Degradation of bone matrix morphogenetic activity by pulverization.

The yield of new bone from implants of pulverized demineralized whole matrix and bone matrix gelatin declines as the particle size decreases in diameter below 125 microns. The corresponding increase in surface area and mechanically-induced free radicals is associated with an increase in solubility of bone matrix proteins. These changes in physiocochemical properties and the concomitant reduction in bone yield suggest that prolonged pulverization denatures a bone morphogenetic protein (BMP).