In-vivo histocompatibility and osteogenic potential of biodegradable PLDLA composites containing silica-based bioactive glass fiber

The purpose of this two-year study was to evaluate the histocompatibility and osteogenic properties of a composite material consisting of poly(l-co-d,l lactide) (PLDLA) and silica-based bioactive glass fibers in vivo. PLDLA and PLDLA/silica-based bioactive glass fibers pins were implanted into the erector spinae muscles and femurs of beagles. Muscle and bone tissue samples were harvested 6, 12, 16, 26, 52, 78, and 104 weeks after implantation. Histology analysis was used to assess the histocompatibility, angiogenesis, and bone-implant contact. Micro-computed tomography was used to evaluate bone formation around the pins. Immunohistochemistry and western blotting revealed the expression level of the osteogenesis-related proteins. Addition of bioactive glass was demonstrated to possess better histocompatibility and reduce the inflammatory reactions in vivo. Moreover, PLDLA/silica-based bioactive glass fibers pins were demonstrated to promote angiogenesis and increase osteogenesis-related proteins expression, and thus played a positive role in osteogenesis and osseointegration after implantation. Our findings indicated that a composite of PLDLA and silica-based bioactive glass fiber is a promising biodegradable material for clinical use.