Manufacturing and morphology structure of polylactide-type microtubules orientation-structured scaffolds

Tissue engineering using scaffold not only should have biodegradability and a certain 3D structure, but also its morphology structure should be mimetic to that of the repaired natural tissue. So to manufacture the scaffold with a biomimetic structure as the natural tissues is important. In this research, highly porous poly(l-lactic acid) (PLLA) and poly(l-lactic-co-glycolic acid) (PLGA) scaffolds with microtubules orientation structure were designed and fabricated by using dioxane as solvent and an improved thermal-induced phase separation (TIPS) technique. All the factors which will affect solvent crystallization and microtubules orientation structure of the scaffold, such as the type of the solvent and polymer, concentration of the polymer solution, and temperature-gradient of the system have been studied carefully. So the porosity, diameter, tubular morphology and orientation of the microtubules could be controlled by adjusting the concentration of the polymer solution and temperature-gradient of the system. The scaffold with diameter of microtubules from 40 to 240 μm and high porosity up to 96% could be obtained by adjusting temperature-gradient during the TIPS process. By increasing concentration of the polymer solution the regularity of the microtubular scaffold has been improved and the thickness of wall of the microtubules has been increased as well. In vitro cell culture results show that after the scaffolds have been improved by the ammonia plasma treatment and then collagen anchorage method, the human transparent cartilage cells H144, could be seeded deeply into the microtubules orientation-structured scaffolds and grew well there.