Osteoconductive and degradable electrospun nonwoven poly(ε- caprolactone)/CaO-SiO2 gel composite fabric

Abstract

A nonwoven ceramic/polymer composite fabric composed of randomly mixed bioactive and fast degradable CaO-SiO2 gel fibers and biodegradable poly(ε-caprolactone) (PCL) fibers is prepared with a simultaneous electrospinning method for potential use as bone grafting materials. A 17% PCL solution is prepared using 1,1,3,3-hexafluoro-2-propanol as the solvent, whereas the CaO-SiO2 gel solution is prepared via a condensation reaction following the hydrolysis of tetraethyl orthosilicate. PCL and CaO-SiO 2 gel solutions are spun simultaneously with two separate nozzles. As controls, pure PCL and CaO-SiO2 gel nonwoven fabrics are also made by the same methods. The three nonwoven fabrics were exposed to simulated body fluid for 1 week and resulted in the deposition of a layer of apatite crystals on the surfaces of both the CaO-SiO2 gel and PCL/CaO-SiO2 gel composite fabrics, but not on the PCL fabric. A tensile strength test showed that the fracture behavior of the CaO-SiO2 gel fabric was brittle, that of the PCL fabric was ductile-tough, and that of the PCL/CaO-SiO 2 gel composite fabric was intermediate between that of the CaO-SiO2 gel and PCL fabrics. Our in vivo tests showed that the CaO-SiO2 gel and PCL/CaO-SiO2 gel composite fabrics had good osteoconductivity and fast degradation rates in calvarial defects of New Zealand white rabbits within 4 weeks, in contrast to the pure PCL fabric. Together, these results suggest that the composite fabric composed of PCL and CaO-SiO2 gel fibers must have a great potential for use in applications such as bone grafting because of its good osteoconductivity and adequate mechanical properties.