The Effect of Nano Hydroxyapatite Particles on Morphology and Mechanical Properties of Microcellular Injection Molded Polylactide/Hydroxyapatite Tissue Scaffold

摘要

The current large demands for transplant organs and tissues has led to extensive research on material synthesis and fabrication methods for biodegradable polymeric scaffolds, which are required to have high porosity, well interconnected pore structure, and good mechanical properties. However, the majority of current scaffold fabrication techniques are either for batch processes or use organic solvents, which can be detrimental to cell survival and tissue growth. The ability to mass produce solvent-free, highly porous, highly interconnected scaffolds with complex geometries is essential to provide off-the-shelf availability [1]. Injection molding has long been used for mass production of complex 3D plastic parts. The low-cost manufacturing, repeatability, and design flexibility inherent in the injection molding process make it an ideal manufacturing process to create 3D scaffolds, as long as high porosity and interconnectivity can be imparted into the finished product. One challenge commonly present when producing highly porous polymeric scaffolds designed for bone tissue engineering is that they generally have a lower compressive modulus and strength when compared to human bone [2]. A match in compressive modulus between the implant (scaffold) and natural tissue is essential due to the fact that any elastic mismatch between the two components is likely to result in debonding under any applied stress [3]. Therefore, fillers such as hydroxyapatite (HA) have been employed to modify the mechanical properties of polymeric scaffolds to more closely match those of bone.