying vasculature from a 3D tessellation of the Weier-Phelan topology. [Figure 6-2] See description of Figure 6-1. [Figure 7] 7A-E show further imaging and development of the liver hydrogel carrier. [Figure 8] 8A-C show the parts and steps of the stereolithography apparatus for tissue engineering (SLATE). [Figure 9] 9A-D are experimental results showing that the addition of xanthan gum to the prehydrogel solution results in a uniform dispersion of cells. [Figure 10] Figure 10A-C show rapid biomanufacturing and non-invasive characterization of cell activity using cryopreserved cell stocks. [Figure 11] Figures 11A-D show the monolithic lung-mimicking perfusion and ventilation tissue culture system. [Figure 12] 12A and 12B are stained sections showing hMSC differentiation in perfused single channel gels. [Figure 13] 13A-E show the fabrication of patent blood vessels within a monolithic hydrogel. [Figure 14] 14A-D show experimental results indicating that fabrication direction and layer thickness affect the fidelity of the printed channels. [Figure 15] 15A-G are experimental results showing that biocompatible light absorbers allow the fabrication of hydrogels with open channels. [Figure 16] 16A-D are experimental results showing that inclusion of tartrazine does not affect the viability and differentiation of human mesenchymal stem cells. [Figure 17] 17A-E are results showing the compatibility of light absorber additives with advanced materials and fabrication strategies. [Figure 18] FIG. 1 is a schematic diagram of an exemplary apparatus for fabricating hydrogel constructs, according to various embodiments. [Figure 19] FIG. 1 is a schematic diagram of a system for producing hydrogel constructs, according to various embodiments. [Figure 20] 1 is a flow chart of an exemplary method for fabricating a 3D hydrogel construct, according to various embodiments. [Figure 21] 1 is a flow chart of an exemplary method for fabricating a hydrogel matrix construct, according to various embodiments. [Figure 22] 1 is a flow chart of an exemplary method for fabricating a 3D hydrogel construct, according to various embodiments. [Figure 23] FIG. 1 is a block diagram illustrating a computer system according to various aspects.

[0015] It should be understood that the drawings are not necessarily drawn to scale, and that objects in the drawings are not necessarily drawn to scale relative to each other. The drawings are representations intended to provide clarity and understanding to various aspects of the devices, systems and methods disclosed herein. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or similar parts. Moreover, it should be understood that the drawings are not intended to limit the scope of the present teachings in any way. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Detailed Description The devices can be formed of a photopolymerizable hydrogel that includes a light absorbing agent. During fabrication, the light absorbing agent can be removed from the device, whether by washing it off or boiling it off, or it can be degraded by another physical or chemical process that allows the light absorbing agent to degrade independently of any other components in the hydrogel matrix. The resulting biocompatible device is biodegradable and porous, making it suitable for implantation in a patient or for scientific study.

[0017] The device is formed to include a complex internal structure, while being monolithic. The internal structure can be one, two, or more than two architectures in the hydrogel. These internal structures can be void architectures in the hydrogel matrix in the form of first and second vascular architectures, each of which is tubular and branched, but fluidically independent of each other, such as a multi-vascular void architecture. The first and second vascular architectures can be complex, intertwined, or the first vascular architecture can be covered by the second vascular architecture. The multi-vascular void architecture can take many forms, such as a torus with a tangled torus knot, a functional valve (such as a bicuspid, tricuspid, monocuspid, or Tesla valve) and / or a fluid static mixer with multiple fin elements. One or both of the first and second vascular architectures can be formed from a model based on a tessellation of a polyhedron, which can represent a blood vessel or an airway.

[0018] Figure 1A-H describes the validation of the generated monolithic hydrogel with a simple functional intravascular topology, in this case a static mixer with fins that homogenize the fluid streams entering it. Figure 1A is a schematic diagram of an internally embedded static mixer in a monolithic hydrogel composed of 3D twisted fin elements of alternating chirality. Figure 1B shows a fabricated hydrogel in which the fin element structure of Figure 1A, which is 150 μm thick, is embedded in a 1 mm cylindrical channel. As shown in the fluorescence image in Figure 1C, two fluid streams (e.g., laminar flows with low Reynolds number (e.g., Re = 0.002)) entering the channel are mixed by interaction with the fins. The fluorescence image in Figure 1C is consistent with a computational model of the flow (Figure 1D). As shown in the merged fluorescent images in Figure 1E of printed monolithic hydrogels (80 wt%, 6 kDa) containing static mixers with 2–10 fin elements and perfused with a fluorescent dye, the interaction of the laminar flow with the static mixer changes with the number of fins.

[0019] Figures 1F-H further quantify the mixing efficiency of perfusable static mixers formed from monolithic hydrogels described herein. Figure 1F shows normalized fluorescence intensity profiles at the outlet of static mixers with 0 or 10 fins (solid lines represent average intensity at a 3 mm long outlet immediately after the fins, shaded areas represent standard deviation). Figure 1G shows the average intensity data from Figure 1F replotted to demonstrate the mixing ratio calculations of the static mixers. Figure 1H shows a plot of the average mixing ratio by number of fins. These data indicate that the fabricated hydrogel devices with endovascular topology have predictable functionality.

[0020] Figures 2A-B show the use of the hydrogel device fabricated in the form of a 3D functional bicuspid venous valve. The valve leaflets are dynamic and rapidly respond to antegrade and retrograde pulsatile flow, promoting the formation of stable mirror-image vortices in the valve sinuses according to established mapping of native tissue. The particle image velocimetry (PIV) image on the right of Figure 2A demonstrates stable mirror-image vortices in the valve sinus region following the opening of the leaflets.

[0021] FIG. 2B shows exemplary compliance measurements of horizontal channels fabricated in hydrogel. On the left and center, vascular distention upon application of air pressure is measured both at rest and when inflated to 120 mmHg (hydrogel composition: 20 wt% 6 kDa PEGDA; channel diameter: 1.5 mm; channel length: 20 mm). The white dashed lines represent the walls of the imaged channel. On the right, graphed data shows that vascular compliance was found to be dependent on the composition of the pre-hydrogel solution. Solutions composed of lower polymer molecular weights and higher wt% yielded less compliant hydrogels. The data in FIG. 2A and 2B demonstrate the feasibility of hydrogel devices for use in multiple vascular systems.

[0022] Solid organs contain distinct fluidic networks that are physically and chemically intertwined. Separate vascular networks generally do not form direct fluidic connections, preventing topological reduction to a single connected network. The multi-vascular topology within a biocompatible and aqueous environment allows for the design of an intertwined network that is a suitable blueprint for fabrication in hydrogels.

[0023] Mathematical space-filling and fractal topology algorithms provide an efficient parametric language for designing complex vascular blueprints and a mathematical means for designing a second vascular architecture that does not intersect with the first. Figure 3A-D show the fits of mathematical space-filling curves to entangled vascular topologies within a hydrogel (20 wt% PEGDA, 6 kDa). This includes a helix surrounding an axial vessel (Figure 3A), first and second order interpenetrating Hilbert curves (Figure 3B), a bicontinuous cubic lattice (based on Schwarz P surface; Figure 3C) and a torus entangled torus knot (Figure 3D). Dye perfusion and micro-CT (μCT) analysis demonstrate pattern fidelity, vessel patency and fluid independence between the two networks.

[0024] The efficiency of intravascular interstitial transport was evaluated by measuring the supply of oxygen from a source vessel to perfused human red blood cells (RBCs) flowing in the adjacent 3D topology. Figure 3E-F shows the tessellation of an axial vessel and a spiral surrounding it while maintaining an intervessel distance of 300 μm along a tortuous path. The top-down photograph in Figure 3E (a magnified view is shown in Figure 3F) is a photograph of the fabricated hydrogel with oxygen and RBC supply to the respective vessels. During ventilation of the tortuous channel with humidified oxygen (7 kPa), perfusion of deoxygenated RBCs (pO2 ≤ 40 mmHg; sO2 ≤ 45%) into the spiral channel resulted in a noticeable discoloration of the RBCs from dark red at the inlet to light red at the outlet.

[0025] Collections of perfused RBCs showed significantly higher oxygen saturation and oxygen tension compared to deoxygenated RBCs added at the inlet and compared to the negative control gel ventilated with humidified nitrogen gas. This is illustrated by FIG. 3G, where perfused RBCs were collected at the outlet and quantified for sO2 and p02. Compared to deoxygenated RBCs perfused at the inlet (dashed line), oxygen flow increased sO2 and p02 of perfused RBCs compared to the nitrogen flow negative control.

[0026] Oxygenation of perfused human red blood cells in serpentine spiral gels is affected by flow rate. Experimental results in Figure 3H-I show that slower perfusion of deoxygenated RBCs through the vascular network (in gaseous oxygen flow) resulted in higher sO2(B) and pO2 of collected RBCs. Dashed lines indicate the measured sO2 and pO2, respectively, of deoxygenated RBCs used for perfusion. Figure 3J shows that the fraction of oxygenated hemoglobin increased significantly with lower flow rates. FHHb = deoxygenated hemoglobin fraction; FMetHb = methemoglobin fraction; FCOHb = carboxyhemoglobin fraction; FO2Hb = oxygenated hemoglobin fraction. These data indicate the feasibility of the hydrogel device for use as a channel to transport RBCs.

[0027] The following establishes the utility of the described process for fabricating structurally complex and functional graft tissues for therapeutic transplantation: The liver, the largest solid organ in the human body, performing hundreds of essential tasks in a manner believed to be closely dependent on its structural topology, is the organ used in these studies.

[0028] Multi-material liver tissues were assembled by creating complex structural features in hydrogels within the expanded design space afforded by SLATE (described below). Bioprinted single-cell tissues and bioprinted hydrogel "carriers" containing hepatocyte aggregates were fabricated (Figure 4A-C). After implantation into nude mice, albumin promoter activity was enhanced in hydrogel carriers containing hepatocyte aggregates. Data from all time points per condition are shown in Figure 4B, and cumulative bioluminescence per condition is shown in Figure 4C. Albumin promoter activity in the aggregate-loaded tissue carriers showed a greater than 60-fold enhancement compared to embedded tissues containing single cells.

[0029] Figure 4D shows macroscopic inspection of the tissue after resection, and the hydrogel carrier tissue appeared to be better integrated with the host tissue and blood. Despite the improved utility of hepatocyte aggregates compared to single cells, the aggregate size imposes significant architectural limitations for 3D printing, as the aggregates are larger in size than the typical minimum voxel resolution (50 μm). To accommodate these design constraints, a more advanced carrier capable of delivering hepatocyte aggregates within a native fibrin gel was used. It has a vascular compartment that can be seeded with endothelial cells and incorporates a structural hydrogel anchor to hold the fibrin gel physically, rather than chemically, and to facilitate remodeling between the graft and the host tissue. Referring to Figure 4E, the microchannel network is seeded with human umbilical vein endothelial cells (HUVECs) while the hydrogel anchor physically captures the fibrin gel containing the hepatocyte aggregates (Hep) observed by confocal microscopy.

[0030] Bioengineered liver tissue survives transplantation in a model of chronic liver injury. 14 days after implantation into mice with chronic liver injury, the hepatocyte hydrogel carriers exhibited albumin promoter activity indicative of functional hepatocyte survival (Figure 4F). Immunohistochemical characterization revealed the presence of hepatocyte aggregates attached to the printed hydrogel components that stained positive for the hepatocyte marker cytokeratin 18 (Figure 4F-G). Further characterization by gross examination and high magnification images of hematoxylin and eosin stained slides indicated the presence of host blood in the explanted tissue. Immunostaining for Ter-119 confirmed the erythrocytic identity of cells within microvessels in close proximity to hepatocyte microaggregates in the explanted tissue (Figure 4G, right). These indicate the efficacy of the hydrogel device for use as an implantable device.

[0031] Additional structural features of the native peripheral lung are included in monolithic bioinspired hydrogel models of alveolar morphology and oxygen transport. 3D hydrogels that contain branching networks and can support mechanical distention during cyclic ventilation of pooled airways can enable investigation of the performance of lung morphologies derived from native structures and provide a broad workflow for developing and interrogating novel functional topologies.

[0032] The complex morphology is mathematically approximated as a 3D space-filling tessellation of polyhedra. To fabricate a hydrogel matrix construct that models alveolar morphology and oxygen transport, a 3D model of the hydrogel construct is created using design software. The construct includes a first computational algorithm that produces a first tubular channel network and a second computational algorithm that produces a second tubular channel network, different from the first computational algorithm. The first and second tubular channel networks are two independent intertwined vascular networks (e.g., alveolar morphology and oxygen transport morphology). The 3D model is converted into a format suitable for use in 3D additive manufacturing software to produce a formatted 3D device that is produced using a 3D additive manufacturing machine.

[0033] The process of creating the tessellated model includes radially symmetrically fusing multiple spheres to create the airway topology, offsetting the airway topology to generate the vascular surface topology (by moving each face in the direction of its local normal and letting this new face serve as a template on which a new vascular skeleton is constructed), and tessellating, skeletonizing, and skinning the vascular surface topology to create the Voronoi vascular topology. Tessellating includes performing a tessellation of the polyhedra as well as performing a Boolean subtraction of the original airway and tessellated Voronoi vascular topology from the solid volume to generate the final 3D model for additive manufacturing. Figures 5A-G show details for the design of the bioinspired alveolar model. In Figure 5A, basic Weir-Ferrand polyhedra are tessellated in 3D to fill the space. Figure 5B shows the procedural derivation of the entangled alveolar model from the Weir-Ferrand tessellation. The manifold air surface is stretched in the normal direction, faces are removed, and edges are wrapped with a smooth polygon mesh to form a highly branched vascular network (containing 185 vessel segments and 113 fluid branching points) that encloses the airways and trajectories within its curves. Figure 5C is a photograph of a printed alveolar model with no RBC flow in the overlying vasculature highlighting that the airways are smaller at rest (left) compared to during inflation and hydrogel distension (right, 10 kPa, 0.5 Hz). Cyclic ventilation of the pooled airways with humidified oxygen gas (10 kPa, 0.5 Hz) produces significant distension and a clear change in the curvature of the concave airway region.

[0034] Figure 5D is a schematic xy cross-sectional view of a model with convex (blue) and concave (green) regions of the airway (white) and associated blood vessels (red). Normal force arrows converge at the concave regions. This simplified 2D computational model of airway expansion predicts anisotropic distension of the airway and compression of adjacent blood vessels, corresponding to the local curve. This is shown in Figure 5E, a 2D computational model of a symmetric airway surrounded by circular blood vessels equidistant from the convex or concave regions of the airway (black edges indicate the starting point). As the airway expands, the concave regions are displaced, compressing the adjacent blood vessels.

[0035] The steps of peripheral lung subunit model design are shown in Figure 5F. First, the airway is designed by fusing a sphere with inlet and outlet channels. The airway topology is offset and used as a template for vessel generation by performing Voronoi 3D surface tessellation, skeletonization and skinning. A Boolean subtraction of these two topologies from the solid volume is performed, which represents the final hydrogel design.

