Synthesis of Poly (L-Lactic Acid) Scaffolds Under Controlled Freezing Conditions

Poly (l-lactic acid) (PLLA) scaffolds for bone grafts were prepared by using Thermally Induced Phase Separation (TIPS) method. Solutions of PLLA-dioxane was formed by dissolving a pre-determined value of PLLA in dioxane (3, 7 and 10% wt/vol) at 323K. These solutions were frozen at controlled cooling rates (1, 10 and 40°C/min) in cylindrical capsules. The frozen solutions were freeze-dried for a period of 48 hours for the frozen dioxane to completely sublimate, leaving the porous PLLA scaffold. The scaffolds which were formed under different processing conditions were characterized in terms of porosity, pore sizes and compressive moduli.