| Synthetic, biodegradable polymer matrices are an integral part of an interdisciplinary field called Tissue Engineering. These matrices, or scaffolds, are generally highly porous with a well interconnected pore structure. Research into the desired pore size, mechanical properties, and biodegradability of scaffolds to support tissue growth has been extensive. Further research in this area promises to bring about revolutionary breakthroughs in tissue and organ replacement procedures.;While many techniques have been developed for manufacturing biodegradable polymer scaffolds for lab-scale research, there has been little focus on the development of a cost-effective, high-volume process. The high-volume techniques that have been explored have either fallen woefully short of scaffold requirements, such as porosity and interconnectivity, or they involve the use of organic solvents, which may be harmful to cells. This research aims to provide a novel method employing microcellular injection molding for the production of biodegradable scaffolds with high porosity and interconnectivity without the use of organic solvents.;Injection molding provides a cost-effective method to mass produce polymeric devices with complex three-dimensional shapes. The challenge in the injection molding of biodegradable scaffolds lies in the generation of porosity in the molded part. In this research, polylactide (PLA) was compounded with water-soluble polyvinyl alcohol (PVOH), sodium chloride (NaCl), and hydroxyapatite (HA) to create a series of novel composite blends. Utilizing microcellular injection molding and subsequent leaching of the samples in water resulted in PLA foams and PLA--HA composite foams of up to 84% porosity with high interconnectivity. The addition of the HA in the PLA matrix increased the compressive strength and modulus of the PLA--HA composite foams when compared to the PLA foams.;Future work involves the optimization of the material formulation and processing conditions to tailor the porosity, pore size, and mechanical properties. Utilization of multicomponent injection molding can be utilized to manufacture hybrid scaffolds with predetermined porosity, pore size, and mechanical properties conducive to bone and cartilage growth. Hybrid scaffolds show great promise for the repair of cartilage defects where they induce bone and cartilage formation in specific areas. |