[0036] FIG. 5G shows the generation of a lung-mimetic model by adding branches of airways and offset vascular networks grown within a given computational 3D bounding volume using peripheral lung subunit models.

[0037] The alveolar morphology is mathematically approximated as a 3D space-filling tessellation of polyhedra that efficiently fills the space and reproduces the overlying vasculature that closely follows the curves of the 3D airway topography. Figure 6A-I show a bioinspired alveolar model with overlying vasculature from a 3D tessellation of the Weier-Phelan topology. Figure 6A shows the architectural design of the alveolar model topology based on the Weier-Phelan 3D tessellation and topology offsets to derive the overlying vasculature. The bottom cutaway view shows the model alveolus with shared airway space. The 3D tessellation produces a surface that contains both convex and concave regions reminiscent of natural alveolar air sacs with shared airway space that supports alveolar buds.

[0038] Figure 6B shows a printed hydrogel (20 wt% 6 kDa PEGDA) patterned with the alveolar model topology in Figure 6A at a voxel resolution of 5 pL and a print time of 1 hr. The figure shows the printed hydrogel when the air sac is ventilated with O2 during RBC perfusion. Perfusion of deoxygenated RBCs at the vascular inlet during cyclic ventilation (10-100 µL / min) leads to observable compression and RBC clearance from the vessel adjacent to the airway concave region (Figure 6B,C). With a sparse RBC flow in the early stages of perfusion, the cyclic compression of the RBC vessel (driven by the airway concave region with each expansion cycle) acts as a switching valve to redirect fluid flow to the adjacent vessel segment.

[0039] Analysis from 3D computational models supports anisotropic distension of the concave regions of the airway during inflation (Figure 6D). Moreover, despite the volume of the alveolar model hydrogel (0.8 mL) being more than four times smaller than that of the serpentine spiral model (3.5 mL), the results are similar oxygenation efficiency between the two designs (Figure 6E). These data suggest that the branching topology, hydrogel distension and redirection of fluid flow during ventilation may boost intravascular mixing and allow faster volumetric absorption of oxygen by well-mixed RBCs. These data demonstrate the benefits of vasoconstriction during breathing realized in a biocompatible material and in an aqueous environment.

[0040] For scalable lung-mimetic design, the locations of vascular inlets, vascular outlets, and airways are integrated so that peripheral lung subunits can be added at the tips of the multi-scale branching architecture. Figure 6F shows the branching airways within a selected computational bounding volume. This refines the lung-mimetic design by generative growth of the airways, offset growth of the opposing inlet and outlet vascular networks, and addition of peripheral lung subunits at the branch tips.

[0041] The centerlines of the inlet and outlet vascular networks grow opposite each other across the airway and topologically offset from it, with the vessels redirecting down to the tips of all the outgrowths. The tip of each peripheral lung is populated with an alveolar unit cell (Figure 6G), whose covering vasculature (containing 354 vessel segments and 233 fluid branching points) is itself an anisotropic Voronoi surface tessellation that follows the topological offset of the local airway. We found that the hydrogel (20 wt% 6 kDa PEGDA) favorably withstood over 10,000 ventilation cycles (24 kPa, frequency 0.5 Hz) over a 6-h period during RBC perfusion, with the inlet gas switched between humidified oxygen and humidified nitrogen (Figure 6H-J). Figure 6I shows a color-filtered view of the early stages of RBC perfusion, demonstrating that ventilation promotes RBC mixing and bidirectional flow within selected vessel segments near the midpoint of the peripheral lung subunit.

[0042] Referring again to FIG. 6E, FIGS. 7A-E show further images and development of the liver hydrogel carrier. In FIG. 7A, the 3D printed hydrogel carrier hosts primary hepatocyte aggregates (green) suspended in fibrin (blue), intertwined with hydrogel anchors (purple), and with an underlying patterned vascular network (red). FIG. 7B shows the 3D printed chamber demonstrating the perfusable vasculature (red) and hydrogel anchors. FIG. 7C is a close-up of the highlighted region of FIG. 7B showing the hydrogel anchors and the underlying perfusable vasculature (red). FIG. 7D is a 250 μm cross-sectional view demonstrating the fibrin seeded volume (blue) and the underlying vasculature (red). FIG. 7E is a confocal maximum intensity projection (Max IP, left) and endothelial cord (red) and hepatocyte (green) volume rendering.

[0043] SLATE studies demonstrate that SLATE fabrication supports rapid biomanufacturing, can maintain the viability of mammalian cell lines, supports normal function and differentiation of primary human stem cells, and suggests an experimentally controllable means to explore stem cell differentiation as a function of soluble factor delivery via vascular perfusion.

[0044] FIG. 8A is a schematic workflow for the fabrication of 3D objects by projection stereolithography, according to various embodiments. A photomask corresponding to a 3D model can be projected into a bath containing a photosensitive liquid solution. Once the successive layer-by-layer photopatterning is completed, a 3D object is obtained. FIG. 8B is a 3D rendering of an exemplary projection stereolithography apparatus 800. The apparatus can include a motor 810 (which can be mounted to a frame 840) controlled by an actuator 815 to which a build platform 820 is attached. The back of the printer can house a motherboard 825 that controls the motor and performs input and output by optional additional sensors or switches. The front of the printer includes a mirror 830 positioned to reflect the incoming pattern from a projector 835 into a dish containing a photosensitive material. All off-white colored parts correspond to parts 3D printed out from consumer grade polylactic acid (PLA) plastic filament. FIG. 8C is a schematic diagram showing photomasks (left) generated at various positions along the height of a 3D rook (chess piece) model.

[0045] The device fits entirely within a typical biosafety cabinet with ample space for cell handling. Although SLATE fabrication is rapid (up to 12 mL / hr for 250 pL voxels), mammalian cells typically settle out of suspension within tens of seconds. To prevent cell settling and facilitate automated bioprinting, xanthan gum (a natural biocompatible and shear-thinning carbohydrate) is added to the pre-hydrogel solution.

[0046] SLATE demonstrates the ability to generate tissue constructs containing mammalian cells using the custom lung-mimetic architecture described above. Hydrogels composed of dozens of layers can be printed in minutes, with a uniform distribution of mammalian cells (Figure 9A,B). Figure 9A,B shows that incorporation of xanthan gum into the pre-hydrogel solution resulted in a uniform distribution of cells along the height of the gel. Figure 9B shows that HEK mCherry cells (20 × 10 6 Figure 9C shows the side (xz) view of the fabricated 20 wt% hydrogel containing 0.8 mm diameter horizontal channels of PEGDA. The experimental results in Figure 9C,D show the total light output of HEK Luc2P cells encapsulated in PEGDA hydrogels containing 0.8 mm diameter horizontal channels at various cell densities (Figure 9C) and various luciferin substrate flow rates (Figure 9D).

[0047] Figure 10A-C show rapid biomanufacturing and non-invasive characterization of cell activity using cryopreserved cell stocks. Figure 10A shows that cryopreserved cell stocks are thawed and immediately used for projection stereolithography to generate perfusable tissue with patterned vascular architecture. The entire procedure from cell thawing to perfusion experiments takes less than an hour. With reference to Figure 10B, this workflow was used to culture mammalian cells (2.5 × 10) expressing firefly luciferase (Luc2P) in vitro. 7 Fabricated tissue constructs containing 1000xygenated RBCs (100xygenated RBCs / mL) are perfused with deoxygenated or oxygenated RBCs and luciferin substrate. Luminescence quantification (3 hours) demonstrates increased luminescence from cells within the gels perfused with oxygenated RBCs. Figure 10C is the full 3 hour time course of the perfusion experiment in Figure 10B plotted as total luminous flux emitted from cells within the hydrogel.

[0048] The hydrogel constructs can also be populated with human lung fibroblasts in most of the interstitial spaces and human epithelial-like cells in the airways, which can facilitate the development of hydrogel analogs of lab-on-a-chip lung designs for monolithic lung-mimicking perfusion-ventilation tissue culture systems. Figure 11A shows the bioinspired design of the alveolar sacs and surrounding pulmonary vasculature. The overall size of the model is 9 × 11.8 × 4.3 mm (x, y, z) with a minimum channel diameter of 400 μm and an alveolar diameter of 600 μm. Figure 11B is a photograph of the fluidic connections to the printed gel for perfusion via vascular channels and ventilation of the airway vessels. Figure 11C shows IMR-90 fibroblasts (10 × 10 6 Hydrogels fabricated with 100 μL / mL of 1000 μL ...

[0049] Figure 12A,B shows the histological results of several weeks of tissue culture of hMSCs with osteogenic differentiation medium, with hMSCs positive for osteogenic markers seen throughout the perfused single channel gel. Figure 12A shows alkaline phosphatase (ALP) staining of hMSC tissue cross-sections from hydrogels that underwent osteogenic medium perfusion for 14 days, with the vascular channels highlighted by dotted circles (Figure 12B is a close-up of the cross-section). ALP staining is seen to be strong along the perimeter of the perfused channel, with some positive staining seen throughout the majority of the gel.

[0050] As mentioned above, synthetic and natural food dyes can be used as biocompatible light absorbers to enable stereolithographic fabrication of hydrogels containing complex and functional vascular architectures. Aqueous prehydrogel solutions containing tartrazine (yellow food dye FD&C Yellow 5, E102), curcumin (from turmeric) or anthocyanin (from blueberries) can each yield hydrogels with patent blood vessels. In addition to these organic molecules, inorganic gold nanoparticles (50 nm), widely recognized for their biocompatibility and light attenuation, also function as effective light absorbing additives to generate perfusable hydrogels (discussed below with reference to Figure 15).

[0051] The light absorbing agent that can be used can be one or more food dyes including tartrazine, sunset yellow FCF (yellow no. 6), brilliant blue FCF (FD&C blue no. 1), indigo carmine (FD&C blue no. 2), fast green FCF (FD&C green no. 3), anthocyanins, anthocyanidins, erythrosine (FD&C red no. 3), allura red AC (FD&C red no. 40), riboflavin (vitamin B2, E101, E101a, E106), ascorbic acid (vitamin C), quinoline yellow WS, carmoisine (azorubine), ponceau 4R (E124), patent blue V (E131), green S (E142), yellow 2G (E107), orange GGN (E111), red 2G (E128), caramel color, phenol red, methyl orange, 4-nitrophenol, and NADH disodium salt. Also available are curcumin (E100), turmeric, alpha-carotene, beta-carotene, canthaxanthin (a ketocarotenoid), cochineal extract, paprika, saffron, ergocalciferol (vitamin D2), cholecalciferol (vitamin D3), citrus red 2, annatto extract and lycopene.

[0052] Figures 13A-E show the fabrication of patent blood vessels within monolithic hydrogels. Figure 13A shows a schematic of a monolithic hydrogel with horizontally oriented blood vessels that can be fabricated by projection stereolithography with one of the appropriate light absorbers (tartrazine, in the case of the experiment shown) added to the prehydrogel solution to minimize excess light penetration into the nascent blood vessels. Figure 13B shows that projection stereolithography with tartrazine produces a hydrogel with minimized excess crosslinking in the vessel lumen. Figure 13C shows the absorbance spectrum of the LAP photoinitiator and the photoabsorber tartrazine. The absorbance spectrum of tartrazine encompasses the light source (vertical bar at 405 nm) that can be used to initiate photocrosslinking via the LAP photoinitiator. Figure 13D shows the photorheology during short (left) and long (right) exposure times (blue shaded area) demonstrating that tartrazine addition (0-3 mM) delays the induction of crosslinking but does not ultimately prevent gelation. FIG. 13E shows that the hydrogels release up to 70% of tartrazine within a few hours (exemplified by a photograph of the gel on a color wheel), making the fabricated hydrogels suitable for color and fluorescent imaging.

[0053] To understand how these light absorbers affect the gelation kinetics of photopolymerizable hydrogels, photorheological characterization was performed at short exposure times. Results show that these additives produce a dose-dependent delay in the induction of photocrosslinking (Figures 13D and 15E). Saturating exposures extending beyond the end of the reaction demonstrate that the appropriate additives did not ultimately interfere with the reaction, as the hydrogels eventually reached equivalent storage moduli independent of additive concentration (Figures 13D and 15E).

[0054] Figures 14A-D show experimental results showing that the fabrication direction and layer thickness affect the fidelity of the printed channels. Figure 14A is a 1 mm diameter circular channel fabricated with the longitudinal axis of the channel parallel to the printing direction. This orientation produces no overhanging features and has high circularity (as quantified in Figure 14D). Figure 14B is a 1 mm side square channel fabricated in a horizontal orientation perpendicular to the light projection axis (asterisks indicate areas where excess light penetration caused exogenous hydrogel crosslinking). Figure 14C shows a 1 mm diameter circular channel in a horizontal orientation printed using layer thicknesses of 200, 100, 50 or 25 μm. Figure 14D plots channel circularity as a function of layer thickness. A print of the horizontal channel is shown to the left of the dashed line and the vertical channel from Figure 14A is shown to the right. As the layer height decreases, the channel shows higher circularity and therefore higher geometric fidelity to the original CAD model.

[0055] Figures 15A-G show experimental results showing that biocompatible light absorbers enable the fabrication of hydrogels with open channels. Figure 15A is the absorbance spectrum of the LAP photoinitiator and the biocompatible light absorbers tartrazine, curcumin, anthocyanin, and 50 nm gold nanoparticles. The absorbance spectrum of these additives encompasses the light source (vertical bar at 405 nm) that can be used to initiate photocrosslinking via the LAP photoinitiator. Figure 15B shows that the amount of tartrazine was found to be less in the printed gel (4 x 4 x 2 mm, containing 1 mm diameter channels) compared to the starting prehydrogel solution due to its decomposition during the radical-mediated photochemical reaction. Figure 15C shows that hydrogels fabricated with the horizontal vessel geometry described in Figure 1A, but without the light absorber additive, produce undesired gelation within the vessels, completely occluding the vessels. Rhodamine-dextran was incorporated into the prehydrogel mixture to enable fluorescence. FIG. 15D shows the fluorescence (left) and color photographic (right) images of curcumin (top), anthocyanin (middle) and 50 nm gold nanoparticles (bottom) as light absorbers for fabricating open horizontal channels using stereolithography. To obtain the fluorescence images, FITC-dextran was formulated into the prehydrogel mixture. FIG. 15E shows the results of photorheology experiments with short (left) and long (right) exposure times with the following additives: curcumin (top), anthocyanin (middle) and 50 nm gold nanoparticles (bottom). FIG. 15F shows the calibration curves of hydrogel compositions with increasing light absorber concentrations. Each data point represents the time required for a monolayer hydrogel of a given thickness to reach its gelation point during dynamic vibration and irradiation, and all data points are shown in tabular form in FIG. 15G.

