Heparin/Collagen Coatings Improve Human Mesenchymal Stromal Cell Response to Interferon Gamma

Mesenchymal stromal cells (MSC) are a promising source for cell-based therapies as they secrete a myriad of reparative factors in response to inflammatory stimuli. In this study, multilayers of heparin and collagen (HEP/COL) were used as a bioactive surface coating to enhance human MSC (hMSC) response to soluble interferon-gamma (IFN-gamma). Multilayers were formed, via layer-by-layer assembly, varying the final layer between COL and HEP and supplemented with IFN-gamma in the culture medium. hMSC adhesion, proliferation, and cytokine expression were assessed. Infrared variable angle spectroscopic ellipsometry confirmed film chemistry, thickness, and roughness. COL-ending films of 12 layers of HEP/COL had an average thickness of 129 +/- 5.8 nm, and 13 layers (HEP-ending) were 178 +/- 28.3 nm thick. Changes in temperature between 25-37 degrees C did not have significant effects on film chemistry, thickness, or roughness. An EdU incorporation assay revealed that IFN-gamma had an antiproliferative effect in all conditions evaluated except when hMSCs were cultured on HEP-ending films supplemented with IFN-gamma. Moreover, hMSCs cultured on HEP-ending films supplemented with IFN-gamma had a higher cytokine expression as compared with cells cultured on tissue culture polystyrene, COL-ending films with and without IFN-gamma, and HEP-ending films without IFN-gamma as measured by Luminex assay. Finally, immunostaining revealed strong integrin binding and FAK phosphorylation for each condition. This study shows that HEP/COL films can modulate hMSC response to soluble factors, which may be exploited in cell manufacturing practices.