Hybrid hydroxyapatite nanoparticles-loaded PCL/GE blend fibers for bone tissue engineering

In order to augment bone formation, a new biodegradable scaffold system was fabricated using different ratios of hydroxyapatite (HAp) blended with synthetic polymer polycaprolactone (PCL) and natural polymer gelatin (GE) followed by electrospinning method. Three different concentrations of HAp were used in PCL/GE to obtain a blend of 10, 30, and 50% (w/v) HAp-PCL/GE. These HAp-loaded PCL/GE blends were then compared with PCL/GE blends by different mechanical and biological in vitro and in vivo studies to understand the applicability of the system. Scanning electron microscopy, X-ray diffraction analysis, and tensile strength measurement were done to obtain physical properties. Fifty Percent HAp-PCL/GE blends possessed the highest mechanical strength. In vitro cytotoxicity and proliferation of osteoblast cells on the PCL/GE and HAp-PCL/GE scaffolds were examined and shown that addition of HAp in PCL/GE was beneficial by increasing cell viability (>85%) proliferation and cell-surface attachment. Expression of collagen and osteopontin was also found higher in 50% HAp-PCL/GE blends than the others. On the other hand, in vivo bone formation was examined using rat models and increased bone formation was observed in 50% HAp-PCL/GE blends within 6 weeks. Based on the combined results of this study, HAp-PCL/GE membranes were found to hold great promise for use in tissue engineering applications, especially in bone tissue engineering.