[0056] Tartrazine has been chosen as an example of a preferred light absorber. In addition to its low toxicity in humans and wide application in the food industry, this hydrophilic dye is easily washed out of the generated hydrogels (e.g., 70% of small gels are dissolved within 3 hours) and gives rise to nearly transparent constructs suitable for imaging. Tartrazine is known to be sensitive to free radicals, so some tartrazine may decompose during polymerization. Also, submerging the gel in water or saline to remove soluble tartrazine will wash out the vascular topology and remove unreacted pre-hydrogel solution. In contrast to tartrazine, curcumin is lipophilic and does not wash out in aqueous solutions, anthocyanins have peak absorbances far away from our intended 405 nm light source, thus requiring high concentrations for adequate efficacy, and gold nanoparticles are physically trapped, making transmission or fluorescence microscopy unfeasible. The use of tartrazine is advantageous as a light absorbing additive suitable for controlling light transmission in the hydrogel prepolymerized solution, which can then be removed from the formed device from the prepolymerized solution to render it transparent or nearly transparent (e.g., transmitting 90% or more of the incident light).

[0057] The hydrogel devices detailed herein can further include cells (plant, bacterial or mammalian) that are in the prepolymerized solution or are subsequently seeded into the porous hydrogel device. Figures 16A-D show experimental results indicating that the inclusion of tartrazine does not affect the viability and differentiation of human mesenchymal stem cells. In Figures 16A,B, human mesenchymal stem cells (hMSCs) incubated for 20 and 60 minutes with 1-10 mM tartrazine (Figure 16A) and 10-50 mM LAP (Figure 16B) give rise to high cell viability. Figure 16C shows that hMSCs within cylindrical bioactive hydrogels demonstrated high cell viability. Figure 16D quantifies osteogenic differentiation of hMSCs encapsulated in hydrogels fabricated with tartrazine, showing that cells within the fabricated cylindrical hydrogels remain viable and can undergo osteogenic differentiation.

[0058] More advanced photoactive materials can also be used to create hydrogel devices. Figures 17A-E show experimental results demonstrating the compatibility of photoabsorber additives with advanced materials and fabrication strategies. Figure 17A shows the photorheology of radical-mediated chain-growth photopolymerization with PEGDA and a photoabsorber, revealing that the hydrogel stiffness increases slowly (also known as the dark reaction) even long after the light (blue shaded region) is turned off. In contrast, as shown in Figure 17B, in PEG-norbornane and PEG-dithiol step-growth polymerizations (thiol-ene click chemistry) in the presence of a photoabsorber additive, the increase in hydrogel stiffness comes to an abrupt halt after the light (blue shaded region) is turned off. Figure 17C shows that the step-like appearance of step-growth reaction kinetics can be continuously repeated with discrete light pulses (blue shaded region) to produce hydrogels of variable stiffness without the complications of the slowly proceeding reactions seen in chain-growth polymerizations. Figure 17D shows that projection stereolithography of thiol-ene materials produces hydrogels while minimizing excess crosslinking in the vessel lumen. Figure 17E shows that serial projection stereolithography of hydrogels containing open channels can be achieved. To obtain fluorescent images, FITC-dextran was incorporated into the pre-hydrogel mixture.

[0059] Strong lamination was observed between adjacent fabricated layers, and rapid response of the patterned hydrogel to mechanical deformation was observed (as shown in the rest / expansion results in Figure 2B). This facile generation of soft hydrogels containing cylindrical patent vessels oriented orthogonally to the optical projection axis suggests significant design flexibility toward the generation of complex vascular topologies, and the optical transparency of the resulting hydrogels implies suitable imaging methods for characterizing and validating fluid flow.

[0060] The method and validation experiments describe how to fabricate 3D hydrogel constructs by creating a 3D model of the construct based on a tessellation of a polyhedron with several faces connected by edges and vertices. The vascular component of the model is then generated by removing the faces and optionally vertices of the polyhedron, using the remaining topology as a vascular skeleton, skinning this skeleton with a polygon mesh, and then smoothing the result to create cylindrical channels along the edges of the model with intervascular junctions located at each vertex location. The airway component of the model can be generated by scaling the faces of the 3D model along local surface normals to fit the airways within the vasculature (blood vessel) component, forming independent fluid connections to the vasculature and airways, performing a Boolean subtraction from the solid volume, and combining the vascular and airway components of the model.

[0061] These 3D models can be used for additive manufacturing with a pre-polymerized solution including a light absorber solution being fed into a 3D additive manufacturing machine. The pre-polymerized solution can have one or more bacterial cells, mammalian cells and plant cells, or the architecture obtained from the 3D model can be a first tubular channel network or a second tubular channel network lined with cells. Alternatively, the cells can be embedded in the hydrogel matrix. The cells can be one or more of liver, lung, bone, endothelial, cardiac, pancreatic, renal, epithelial, muscle, cartilage, stem cells, skin or eye cells.

[0062] When the 3D additive manufacturing machine creates a hydrogel based on the 3D model, heat can be applied via silicone heaters, heat lamps, or infrared LEDs. The constructing hydrogel can be enclosed in a heated enclosure while it is being created. Once fabricated, the hydrogel device can be implanted into a subject for medical intervention, or multiple devices can be joined into a larger implant for therapeutic use.

[0063] According to various embodiments, a device is provided that includes a hydrogel matrix. According to various embodiments, the hydrogel matrix is ​​a photopolymerized hydrogel. According to various embodiments, the hydrogel matrix includes a light absorber and a void architecture in the matrix having a first vascular architecture and a second vascular architecture that are tubular and branched, respectively, and the first and second vascular architectures are fluidically independent from each other.

[0064] According to various embodiments, the device allows for about 50%-99.9% of visible light (wavelength 400-700 nm) incident on the device to be transmitted through the device for imaging. According to various embodiments, the device allows for about 60%-99.8%, about 70%-99.6%, about 80%-99.5%, or about 85%-99.0% of visible light incident on the device to be transmitted through the device for imaging. According to various embodiments, the device allows for at least 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 90% of visible light incident on the device (including any percentage of visible light incident on the device) to be transmitted through the device for imaging. According to various embodiments, the light absorber may not result in a transparent hydrogel.

[0065] According to various embodiments, the light absorber is at least partially washed off the device. For example, some percentage of the light absorber may not be completely washed off. This can result in, for example, a gel that is clear but has a slight "yellow" tint. According to various embodiments, the light absorber is at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% (including any values ​​therebetween) washed off. According to various embodiments, the light absorber is degradable independent of any degradation of the remaining hydrogel matrix. According to various embodiments, the light absorber is degradable by chemical or physical processes. For example, a light absorber such as tartrazine can be at least 70% washed off within 3 hours after printing is completed.

[0066] According to various embodiments, the light absorber is photobleachable by exposure to absorbing light having a wavelength between 365 and 450 nm, removable by chemical decomposition, such as with peroxide or any other suitable substance, or removable by exposure to a boiling aqueous solution, e.g., water or any other suitable substance.

[0067] According to various aspects, the void architecture is a multi-vascular void architecture and further comprises a torus entangled with a torus knot. According to various aspects, one or both of the first vascular architecture and the second vascular architecture are formed from a model based on a tessellation of polyhedra. According to various aspects, the model based on a tessellation of polyhedra represents a blood vessel. According to various aspects, the model based on a tessellation of polyhedra represents an airway.

[0068] According to various embodiments, the void architecture is a multi-vessel void architecture and further comprises a functional valve. According to various embodiments, the valve is a bicuspid valve, a tricuspid valve, a monocuspid valve, or a Tesla valve.

[0069] According to various embodiments, the void architecture includes a fluid static mixer. According to various embodiments, the fluid static mixer has 2-50 fin elements. According to various embodiments, the fluid static mixer has 2-50, 3-40, 4-30, 5-25, 6-20, 7-15, or 8-12 fin elements (including any range therebetween). According to various embodiments, the functional valves can be positioned anywhere in the multi-vessel void architecture.

[0070] According to various embodiments, the device is monolithic. According to various embodiments, the hydrogel matrix is ​​a photopolymerized hydrogel matrix and / or a biodegradable hydrogel matrix. According to various embodiments, the device is manufactured by additive manufacturing methods.

[0071] According to various embodiments, the first vascular architecture and the second vascular architecture are intertwined. According to various embodiments, the first vascular architecture is covered by the second vascular architecture. According to various embodiments, the hydrogel matrix is ​​porous. According to various embodiments, the porosity ranges from about 10 nm (100 Angstroms) to about 10 μm, 20 nm to about 8 μm, 30 nm to about 7 μm, 40 nm to about 6 μm, 50 nm to about 5 μm, 60 nm to about 4 μm, 70 nm to about 3 μm, 80 nm to about 2 μm, or 100 nm to 1 μm (including any porosity range therebetween). According to various embodiments, the device is implantable. According to various embodiments, the light absorber is hydrophilic.

[0072] According to various embodiments, the light absorber is one of food coloring, tartrazine, Sunset Yellow FCF (Yellow No. 6), Brilliant Blue FCF (FD&C Blue No. 1), Indigo Carmine (FD&C Blue No. 2), Fast Green FCF (FD&C Green No. 3), anthocyanin, anthocyanidin, erythrosine (FD&C Red No. 3), Allura Red AC (FD&C Red No. 40), riboflavin (vitamin B2, E101, E101a, E106), ascorbic acid (vitamin C), quinoline yellow WS, carmoisine (azorubine), Ponceau 4R (E124), patent blue V (E131), green S (E142), yellow 2G (E107), orange GGN (E111), red 2G (E128), caramel color, phenol red, methyl orange, 4-nitrophenol, and NADH disodium salt. According to various embodiments, the light absorber can include a concentration of about 0.1 mM to about 100 mM, about 0.2 mM to about 90 mM, about 0.3 mM to about 80 mM, about 0.4 mM to about 70 mM, about 0.5 mM to about 60 mM, about 0.6 mM to about 50 mM, about 0.7 mM to about 40 mM, about 0.8 mM to about 30 mM, about 0.9 mM to about 20 mM, about 1.0 mM to about 10 mM (including any concentration range therebetween).

[0073] According to various embodiments, the light absorber is hydrophobic. According to various embodiments, the light absorber is one of curcumin (E100), turmeric, alpha-carotene, beta-carotene, canthaxanthin (ketocarotenoid), cochineal extract, paprika, saffron, ergocalciferol (vitamin D2), cholecalciferol (vitamin D3), citrus red 2, annatto extract, and lycopene. According to various embodiments, the hydrophobic light absorbing agent can include a concentration of about 0.1 mM to about 100 mM, about 0.2 mM to about 90 mM, about 0.3 mM to about 80 mM, about 0.4 mM to about 70 mM, about 0.5 mM to about 60 mM, about 0.6 mM to about 50 mM, about 0.7 mM to about 40 mM, about 0.8 mM to about 30 mM, about 0.9 mM to about 20 mM, about 1.0 mM to about 10 mM (including any concentration range therebetween). According to various embodiments, the hydrophobic light absorbing agent can include a solvent. The solvent may be selected from the group consisting of dimethylsulfoxide, ethanol (50-100%), isopropyl alcohol, (50-100%) dimethylformamide, N-methyl-2-pyrrolidone, tetrahydrofuran, chloroform, methylene chloride, toluene, hexafluoro-2-propanol, and any combination thereof.

[0074] According to various embodiments, the device includes three or more vascular architectures that are fluidly independent from each other and from the first and second vascular architectures.

[0075] According to various embodiments, the fluid static mixer includes a light absorbing agent. According to various embodiments, the fluid static mixer includes tartrazine. According to various embodiments, the fluid static mixer includes a fin element having a 180° twist. According to various embodiments, the fluid static mixer includes a fin element having a twist angle of 30°-180°, 40°-180°, 45°-180°, 50°-180°, 60°-180°, 65°-180°, 70°-180°, 75°-180°, 80°-180°, 85°-180°, 90°-180°, 120°-180°, or 150°-180° (including any range of twist angles therebetween). According to various embodiments, the fluid static mixer is manufactured by additive manufacturing.

[0076] According to various embodiments, the device further comprises a thickening agent to prevent cell sedimentation. According to various embodiments, the thickening agent comprises xanthan gum having a concentration of about 0.02% to about 2%, about 0.03% to about 1.5%, about 0.04% to about 1.0%, or about 0.05% to about 0.5% by weight (including any thickening agent value therebetween).

[0077] According to various aspects, a prepolymerized solution is provided. According to various aspects, the prepolymerized solution includes a photosensitive polymer and a light absorber additive suitable for controlling the transmission of light, the additive being at least partially removable from a solid formed from the prepolymerized solution. According to various aspects, the photosensitive polymer is a polymer that can be polymerized by a photosensitive reaction. According to various aspects, the light absorber can include a light absorber covalently or non-covalently bound to the polymer. According to various aspects, the prepolymerized solution can also include a photoinitiator. According to various aspects, the photoinitiator can be covalently or non-covalently bound to the polymer.

[0078] According to various embodiments, the prepolymerized solution can include a thickening agent to prevent cell sedimentation. According to various embodiments, the thickening agent includes xanthan gum having a concentration of about 0.02% to about 2% by weight, about 0.03% to about 1.5% by weight, about 0.04% to about 1.0% by weight, or about 0.05% to about 0.5% by weight (including any thickening agent value therebetween).

[0079] According to various embodiments, the prepolymerization solution comprises a pH of from about 1 to about 10, from about 1.5 to about 9.8, from about 2.5 to about 9.5, from about 3.5 to about 9.3, from about 4.5 to about 9, from about 5.5 to about 8.8, from about 6 to about 8.6, or from about 6.5 to about 8.5 (including any pH value therebetween).

[0080] According to various embodiments, the photosensitive polymer can include polyethylene glycol diacrylate, gelatin methacrylate, collagen methacrylate, silk methsylate, hyaluronic acid methacrylate, chondroitin sulfate methacrylate, elastin methacrylate, cellulose acrylate, dextran methacrylate, heparin methacrylate, NIPAAm methacrylate, chitosan methacrylate, polyethylene glycol norbornene, polyethylene glycol dithiol, thiolated gelatin, thiolated chitosan, thiolated silk, PEG-based peptide conjugates, or any combination thereof.

[0081] According to various embodiments, the range of polymer in the prepolymerization solution can be about 5% to about 30% by weight, about 10% to about 25% by weight, or about 15% to about 20% by weight (including any range therebetween). According to various embodiments, the range of light absorber in the prepolymerization solution can include concentrations of about 0.1 mM to about 100 mM, about 0.2 mM to about 90 mM, about 0.3 mM to about 80 mM, about 0.4 mM to about 70 mM, about 0.5 mM to about 60 mM, about 0.6 mM to about 50 mM, about 0.7 mM to about 40 mM, about 0.8 mM to about 30 mM, about 0.9 mM to about 20 mM, about 1.0 mM to about 10 mM (including any concentration range therebetween). According to various embodiments, the photoinitiator can include a concentration of about 5 mM to about 50 mM, about 6 mM to about 40 mM, about 7 mM to about 30 mM, about 8 mM to about 20 mM, about 9 mM to about 30 mM, about 10 mM to about 50 mM (including any concentration range therebetween).

