High Performance Composites of Bioactive Glass Fibers Reinforced Degradable PCL-b-PLLA Potential for Load-bearing Bone Repair

Abstract

High performance is the necessary property for materials to repair load-bearing bones. devices. The elastic moduli of conventional metals such as stainless steel and titanium alloys are significantly higher than those of human cancellous and cortical bone, leading to severe stress shielding effects and requiring secondary surgery for removal. The insufficient mechanical strength of biodegradable polymers or hydroxyapatite-blended biodegradable polymers limits their applications in load-bearing bone repair. In this paper, we developed bioactive glass fibers reinforced biodegradable polymer composites for the repair of load-bearing bones. The biodegradable polymer matrix was poly(ε-caprolactone)-b-poly(L-lactide) diblock copolymers. Bioactive glass 13-93 was melt-spun into continuous fibers and subsequently laminated with the diblock copolymers through hot pressing. The melt-spinning of bioactive glass fiber and composite manufacturing were investigated. The composites with the glass fibers of 30 wt% and 50 wt% were prepared, the mechanical testing revealed that the elastic modulus of the composite plates containing 50 wt% bioactive glass fibers was as high as approximating 5 GPa, which exceeded the human cancellous bone and approached the range of cortical bone modulus. The biocompatibility tests revealed that the composites were not cytotoxic and promoted osteoblast mineralization. With the Addition of bioactive glass fibers, the composites exhibited excellent antibacterial properties to Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The bioactive glass fibers reinforced PCL-b-PLLA composites are favorable for the reparation of load-bearing bones.