Biocompatibility of the Composite Scaffold of Sol―Gel Bioactive Glass/Collagen

Biomimetic scaffold for bone tissue engineering was prepared by mixing Sol―Gel bioactive glass with type I collagen through freeze―drying technique. In vitro, the biocompatibility of the scaffold was investigated by observing the adhesive, proliferative and differential behaviors of the rat mesenchymal stem cells (rMSCs). In vivo, the composite scaffold seeded with osteoblasts was implanted subcutaneously into the immunodeficient mice for 6w. It was proved that the composite scaffold was non―cytotoxic and suitable for cells’ proliferation, which was confirmed by the increase of double stranded DNA (ds DNA). The differentiation of rMSCs on the composite scaffold was also observed by positive expressions of alkaline phosphatase (ALP) and osteocalcin after osteoinduction for 14d. The results of general and histological observation showed that cells successfully spread on the surface and migrated into the interior of the scaffold. Moreover, bone formation analysis of cell―scaffold constructs in vivo showed that bone tissue and blood vessels were regenerated both inside and on the border of the scaffold―stack. All results demonstrate the Sol―Gel bioactive glass―type I collagen scaffold with good biocompatibility and osteogenesis is a new ideal scaffold for bone tissue repair and regeneration.