Evaluation of Partially Demineralized Osteoporotic Cancellous Bone Matrix Combined with Human Bone Marrow Stromal Cells for Tissue Engineering: An In Vitro and In Vivo Study

Abstract

Allogenous demineralized bone matrix (DBM) represents a potential scaffold for bone tissue engineering due to its close relation in structure and function with autologous bone, but its supply is often restricted by donor availability. Thus, an expanded source of human bone is needed. The aim of this study was to evaluate the capacity of partially DBM scaffolds derived from allogenous cancellous bone of osteoporotic femurs to support osteogenesis of human bone marrow stromal cells (BMSCs) in vitro and in vivo in order to assess their potential use in bone tissue-engineering strategies. Human BMSCs of passage 2 were seeded either on osteoporotic bone-derived DBM scaffolds or on normal bone-derived scaffolds and cultured in osteogenic medium for 14 days. To assess the in vitro proliferation potential and osteogenic differentiation of BMSCs on scaffolds, scanning electronic microscopy observation, DNA content assays, and measurements of alkaline phosphatase activity and osteocalcin content were applied; the results displayed no significant differences between the osteoporotic DBM group and the normal DBM group. After 2 weeks of subculture in vitro, the BMSC/DBM composites were subcutaneously implanted into athymic mice for 8 weeks to evaluate their in vivo bone-forming ability. Histological examination showed tissue-engineered bone formation in the DBM pores in both groups, and no significant differences were observed in either the extent or frequency of new bone formation between these two groups. Based on these results, it can be concluded that osteoporotic bone-derived DBM may serve as a promising scaffold for bone tissue engineering.