A Composite Foam of Dermal Matrix-Demineralized Bone Matrix for Enhanced Bone Regeneration

Allogenic demineralized bone matrix (DBM) is widely used for bone repair and regeneration due to its osteoinductivity and osteoconductivity. The present study utilized acellular dermis microfibers to improve the DBM's clinical handling properties and to enhance bone regeneration. Donated human cadaver skin was de-epidermized and decellularized to be acellular dermal matrix (ADM), which was further processed into microfibers. Donated human bone was micronized and partially demineralized (∼30% calcium removal) for optimal bone regeneration. A flexible ADM/DBM composite foam was fabricated with ADM microfibers and DBM particles. Structural analysis found that the ADM/DBM composite foam had proper porosity with interconnected micropores and rapid wettability, and good stability upon cyclic compressions, whereas cytotoxicity test, in vitro collagenase degradation, and rat subcutaneous implantation showed good biocompatibility and biodegradability. The composite foam, used for in vitro coculture, significantly increased the alkaline phosphatase activity of C2C12 cells and upregulated the expression of osteogenesis-related genes of human umbilical cord mesenchymal stem cells. Using the rat Φ8 mm calvarium defect repair model, the ADM/DBM composite foam demonstrated superior osteogenicity by rapidly inducing new bone formation and achieving complete closure of the bone defects, as compared with the commercially available bone graft for skull repair (SkuHeal). Therefore, the ADM/DBM composite foam holds promise as a superior DBM-based product for repairing critical bone defects.