Preparation and Characterization of Polylactide-<i>co-</i>glycolide/Carbonate Apatite (PLGA/CHA) Composite Scaffolds

Abstract

Both natural and synthetic materials have been utilized to provide three dimensional scaffold environments ideal for bone repair. The biomechanical and biocompatibility characteristics of these scaffolds play a vital role in successful tissue engineering constructs. Polymer/carbonate apatite (CHA) composites have shown to improve cell adhesion and proliferation on the scaffold as well as increase elastic modulus, toughness and strength. The aim of this study is to prepare CHA- polylactic-co-glycolide (PLGA) composites in the form of microsphere, scaffold and disc and evaluate their physico-chemical properties, mechanical properties and in vitro bioactivity. 3-D porous cylindrical composite scaffolds were prepared using PLGA/CHA composites with varying PLGA/CHA ratios (30:70 and 50:50). The CHA was prepared by hydrolysis method and characterized using x-ray diffraction (XRD) and Fourier Transform Infrared spectroscopy (FTIR). The physico-chemical and mechanical properties of the composite scaffolds were evaluated using scanning electron microscopy (SEM), micro-computed tomography (μCT), XRD, FTIR, and thermogravimetry (TGA). Flexural strength was determined using Instron. In vitro bioactivity was determined by the formation of apatite on composite disc surfaces after immersion in simulated body fluid (SBF). SEM and μCT analyses showed high porosity and interconnectivity between microspheres in the composite scaffolds. In vitro bioactivity was observed by the development of an apatite layer on the surfaces of the composite scaffolds after immersion in simulated body fluid. The mechanical strength of the scaffolds was to be dependent on the PLGA-CHA ratio. The elastic modulus, toughness and strength values obtained for the composites were similar to those of reported bone substituted materials. Results from this study provided information on the fabrication of PLGA-CHA scaffolds and their properties that may be useful for their potential application in bone repair and as scaffolds in tissue engineering for bone regeneration.