| 초록 |
A non-woven ceramic/polymer composite fabric composed of randomly mixed bioactive and fast degradable SiO2-CaO gel fibers and biodegradable poly(ε-caprolactone) (PCL) fibers is prepared with a simultaneous electrospinning method for potential use as a bone grafting material. A 17% PCL solution is prepared using 1,1,3,3-hexafluoro-2-propanol as the solvent while the SiO2-CaO gel solution is prepared via a condensation reaction following hydrolysis of tetraethyl orthosilicate under acidic condition. PCL and SiO2-CaO gel solutions are spun simultaneously with two separate nozzles. As controls, pure PCL and SiO2-CaO gel non-woven fabrics are also made by the same methods. The three non-woven fabrics were exposed to simulated body fluid (SBF) for 1 week. SBF exposure resulted in the deposition of a layer of apatite crystals on the surfaces of both the SiO2-CaO gel and PCL/SiO2-CaO gel composite fabrics, but not on the PCL fabric. Observation on fractured surfaces of the SiO2-CaO gel and PCL/SiO2-CaO gel composite fabrics after SBF exposure showed that SiO2-CaO gel fibers were completely dissolved out from the apatite envelope in both specimens whereas PCL fibers remained intact in the apatite envelope. A tensile strength test showed that the fracture behavior of the SiO2-CaO gel fabric was brittle, that of the PCL fabric was ductile-tough, and that of the PCL/SiO2-CaO gel composite fabric was intermediate between that of the SiO2-CaO gel and PCL fabrics. Our in vivo tests showed that the SiO2-CaO gel, PCL/SiO2-CaO 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 SiO2-CaO gel fibers can be free from the risk of carcinogenesis due to fast degradation and low elastic modulus of SiO2-CaO gel fibers while maintaining bioactivity and adequate mechanical properties. Thus, this composite fabric must have great potential for use in applications such as bone grafting. |
