Surface chemical functionalities affect the behavior of human adipose-derived stem cells in vitro

This study examines the effect of surface chemical functionalities on the behavior of human adipose-derived stem cells (hASCs) in vitro. Plasma polymerized films rich in amine (single bondNH2), carboxyl (single bondCOOH) and methyl (single bondCH3), were generated on hydroxyapatite (HAp) substrates. The surface chemical functionalities were characterized by X-ray photoelectron spectroscopy (XPS). The ability of different substrates to absorb proteins was evaluated. The results showed that substrates modified with hydrophilic functional group (single bondCOOH and single bondNH2) can absorb more proteins than these modified with more hydrophobic functional group (single bondCH3). The behavior of human adipose-derived stem cells (hASCs) cultured on different substrates was investigated in vitro: cell counting kit-8 (CCK-8) analysis was used to characterize cell proliferation, scanning electronic microscopy (SEM) analysis was used to characterize cell morphology and alkaline phosphatase (ALP) activity analysis was used to account for differentiation. The results of this study demonstrated that the single bondNH2 modified surfaces encourage osteogenic differentiation; the single bondCOOH modified surfaces promote cell adhesion and spreading and the single bondCH3 modified surfaces have the lowest ability to induce osteogenic differentiation. These findings confirmed that the surface chemical states of biomaterials can affect the behavior of hASCs in vitro.