Collagen Matrix, Inc.

Debbie Yuen

Shu-Tung Li

Hui-Chen Chen

Natsuyo Shishido Lee

Peggy Hansen

Horng-Ban Lin

An implant for the repair of bone and cartilage that includes a cell conductive zone that contains biopolymeric fibers and an osteoconductive zone that contains biopolymeric fibers and calcium-containing mineral particles. The biopolymeric fibers from one zone overlap with the fibers in the other zone forming a stable physical and mechanical integration of the two zones, thus conferring in vivo stability to the implant.

Implants for bone and cartilage repair

A density gradient biopolymeric matrix implant is disclosed. The implant includes a first homogeneous matrix layer and a second homogeneous matrix layer having a density different from that of the first homogeneous matrix layer. Biopolymeric fibers at the surface of the first homogeneous matrix layer are physically in contact with and cross-linked to the biopolymeric fibers at the surface of the second homogeneous matrix layer. Also disclosed is a three-dimensional density gradient biopolymeric matrix implant that includes a first homogeneous matrix surrounding a second homogeneous matrix having a different density. Biopolymeric fibers at an inner surface of the first homogeneous matrix are physically in contact with and cross-linked to biopolymeric fibers at an outer surface of the second homogeneous matrix. Furthermore, methods for preparing the density gradient biopolymeric matrix implant and the three-dimensional density gradient biopolymeric matrix implant are provided.

Density gradient biopolymeric matrix implants

A carbonate apatite prepared from natural bone. The carbonate apatite has a protein content of 2000-8000 parts per million and a surface area of 15 to 70 m/g. Also provided is a method for preparing the carbonate apatite from cancellous bone particles.

Method of preparing porous carbonate apatite from natural bone

A collagen-coated tissue based membrane that is smooth on both sides so as to inhibit cell and tissue adhesion. Also disclosed are methods for making a collagen-coated tissue-based membrane.

Collagen-coated tissue-based membranes

A collagen-coated tissue-based membrane that is smooth on both sides so as to inhibit cell and tissue adhesion. The tissue-based membrane is a serous membrane having a fibrous surface and a smooth surface and the collagen is coated on the fibrous surface. Also provided are methods for making the collagen-coated tissue-based membrane.

A flat self-curling permeable sheet membrane containing a matrix formed of crosslinked biopolymeric fibers. The matrix self-curls into a predetermined shape upon absorption of an aqueous fluid and is permeable to molecules having molecular weights not greater than 1&#xd7;10daltons. Also disclosed is a method of preparing such a flat self-curling permeable membrane.

Flat self-curling permeable sheet membrane

A re-rollable membrane for wrapping around and protecting a cylindrical tissue having an injury site. The membrane includes a sheet of a porous matrix formed of cross-linked biopolymeric fibers. In one implementation, the sheet can be spirally rolled so that at least one portion overlaps another portion of the sheet and, upon absorption of a fluid, the overlapping portions adhere to each other closely so as to exclude penetration of cells. In another implementation, the sheet can be helically rolled to form a helix having a pitch of 2 mm to 40 mm and an inner diameter of 1 mm to 50 mm. Also disclosed are methods for making and using such re-rollable membranes.

Re-rollable wrapping implant

A method for preparing carbonate apatite from natural bones. The method includes obtaining cancellous bone particles; treating the bone particles with hot water and an organic solvent; repeating the treating step at least once; drying the bone particles; and heating the bone particles at 500&#xb0; C. to 620&#xb0; C. for 10 to 50 hours.

A compressed implant composite for repairing mineralized tissue. The compressed implant composite includes a matrix formed of biopolymeric fibers and a plurality of calcium- and/or silicate-based mineral particles dispersed in the matrix. The matrix constitutes 4 to 80% by weight and the mineral particles constitute 20 to 96% by weight of the composite. The composite is free of soluble collagen and is expandable to a volume 2 to 100 times of its compressed volume (e.g., upon absorption of water). Also disclosed are methods of preparing the above-described composite.

Self-expandable biopolymer-mineral composite

This invention relates to a sheet membrane for repairing a damaged tissue. The membrane includes an isotropic layer of cross-linked biopolymeric fibers in which the fibers are 10 to 1,000 cm in length. This invention also relates to a method of making an isotropic layer of cross-linked biopolymeric fibers. The method includes: (1) coacervating biopolymeric fibers (e.g., collagen-based fibers) having lengths of less than 1 cm dispersed in an aqueous solution to obtain coacervated biopolymeric fibers having lengths of 10 to 1,000 cm; (2) flattening the coacervated biopolymeric fibers into a layer; (3) drying the layer; and (4) cross-linking the biopolymeric.

Biopolymeric membranes

The present invention relates to a conformable and semi-permeable biopolymeric membrane suitable for tissue repair and protection. This membrane contains a first layer made from randomly oriented, reconstituted biopolymer fibers and, on top of the first layer, a coating layer made from biopolymer fibers.

Biopolymeric membrane for wound protection and repair

This invention relates to a method for preparing a porous bone implant containing a calcium-based mineral. The method includes immersing a porous matrix in an acidic solution containing a calcium-based mineral; removing the matrix from the solution; and exposing the matrix to an alkali to neutralize the acidic solution, thereby causing precipitation of the calcium-based mineral to obtain a porous bone implant containing a calcium-based mineral.

Calcium-containing bone implants

A bone implant composite comprising a collagen matrix and a calcium-based mineral, the calcium-based mineral having a particle size of 25-2000 &#x3bc;m and being interspersed in the collagen matrix; wherein the bone implant composite contains 3-60% by weight the collagen matrix and 40-97% by weight the calcium-based mineral, and has a pore size of 50-500 &#x3bc;m, a density range of 0.02-0.8 g/cm, a tensile strength range of 0.4-100 kg/cm, and a compression modulus range of 0.2-10 kg/cm. Also disclosed are methods of preparing the above-described composite.

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Woodcliff Lake, NJ, United States of America

Debbie Yuen