[0082] According to various embodiments, the prepolymerization solution includes plant cells, bacterial cells, or mammalian cells. According to various embodiments, the range of cells is from 1×10 per milliliter for mammalian and plant cells. 6 ~200×10 6 According to various embodiments, the range of cells is from 1×10 per milliliter for mammalian and plant cells. 7 ~1×10 8 According to various embodiments, the range of cells can include up to 1×10 per milliliter for bacteria and other archaea, e.g., fungi. 3 ~1×10 11 According to various embodiments, the range of cells can include 1×10 for bacteria and other archaea, e.g., fungi. 8 ~1×10 11 It may include pieces.

[0083] According to various embodiments, the light absorber additive is biocompatible. According to various embodiments, the light absorber additive is hydrophilic. According to various embodiments, the light absorber additive is one of food color, tartrazine, Sunset Yellow FCF (Yellow No. 6), Brilliant Blue FCF (FD&C Blue No. 1), Indigo Carmine (FD&C Blue No. 2), Fast Green FCF (FD&C Green No. 3), anthocyanin, anthocyanidin, erythrosine (FD&C Red No. 3), Allura Red AC (FD&C Red No. 40), riboflavin (vitamin B2, E101, E101a, E106), ascorbic acid (vitamin C), quinoline yellow WS, carmoisine (azorubine), Ponceau 4R (E124), patent blue V (E131), green S (E142), yellow 2G (E107), orange GGN (E111), red 2G (E128), caramel color, phenol red, methyl orange, 4-nitrophenol, and NADH disodium salt.

[0084] According to various embodiments, the light absorber additive is hydrophobic. According to various embodiments, the light absorber additive is one of curcumin (E100), turmeric, alpha carotene, beta carotene, canthaxanthin (ketocarotenoid), cochineal extract, paprika, saffron, ergocalciferol (vitamin D2), cholecalciferol (vitamin D3), citrus red 2, annatto extract, and lycopene. According to various embodiments, the hydrophobic light absorber additive can include a solvent. The solvent can be selected from the group consisting of dimethyl sulfoxide, ethanol (50-100%), isopropyl alcohol, (50-100%) dimethylformamide, N-methyl-2-pyrrolidone, tetrahydrofuran, chloroform, methylene chloride, toluene, hexafluoro-2-propanol, and any combination thereof.

[0085] According to various embodiments, a method for processor-based fabrication of a 3D hydrogel construct is provided. According to various embodiments, the method includes the steps of: creating a 3D model of the construct based on a tessellation of a polyhedron with some faces connected by edges and vertices; removing faces and / or vertices of the polyhedron and using the remaining topology as a vascular skeleton, and generating a first vascular component of the model by skinning this skeleton with a polygon mesh and then smoothing the result to create cylindrical channels along the edges of the model with intervascular junctions located at each vertex location; generating a second vascular component of the model by scaling the faces of the 3D model along local surface normals to fit the second vascular component within the first vascular component, forming independent fluid connections to the first vascular component and the second vascular component, and performing a Boolean subtraction from the solid volume; and combining the two vascular components of the model.

[0086] According to various embodiments, the method also includes fabricating the hydrogel alveolar construct by radially symmetrically fusing the multiple spheres to create an airway topology; offsetting the airway topology to generate a vascular surface topology; tessellating, skeletonizing, and skinning the vascular surface topology to create a Voronoi vascular topology (tessellation includes performing tessellation of polyhedra); and performing a Boolean subtraction of the original airway and tessellated Voronoi vascular topology from the solid volume to generate a final 3D model for additive manufacturing. According to various embodiments, the method further includes providing heat as the 3D additive manufacturing machine generates the 3D model.

[0087] According to various aspects, the tessellation of the polyhedron is a Weir-Phelan space-filling form model of two dodecahedral cells and six tetradecahedral cells.

[0088] According to various embodiments, a method for manufacturing a hydrogel matrix construct is provided. According to various embodiments, the method includes using design software to create a 3D model of the hydrogel matrix construct, the 3D model of the hydrogel matrix construct includes a first computational algorithm that generates a first tubular channel network in the hydrogel matrix construct and a second computational algorithm that is different from the first computational algorithm that generates a second tubular channel network in the hydrogel matrix, the first and second tubular channel networks being two independent intertwined vascular networks; converting the 3D model into a format suitable for use in 3D additive manufacturing software to generate a formatted 3D model that is generated using a 3D additive manufacturing machine; and instructing the additive manufacturing machine to generate the model.

[0089] According to various aspects, the first computational algorithm is a tessellation of a polyhedron. According to various aspects, the first computational algorithm is a torus and the second algorithm is a torus knot.

[0090] According to various embodiments, the method also includes providing a pre-polymerized solution including a light absorber to the 3D additive manufacturing machine. According to various embodiments, the pre-polymerized solution includes one or more types of bacterial cells, mammalian cells, and plant cells.

[0091] According to various embodiments, the method includes lining the first tubular channel network or the second tubular channel network with cells. According to various embodiments, the method includes embedding the cells in a hydrogel matrix. According to various embodiments, the cells are one or more of liver, lung, bone, endothelial, cardiac, pancreatic, renal, epithelial, muscle, cartilage, stem cell, skin or eye cells. According to various embodiments, the range of cells is from 1×10 per milliliter for mammalian cells. 6 ~200×10 6According to various embodiments, the range of cells can be from 1×10 per milliliter for mammalian cells. 7 ~1×10 8 It may include pieces.

[0092] According to various embodiments, the method includes providing heat as the 3D additive manufacturing machine generates the 3D model. According to various embodiments, the heat is applied via a silicone heater, a heat lamp, or an infrared LED. According to various embodiments, the range of temperatures from the heating can include about 27°C to about 100°C, about 28°C to about 95°C, about 29°C to about 90°C, about 30°C to about 85°C, about 31°C to about 80°C, about 32°C to about 75°C, about 33°C to about 70°C, about 34°C to about 65°C, or about 35°C to about 60°C (including any temperature or temperature range therebetween). According to various embodiments, the method includes enclosing the 3D model in a heated enclosure during generation of the 3D model.

[0093] According to various embodiments, a method of fabricating a 3D hydrogel construct is provided. According to various embodiments, the method includes the steps of: using a computer-implemented process to create a 3D model of the construct based on a tessellation of a polyhedron having several faces connected by edges and vertices; generating a first vascular component of the model; generating a second vascular component of the model; and combining the first and second vascular components of the model.

[0094] According to various aspects, generating a first vascular component of the model using a computer-implemented process includes removing faces of the polyhedron and using the remaining vertices and edges of the topology as a vascular skeleton.

[0095] According to various aspects, generating a first vascular component of the model using a computer-implemented process further includes skinning the skeleton with a polygon mesh and then smoothing the result to create cylindrical channels along the edges of the model with inter-vascular junctions located at each vertex location.

[0096] Generating a second vascular component of the model using a computer-implemented process includes scaling faces of the 3D model along local surface normals to fit the second vascular component within the first vascular component, forming independent fluid connections to the first vascular component and the second vascular component, and performing a Boolean subtraction from the solid volume.

[0097] According to various aspects, the method further includes constructing a hydrogel alveolar structure by radially symmetrically fusing a plurality of spheres to create an airway topology; offsetting the airway topology to generate a vascular surface topology; and tessellating, skeletonizing, and skinning the vascular surface topology to create a Voronoi vascular topology (wherein tessellating includes performing tessellation of a polyhedron).

[0098] According to various aspects, the method includes performing a Boolean subtraction of the original airway and tessellated Voronoi vascular topology from the solid volume to generate a final 3D model for additive manufacturing. According to various aspects, the polyhedral tessellation is a Weir-Phelan space-filling form model of two dodecahedral cells and six tetradecahedral cells.

[0099] According to various embodiments, a method of treating a subject in need of treatment includes implanting any of the devices in the subject.

[0100] According to various aspects, a device is provided that includes a plurality of joined subunits, each of the subunits including a device as disclosed herein.

[0101] According to various embodiments, an apparatus for manufacturing a hydrogel matrix construct is provided. The apparatus can include a frame, a stage with a z-axis drive motor attached to the frame, an electronics board for controlling the movement of the stage relative to the frame, a container configured to hold a solution, a projector for projecting an image that is an image slice of a 3D model of the hydrogel matrix construct, and a build platform configured to hold a substrate on which the hydrogel matrix construct is formed. According to various embodiments, an optional 45° mirror can be configured to reflect the image projected from the projector into the container.

[0102] According to various embodiments, the substrate can include compositions having organic or inorganic glass with or without a textured surface that is inert or functionalized with tether groups. According to various embodiments, the tether groups can covalently or non-covalently assist in the attachment of the hydrogel to the substrate, e.g., 3-(trimethoxysilyl)propyl methacrylate. According to various embodiments, the substrate composition can also include mica, polycarbonate, polysulfone, polymethylmethacrylate, polystyrene, cyclic olefin copolymer, polyethylene, polypropylene, or quartz, with or without a textured surface that can be optionally modified with tether groups that can covalently or non-covalently assist in the attachment of the hydrogel to the substrate. According to various embodiments, all of these various components can be provided as part of a single device (as illustrated in FIG. 18 described herein and described in detail below). However, these various components can also be provided in various other configurations in which any one or more components are provided as part of an additional sub-device that interacts with the main device to provide essentially the same functionality together as the embodiment in which all components are provided within a single device. Furthermore, it should not be assumed that all of the components described are necessary for the correct functionality of the apparatus for producing hydrogel matrix constructs, and therefore various embodiments may include only a portion of the components provided above.

[0103] According to various aspects, the solution can be a pre-polymerized solution including a photosensitive polymer and a light absorber additive suitable for controlling the transmission of light. The additive can be removable from the solid formed from the pre-polymerized solution. The light absorber additive can be biocompatible. The light absorber additive can be hydrophilic. The light absorber additive can be hydrophobic.

[0104] According to various embodiments, the light absorber additive may be food coloring, tartrazine, Sunset Yellow FCF (Yellow No. 6), Brilliant Blue FCF (FD&C Blue No. 1), Indigo Carmine (FD&C Blue No. 2), Fast Green FCF (FD&C Green No. 3), anthocyanins, anthocyanidins, erythrosine (FD&C Red No. 3), Allura Red AC (FD&C Red No. 40), riboflavin (vitamins B2, E101, E102, E103, E104, E105, E106, E107, E108, E109, E1101, E111, E112, E113, E114, E115, E116, E117, E118, E120, E121, E122, E123, E124, E1 1a, E106), ascorbic acid (vitamin C), quinoline yellow WS, carmoisine (azorubine), ponceau 4R (E124), patent blue V (E131), green S (E142), yellow 2G (E107), orange GGN (E111), red 2G (E128), caramel color, phenol red, methyl orange, 4-nitrophenol, and NADH disodium salt.

[0105] According to various embodiments, the hydrophobic light absorber can include a solvent, which can be selected from the group consisting of dimethylsulfoxide, ethanol (50-100%), isopropyl alcohol, dimethylformamide (50-100%), N-methyl-2-pyrrolidone, tetrahydrofuran, chloroform, methylene chloride, toluene, hexafluoro-2-propanol, and any combination thereof.

[0106] According to various embodiments, the light absorber additive can be one of curcumin (E100), turmeric, alpha carotene, beta carotene, canthaxanthin (a ketocarotenoid), cochineal extract, paprika, saffron, ergocalciferol (vitamin D2), cholecalciferol (vitamin D3), citrus red 2, annatto extract, and lycopene.

[0107] According to various embodiments, the device may further comprise a plant cell, a bacterial cell, or a mammalian cell. The device may further comprise one or more of liver, lung, bone, endothelial, cardiac, pancreatic, kidney, epithelial, muscle, cartilage, stem cell, skin, or eye cells.

[0108] 18, a schematic diagram of an exemplary apparatus 100 for fabricating hydrogel constructs according to various embodiments is provided. The apparatus 100 can include, for example, a frame 110, a stage 120, an electronics board 130, a container 140, a projector 160, an optional mirror 170, and a build platform 180. The stage 120 can be mounted to the frame 110 and can include a motor mounted to the frame 110. The motor can be a z-axis drive motor. The electronics board 130 can be configured to control the movement of the stage relative to the frame. The projector 160 can be configured to project an image. The image can be an image slice of a 3D model of a hydrogel matrix construct. The mirror 170 can be a 45° mirror. The mirror 170 can be configured to reflect the image projected from the projector 160 into the container 140. Note that optional mirror 170 can be omitted from the apparatus if the lens on the projector is already at an angle that does not require a mirror, for example, if the projector projects an image directly onto the desired surface. Build platform 180 can be configured to hold a substrate 190 upon which a hydrogel matrix construct can be formed. Substrate 190 can be incorporated into apparatus 100 or can be an entirely separate component of the apparatus and therefore not considered part of the apparatus.

[0109] The container 140 can be configured to receive the solution 150. As mentioned above, the solution 150 can be a pre-polymerized solution that includes a photopolymer and a light absorber additive suitable for controlling the transmission of light.

[0110] Referring again to the example apparatus 800 of FIG. 8B above, the apparatus 800 can include a motor 810 (which can be mounted to a frame 840) controlled by an actuator 815 to which a build platform 820 is attached. The back of the printer can house a motherboard 825 that controls the motor and provides input and output via any additional sensors or switches. The front of the printer includes an optional mirror 830 positioned to reflect an incoming pattern from a projector 835 onto a plate containing photosensitive material. Note that the optional mirror 830 can be omitted from the apparatus if the lens on the projector is already at an angle that does not require a mirror, for example if the projector projects an image directly onto the desired surface.

[0111] According to various embodiments, the various device embodiments can be incorporated as part of a system. An exemplary system 200 for producing a hydrogel matrix construct is shown in Figure 19 and described in further detail below.

[0112] The system for manufacturing a hydrogel matrix construct can include a processor. The processor can include a modeling engine. The modeling engine can be configured to create a 3D model of the hydrogel matrix construct based on a tessellation of a polyhedron having some number of faces connected by edges and vertices. The modeling engine can be configured to generate a first vascular component of the model. The modeling engine can be configured to generate a second vascular component of the model. The modeling engine can be configured to combine the first and second vascular components of the model.

[0113] The system may further include an apparatus configured to manufacture the hydrogel matrix construct. The apparatus may include a frame, a stage with a z-axis drive motor attached to the frame, an electronics board for controlling the movement of the stage relative to the frame, a container configured to hold the solution, a projector for projecting an image that is an image slice of a 3D model of the hydrogel matrix construct, an optional 45° mirror for reflecting the image projected from the projector into the container, and a build platform configured to hold a substrate on which the hydrogel matrix construct is formed. Note that the optional 45° mirror may be omitted from the apparatus if the lens on the projector is already at an angle that does not require a mirror, for example, if the projector projects an image directly onto the desired surface. According to various embodiments, all of these various components may be provided as part of a single device. However, these various components may also be provided in various other configurations where any one or more components are provided as part of additional sub-devices that interact with the main device to provide essentially the same functionality together as the embodiments in which all components are provided within a single device. Furthermore, it should not be assumed that all of the components described are necessary for the correct functionality of the apparatus for producing hydrogel matrix constructs, and therefore various embodiments may include only a portion of the components provided above.

