5285 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.

The present invention provides a biocompatible coating comprising calcium phosphate that is functionally graded across the thickness of the coating. The coating, which preferably includes hydroxyapatite, is particularly useful for coating implants, such as dental or orthopedic implants. The functionally graded coating is generally crystalline near the interface with the surface of the implant, with crystallinity and crystal diameter decreasing toward the outer layer of the coating. The invention further provides methods for preparing a coated implant comprising a functionally graded calcium phosphate coating thereon.

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.

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.

An improved spinal fixation system is provided for human implantation, including a set of screws with interconnecting rods for implantation into the pedicle and between two adjacent vertebrae or a plate with screws for fixating two adjacent vertebrae. The screws, rods, and plates include a substrate portion of high strength biocompatible material and a controlled porosity analogous to natural bone. The substrate portion 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 fixation system provides a desired combination of mechanical strength together with osteoconductivity and bio-activity to promote bone ingrowth and fusion, as well as radiolucency for facilitated post-operative monitoring. The fixation system may additionally carry one or more natural or synthetic therapeutic agents for further promoting bone ingrowth and fusion.

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.

Shaped, composite bodies are provided. One portion of the shaped bodies comprises an RPR-derived porous inorganic material, preferably a calcium phosphate. Another portion of the composite bodies is a different solid material, preferably metal, glass, ceramic or polymeric. The shaped bodies are especially suitable for orthopaedic and other surgical use.

The invention is a medical implantable device which is coated by the method according to the invention. The surface of the substrate used for the implantable device, in the raw condition, following a cleaning regime and physiochemical pretreatments, is coated using a biomimetic process in a supersaturated calcium phosphate solution (SCPS) to obtain the desired coating coverage and morphology maintaining a ratio of calcium to phosphorus pH, as well as solution temperature plays a major role in yielding precipitation of the proper phase of CaP so that composition, morphologies, crystal structures, and solubility characteristics are optimal for the deposition process. The biomimetic coating adds the attribute of osteoconductivity to the implant device. To maximize bone growth, the implant must also induce bone growth, or possess the attribute of osteoinductivity. This attribute is acquired by the use of therapeutic agents, i.e. bone morphogenic proteins (BMP), growth factors, stem cells, etc. The preparation of the SCPS solution is slightly altered so that during the immersion of the implant in the SCPS, the therapeutic agents are co-precipitated and bonded with the CaP directly on the underlying surface of the implant device. A final dipping process into a BMP solution provides an initial burst of cellular activity. For delivering stem and/or progenitor cell, after drying the dipped solution of BMP, the cells are cultured on the surface of the implant.

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.

A composition and method for producing interconnective macroporous, resorbable and injectable calcium phosphate-based cements (MICPCs). The composition of the invention sets to poorly crystalline apatitic calcium phosphate after mixing a powder component and an aqueous solution. The multiphasic calcium phosphate components in the cement resorb at different rates allowing the timely replacement by new bone. The interconnected macroporosity in the cement allows for vascularization, entrapment of growth factors, cell colonization and tissue ingrowth. This MICPC can be used for dental and medical applications relating to bone repair, augmentation, reconstruction, regeneration, and osteoporosis treatment, and also for drug delivery, and as scaffolds for tissue engineering.

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.