Low-modulus Mg/PCL Hybrid Bone Substitute for Osteoporotic Fracture Fixation

In this paper, we describe a new biodegradable composite composed of polycaprolactone and magnesium. Incorporation of magnesium micro-particles into the polycaprolactone matrix yields mechanical properties close to those of human cancellous bone, and in vitro studies indicate that the silane-coated Mg/PCL composites have excellent cytocompatibility and osteoblastic differentiation properties. The bioactivity of the composites is manifested by the formation of calcium and phosphate after immersion in simulated body fluids. The bulk mechanical properties can be maintained for 2 months before obvious degradation takes place. The in vivo animal study reveals a larger amount of new bone formation on the silane-coated Mg/PCL composites compared to conventional PMMA and pure polycaprolactone and our results suggest potential clinical applications of the sliane-coated Mg/PCL composites.