[0114] According to various aspects, the solution can be a pre-polymerized solution including a photosensitive polymer and a light absorber additive suitable for controlling the transmission of light. The additive can be removable from the solid formed from the pre-polymerized solution. The light absorber additive can be biocompatible. The light absorber additive can be hydrophilic. The light absorber additive can be hydrophobic.

[0115] According to various embodiments, the hydrophobic light absorber additive can include a solvent, which can be selected from the group consisting of dimethylsulfoxide, ethanol (50-100%), isopropyl alcohol, dimethylformamide (50-100%), N-methyl-2-pyrrolidone, tetrahydrofuran, chloroform, methylene chloride, toluene, hexafluoro-2-propanol, and any combination thereof.

[0116] According to various embodiments, the solution can include a thickening agent to prevent cell sedimentation. According to various embodiments, the thickening agent includes xanthan gum having a concentration of about 0.02% to about 2%, about 0.03% to about 1.5%, about 0.04% to about 1.0%, or about 0.05% to about 0.5% by weight (including any thickening agent value therebetween).

[0117] According to various embodiments, the light absorber additive may be food coloring, tartrazine, Sunset Yellow FCF (Yellow No. 6), Brilliant Blue FCF (FD&C Blue No. 1), Indigo Carmine (FD&C Blue No. 2), Fast Green FCF (FD&C Green No. 3), anthocyanins, anthocyanidins, erythrosine (FD&C Red No. 3), Allura Red AC (FD&C Red No. 40), riboflavin (vitamins B2, E101, E102, E103, E104, E105, E106, E107, E108, E109, E1101, E111, E112, E113, E114, E115, E116, E117, E118, E120, E121, E122, E123, E124, E1 1a, E106), ascorbic acid (vitamin C), quinoline yellow WS, carmoisine (azorubine), ponceau 4R (E124), patent blue V (E131), green S (E142), yellow 2G (E107), orange GGN (E111), red 2G (E128), caramel color, phenol red, methyl orange, 4-nitrophenol, and NADH disodium salt.

[0118] According to various embodiments, the light absorber additive can be one of curcumin (E100), turmeric, alpha carotene, beta carotene, canthaxanthin (a ketocarotenoid), cochineal extract, paprika, saffron, ergocalciferol (vitamin D2), cholecalciferol (vitamin D3), citrus red 2, annatto extract, and lycopene.

[0119] According to various embodiments, the device may further comprise a plant cell, a bacterial cell, or a mammalian cell. The device may further comprise one or more of liver, lung, bone, endothelial, cardiac, pancreatic, kidney, epithelial, muscle, cartilage, stem cell, skin, or eye cells.

[0120] According to various aspects, generating a first vascular component of the model can include removing faces and / or vertices of a polyhedron and using the remaining topology as a vascular skeleton. Generating a first vascular component of the model can further include skinning this skeleton with a polygon mesh and then smoothing the result to create cylindrical channels along the edges of the model with inter-vascular junctions located at each vertex location.

[0121] According to various embodiments, generating a second vascular component of the model can include scaling faces of the 3D model along local surface normals to fit the airways within the vascular component, forming independent fluid connections to the vasculature and airways, and performing a Boolean subtraction from the solid volume.

[0122] According to various aspects, the processor can be further configured to fabricate the hydrogel alveolar construct. The processor can fabricate the hydrogel alveolar construct by radially symmetrically fusing a plurality of spheres to create an airway topology and offsetting the airway topology to generate a vascular surface topology. The fabrication of the hydrogel alveolar construct can further include tessellating, skeletonizing, and skinning the vascular surface topology to create a Voronoi vascular topology. The tessellation can include performing a tessellation of a polyhedron. The tessellation of the polyhedron can be a Weir-Phelan space-filling form model of two dodecahedral cells and six tetradecahedral cells. The fabrication of the hydrogel alveolar construct can further include performing a Boolean subtraction of the original airway and tessellated Voronoi vascular topology from a solid volume to generate a final 3D model for additive manufacturing.

[0123] Referring now to Figure 19, a schematic diagram of an exemplary system 200 for fabricating hydrogel constructs, according to various embodiments, is provided. The system 200 can include an apparatus and a processor. The exemplary apparatus shown in Figure 19 is the apparatus 100 shown in Figure 18. See above for a detailed description of the apparatus 100 of Figure 18. The processor 220 can include a modeling engine 250.

[0124] The processor 220 can be communicatively connected to the device 100. In various aspects, the processor 220 can be communicatively connected to the device 100 via a network connection, which can be either a "hardwired" physical network connection (e.g., Internet, LAN, WAN, VPN, etc.) or a wireless network connection (e.g., Wi-Fi, WLAN, etc.). In various aspects, the processor 220 can be part of a workstation, a mainframe computer, a distributed computing node (part of a "cloud computing" or distributed networking system), a personal computer, a mobile device, etc.

[0125] In accordance with various aspects, the processor 220 and the apparatus 100 can be part of an integrated apparatus. As such, in FIG. 19, the processor 220 can be provided within the apparatus 100. Alternatively, the processor 220 can be hosted by a different device than the apparatus 100. Moreover, the processor 220 can be part of a distributed network system.

[0126] As discussed above, according to various embodiments, build platform 180 can be configured to hold a substrate 190 upon which a hydrogel matrix construct can be formed. Substrate 190 can be integrated into device 100 or can be an entirely separate component of the device and therefore not considered part of the device.

[0127] As discussed above, according to various embodiments, container 140 can be configured to receive solution 150. As discussed above, solution 150 can be a pre-polymerized solution that includes a photopolymer and a light absorber additive suitable for controlling the transmission of light.

[0128] As described above, according to various embodiments, the modeling engine 250 can be configured to create a 3D model of the hydrogel matrix construct based on a tessellation of polyhedra having some number of faces connected by edges and vertices. The modeling engine can be configured to generate a first vascular component of the model. The modeling engine can be configured to generate a second vascular component of the model. The modeling engine can be configured to combine the first and second vascular components of the model.

[0129] It should be appreciated that, according to various aspects, modeling engine 250 can be configured to handle all of the necessary steps accomplished within processor 220. This is exemplified by the example processor 220 and associated modeling engine 250 of FIG.

[0130] Further, according to various embodiments, the functions and steps described in connection with modeling engine 250 can be divided into any number of separate engines or modules within processor 220. For example, the steps of creating the 3D model, generating the first and second vascular components of the model, and combining the vascular components can each be accomplished by a separate engine (e.g., a creation engine, a generation engine, and a combination engine) and / or by a separate processor including one or more separate engines. Moreover, at least a portion of these steps can also be combined into a single engine (e.g., a component engine providing the generation and combination steps).

[0131] 20 is a flow chart of an exemplary method S100 of fabricating a 3D hydrogel construct, according to various embodiments. As shown in FIG. 20, the method S100 includes, at step S110, creating a 3D model of the construct based on a tessellation of a polyhedron having some number of faces connected by edges and vertices. The method S100 also includes, at step S120, generating a first vascular component of the model. According to various embodiments herein, generating the first vascular component of the model includes removing the faces and / or vertices of the polyhedron and using the remaining topology as a vascular skeleton, and skinning the skeleton with a polygon mesh and then smoothing the result to create cylindrical channels along the edges of the model with intervascular junctions located at each vertex location.

[0132] Method S100 further includes generating a second vascular component of the model at step S130. According to various aspects, generating the second vascular component of the model includes scaling faces of the 3D model along local surface normals to fit the second vascular component within the first vascular component, forming independent fluid connections to the first vascular component and the second vascular component, and performing a Boolean subtraction from the solid volume.

[0133] As shown in FIG. 20, the method S100 includes, at step S140, matching first and second vascular components of the model.

[0134] According to various embodiments, the method S100 optionally includes, at step S150, fabricating the hydrogel alveolar construct. According to various embodiments, fabricating the hydrogel alveolar construct includes radially symmetrically fusing a plurality of spheres to create an airway topology, offsetting the airway topology to generate a vascular surface topology, tessellating, skeletonizing, and skinning the vascular surface topology to create a Voronoi vascular topology (wherein the tessellation includes performing a tessellation of a polyhedron), and performing a Boolean subtraction of the original airway and tessellated Voronoi vascular topology from a solid volume to generate a final 3D model for additive manufacturing. According to various embodiments, the tessellation of the polyhedron is a Weir-Phelan space-filling foam model of two dodecahedral cells and six tetradecahedral cells.

[0135] 21 is a flow chart of an exemplary method S200 of manufacturing a hydrogel matrix construct according to various embodiments. As shown in FIG. 21, the method S200 includes, at step 210, creating a 3D model of the hydrogel matrix construct using design software. According to various embodiments, the 3D model of the hydrogel matrix construct includes a first computational algorithm that generates a first tubular channel network in the hydrogel matrix construct and a second computational algorithm, different from the first computational algorithm, that generates a second tubular channel network in the hydrogel matrix, the first and second tubular channel networks being two independent intertwined vascular networks.

[0136] At step S220, the method S200 includes converting the 3D model into a format suitable for use in 3D additive manufacturing software to produce a formatted 3D model that is generated using a 3D additive manufacturing machine. The method S200 further includes, at step S230, instructing the additive manufacturing machine to generate the model.

[0137] According to various aspects, the first computational algorithm is a tessellation of a polyhedron. According to various aspects, the first computational algorithm is a torus and the second algorithm is a torus knot.

[0138] 21, the method S200 optionally includes, at step S240, providing a pre-polymerized solution including a light absorber to the 3D additive manufacturing machine. According to various embodiments, the pre-polymerized solution includes one or more types of bacterial cells, mammalian cells, and plant cells.

[0139] The method S200 further optionally includes, at step S250, lining the first tubular channel network or the second tubular channel network with cells.

[0140] At step S260, method S200 optionally includes embedding cells in the hydrogel matrix. According to various embodiments, the cells are one or more of liver, lung, bone, endothelial, cardiac, pancreatic, renal, epithelial, muscle, cartilage, stem cells, skin, or eye cells.

[0141] The method S200 further optionally includes, in step S270, providing heat as the 3D additive manufacturing machine generates the 3D model. According to various embodiments, the heat is applied via a silicone heater, a heat lamp, or an infrared LED.

[0142] The method S200 optionally includes, at step S280, enclosing the 3D model in a heated enclosure during generation of the 3D model.

[0143] FIG. 22 is a flow chart of an exemplary method S300 of fabricating a 3D hydrogel construct, according to various embodiments. As shown in FIG. 22, the method S300 includes, at step S310, using a computer-implemented process to create a 3D model of the construct based on a tessellation of polyhedra having several faces connected by edges and vertices. At step S320, the method S300 includes using a computer-implemented process to generate a first vascular component of the model. The method S300 further includes, at step S330, using a computer-implemented process to generate a second vascular component of the model. The method S300 includes, at step S340, mating the first and second vascular components of the model.

[0144] As shown in FIG. 22, method S300 further includes, in step S350, generating a first vascular component of the model using a computer-implemented process by removing faces of the polyhedron and using the remaining vertices and edges of the topology as a vascular skeleton.

[0145] Method S300 optionally includes, at step S360, generating a first vascular component of the model by using a computer-implemented process to skin the skeleton with a polygon mesh and then smooth the result to create cylindrical channels along the edges of the model with inter-vascular junctions located at each vertex location.

[0146] Method S300 optionally includes, at step S370, generating a second vascular component of the model using a computer-implemented process by scaling faces of the 3D model along local surface normals to fit the second vascular component within the first vascular component, forming independent fluid connections to the first vascular component and the second vascular component, and performing a Boolean subtraction from the solid volume.

[0147] As shown in FIG. 22, the method S300 further includes, in step S380, fabricating the hydrogel alveolar construct by radially symmetrically fusing a plurality of spheres to create an airway topology, offsetting the airway topology to generate a vascular surface topology, and tessellating, skeletonizing, and skinning the vascular surface topology to create a Voronoi vascular topology (wherein tessellating includes performing tessellation of polyhedra).

[0148] Method S300 optionally includes performing a Boolean subtraction of the original airway and tessellated Voronoi vascular topology from the solid volume to generate a final 3D model for additive manufacturing at step S390. According to various aspects, the polyhedral tessellation is a Weir-Phelan space-filling form model of two dodecahedral cells and six tetradecahedral cells.

[0149] According to various embodiments, a non-transitory computer readable medium is provided having a program stored thereon for causing a computer to execute a method for fabricating a 3D hydrogel construct. According to various embodiments, the method includes creating a 3D model of the construct based on a tessellation of a polyhedron having several faces connected by edges and vertices. According to various embodiments, the method includes generating a first vascular component of the model, generating a second vascular component of the model, and mating the first and second vascular components of the model. According to various embodiments, the method includes generating the first vascular component of the model by removing faces and / or vertices of the polyhedron and using the remaining topology as a vascular skeleton. According to various embodiments, the method includes generating the first vascular component of the model by skinning the skeleton with a polygon mesh and then smoothing the result to create cylindrical channels along the edges of the model with intervascular junctions located at each vertex location.

[0150] According to various aspects, the method includes generating an airway component of the model by scaling faces of the 3D model along local surface normals to fit the airway within the vasculature (blood vessel) component, forming independent fluid connections to the vasculature and airway, and performing a Boolean subtraction from the solid volume. According to various aspects, the method includes fabricating the hydrogel alveolar construct by radially symmetrically fusing a plurality of spheres to create an airway topology, offsetting the airway topology to generate a vascular surface topology, tessellating, skeletonizing, and skinning the vascular surface topology to create a Voronoi vascular topology (wherein the tessellating includes performing a tessellation of a polyhedron), and performing a Boolean subtraction of the original airway and tessellated Voronoi vascular topology from the solid volume to generate a final 3D model for additive manufacturing. According to various aspects, the tessellation of the polyhedron is a Weir-Phelan space-filling form model of two dodecahedral cells and six tetradecahedral cells.

[0151] 23 is a block diagram illustrating various aspects of a computer system 300 that can be implemented to perform various aspects described herein, including, for example, various non-transitory computer-readable media having stored thereon programs for causing a computer to perform various methods herein. In various aspects, the computer system 300 can be a workstation, a mainframe computer, a distributed computing node (part of a "cloud computing" or distributed networking system), a personal computer, a mobile device, etc.

[0152] According to various aspects, computer system 300 may include a bus 302 or other communication mechanism for communicating information, and a processor 304 coupled with bus 302 for processing information. In various aspects, computer system 300 may also include memory, which may be a random access memory (RAM) 306 or other dynamic storage device, coupled to bus 302 for determining instructions to be executed by processor 304. The memory may also be used to store temporary variables or other intermediate information during execution of instructions to be executed by processor 304. In various aspects, computer system 300 may further include a read-only memory (ROM) 308 or other static storage device coupled to bus 302 for storing static information and instructions for processor 304. A storage device 310, such as a magnetic disk or optical disk, may be provided and coupled to bus 302 for storing information and instructions.

