Tailoring PLLA scaffolds for tissue engineering applications: Morphologies for 2D and 3D cell cultures

PLLA scaffold suitable for dermis regeneration were realized by Thermally Induced Phase Separation (TIPS) starting from a ternary solution PLLA/dioxane/water. The reconstruction of a complex tissues as the dermis implies the use of different cellular types (coculture), with different growth behaviour (2D vs. 3D). The scaffolds present an homogeneous porous surface to allow the keratinocytes 2D growth and a porous internal structure for the fibroblasts 3D growth. Our results show that the porosity of the surface can be tuned by changing the chemical nature of the sample holder (aluminium, teflon, polypropylene). A large variety of morphologies, in terms of average pore size and interconnection were obtained upon modifying the demixing time and temperature. WAXD analysis and DSC scanning tests showed only slight differences among the scaffolds prepared at the various conditions. Finally, a biocompatibility test was carried out by using human fibroblast and keratinocytes, indicating a good proliferation of the cells both on the surface and in the bulk of the scaffold.