2407 results about "Calcium biphosphate" patented technology

A system is provided for the storage, preparation and administration of calcium phosphate cements. The subject invention provides a storage means for storing a two component calcium phosphate cement having a liquid component and a dry component. Also provided is a preparation means for combining the two components of the cement while present in the storage means. The subject invention further provides a means for administering the prepared cement to a physiological site. The subject devices and methods find use in a variety of applications where the introduction of a flowable material capable of setting to a solid calcium phosphate mineral to a physiological site is desired, including dental and orthopedic applications.

An improved bone graft is provided for human implantation, bone graft includes a substrate block of high strength biocompatible material having a selected size and shape to fit the anatomical space, and a controlled porosity analogous to natural bone. The substrate block may be coated with a bio-active surface coating material such as hydroxyapatite or a calcium phosphate to promote bone ingrowth and enhanced bone fusion. Upon implantation, the bone graft provides a spacer element having a desired combination of mechanical strength together with osteoconductivity and osteoinductivity to promote bone ingrowth and fusion, as well as radiolucency for facilitated post-operative monitoring. The bone graft may additionally carry one or more natural or synthetic therapeutic agents for further promoting bone ingrowth and fusion.

This invention relates to novel room-temperature process for obtaining calcium phosphate, in particular hydroxyapatite, coatings and microspheres that encapsulate drugs, proteins, genes, DNA for therapeutical use. The coatings and microspheres are designed to perform a defined biological function related to drug delivery, such as gene therapy through gene delivery. A novel method for encapsulation, and subsequent controlled release of therapeutically active agents from such biofunctional coatings and microspheres is disclosed. Such coatings and microspheres are useful for side-effects free, long-term, targeted, controlled release and delivery of drugs, proteins, DNA, and other therapeutic agents.

A spinal cage insert for a spinal cage is provided. The spinal cage insert has a shape suitable to be inserted into and fit closely in an interior of the spinal cage. The insert may comprise a member of the calcium phosphate family. The spinal cage insert may be made to a desired shape of porous ceramic, and it may include channels and/or surface features. Various shapes of filler pieces are also provided, wherein the filler pieces may be suitable to augment external regions of vertebrae which have been fused to each other so as to promote build-up of bone. The spinal cage insert and/or the filler pieces may be osteoconductive and may also contain osteoinductive substances or material. The articles may also contain cavities suitable for containing particles of demineralized bone matrix (DBM). Methods of use and methods of manufacturing the spinal cage insert and filler pieces are also provided.

The invention provides methods, apparatus and kits for regenerating dental tissue in vivo that are useful for treating a variety of dental conditions, exemplified by treatment of caries. The invention uses tissue scaffold wafers, preferably made of PGA, PLLA, PDLLA or PLGA dimensioned to fit into a hole of corresponding sized drilled into the tooth of subject to expose dental pulp in vivo. In certain embodiments the tissue scaffold wafer further comprises calcium phosphate and fluoride. The tissue scaffold wafer may be secured into the hole with a hydrogel, a cement or other suitable material. Either the wafer or the hydrogel or both contain a morphogenic agent, such as a member encoded by the TGF-β supergene family, that promotes regeneration and differentiation of healthy dental tissue in vivo, which in turn leads to remineralization of dentin and enamel. The tissue scaffold may further include an antibiotic or anti-inflammatory agent.

The invention describes a new calcium phosphate cement powder, whose composition can best be described over the Ca/P molar ratio range of 1.35 to 1.40, most preferably 1.39, and whose two components were prepared by wet chemical synthesis procedures. One component is chemically-synthesized, bi-phasic alpha-TCP (Ca₃(PO₄)₂, 95 wt %)+HA (Ca₁₀(PO₄)₆(OH)₂, 5 wt %) powder, while the second component is again a chemically-synthesized, single-phase DCPD (CaHPO₄·2H₂O) powder. A setting solution (Na₂HPO₄·2H₂O) is used to form a self-setting calcium phosphate cement from the powder mixture. This cement can be used as bone filler or bone substitute in applications, which require higher rates of resorption.

