A collagen-silica-based biocomposite for potential application in bone tissue engineering.

Bone is a hierarchical material that has inspired the design of biopolymer-derived biocomposites for tissue engineering purposes. The present study sought to synthesize and perform the physicochemical characterization and biocompatibility of a collagen-silica-based biocomposite for potential application in bone tissue engineering. Ultrastructure, biodegradability, swelling behavior, and biocompatibility properties were analyzed to gain insight into the advantages and limitations to the use of this biomaterial as a bone substitute. Scanning electron microscopy analysis showed a packed-collagen fibril matrix and silica particles in the biocomposite three-dimensional structure. As shown by analysis of in vitro swelling behavior and biodegradability, it would seem that the material swelled soon after implantation and then suffered degradation. Biocompatibility properties were analyzed in vivo 14-days postimplantation using an experimental model in Wistar rats. The biocomposite was placed inside the hematopoietic bone marrow compartment of both tibiae (n = 16). Newly formed woven bone was observed in response to both materials. Unlike the pure-collagen-tissue interface, extensive areas of osseointegration were observed at the biocomposite-tissue interface, which would indicate that silica particles stimulated new bone formation. Agglomerates of finely particulate material with no inflammatory infiltrate or multinucleated giant cells were observed in the bone marrow implanted with the biocomposite. The biocomposite showed good biocompatibility properties. Further studies are necessary to evaluate their biological behavior over time.