Abstract: Biological-based polyurethanes and methods of making the same. The polyurethanes are formed by reacting a biodegradable polyisocyanate (such as lysine diisocyanate) with an optionally hydroxylated biomolecule to form polyurethane. The polymers formed may be combined with ceramic and/or bone particles to form a composite, which may be used as an osteoimplant.

Abstract: An implant system for fusing vertebrae includes a variety of shapes that may be stacked to accommodate different intervertebral spacings and curvatures. The implants comprise polymer-bone composites that have osteogenic properties. By selection of an appropriate set of shapes, the surgeon can tailor the overall shape of the implant before or during surgery, in order to best match the shape of the intervertebral cavity for a particular patient.

Abstract: An implant including a substantially cohesive aggregate comprising bone-derived particles. Cohesiveness is maintained by a member of mechanical interlocking, engagement of adjacent bone-derived particles with one another through engagement with a binding agent, thermal bonding, chemical bonding, or a matrix material in which the bone-derived particles are retained. The aggregate is shaped as a one-dimensional or two-dimensional body.

Abstract: An implant including a cell conducting phase and a binder phase. At least a portion of the surface of the implant includes the cell conducting phase, and the cell conducting phase defines a path from the surface of the implant to an interior of the implant.

Abstract: Biological-based polyurethanes and methods of making the same. The polyurethanes are formed by reacting a biodegradable polyisocyanate (such as lysine diisocyanate) with an optionally hydroxylated biomolecule to form polyurethane. The polymers formed may be combined with ceramic and/or bone particles to form a composite, which may be used as an osteoimplant.

Abstract: The invention provides a method for the preparation of bone-polymer composites wherein the mineral portion of the bone is treated with a coupling agent before being incorporated into a biocompatible polymeric matrix. The resulting composites may be used as such or be further processed to form an osteoimplant.

Abstract: A method of producing a bone-polymer composite. The method comprises the steps of providing a plurality of bone particles, combining the bone particles with a polymer precursor, and polymerizing the polymer precursor.

Abstract: An improved demineralized bone matrix (DBM) or other matrix composition is provided that has been mixed with a stabilizing agent that acts as (1) a diffusion barrier, (2) a enzyme inhibitor, (3) a competitive substrate, or (4) a masking moiety. A diffusion barrier acts as a barrier so as to protect the osteoinductive factors found in DBM from being degraded by proteolytic and glycolytic enzymes at the implantation site. Stabilizing agents may be any biodegradable material such as starches, modified starches, cellulose, dextran, polymers, proteins, and collagen. As the stabilizing agents degrades or dissolves in vivo, the osteoinductive factors such as TGF-&bgr;, BMP, and IGF are activated or exposed, and the activated factors work to recruit cells from the preivascular space to the site of injury and to cause differentiation into bone-forming cells. The invention also provides methods of preparing, testing, and using the inventive improved osteodinductive matrix compositions.

Abstract: A malleable implant for implantation into living tissue is prepared having access means for cells into the interior of the implant. The implant is capable of being deformed under pressure required to insert the implant into an implant site. The access means can be hollow or solid. The solid comprises a material that more rapidly resorbs in vivo than the malleable implant to provide channels, or comprises a mechanically weak material that fractures under force at an implant site to produce channels or cracks. The access means may be inserted in the malleable implant at an implant site. A multilaminar structure may be formed having layers of malleable implant and layers of access means, or the access means may be heterogeneously distributed throughout the malleable implant. A kit can contain a powder such as calcium phosphate for making a paste implant material, and an access means insertable into the paste.

Abstract: A line of .beta. cells is described which is capable of maintaining high levels of insulin secretion in culture. Such cells are useful in the treatment of diabetes, for example, by encapsulation of the cells in an insulin-permeable membrane device, followed by implantation into a diabetes patient.

Abstract: A cell culture of correctly regulated .beta.-cells having enhanced secretion of insulin is described. A method of selecting such correctly regulated .beta.-cells is also described comprising the following steps:(a) providing a population of cells comprising .beta.-cells in which increased intracellular concentrations of calcium ions is correlated with the extracellular presence of glucose;(b) exposing the population to a vital calcium-activated labelling agent;(c) exposing the population to glucose in a concentration sufficient to result in secretion of the insulin; and(d) selecting from the population, cells which exhibit a higher level of intracellular free calcium or insulin secretion when exposed to said concentration.

Abstract: A method of selecting cells with enhanced secretion of a secretory product is disclosed. The method comprises exposing a population of cells to a secretagogue to result in the secretion of a secretory product from the cells and selecting from the population, cells that exhibit increased amounts of intracellular free calcium when exposed to the secretagogue. The method enables the selection of correctly regulated .beta. cells that secrete appropriate amounts of insulin in response to varying glucose levels.