Abstract: An enhanced osteoinductive composition is prepared by subjecting particulate bone to a demineralization process that is optimized based on the particle size. In broad particle size ranges, ground bone is separated by particle size and each size range is subjected to independent demineralization conditions that maintain high levels of endogenous growth factors found in bone. Following demineralization, the size ranges are recombined to create an enhanced osteoinductive composition. In narrow particle size ranges, bone is milled to achieve a predetermined size, and the demineralization process is adjusted to this size range. Size-optimized demineralization is also used to create enhanced demineralized bone matrix particles in the size range of <125 ?m. Enhanced osteoinductive compositions using size-optimized demineralization bone matrix and protein isolation and/or bone gelatin creation techniques are disclosed. Tissue repair compositions using the enhanced osteoinductive particles are also disclosed.