Self-expandable biopolymer-mineral composite
Inventors
Li, Shu-Tung • Chen, Hui-Chen • Yuen, Debbie
Assignees
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Publication Number
US-8877220-B2
Publication Date
2014-11-04
Expiration Date
Abstract
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.
Core Innovation
The invention provides a compressed implant composite for repairing mineralized tissue. The composite includes a cross-linked matrix formed of biopolymeric fibers and a plurality of calcium- 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.
The composite is free of soluble collagen and is self-expandable to a volume 2 to 100 times of its compressed volume. The self-expansion is associated with hydration by water or body fluid, where the composite forms a porous scaffold by expansion in a defect site. The document describes material property ranges for the composite, including pore size about 25 to 350 µm and density about 0.05 to 0.8 g/cm3.
The biopolymeric-fiber matrix can include insoluble collagen, while the mineral particles can include carbonate apatite and other calcium phosphate or calcium sulfate minerals, or silicate-based bioactive glasses such as 45S5. The composite is prepared using a sequence that includes dispersing or homogenizing the fibers in an aqueous solution, mixing with the mineral particles, freeze-drying, cross-linking, and compressing to a compressed implant composite.
Claims Coverage
The patent includes one independent claim defining the compressed, cross-linked biopolymeric-fiber/mineral composite for mineralized tissue repair, with multiple dependent claims adding quantitative refinements and specific material chemistries. The independent claim is complemented by dependents that constrain expansion behavior, particle size, density, pore/scaffold properties, and fiber/mineral types, and that include preparation sequences for the composite.
Compressed implant composite for repairing mineralized tissue
A compressed implant composite comprising a cross-linked matrix formed of biopolymeric fibers and a plurality of calcium- or silicate-based mineral particles dispersed in the matrix, where the matrix constitutes 4 to 80% by weight, the mineral particles constitute 20 to 96% by weight, the composite is free of soluble collagen, and the composite is self-expandable to a volume 2 to 100 times of its compressed volume.
Expanded self-expansion volume range
The composite can expand to a volume 5 to 50 times its compressed volume.
Calcium- or silicate-based mineral particle size range
The composite comprises calcium- or silicate-based mineral particles having a particle size between 0.001 mm and 5 mm.
Self-expanded density range
When the composite undergoes self-expansion, it has a density in the range of 0.05 g/cm3 to 0.8 g/cm3.
Insoluble collagen biopolymeric fibers
The biopolymeric fibers are insoluble collagen fibers.
Manufacturing sequence for a bone implant composite
A method for preparing a bone implant composite by dispersing biopolymeric fibers in aqueous solution to make a suspension, homogenizing it, mixing it with calcium- or silicate-based mineral particles, freeze-drying, crosslinking, and then compressing the resulting composite.
Overall, claim coverage centers on a self-expandable compressed implant composite with a cross-linked biopolymeric-fiber matrix and dispersed calcium- or silicate-based mineral particles, explicitly excluding soluble collagen and requiring expansion to a defined multiple of the compressed volume. Dependent claims further refine expansion range, mineral particle size, expanded density, fiber type as insoluble collagen, and add a specific preparation sequence including dispersion or homogenization, mineral mixing, freeze-drying, crosslinking, and compression.
Stated Advantages
Provides a self-expandable composite that can increase volume 2 to 100 times of its compressed volume upon hydration.
Is free of soluble collagen.
Enables formation of a porous scaffold by expansion in a defect site.
Documented Applications
Repairing mineralized tissue, including bone and teeth, using the compressed implant composite that expands at a defect site to form a porous scaffold.
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