Preparation and Characterization of Gamma-Irradiated Porous Composite Containing UHMWPE, Hydroxyapatite, and Chitosan

Ultra-high molecular weight polyethylene (UHMWPE), hydroxyapatite (HA), and chitosan have been extensively utilized in the fields of bone regeneration because of their excellent biocompatibility. This study investigated the effect of chitosan concentrations and gamma irradiation on the physicochemical and mechanical properties of porous composites comprised of surface-modified UHMWPE, HA, and chitosan. A hot press method using sodium chloride as a porogen was successfully used to prepare the porous UHMWPE composites. Functional group analysis using Fourier transform infrared spectroscopy and water contact angle measurement revealed that the composites were modified due to oxidation in the UHWMPE and chitosan structures. Mechanical testing analyses demonstrated that the compressive strength values of the composites are similar to those reported for cancellous bone. The addition of chitosan significantly reduced the composite's stiffness and strength (p < 0.05), while gamma-irradiation up to 50 kGy had no significant effect (p > 0.05). These findings suggest that gamma-irradiation can be utilized to sterilize the composites without affecting their mechanical properties. Scanning electron microscope images revealed the pore interconnectivity and the successful integration of the components in the composites. These findings suggest that the composite has the potential to be used in bone regeneration.