Surface patterning of poly(L-lactide) upon melt processing: In vitro culturing of fibroblasts and osteoblasts on surfaces ranging from highly crystalline with spherulitic protrusions to amorphous with nanoscale indentations

Large-scale and reproducible manufacturing of scaffolds for tissue engineering applications will necessitate the adoption of methods relying on the processing of the biodegradable polymers directly from the melt. Such solventless processing will give rise to bulk and surface properties that will differ significantly from those generated upon processing from solution-based methods. Thus, detailed understanding of the microstructures that are developed during melt processing and the resulting surface/cell interactions is needed. Here, surfaces of melt-cast poly(L-lactide) (PLLA) were patterned to furnish membrane samples with a wide range of crystallinity and significant differences in surface topographies, ranging from highly crystalline (60%) with spherulitic protrustions at the surface to amorphous with nanoscale indentations. The PLLA membranes were used to culture in vitro mouse 3T3-Swiss albino fibroblast cells and osteoblast-like MC373-E1 cells. The growth rates of 3T3 fibroblasts were significantly lower on highly crystalline PLLA membranes with spherulitic protrusions and amorphous surfaces with 5-10-nm-deep indentations. However, the differences in the growth rates of osteoblast-like cells cultured on the PLLA membranes with different surface patterns were only marginally different. (C) 2008 Wiley Periodicals, Inc. J Biomed Mater Res 88A: 53-64, 2009