[0153] In various embodiments, the computer system 300 can be coupled via bus 302 to a display device 312, such as a cathode ray tube (CRT) or liquid crystal display (LCD), for displaying information to a computer user. An input device 314, including alphanumeric and other keys, can be coupled to bus 302 for sending information and command selections to the processor 304. Another type of user input device is a cursor control device 316, such as a mouse, trackball or cursor direction keys, for sending instructional information and command selections to the processor 304 and for controlling cursor movement on the display device 312. This input device 314 typically has two degrees of freedom in two axes, a first axis (i.e., x) and a second axis (i.e., y), that allow the device to specify a position on a plane. However, it should be understood that input devices 314 for allowing three-dimensional (x, y and z) cursor movement are also contemplated herein.

[0154] Consistent with certain embodiments of the present teachings, results may be provided by computer system 300 in response to processor 304 executing one or more sequences of one or more instructions contained in memory 306. Such instructions may be read into memory 306 from another computer-readable medium or computer-readable storage medium, such as storage device 310. Execution of the sequences of instructions contained in memory 306 may cause processor 304 to perform the processes described herein. Alternatively, hardwired circuitry may be used in place of or in combination with software instructions to implement the present teachings. Thus, embodiments of the present teachings are not limited to any specific combination of hardware circuitry and software.

[0155] As used herein, the term "computer-readable medium" (e.g., data store, data storage, etc.) or "computer-readable storage medium" refers to any medium that participates in providing instructions to the processor 304 for execution. Such media may take many forms, including non-volatile media, volatile media, and transmission media. Examples of non-volatile media may include, but are not limited to, optical disks, solid-state disks, and magnetic disks, such as the storage device 310. Examples of volatile media may include, but are not limited to, dynamic memory, such as the memory 306. Examples of transmission media may include, but are not limited to, coaxial cables, copper wire and fiber optics, such as the wires that comprise the bus 302.

[0156] Common forms of computer readable media include, for example, floppy disks, flexible disks, hard disks, magnetic tape or any other magnetic medium, CD-ROMs, any other optical medium, punch cards, paper tape, any other physical medium with a pattern of holes, RAM, PROMs and EPROMs, FLASH-EPROMs, any other memory chip or cartridge or any other tangible medium from which a computer can read.

[0157] In addition to computer-readable media, instructions or data may also be provided as signals on a transmission medium included in a communication device or system to provide a sequence of one or more instructions to the processor 304 of the computer system 300 for execution. For example, a communication device may include a transceiver having signals indicative of instructions and data. The instructions and data are configured to cause one or more processors to implement the functions outlined in the disclosure herein. Representative examples of data communication transmission connections may include, but are not limited to, a telephone modem connection, a wide area network (WAN), a local area network (LAN), an infrared data connection, an NFC connection, and the like.

[0158] It should be understood that the methods described in this specification, the flowcharts, the drawings, and the accompanying disclosure can be implemented using computer system 300 as a stand-alone device or can be implemented on a distributed network of shared computer processing resources, such as a cloud computing network.

[0159] The methods described herein may be realized by various means depending on the application. For example, these methods may be implemented in hardware, firmware, software, or any combination thereof. In the case of hardware implementation, the processing unit may be implemented in one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, electronic devices, other electronic units designed to perform the functions described herein, or combinations thereof.

[0160] In various embodiments, the methods of the present teachings may be implemented as firmware and / or software programs and applications written in conventional programming languages ​​such as C, C++, Python, etc. When implemented as firmware and / or software, the embodiments described herein may be implemented on a non-transitory computer-readable medium having a program stored thereon for causing a computer to execute the methods. It should be understood that the various engines described herein may be provided on a computer system, such as computer system 300, such that processor 304 will perform the analysis and decisions provided by these engines according to instructions provided by any one or combination of memory components 306 / 308 / 310 and user input provided via input device 314.

[0161] Although the present specification contains many details of specific embodiments, these should not be construed as limitations on the scope of what can be claimed, but as descriptions of features that can be specific to a particular embodiment. Also, certain features described herein with respect to separate embodiments can be combined and realized in a single embodiment. Conversely, various features described with respect to a single embodiment can be realized in multiple embodiments separately or in any suitable subcombination. Moreover, the features may be described as acting in a particular combination and initially claimed as such, but one or more features from the claimed combination may be deleted from the combination in some cases, and the claimed combination may relate to a subcombination or a variation of the subcombination.

[0162] Particular embodiments of the subject matter have been described. As will be apparent to those skilled in the art, other embodiments, variations, and permutations of the described embodiments are within the scope of the following claims. Although operations are shown in a particular order in the drawings or claims, this should not be understood as requiring that such operations be performed in the particular order shown, or in the order in which they occur, to achieve desirable results, or that all of the operations shown be performed (some operations are considered optional). In certain situations, multitasking or parallel processing (or a combination of multitasking and parallel processing) may be advantageous and may also be performed as appropriate.

[0163] Accordingly, the exemplary embodiments do not define or constrain the present disclosure. Other changes, substitutions, and alterations are possible without departing from the spirit and scope of the present disclosure.

[0164] Furthermore, any claimed embodiment is believed to be applicable to a computer system including at least a computer-implemented method; a non-transitory computer-readable medium storing computer-readable instructions for performing the computer-implemented method; and a computer memory interoperably coupled with a hardware processor configured to execute the computer-implemented method or the instructions stored in the non-transitory computer-readable medium.

