In Vitro Studies on Nanoporous, Nanotubular and Nanosponge-Like Titania Coatings, with the Use of Adipose-Derived Stem Cells

In vitro biological research on a group of amorphous titania coatings of different nanoarchitectures (nanoporous, nanotubular, and nanosponge-like) produced on the surface of Ti6Al4V alloy samples have been carried out, aimed at assessing their ability to interact with adipose-derived mesenchymal stem cells (ADSCs) and affect their activity. The attention has been drawn to the influence of surface coating architecture and its physicochemical properties on the ADSCs proliferation. Moreover, in vitro co-cultures: (1) fibroblasts cell line L929/ADSCs and (2) osteoblasts cell line MG-63/ADSCs on nanoporous, nanotubular and nanosponge-like TiO coatings have been studied. This allowed for evaluating the impact of the surface properties, especially roughness and wettability, on the creation of the beneficial microenvironment for co-cultures and/or enhancing differentiation potential of stem cells. Obtained results showed that the nanoporous surface is favorable for ADSCs, has great biointegrative properties, and supports the growth of co-cultures with MG-63 osteoblasts and L929 fibroblasts. Additionally, the number of osteoblasts seeded and cultured with ADSCs on TNT5 surface raised after 72-h culture almost twice when compared with the unmodified scaffold and by 30% when compared with MG-63 cells growing alone. The alkaline phosphatase activity of MG-63 osteoblasts co-cultured with ADSCs increased, that indirectly confirmed our assumptions that TNT-modified scaffolds create the osteogenic niche and enhance osteogenic potential of ADSCs.