This invention relates to novel calcium phosphate-coated implantable medical devices and processes of making same. The calcium-phosphate coatings are designed to minimize the immune response to the implant (e.g. restenosis in stenting procedures) and can be used to store and release a medicinally active agent in a controlled manner. Such coatings can be applied to any implantable medical devices and are useful for a number of medical procedures including (but not limited to) balloon angioplasty in cardiovascular stenting, ureteral stenting and catheterisation. The calcium phosphate coatings can be applied to a substrate as one or more coatings by a sol-gel deposition process, an aerosol-gel deposition process, a biomimetic deposition process, a calcium phosphate cement deposition process, an electro-phoretic deposition process or an electrochemical deposition process. The coating can contain and elude a drug in an engineered manner.

The present invention provides a novel process for producing a calcium phosphate cement or filler which hardens in a temperature dependent fashion in association with an endothermic reaction. In the reaction a limited amount of water is mixed with dry calcium phosphate precursors to produce a hydrated precursor paste. Hardening of the paste occurs rapidly at body temperature and is accompanied by the conversion of one or more of the reactants to poorly crystalline apatitic calcium phosphate. The hardened cements, fillers, growth matrices, orthopedic and delivery devices of the invention are rapidly resorbable and stimulate hard tissue growth and healing. A composite material is provided including a strongly bioresorbable, poorly crystalline apatitic calcium phosphate composite and a supplementary material. The supplementary material is in intimate contact with the hydroxyapatite material in an amount effective to impart a selected characteristic to the composite. The supplemental material may be biocompatible, bioresorbable or non-resorbable. A method for treating a bone defect also is provided by identifying a bone site suitable for receiving an implant, and introducing a strongly resorbable, poorly crystalline apatitic calcium phosphate at the implant site, whereby bone is formed at the implant site. The implant site may be a variety of sites, such as a tooth socket, non-union bone, bone prosthesis, an osteoporotic bone, an intervertebral space, an alveolar ridge or a bone fracture.

Ceramic materials operable to repair a defect in bone of a human or animal subject comprising a porous ceramic scaffold having a bioresorbable coating, and a carrier comprising denatured demineralized bone. The ceramic may contain a material selected from the group consisting of hydroxyapatite, tricalcium phosphate, calcium phosphates, calcium carbonates, calcium sulfates, and combinations thereof. The compositions may also contain a bone material selected from the group consisting of: bone powder, bone chips, bone shavings, and combinations thereof. The bioresorbable coating may be, for example, demineralized bone matrix, gelatin, collagen, hyaluronic acid, chitosan, polyglycolic acid, polylactic acid, polypropylenefumarate, polyethylene glycol, or mixtures thereof.

The invention features delayed-setting calcium phosphate pastes which are useful for the preparation of delivery vehicles for biologically active agents, useful for the treatment of orthopedic conditions and can be stored for long periods without prematurely setting.

A polymer scaffold is provided comprising an extensively interconnected macroporous network. The polymer scaffold embodies macropores having a diameter in a range of 0.5-3.5 mm, and preferably in a range of about 1.0-2.0 mm. The polymer scaffold is prepared using a novel process which advantageously combines the techniques of particulate leaching and phase inversion to render a process that provides amplified means by which to control the morphology of the resulting polymer scaffold. The polymer scaffold has utility in the area of tissue engineering, particularly as a scaffold for both in vitro and in vivo cell growth. The polymer scaffold may be produced using pure polymer or alternatively a composite material may be formed consisting of a macroporous polymer scaffold and osteoclast-resorbable calcium phosphate particles with a binding agent binding the calcium phosphate particles to the polymer scaffold.

