Collagen Corporation

Saeid Seyedin

Thomas Thomas

Hanne Bentz

Rosa Armstrong

Larry Ellingsworth

Ranga Nathan

Karl A Piez

George H Chu

Donald G Wallace

Thomas L Smestad

John M McPherson

Andrea Thompson

A composition suitable for inductive bone implants is disclosed. The composition comprises a purified form of osteogenic factor in admixture with a carrier having a percentage of mineral carrier. The resulting implants are sufficiently hypoimmunogenic to be effective when implanted in xenogeneic hosts.

Inductive collagen-based bone repair preparations

An improved process for the preparation of mineral/collagen/OF (osteogenic factor) inductive implants for bone repair utilizes drying, under ambient pressure conditions, a suspension of 75-95% mineral particles, 5-25% collagen, and an effective amount of OF, such as 0.5-4% partially purified OFE or its equivalent wherein the concentration of collagen in the suspension subjected to drying is 30-100 mg/ml. The resulting implants are improved. They are homogeneous in composition and have a high compressive modulus as well as containing OF in a biologically active and available form.

Aqueous suspensions of fibrillar atelopeptide collagen and osteogenic factor are effective injectable preparations for the repair of bone defects.

Injectable composition for inductive bone repair

Two proteins that are found in bone and that have in vivo chondrogenic/osteogenic activity in combination with a co-factor are described. Both proteins also were active in combination with EGF in the in vitro TGF-.beta. assay. Each has a molecular weight of approximately 26,000 daltons by SDS-PAGE. Each is reduced to a single polypeptide indicating that the proteins are probably homodimers. One has an N-terminal sequence identical to that of human placenta-derived TGF-.beta. whereas the other has an N-terminal sequence that is different from that of TGF-.beta. derived from human placenta. The two proteins may be purified to hmogeneity using RP-HPLC or acetic acid-urea gel electrophoresis.

Polypeptide cartilage-inducing factors found in bone

Two proteins that are found is bone and that have in vivo chondrogenic/osteogenic activity in combination with a co-factor are described. Both proteins also were active in combination with EGF in the in vitro TGF-.beta. assay. Each has a molecular weight of approximately 26,000 daltons by SDS-PAGE. Each is reduced to a single polypeptide indicating that the proteins are probably homodimers. One has an N-terminal sequence identical to that of human placenta-derived TGF-.beta. whereas the other has an N-terminal sequence that is different from that of TGF-.beta. derived from human placenta. The two proteins may be purified to homogeneity using RP-HPLC or acetic acid-urea gel electrophoresis.

A method of repairing bone defects by use of suspensions containing purified atelopeptide, reconstituted, fibrillar skin collagen or bone collagen powder or mixtures thereof is disclosed. The suspensions provide matrices for conductive growth of bone into the defect. The skin collagen may also be lyophilized and used in the form of mats.

Methods of bone repair using collagen

Two proteins that are found in bone and that have in vivo chondrogenic/osteogenic activity in combination with a co-factor are described. Both proteins also were active in combination with EGF in the in vitro TGF-.beta. assay. Each has a molecular weight of approximately 26,000 daltons by SDS-PAGE. Each is reduced to a single polypeptide indicating that the proteins are probably homodimers. One has an N-terminal sequence identical to that of human placenta-derived TGF-.beta. whereas the other has an N-terminal sequence that is different from that of TGF-.beta. derived from human placenta. The two proteins may be purified to homogeneity using RP-HPLC or acetic acid-urea gel electrophoresis.

Polypeptide cartilage-inducing factors found in bone used in tissue

A partially purified proteinaceous bone-inducing factor of 10,000 to 30,000 daltons is described. It is derived from demineralized bovine bone by extraction with a chaotropic agent, gel filtration, cation exchange chromatography using carboxymethyl cellulose at pH 4.8 and gradient elution with NaCl at 10 mM to about 150 mM.

Partially purified bone-inducing factor

A process for partially purifying an osteogenic factor from demineralized bone particles in which nonfibrous proteins are extracted from the demineralized bone with a dissociative extractant for nonfibrous proteins, such as urea or guanidine hydrochloride, the extracted nonfibrous proteins are fractionated by anion exchange chromatography using DEAE cellulose at pH 7, the fraction not adsorbed by the DEAE cellulose is further fractionated by cation exchange chromatography using CM cellulose at pH 4.8, the fraction adsorbed by the CM cellulose is eluted therefrom and the partially purified osteogenic factor is recovered from the eluate as a .ltoreq.30,000 dalton protein isolate.

Growing community of inventors

Sunnyvale, CA, United States of America

Saeid Seyedin