A novel, composite scaffold for bone repair

Biodegradable polymer-ceramic composite scaffolds have gained importance in recent years in the field of orthopedic biomaterials and tissue engineering scaffolds in order to improve limited mechanical properties of bioactive ceramics. In this study, electrospun composites consisting of 20%hydroxyapatite/80%szlig-tricalciumphosphate and poly(epsiv-caprolactone) were fabricated. For electrospinning, poly(epsiv-caprolactone) was dissolved in either methylene chloride (composite-MC) or a combination of methylene chloride (80%) and dimethylformamide (20%) (Composite-MC+DMF). Composite-MC mats contained a bimodal distribution of fiber diameters with nanofibers in between larger, micron-sized fibers. Fiber size, pore size and porosity of composite-MC mats were significantly higher than those produced by composite-MC+DMF. Scanning electron microscope.energy dispersive X-ray analysis (SEM-EDXA) confirmed the presence of calcium and phosphorous and that the ceramic was uniformly dispersed in the mats. Thermal analyses results showed that the ceramic acted as a nucleating agent and also showed that there is molecular interaction between the polymer and ceramic in the electrospun composites. The osteogenic differentiation of human mesenchymal stem cells on the mats was performed. Alkaline phosphatase activity, which is a marker for an osteoblast, was higher on composite-MC. Microscopy data demonstrated a mineralized extracellular matrix was deposited on the composite mats, but not on the pure polymer mats.