(17e) Producing Shape-Specific Scaffolds for T M J Tissue Engineering Utilizing Dense-Phase C O2

The temporomandibular joint (TMJ), or jaw joint, is one of the most challenging and fastest growing areas in tissue engineering, which requires scaffolds of complex geometries with biodegradable polymers. This study employed a novel compressed/supercritical CO₂ technique to produce polymeric foams composed of poly(lactide-co-glycolide) [PLGA] foams with controlled porosity and shape. Key scaffold properties such as the compressive modulus, porosity, and pore size could be controlled by the pressure, temperature, copolymer ratio, and venting-time of the process. Generally, porosity ranged from 75% to about 90%, which decreased with an increase in CO₂ pressure and increased with increased glycolide content in the co-polymer. Temperature had only a minor effect on the porosity of the material. Pore sizes could be created at different conditions from 20 to 300 μm. A variation in compressive modulus was also seen, with moduli ranging from 10 to 530 kPa. In addition, the ability of cells to adhere and proliferate on the scaffolds was evaluated. Most importantly, we were able to demonstrate that shape-specific PLGA scaffolds can be created in complex geometries, such as the TMJ condyle, without the use of organic solvents. Moreover, given the low temperature of the process (20°-40°C), this method has promise for encapsulating bioactive molecules for cellular proliferation and differentiation in the future.