A new recombinant human bone morphogenetic protein-2 carrier for bone regeneration

A gelatin sponge was formed by foaming and heat treating a gelatin solution , followed by coating the solid with poly(D, L-lactic-co-glycolic acid) to reinforce the gelatin framework. This sponge was tested for its suitability as a biodegradable porous, recombinant human bone morphogenetic protein (r hBMP)-2 carrier. Incorporation of rhBMP-2 into the sponge was closely relat ed to its bulk density of gelatin sponge. The calcium content in the sponge s, as assessed by an ectopic bone formation assay in rats, increased with t he increasing sponge bulk density. Histologic and peripheral quantitative c omputed tomography analysis of implants in this ectopic assay system reveal ed cell growth throughout the carrier in 4 weeks after implantation regardl ess gelatin bulk density. The carrier containing rhBMP-2 maintained its thr ee-dimensional structure after implantation; the carrier resisted collapse caused by soft tissue pressure during rapid bone formation as assessed by s oft X-ray photographs. These results indicate that this newly developed spo nge has excellent carrier characteristics to introduce rhBMP-2 into areas n eeded for bone regeneration. (C) 2001 Elsevier Science B.V. All rights rese rved.