Generation of porous microcellular 85/15 poly (DL-lactide-co-glycolide) foams for biomedical applications.

Porous 85/15 poly (DL-lactide-co-glycolide) or PLGA foams were produced by the pressure quench method using supercritical CO2 as the blowing agent. The rate of CO2 uptake and CO2 equilibrium concentration in PLGA at different processing conditions were studied by performing sorption experiments. The effects of saturation pressure and temperature on average cell size and relative density of the resulting foams were also studied. The time required to approach equilibrium exhibited a minimum with increasing saturation pressure. The diffusion coefficient and equilibrium concentration of CO2 in PLGA increased with an increasing pressure in an approximately linear relationship. Porous PLGA foams were generated with relative densities ranging from 0.107 to 0.232. Foams showed evidence of interconnected cells with porosities as high as 89%. The pore size ranged from 30 to 100 microm.