A bone implant comprises an active agent on at least a portion thereof. The active agent is locally deliverable to bone proximate the implant in at least a two-phased release scheme. A first phase rapidly releases a first quantity of the active agent, and at least a second phase gradually releases a second quantity of the active agent, whereby bone formation stimulated by the active agent is modulated. In one embodiment, a porous implant comprises a porous portion coated with a calcium phosphate compound and which is contacted with a bisphosphonate compound to form a bisphosphonate layer chemically bound to the calcium phosphate at the surface of the porous portion and to form bisphosphonate molecules being non-chemically attached inside the pores of the porous portion. The non-chemically attached bisphosphonate molecules are released in the subject at a rate greater than that of the chemically bound bisphosphonate layer.

A porous three-dimensional bone grafting matrix is provided which is biodegradable. The matrix is preferably formed from mineralized collagen where the mineral comprises particulate calcium phosphate immobilized in the matrix and having a particle size of 5 microns or less.

The present invention is a bioactive endodontic material and its use for filling the tooth and bone cavities. The present invention, by using calcium salt, calcium oxide, calcium silicate, and calcium phosphate compounds as essential constituents, and mixing them with a water base solution, prepares a bioactive calcium and phosphate enriched material. The enriched material (cement) comprises high concentration of water-soluble calcium and phosphate, and immediately forms hydroxyapatite during and after setting. The cement is biocompatible, antibacterial, capable to form an effective seal against reentrance of microorganisms into the filled cavity, compatible to handle and set in an aqueous environment, and able to stimulate hard tissue healing.

Disclosed herein are methods for preparing and using porous, crystalline biomimetic bioactive compositions of calcium phosphate with at least one therapeutic agent. The bioactive composition has strong adsorption properties for therapeutic agents which adsorb to the calcium phosphate with a high affinity. The bioactive composition also provides a sustained release implant that can be used for localized delivery of therapeutic agents. This localized delivery of therapeutic agents, promotes repair, healing, or regeneration of hard and soft tissues.

The present invention provides machinable calcium phosphate bone substitute material implants having mechanical properties comparable to those of natural bone. The implants include intimately mixed solid precursor materials that react under physiological conditions to form poorly-crystalline hydroxyapatite and eventually are remodeled into bone in vivo. The implants can include a biocompatible polymer to increase density and strength and control resorbability.

Calcium-phosphate nanofiber matrices comprising randomly dispersed crystalline calcium-phosphate nanofibers are provided. The nanofibers are synthesized using sol-gel methods combined with electrospinning. The nanofibers may be hollow, solid or may comprise a calcium-phosphate shell surrounding a polymer containing inner core to which biologically functional additives may be added. The nanofiber matrices may be used to culture bone and dental cells, and as implants to treat bone, dental or periodontal diseases and defects.

The present invention discloses a method for making a porous calcium phosphate article including i) preparing a shaped article from a paste containing a calcium phosphate cement, a pore-forming powder and a setting liquid; ii) immersing the shaped article in an immersing liquid for a period of time so that the pore-forming powder is dissolved in the immersing liquid, creating pores in said shaped article; and iii) removing the resulting porous shaped article from the immersing liquid, wherein the resulting porous shaped article has an improved compressive strength. The porous shaped calcium phosphate article of the present invention may be used as a tissue-engineered scaffold, medical implant or a reinforcing constituent of a composite.

The present invention relates to the use of calcium phosphate particles in formulation with allergens for allergic desensitization. Particularly, the invention relates to novel calcium phosphate core particles, particularly nano- and micron-sized particles, as allergen adjuvants and in compositions for inducing allergic desensitization. Methods of making such particles and to methods of inducing a specific immune response using the particles of this invention are also provided.

Methods for performing spinal fusions using an injectable calcium phosphate-based bone substitute are provided. The injectable bone substitute is injected into the anterior portion of an interbody space and allowed to solidify in vivo. The injectable bone substitute has a minimum compression strength of 10 MPa after setting for about 30 minutes and preferably solidifies to a compression strength of 25 MPa within 24 hours of injection. Optionally, the posterior portion of the interbody space is fixed using a metallic implant selected from rods and pedicle screws or plates and pedicle screws by attachment thereof to adjacent vertebrae.

