A novel nanocomposite and its application in repairing bone defects

Many commercial bone graft substitutes (BGS) and experimental bone tissue engineering scaffolds have been developed for bone repair and regeneration. Among them, sol-gel processed bioactive glasses showed promise due to their unique nanostructure. This study reports the in vivo bone regeneration using a newly developed porous bioactive and resorbable nanoscomposite that is composed of nano-bioactive glass (BG), collagen (COL), hyaluronic acid (HYA) and phosphatidylserine (PS), BG-COL-HYA-PS. The nanocomposite was prepared by a combination of sol-gel and freeze-drying methods. A rabbit radius defect model was used to evaluate bone regeneration at time points of 2, 4 and 8 weeks. Techniques including radiography, histology, fluorescent marker, and micro-CT were applied to characterize the new bone formation. In addition, ectopic bone formation was also investigated for the osteoinductivity of the materials. 8 weeks´ results showed that (1) nearly complete bone regeneration was achieved for the BG-COL-HYA-PS nanocomposite that was combined with a bovine bone morphogenetic protein (BMP); (2) partial bone regeneration was achieved for the BG-COL-HYA-PS composites alone; and (3) control remained empty. This study demonstrated that the novel BG-COL-HYA-PS nanocomposite with or without the grafting of BMP, is a promising BGS or a tissue engineering scaffold for non-load bearing orthopaedic applications.