[0165] List of Aspects Aspect 1: a hydrogel matrix containing a photoabsorber; a void architecture in the matrix having a first vascular architecture and a second vascular architecture, which are tubular and branched, respectively; Including, the first and second vascular architectures being fluidly independent of each other; device. Aspect 2: The device of embodiment 1, wherein at least 90% of visible light incident on said device is transmitted through said device, allowing said device to be imaged. Aspect 3: The device of any preceding embodiment, wherein the light absorber has been at least partially washed from the device. Aspect 4: The device of any of the preceding embodiments, wherein the light absorber is degradable independently of any degradation of the remainder of the hydrogel matrix. Aspect 5: The device of any of the previous embodiments, wherein the light absorber is decomposable by chemical or physical processes. Aspect 6: The device of embodiment 5, wherein the light absorber is photobleachable or removable by boiling. Aspect 7: The device of any preceding embodiment, wherein the void architecture is a multi-vascular void architecture and further comprises a torus entangled with a torus knot. Aspect 8: The device of any preceding aspect, wherein one or both of the first vascular architecture and the second vascular architecture are formed from a model based on a tessellation of a polyhedron. Aspect 9: The device of embodiment 8, wherein a model based on a tessellation of polyhedra represents blood vessels. Aspect 10: The device of embodiment 8, wherein a model based on a tessellation of polyhedra represents the airways. Aspect 11: The device of any preceding embodiment, wherein the void architecture is a multi-vessel void architecture and further comprises a functional valve. Aspect 12: The device of embodiment 11, wherein the valve is a bicuspid valve, a tricuspid valve, a monocuspid valve, or a Tesla valve. Aspect 13: The device of any preceding aspect, wherein the void architecture is a multi-vessel void architecture and further comprises a fluid static mixer. Aspect 14: The device of embodiment 13, wherein the fluid static mixer has between 2 and 50 fin elements. Aspect 15: The device of embodiments 11-12, wherein the functional valve is positionable anywhere in the multi-vessel void architecture. Aspect 16: 20. The device of any preceding aspect, which is monolithic. Aspect 17: The device of any of the previous embodiments, wherein the hydrogel matrix is ​​a photopolymerized hydrogel matrix and / or a biodegradable hydrogel matrix. Aspect 18: 13. The device of any preceding aspect, wherein the device is manufactured by additive manufacturing. Aspect 19: The device of any preceding aspect, wherein the first vascular architecture and the second vascular architecture are intertwined. Aspect 20: The device of any preceding aspect, wherein the first vascular architecture is covered by a second vascular architecture. Aspect 21: The device of any of the previous embodiments, wherein the hydrogel matrix is ​​porous. Aspect 22: 20. The device of any preceding aspect, which is implantable. Aspect 23: The device of any of the previous embodiments, wherein the light absorber is hydrophilic. Aspect 24: 24. The device of embodiment 23, wherein the light absorber is one of food color, tartrazine, Sunset Yellow FCF (Yellow No. 6), Brilliant Blue FCF (FD&C Blue No. 1), Indigo Carmine (FD&C Blue No. 2), Fast Green FCF (FD&C Green No. 3) anthocyanin, anthocyanidin, erythrosine (FD&C Red No. 3), Allura Red AC (FD&C Red No. 40), riboflavin (vitamin B2, E101, E101a, E106), ascorbic acid (vitamin C), quinoline yellow WS, carmoisine (azorubine), Ponceau 4R (E124), patent blue V (E131), green S (E142), yellow 2G (E107), orange GGN (E111), red 2G (E128), caramel color, phenol red, methyl orange, 4-nitrophenol, and NADH disodium salt. Aspect 25: The device of any of the previous embodiments, wherein the light absorber is hydrophobic. Aspect 26: The device of embodiment 25, wherein the light absorber is one of curcumin (E100), turmeric, alpha carotene, beta carotene, canthaxanthin (a ketocarotenoid), cochineal extract, paprika, saffron, ergocalciferol (vitamin D2), cholecalciferol (vitamin D3), citrus red 2, annatto extract, and lycopene. Aspect 27: The device of any preceding embodiment, comprising three or more vascular architectures that are fluidly independent from each other and from the first and second vascular architectures. Aspect 28: With photosensitive polymer; A light absorber additive suitable for controlling light transmission; wherein the additive is at least partially removable from a solid formed from the prepolymerized solution. Aspect 29: 30. The pre-polymerized solution of embodiment 28, further comprising plant cells, bacterial cells, or mammalian cells. Aspect 30: 30. The prepolymerized solution of embodiment 28-29, wherein the light absorber additive is hydrophilic. Aspect 31: Light absorbing additives include food coloring, tartrazine, Sunset Yellow FCF (Yellow No. 6), Brilliant Blue FCF (FD&C Blue No. 1), Indigo Carmine (FD&C Blue No. 2), Fast Green FCF (FD&C Green No. 3), anthocyanins, anthocyanidins, erythrosine (FD&C Red No. 3), Allura Red AC (FD&C Red No. 40), riboflavin (vitamin B2, E101, E101a, E106), aspartame, glycerin, glyceryl stearate ... 31. The prepolymerization solution of embodiment 28-30, wherein the prepolymerization solution is one of: corbic acid (vitamin C), quinoline yellow WS, carmoisine (azorubine), ponceau 4R (E124), patent blue V (E131), green S (E142), yellow 2G (E107), orange GGN (E111), red 2G (E128), caramel color, phenol red, methyl orange, 4-nitrophenol, and NADH disodium salt. Aspect 32: 30. The prepolymerized solution of embodiment 28-29, wherein the light absorber additive is hydrophobic. Aspect 33: 33. The prepolymerized solution of embodiment 28, 29, or 32, wherein the light absorber additive is one of curcumin (E100), turmeric, alpha carotene, beta carotene, canthaxanthin (a ketocarotenoid), cochineal extract, paprika, saffron, ergocalciferol (vitamin D2), cholecalciferol (vitamin D3), citrus red 2, annatto extract, and lycopene. Aspect 34: creating a 3D model of the construction based on a tessellation of polyhedra having several faces connected by edges and vertices; removing the faces and / or the vertices of the polyhedron and using the remaining topology as a vessel skeleton; and skinning the skeleton with a polygon mesh and then smoothing the result to create cylindrical channels along the edges of the model with inter-vessel junctions located at each vertex location; generating a first vascular component of the model by: scaling the surface of the 3D model along a local surface normal to fit a second vessel component within the first vessel component; forming independent fluid connections to the first vascular component and the second vascular component; Performing a Boolean subtraction from a solid volume generating a second vascular component of the model by: combining the two vascular components of the model. A method for fabricating a 3D hydrogel construct by a processor, comprising: Aspect 35: radially symmetrically fusing multiple spheres to create a second vascular topology; offsetting the second vascular topology to generate a vascular surface topology; tessellating, skeletonizing, and skinning the vascular surface topology to create a Voronoi vascular topology, where tessellating includes performing a tessellation of a polyhedron; and performing a Boolean subtraction of the second vascular topology and the tessellated Voronoi vascular topology from a solid volume to generate a final 3D model for additive manufacturing. The method of embodiment 34, comprising fabricating a hydrogel alveolar construct by: Aspect 36: 36. The method of claim 34, wherein the tessellation of the polyhedron is a Weir-Phelan space-filling form model of two dodecahedral cells and six tetradecahedral cells. Aspect 37: creating a 3D model of a hydrogel matrix construct using design software, the 3D model of the hydrogel matrix construct comprising a first computational algorithm that generates a first tubular channel network in the hydrogel matrix construct and a second computational algorithm, different from the first computational algorithm, that generates a second tubular channel network in the hydrogel matrix, the first and second tubular channel networks being two independent intertwined vascular networks; Converting the 3D model into a format suitable for use in 3D additive manufacturing software to produce a formatted 3D model that is generated using a 3D additive manufacturing machine; and commanding an additive manufacturing machine to generate the model. A method for producing a hydrogel matrix construct, comprising: Aspect 38: 38. The method of embodiment 37, wherein the first computational algorithm is a tessellation of a polyhedron. Aspect 39: The method of any one of embodiments 37 to 38, wherein the first computational algorithm is a torus and the second algorithm is a torus knot. Aspect 40: 40. The method of any of embodiments 37-39, comprising providing a pre-polymerized solution comprising a light absorber to a 3D additive manufacturing machine. Aspect 41: The method of embodiment 40, wherein the prepolymerization solution comprises one or more types of bacterial cells, mammalian cells, and plant cells. Aspect 42: The method of any of embodiments 37-41, comprising lining the first tubular channel network or the second tubular channel network with cells. Aspect 43: The method of any of aspects 37 to 42, comprising embedding cells in a hydrogel matrix. Aspect 44: The method of any of embodiments 41 and 43, wherein the cell is one or more of a liver, lung, bone, endothelial, cardiac, pancreatic, renal, epithelial, muscle, cartilage, stem cell, skin or eye cell. Aspect 45: 38. The method of claim 34 or 37, comprising providing heat as the 3D additive manufacturing machine generates the 3D model. Aspect 46: 46. ​​The method of claim 45, wherein the heat is applied via a silicone heater, a heat lamp, or an infrared LED. Aspect 47: 46. ​​The method of claim 45, further comprising enclosing the 3D model in a heated enclosure during generation of the 3D model. Aspect 48: A method of fabricating a 3D hydrogel construct, comprising using a computer-implemented process to: Creating 3D models of constructions based on tessellations of polyhedrons, which have several faces connected by edges and vertices; generating a first vascular component of the model; generating a second vascular component of the model; and The first and second vascular components of the model are combined. Aspect 49: The method of embodiment 48, wherein generating a first vascular component of the model using a computer-implemented process includes removing faces of polyhedra and using the remaining vertices and edges of the topology as a vascular skeleton. Aspect 50: generating a first vascular component of the model using a computer-implemented process, skinning the skeleton with a polygon mesh and then smoothing the result to create cylindrical channels along the edges of the model with inter-vessel junctions located at each vertex location; The method of embodiment 49, further comprising: Aspect 51: generating a second vascular component of the model using a computer-implemented process; scaling a surface of the 3D model along a local surface normal to fit the second vessel component within the first vessel component; forming independent fluid connections to the first vascular component and the second vascular component; and Performing a Boolean subtraction from a solid volume The method of any one of embodiments 48 to 50, comprising: Aspect 52: radially symmetrically fusing multiple spheres to create a second vascular topology; offsetting the second vascular topology to generate a vascular surface topology; tessellating, skeletonizing, and skinning the vascular surface topology to create a Voronoi vascular topology, where tessellating includes performing a tessellation of a polyhedron. A process for producing a hydrogel alveolar construct by 52. The method of any of embodiments 48 to 51, further comprising: Aspect 53: performing a Boolean subtraction of the second vascular topology and the tessellated Voronoi vascular topology from the solid volume to generate a final 3D model for additive manufacturing. The method of embodiment 52, further comprising: Aspect 54: 54. The method of any of aspects 48-53, wherein the tessellation of the polyhedron is a Weir-Phelan space-filling form model of two dodecahedral cells and six tetradecahedral cells. Aspect 55: creating a 3D model of the construction based on a tessellation of polyhedra having several faces connected by edges and vertices; generating a first vascular component of the model; generating a second vascular component of the model; and combining the first and second vascular components of the model. A non-transitory computer-readable medium having stored thereon a program for causing a computer to execute a method for fabricating a 3D hydrogel construct, comprising: Aspect 56: generating a first vascular component of the model, Removing faces and / or vertices of a polyhedron; and Using the remaining topology as a vascular skeleton 56. The method of embodiment 55, comprising: Aspect 57: generating a first vascular component of the model, skinning the skeleton with a polygon mesh and then smoothing the result to create cylindrical channels along the edges of the model with inter-vessel junctions located at each vertex location; 57. The method of any of embodiments 55 and 56, further comprising: Aspect 58: generating a second vascular component of the model, scaling a surface of the 3D model along a local surface normal to fit the second vessel component within the first vessel component; forming an independent fluid connection to the vascular system and the airways; and Performing a Boolean subtraction from a solid volume The method of any of embodiments 55 and 57, comprising: Aspect 59: radially symmetrically fusing multiple spheres to create a second vascular topology; offsetting the second vascular topology to generate a vascular surface topology; tessellating, skeletonizing, and skinning the vascular surface topology to create a Voronoi vascular topology, where tessellating includes performing a tessellation of a polyhedron; and performing a Boolean subtraction of the second vascular topology and the tessellated Voronoi vascular topology from a solid volume to generate a final 3D model for additive manufacturing. The method of any of embodiments 55 and 58, comprising fabricating a hydrogel alveolar construct by: Aspect 60: 60. The method of any of aspects 55-59, wherein the tessellation of the polyhedron is a Weir-Phelan space-filling form model of two dodecahedral cells and six tetradecahedral cells. Aspect 61: 1. An apparatus for producing a hydrogel matrix construct, comprising: Frame; a stage having a z-axis drive motor attached to the frame; an electronics board for controlling movement of the stage relative to the frame; a container configured to hold a solution; a projector for projecting an image that is an image slice of a 3D model of the hydrogel matrix construct; and a build platform configured to hold a substrate on which the hydrogel matrix construct is formed; The apparatus. Aspect 62: The solution is a prepolymerized solution, With photosensitive polymer; a light absorber additive suitable for controlling the transmission of light, the light absorber additive being at least partially removable from a solid formed from the prepolymerized solution; 62. The apparatus of embodiment 61, comprising: Aspect 63: The apparatus of any of embodiments 61 and 62, further comprising a plant cell, a bacterial cell, or a mammalian cell. Aspect 64: The device of any of embodiments 61-63, further comprising one or more of liver, lung, bone, endothelial, cardiac, pancreatic, renal, epithelial, muscle, cartilage, stem cells, skin or eye cells. Aspect 65: The device of any one of embodiments 61-64, wherein the light absorber additive is biocompatible. Aspect 66: The device of any one of embodiments 61-65, wherein the light absorber additive is hydrophilic. Aspect 67: Light absorbing additives include food coloring, tartrazine, Sunset Yellow FCF (Yellow No. 6), Brilliant Blue FCF (FD&C Blue No. 1), Indigo Carmine (FD&C Blue No. 2), Fast Green FCF (FD&C Green No. 3), anthocyanins, anthocyanidins, erythrosine (FD&C Red No. 3), Allura Red AC (FD&C Red No. 40), riboflavin (vitamin B2, E101, E101a, E106), aspartame, glycerin, glyceryl stearate ... The device of any of embodiments 61-66, wherein the active ingredient is one of corbic acid (vitamin C), quinoline yellow WS, carmoisine (azorubine), ponceau 4R (E124), patent blue V (E131), green S (E142), yellow 2G (E107), orange GGN (E111), red 2G (E128), caramel color, phenol red, methyl orange, 4-nitrophenol, and NADH disodium salt. Aspect 68: 66. The device of any one of embodiments 61-65, wherein the light absorber additive is hydrophobic. Aspect 69: The device of any of embodiments 61-65 and 68, wherein the light absorber additive is one of curcumin (E100), turmeric, alpha carotene, beta carotene, canthaxanthin (a ketocarotenoid), cochineal extract, paprika, saffron, ergocalciferol (vitamin D2), cholecalciferol (vitamin D3), citrus red 2, annatto extract and lycopene. Aspect 70: Creating a 3D model of a hydrogel matrix construct based on a tessellation of polyhedra having several faces connected by edges and vertices; generating a first vascular component of the model; generating a second vascular component of the model; and Aligning the first and second vascular components of the model. a processor including a modeling engine configured to Frame, a stage having a z-axis drive motor attached to the frame; an electronics board for controlling movement of the stage relative to the frame; A container configured to hold a solution; a projector for projecting an image that is an image slice of the model; and A build platform configured to hold a substrate. an apparatus configured to produce the hydrogel matrix construct, comprising: A system for producing a hydrogel matrix construct comprising: Aspect 71: The solution is a prepolymerized solution, With photosensitive polymer; a light absorber additive suitable for controlling the transmission of light, said light absorber additive being removable from a solid formed from said prepolymerized solution; The system of embodiment 70, comprising: Aspect 72: The system of any of embodiments 70 and 71, further comprising a plant cell, a bacterial cell, or a mammalian cell. Aspect 73: The system of any of embodiments 70-72, further comprising one or more of liver, lung, bone, endothelial, cardiac, pancreatic, renal, epithelial, muscle, cartilage, stem cells, skin or eye cells. Aspect 74: The system of any of embodiments 70-73, wherein the light absorber additive is biocompatible. Aspect 75: The system of any of embodiments 70-74, wherein the light absorber additive is hydrophilic. Aspect 76: Light absorbing additives include food coloring, tartrazine, Sunset Yellow FCF (Yellow No. 6), Brilliant Blue FCF (FD&C Blue No. 1), Indigo Carmine (FD&C Blue No. 2), Fast Green FCF (FD&C Green No. 3), anthocyanins, anthocyanidins, erythrosine (FD&C Red No. 3), Allura Red AC (FD&C Red No. 40), riboflavin (vitamin B2, E101, E101a, E106), and ascorbic acid. 76. The system of any of aspects 70-75, wherein the active ingredient is one of: rubicic acid (vitamin C), quinoline yellow WS, carmoisine (azorubine), ponceau 4R (E124), patent blue V (E131), green S (E142), yellow 2G (E107), orange GGN (E111), red 2G (E128), caramel color, phenol red, methyl orange, 4-nitrophenol, and NADH disodium salt. Aspect 77: The system of any of embodiments 70-73, wherein the light absorber additive is hydrophobic. Aspect 78: 78. The system of any of aspects 70-73 and 77, wherein the light absorber additive is one of curcumin (E100), turmeric, alpha carotene, beta carotene, canthaxanthin (a ketocarotenoid), cochineal extract, paprika, saffron, ergocalciferol (vitamin D2), cholecalciferol (vitamin D3), citrus red 2, annatto extract and lycopene. Aspect 79: generating a first vascular component of the model, Removing faces and / or vertices of a polyhedron; Using the remaining topology as a vascular skeleton The system of any one of aspects 70 to 78, comprising: Aspect 80: generating a first vascular component of the model, skinning the skeleton with a polygon mesh and then smoothing the result to create cylindrical channels along the edges of the model with inter-vessel junctions located at each vertex location; The system of embodiment 79, further comprising: Aspect 81: generating a second vascular component of the model; scaling a surface of the 3D model along a local surface normal to fit the second vessel component within the first vessel component; forming independent fluid connections to the first vascular component and to the second vascular component; and Performing a Boolean subtraction from a solid volume The system of any one of aspects 70 to 80, comprising: Aspect 82: The processor: radially symmetrically fusing multiple spheres to create a second vascular topology; offsetting the second vascular topology to generate a vascular surface topology; tessellating, skeletonizing, and skinning the vascular surface topology to create a Voronoi vascular topology, where tessellating includes performing a tessellation of a polyhedron; and performing a Boolean subtraction of the second vascular topology and the tessellated Voronoi vascular topology from a solid volume to generate a final 3D model for additive manufacturing. The system of any of aspects 70 to 81, wherein the system is configured to fabricate a hydrogel alveolar construct by: Aspect 83: 83. The system of any of embodiments 70-82, wherein the tessellation of the polyhedron is a Weir-Phelan space-filling form model of two dodecahedral cells and six tetradecahedral cells. Aspect 84: The device of embodiment 13, wherein the fluid static mixer comprises a light absorbing material. Aspect 85: The device of embodiment 13, wherein the fluid static mixer comprises tartrazine. Aspect 86: 14. The device of embodiment 13, wherein the fluid static mixer comprises a fin element having a 180° twist. Aspect 87: The device of embodiment 13, wherein the fluid static mixer is manufactured by additive manufacturing. Aspect 88: A method of treating a subject in need of treatment, comprising the step of implanting into said subject any of the devices of embodiments 1-27. Aspect 89: A device comprising a plurality of joined subunits, each subunit being any of the devices of embodiments 1-27. Aspect 90: 28. The device of any of the preceding embodiments, further comprising a thickening agent to prevent cell sedimentation, the thickening agent comprising xanthan gum having a concentration of 0.02% to 2% by weight. Aspect 91: 34. The prepolymerization solution of any of aspects 28 to 33, further comprising a thickening agent to prevent cell sedimentation, the thickening agent comprising xanthan gum having a concentration of 0.02% by weight to 2% by weight. Aspect 92: 72. The system of embodiment 71, further comprising a thickening agent to prevent cell sedimentation, the thickening agent comprising xanthan gum having a concentration of 0.02% to 2% by weight.

Claims

1. a hydrogel matrix including a photoabsorber; a void architecture in the matrix having a first vascular architecture and a second vascular architecture, the first vascular architecture and the second vascular architecture being tubular and branched, respectively; Including, the first and second vascular architectures being fluidly independent of each other; device.

2. 10. The device of claim 1, wherein at least 90% of visible light incident on the device is transmitted through the device, allowing the device to be imaged.

3. 10. The device of claim 1, wherein the light absorber has been at least partially washed from the device.

4. 10. The device of claim 1, wherein the light absorber is degradable independently of any degradation of the remainder of the hydrogel matrix.

5. 10. The device of claim 1, wherein the light absorber is decomposable by a chemical or physical process.

6. 6. The device of claim 5, wherein the light absorbing agent is photobleachable or removable by boiling.

7. 2. The device of claim 1, wherein the void architecture is a multi-vascular void architecture and further comprises a torus entangled with a torus knot.

8. The device of claim 1, wherein one or both of the first vascular architecture and the second vascular architecture are formed from a model based on a tessellation of a polyhedron.

9. The device of claim 8, wherein the model is based on a tessellation of polyhedra to represent blood vessels.

10. 10. The device of claim 8, wherein a model based on a tessellation of polyhedra represents the airways.

11. The device of claim 1, wherein the void architecture is a multi-vessel void architecture and further comprises a functional valve.

12. 12. The device of claim 11, wherein the valve is a bicuspid valve, a tricuspid valve, a monocuspid valve, or a Tesla valve.

13. The device of claim 1, wherein the void architecture is a multi-vessel void architecture and further comprises a fluid static mixer.

14. 14. The device of claim 13, wherein the fluid static mixer has between 2 and 50 fin elements.

15. 13. The device of claim 11 or 12, wherein the functional valve is positionable anywhere in the multi-vessel void architecture.

16. 13. The device of claim 1, wherein the device is monolithic.

17. The device of claim 1, wherein the hydrogel matrix is ​​a photopolymerized hydrogel matrix and / or a biodegradable hydrogel matrix.

18. 13. The device of claim 1, manufactured by additive manufacturing.

19. The device of claim 1, wherein the first vascular architecture and the second vascular architecture are intertwined.

20. The device of claim 1, wherein the first vascular architecture is covered by a second vascular architecture.

21. The device of claim 1, wherein the hydrogel matrix is ​​porous.

22. 13. The device of claim 1, which is implantable.

23. 10. The device of claim 1, wherein the light absorber is hydrophilic.

24. 24. The device of claim 23, wherein the light absorbing agent is one of food coloring, tartrazine, Sunset Yellow FCF (Yellow No. 6), Brilliant Blue FCF (FD&C Blue No. 1), Indigo Carmine (FD&C Blue No. 2), Fast Green FCF (FD&C Green No. 3) anthocyanins, anthocyanidins, erythrosine (FD&C Red No. 3), Allura Red AC (FD&C Red No. 40), riboflavin (vitamin B2, E101, E101a, E106), ascorbic acid (vitamin C), quinoline yellow WS, carmoisine (azorubine), Ponceau 4R (E124), patent blue V (E131), green S (E142), yellow 2G (E107), orange GGN (E111), red 2G (E128), caramel color, phenol red, methyl orange, 4-nitrophenol, and NADH disodium salt.

25. 10. The device of claim 1, wherein the light absorbing agent is hydrophobic.

26. 26. The device of claim 25, wherein the light absorber is one of curcumin (E100), turmeric, alpha carotene, beta carotene, canthaxanthin (a ketocarotenoid), cochineal extract, paprika, saffron, ergocalciferol (vitamin D2), cholecalciferol (vitamin D3), citrus red 2, annatto extract, and lycopene.

27. The device of claim 1, comprising three or more vascular architectures that are fluidly independent from each other and from the first and second vascular architectures.

28. a photosensitive polymer; A light absorber additive suitable for controlling light transmission; wherein the additive is at least partially removable from a solid formed from the prepolymerized solution.

29. 30. The pre-polymerized solution of claim 28, further comprising plant cells, bacterial cells or mammalian cells.