A bone or dental implant material in the form of a paste includes a mixture of calcium phosphate and/or calcium-containing powders, liquid glycerol, organic acid and gelling agent. The paste is stable, resistant to washout and will harden upon exposure to water. Physical characteristics of the paste, including consistency, porosity, and hardening time, are controlled by the choice and ratio of constituents.

The present invention discloses a method for making a porous calcium phosphate article including i) preparing a shaped article from a paste containing a calcium phosphate cement, a pore-forming powder and a setting liquid; ii) immersing the shaped article in an immersing liquid for a period of time so that the pore-forming powder is dissolved in the immersing liquid, creating pores in said shaped article; and iii) removing the resulting porous shaped article from the immersing liquid, wherein the resulting porous shaped article has an improved compressive strength. The porous shaped calcium phosphate article of the present invention may be used as a tissue-engineered scaffold, medical implant or a reinforcing constituent of a composite.

The invention concerns injectable bone filling cements, in particular hydraulic calcium phosphate cements, the latter being prepared from at least two initial liquid or pasty constituents comprising each a species reactive in solution or in suspension, the solidification process being initiated when said constituents are being mixed.

A bone or dental implant material in the form of a paste includes a mixture of calcium phosphate and/or calcium-containing powders and a solution that is (1) an acidic calcium phosphate solution saturated with respect to one or more calcium phosphate compounds, (2) a concentrated acid solution, or (3) salt solutions with a cationic component other than calcium. The paste is stable, resistant to washout and will form hydroxyapatite and harden relatively rapidly to a cement.

Biologically active composites containing calcium phosphate, more specifically beta-tri-calcium phosphate, and methods of preparing the same are disclosed herein. Also disclosed are methods of restoring an osseous void and complimentary kits for the disclosed composites.

The present invention discloses a method for making a porous calcium phosphate article including i) preparing a shaped article from a paste containing a calcium phosphate cement, a pore-forming powder and a setting liquid; ii) immersing the shaped article in an immersing liquid for a period of time so that the pore-forming powder is dissolved in the immersing liquid, creating pores in said shaped article; and iii) removing the resulting porous shaped article from the immersing liquid, wherein the resulting porous shaped article has an improved compressive strength. The porous shaped calcium phosphate article of the present invention may be used as a tissue-engineered scaffold, medical implant or a reinforcing constituent of a composite.

A composition of porous material and gel for preparing artificial bone is prepared from collagen and porous material chosen from alpha-tricalcium phosphate/hydroxy apatite, beta-tricalcium phosphate/hydroxy apatite-coral, calcium phosphate/hydroxy apatite, calcium carbonatel tricalcium phosphate, etc.

A porous composite comprising a porous layer containing a calcium phosphate ceramic, and a dense layer formed on part of the porous layer and having a smaller average pore size than that of the porous layer. The porous composite can be produced by (1) introducing a slurry containing a calcium phosphate ceramic/collagen composite and collagen into a molding die having a high thermal conductivity, (2) rapidly freezing and drying the slurry in the molding die, to form a porous body comprising a porous layer and a dense layer formed on the porous layer, (3) cross-linking collagen in the porous body, and (4) removing the dense layer except for a portion thereof on a surface coming into contact with a soft tissue when implanted in a human body, so that the porous layer is exposed.

In some embodiments, an implant may include a porous component and a load bearing component at least partially surrounding the porous component. The porous component has a porosity that is greater than the porosity of the load bearing component. One or more protrusions may be present on the load bearing component. The porous component and/or a load bearing component may be at least partially composed of calcium phosphate.

Uniform, rigid, spherical nanoporous calcium phosphate particles that define an internal space and an amount of active agent present in the internal space are provided. Also provided are topical delivery compositions that include the active agent loaded particles, as well as methods of making the particles and topical compositions. The particles and compositions thereof find use in a variety of different applications, including active agent delivery applications.