New methodologies capable of extensively analyzing the cell-material interactions are necessary to improve current in vitro characterization methods, and proteomics is a viable alternative. Also, many studies are focused on monocultures, even though co-cultures model better the natural tissue. For instance, human mesenchymal stem cells (MSCs) modulate immune responses and promote bone repair through interaction with other cell types. Here, label-free liquid chromatography tandem mass spectroscopy proteomic methods were applied for the first time to characterize HUCPV (MSC) and CD14+ monocytes co-cultures exposed to a bioactive sol-gel coating (MT). PANTHER, DAVID, and STRING were employed for data integration. Fluorescence microscopy, enzyme-linked immunosorbent assay, and ALP activity were measured for further characterization. Regarding the HUCPV response, MT mainly affected cell adhesion by decreasing integrins, RHOC, and CAD13 expression. In contrast, MT augmented CD14+ cell areas and integrins, Rho family GTPases, actins, myosins, and 14-3-3 expression. Also, anti-inflammatory (APOE, LEG9, LEG3, and LEG1) and antioxidant (peroxiredoxins, GSTO1, GPX1, GSHR, CATA, and SODM) proteins were overexpressed. On co-cultures, collagens (CO5A1, CO3A1, CO6A1, CO6A2, CO1A2, CO1A1, and CO6A3), cell adhesion, and pro-inflammatory proteins were downregulated. Thus, cell adhesion appears to be mainly regulated by the material, while inflammation is impacted by both cellular cross-talk and the material. Altogether, we conclude that applied proteomic approaches show its potential in biomaterial characterization, even in complex systems.
Keywords: biomaterials; co-cultures; osteoimmunology; proteomics; sol−gel coatings.