30. 30. The prepolymerized solution of claim 28, wherein the light absorber additive is hydrophilic.

31. 31. The prepolymerization solution of claim 30, wherein the light absorber additive is one of food color, tartrazine, Sunset Yellow FCF (Yellow No. 6), Brilliant Blue FCF (FD&C Blue No. 1), Indigo Carmine (FD&C Blue No. 2), Fast Green FCF (FD&C Green No. 3), anthocyanins, anthocyanidins, erythrosine (FD&C Red No. 3), Allura Red AC (FD&C Red No. 40), riboflavin (vitamin B2, E101, E101a, E106), ascorbic acid (vitamin C), quinoline yellow WS, carmoisine (azorubine), Ponceau 4R (E124), patent blue V (E131), green S (E142), yellow 2G (E107), orange GGN (E111), red 2G (E128), caramel color, phenol red, methyl orange, 4-nitrophenol, and NADH disodium salt.

32. 30. The prepolymerized solution of claim 28, wherein the light absorber additive is hydrophobic.

33. 33. The prepolymerized solution of claim 32, wherein the light absorber additive is one of curcumin (E100), turmeric, alpha carotene, beta carotene, canthaxanthin (a ketocarotenoid), cochineal extract, paprika, saffron, ergocalciferol (vitamin D2), cholecalciferol (vitamin D3), citrus red 2, annatto extract, and lycopene.

34. creating a 3D model of the construction based on a tessellation of polyhedra having several faces connected by edges and vertices; removing the faces and / or the vertices of the polyhedron and using the remaining topology as a vessel skeleton; and skinning the skeleton with a polygon mesh and then smoothing the result to create cylindrical channels along the edges of the model with inter-vessel junctions located at each vertex location; generating a first vascular component of the model by: scaling the surface of the 3D model along a local surface normal to fit a second vessel component within the first vessel component; forming independent fluid connections to the first vascular component and the second vascular component; Performing a Boolean subtraction from a solid volume generating a second vascular component of the model by: combining the two vascular components of the model. A method for fabricating a 3D hydrogel construct by a processor, comprising:

35. radially symmetrically fusing the plurality of spheres to create a second vascular topology; offsetting the second vascular topology to generate a vascular surface topology; tessellating, skeletonizing, and skinning the vascular surface topology to create a Voronoi vascular topology, where tessellating includes performing a tessellation of a polyhedron; and performing a Boolean subtraction of the second vascular topology and the tessellated Voronoi vascular topology from a solid volume to generate a final 3D model for additive manufacturing. The method of claim 34, comprising fabricating a hydrogel alveolar construct by:

36. 36. The method of claim 34 or 35, wherein the tessellation of the polyhedron is a Weir-Phelan space-filling form model of two dodecahedral cells and six tetradecahedral cells.

37. creating a 3D model of a hydrogel matrix construct using design software, the 3D model of the hydrogel matrix construct comprising a first computational algorithm that generates a first tubular channel network in the hydrogel matrix construct and a second computational algorithm, different from the first computational algorithm, that generates a second tubular channel network in the hydrogel matrix, the first and second tubular channel networks being two separate intertwined vascular networks; Converting the 3D model into a format suitable for use in 3D additive manufacturing software to produce a formatted 3D model that is generated using a 3D additive manufacturing machine; and commanding an additive manufacturing machine to generate the model. A method for producing a hydrogel matrix construct, comprising:

38. 40. The method of claim 37, wherein the first computational algorithm is tessellation of a polyhedron.

39. 38. The method of claim 37, wherein the first computational algorithm is torus and the second algorithm is torus knotting.

40. 40. The method of claim 37, comprising providing a pre-polymerized solution comprising the light absorber to a 3D additive manufacturing machine.

41. 41. The method of claim 40, wherein the prepolymerized solution comprises one or more types of bacterial cells, mammalian cells and plant cells.

42. 40. The method of claim 37, comprising lining the first tubular channel network or the second tubular channel network with cells.

43. 38. The method of claim 37, comprising embedding the cells in a hydrogel matrix.

44. 44. The method of claim 41 or 43, wherein the cell is one or more of a liver, lung, bone, endothelial, cardiac, pancreatic, renal, epithelial, muscle, cartilage, stem cell, skin or eye cell.

45. 38. The method of claim 34 or 37, comprising providing heat as the 3D additive manufacturing machine generates the 3D model.

46. 46. ​​The method of claim 45, wherein the heat is applied via a silicone heater, a heat lamp, or an infrared LED.

47. 46. ​​The method of claim 45, further comprising enclosing the 3D model in a heated enclosure during generation of the 3D model.

48. A method of fabricating a 3D hydrogel construct, comprising using a computer-implemented process to: Create 3D models of constructions based on tessellations of polyhedrons, which have several faces connected by edges and vertices; generating a first vascular component of the model; generating a second vascular component of the model; and The first and second vascular components of the model are combined.

49. 49. The method of claim 48, wherein generating a first vascular component of the model using a computer-implemented process comprises removing faces of polyhedra and using remaining vertices and edges of the topology as a vascular skeleton.

50. generating a first vascular component of the model using a computer-implemented process, skinning the skeleton with a polygon mesh and then smoothing the result to create cylindrical channels along the edges of the model with inter-vessel junctions located at each vertex location; 50. The method of claim 49, further comprising:

51. generating a second vascular component of the model using a computer-implemented process; scaling a surface of the 3D model along a local surface normal to fit the second vessel component within the first vessel component; forming independent fluid connections to the first vascular component and the second vascular component; and Performing a Boolean subtraction from a solid volume 49. The method of claim 48, comprising:

52. radially symmetrically fusing the plurality of spheres to create a second vascular topology; offsetting the second vascular topology to generate a vascular surface topology; tessellating, skeletonizing, and skinning the vascular surface topology to create a Voronoi vascular topology, where tessellating includes performing a tessellation of a polyhedron. A process for producing a hydrogel alveolar construct by 49. The method of claim 48, further comprising:

53. performing a Boolean subtraction of the second vascular topology and the tessellated Voronoi vascular topology from the solid volume to generate a final 3D model for additive manufacturing.

53. The method of claim 52, further comprising:

54. 54. The method of any one of claims 48 to 53, wherein the tessellation of the polyhedron is a Weir-Phelan space-filling form model of two dodecahedral cells and six tetradecahedral cells.

55. creating a 3D model of the construction based on a tessellation of polyhedra having several faces connected by edges and vertices; generating a first vascular component of the model; generating a second vascular component of the model; and combining the first and second vascular components of the model. A non-transitory computer-readable medium having stored thereon a program for causing a computer to execute a method for fabricating a 3D hydrogel construct, comprising:

56. generating a first vascular component of the model, removing faces and / or vertices of a polyhedron; and Using the remaining topology as a vascular skeleton 56. The method of claim 55, comprising:

57. generating a first vascular component of the model, skinning the skeleton with a polygon mesh and then smoothing the result to create cylindrical channels along the edges of the model with inter-vessel junctions located at each vertex location; 56. The method of claim 55, further comprising:

58. generating a second vascular component of the model, scaling a surface of the 3D model along a local surface normal to fit the second vessel component within the first vessel component; forming an independent fluid connection to the vascular system and the airways; and Performing a Boolean subtraction from a solid volume 56. The method of claim 55, comprising:

59. radially symmetrically fusing the plurality of spheres to create a second vascular topology; offsetting the second vascular topology to generate a vascular surface topology; tessellating, skeletonizing, and skinning the vascular surface topology to create a Voronoi vascular topology, where tessellating includes performing a tessellation of a polyhedron; and performing a Boolean subtraction of the second vascular topology and the tessellated Voronoi vascular topology from a solid volume to generate a final 3D model for additive manufacturing. The method of claim 55, comprising fabricating a hydrogel alveolar construct by:

60. 60. The method of any one of claims 55 to 59, wherein the tessellation of the polyhedron is a Weir-Phelan space-filling form model of two dodecahedral cells and six tetradecahedral cells.

61. 1. An apparatus for producing a hydrogel matrix construct, comprising: Frame; a stage having a z-axis drive motor attached to the frame; an electronics board for controlling movement of the stage relative to the frame; a container configured to hold the solution; a projector for projecting an image, the image slice of the 3D model of the hydrogel matrix construct; and a build platform configured to hold a substrate on which the hydrogel matrix construct is formed; The apparatus.

62. The solution is a prepolymerized solution, a photosensitive polymer; a light absorber additive suitable for controlling the transmission of light, the light absorber additive being at least partially removable from a solid formed from the prepolymerized solution; 62. The apparatus of claim 61, comprising:

63. 63. The device of claim 62, further comprising a plant cell, a bacterial cell or a mammalian cell.

64. 63. The device of claim 62, further comprising one or more of liver, lung, bone, endothelial, cardiac, pancreatic, renal, epithelial, muscle, cartilage, stem cells, skin or eye cells.

65. 63. The device of claim 62, wherein the light absorber additive is biocompatible.

66. 63. The device of claim 62, wherein the light absorber additive is hydrophilic.

67. 63. The device of claim 62, wherein the light absorber additive is one of food color, tartrazine, Sunset Yellow FCF (Yellow No. 6), Brilliant Blue FCF (FD&C Blue No. 1), Indigo Carmine (FD&C Blue No. 2), Fast Green FCF (FD&C Green No. 3) anthocyanins, anthocyanidins, erythrosine (FD&C Red No. 3), Allura Red AC (FD&C Red No. 40), riboflavin (vitamin B2, E101, E101a, E106), ascorbic acid (vitamin C), quinoline yellow WS, carmoisine (azorubine), Ponceau 4R (E124), patent blue V (E131), green S (E142), yellow 2G (E107), orange GGN (E111), red 2G (E128), caramel color, phenol red, methyl orange, 4-nitrophenol, and NADH disodium salt.

68. 63. The device of claim 62, wherein the light absorber additive is hydrophobic.

69. 63. The device of claim 62, wherein the light absorber additive is one of curcumin (E100), turmeric, alpha carotene, beta carotene, canthaxanthin (a ketocarotenoid), cochineal extract, paprika, saffron, ergocalciferol (vitamin D2), cholecalciferol (vitamin D3), citrus red 2, annatto extract, and lycopene.

70. Creating a 3D model of a hydrogel matrix construct based on a tessellation of polyhedra having several faces connected by edges and vertices; generating a first vascular component of the model; generating a second vascular component of the model; and Aligning the first and second vascular components of the model. a processor including a modeling engine configured to Frame, a stage having a z-axis drive motor attached to the frame; an electronics board for controlling movement of the stage relative to the frame; A container configured to hold a solution; a projector for projecting an image that is an image slice of the model; and A build platform configured to hold a substrate. an apparatus configured to produce the hydrogel matrix construct, comprising: A system for producing a hydrogel matrix construct comprising:

71. The solution is a prepolymerized solution, a photosensitive polymer; a light absorber additive suitable for controlling the transmission of light, said light absorber additive being removable from a solid formed from said prepolymerized solution; 71. The system of claim 70, comprising:

72. 72. The system of claim 71, further comprising a plant cell, a bacterial cell or a mammalian cell.

73. 72. The system of claim 71, further comprising one or more of liver, lung, bone, endothelial, cardiac, pancreatic, renal, epithelial, muscle, cartilage, stem cells, skin or eye cells.

74. 72. The system of claim 71, wherein the light absorber additive is biocompatible.

75. 72. The system of claim 71, wherein the light absorber additive is hydrophilic.

76. 72. The system of claim 71, wherein the light absorber additive is one of food color, tartrazine, Sunset Yellow FCF (Yellow No. 6), Brilliant Blue FCF (FD&C Blue No. 1), Indigo Carmine (FD&C Blue No. 2), Fast Green FCF (FD&C Green No. 3) anthocyanins, anthocyanidins, erythrosine (FD&C Red No. 3), Allura Red AC (FD&C Red No. 40), riboflavin (vitamin B2, E101, E101a, E106), ascorbic acid (vitamin C), quinoline yellow WS, carmoisine (azorubine), Ponceau 4R (E124), patent blue V (E131), green S (E142), yellow 2G (E107), orange GGN (E111), red 2G (E128), caramel color, phenol red, methyl orange, 4-nitrophenol, and NADH disodium salt.

77. 72. The system of claim 71, wherein the light absorber additive is hydrophobic.

78. 72. The system of claim 71, wherein the light absorber additive is one of curcumin (E100), turmeric, alpha carotene, beta carotene, canthaxanthin (a ketocarotenoid), cochineal extract, paprika, saffron, ergocalciferol (vitamin D2), cholecalciferol (vitamin D3), citrus red 2, annatto extract, and lycopene.

79. generating a first vascular component of the model, Removing faces and / or vertices of a polyhedron; Using the remaining topology as a vascular skeleton 71. The system of claim 70, comprising:

80. generating a first vascular component of the model, skinning the skeleton with a polygon mesh and then smoothing the result to create cylindrical channels along the edges of the model with inter-vessel junctions located at each vertex location; 80. The system of claim 79, further comprising:

81. generating a second vascular component of the model; scaling a surface of the 3D model along a local surface normal to fit the second vessel component within the first vessel component; forming independent fluid connections to the first vascular component and to the second vascular component; and Performing a Boolean subtraction from a solid volume 71. The system of claim 70, comprising:

82. The processor: radially symmetrically fusing the plurality of spheres to create a second vascular topology; offsetting the second vascular topology to generate a vascular surface topology; tessellating, skeletonizing, and skinning the vascular surface topology to create a Voronoi vascular topology, where tessellating includes performing a tessellation of a polyhedron; and performing a Boolean subtraction of the second vascular topology and the tessellated Voronoi vascular topology from a solid volume to generate a final 3D model for additive manufacturing. The system of claim 70, configured to fabricate a hydrogel alveolar construct by:

83. 82. The system of any one of claims 70-81, wherein the tessellation of the polyhedron is a Weir-Phelan space-filling form model of two dodecahedral cells and six tetradecahedral cells.

84. 14. The device of claim 13, wherein the fluid static mixer comprises a light absorbing material.

85. 14. The device of claim 13, wherein the fluid static mixer comprises tartrazine.

86. 14. The device of claim 13, wherein the fluid static mixer comprises a fin element having a 180 degree twist.

87. 14. The device of claim 13, wherein the fluid static mixer is manufactured by additive manufacturing.

88. 28. A method of treating a subject in need of treatment comprising implanting in said subject any of the devices of claims 1-27.

89. A device comprising a plurality of joined subunits, each subunit being any of the devices of claims 1-27.

90. 10. The device of claim 1, further comprising a thickening agent to prevent cell sedimentation, the thickening agent comprising xanthan gum having a concentration of 0.02% to 2% by weight.

91. 30. The prepolymerized solution of claim 28, further comprising a thickening agent to prevent cell sedimentation, the thickening agent comprising xanthan gum having a concentration of 0.02% to 2% by weight.

92. 72. The system of claim 71, further comprising a thickening agent to prevent cell sedimentation, the thickening agent comprising xanthan gum having a concentration of 0.02% to 2% by weight.

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