Development of a 95/5 poly(L‐lactide‐co‐glycolide)/hydroxylapatite and β‐tricalcium phosphate scaffold as bone replacement material via selective laser sintering

Abstract

95/5 Poly(L-lactide-co-glycolide) was investigated for the role of a porous scaffold, using the selective laser sintering (SLS) fabrication process, with powder sizes of 50-125 and 125-250 microm. SLS parameters of laser power, laser scan speed, and part bed temperature were altered and the degree of sintering was assessed by scanning electron microscope. Composites of the 125-250 microm polymer with either hydroxylapatite or hydroxylapatite/beta-tricalcium phosphate (CAMCERAM II were sintered, and SLS settings using 40 wt % CAMCERAM II were optimized for further tests. Polymer thermal degradation during processing led to a reduction in number and weight averaged molecular weight of 9% and 12%, respectively. Compression tests using the optimized composite sintering parameters gave a Young's modulus, yield strength, and strain at 1% strain offset of 0.13 +/- 0.03 GPa, 12.06 +/- 2.53 MPa, and 11.39 +/- 2.60%, respectively. Porosity was found to be 46.5 +/- 1.39%. CT data was used to create an SLS model of a human fourth middle phalanx and a block with designed porosity was fabricated to illustrate the process capabilities. The results have shown that this composite and fabrication method has potential in the fabrication of porous scaffolds for bone tissue engineering.