Evaluation of Plasma Modified Polycaprolactone Honeycomb Scaffolds by Human Mesenchymal Stem Cells Cultured in Vitamin D Differentiation Medium

Polycaprolactone (PCL) scaffolds with a honeycomb (hc) microstructure have been prepared, modified at surface level by plasma processes and evaluated with human mesenchymal stem cells (hMSCs). Thin scaffolds were fabricated by self-assembly of PCL in the presence of an amphiphilic copolymer under controlled humidity. The surface of the so formed PCLhc scaffolds was modified by Ar and Ar-O-2 plasma discharges and by plasma deposition of allylamine (ALA). Such modification induces composition changes and microstructure modifications as determined by Fourier transformed infrared spectroscopy and scanning electron microscopy. As a consequence of these treatments, the hydrophobic character of PCLhc scaffolds is rectified as derived from water contact angle measurements. The hMSC cytocompatibility of these scaffolds was initially assayed under proliferation conditions evaluating surface cell interactions by fluorescence and confocal microscopy. Most relevant behaviour was observed for hMSCs cultured onto ALA modified scaffolds in view of the cytoskeleton polarization. These modified surfaces were further explored for differentiation of hMSCs in the presence of vitamin D, giving rise to secreting vesicles and increased extension of the cytoskeleton. These results are promising for the development of cell monolayer tissue regenerating platforms.