The use of dynamic surface chemistries to control msc isolation and function

Material modifications can be used to induce cell responses, in particular–CH3 and –NH2 have shown potential in enhancing the ability of a material to support mesenchymal stem cell (MSC) adhesion and differentiation. Currently this process is variable, due to the lack of definition of controlled contextual presentation of the chemical group of interest across the surface. This paper defines the potential of –CH3 modified surfaces, with optimised dynamic surface chemistry, to manipulate initial MSC adhesive events, integrin binding, and subsequent cell function. An array of –CH3 silane modified glass substrates was produced using different –CH3 chain lengths and mechanisms of bonding to the base substrate. We show that changing the chain length affects the ability of the surfaces to support viable adult MSC adhesion, directly related to induced FGF release, and expression of STRO-1, CD29, 73, 90 and 105. Chlorodimethyloctylsilane (ODMCS) modified surfaces resulted in significant increases of associated adult MSC markers compared to all other –CH3 modified and control substrates. In contrast Dichlorodimethylsilane (DMDCS) modified surfaces did not support adult MSC adhesion due to high levels of early FGF release, which had an inhibitory effect on adult MSC culture, but enhanced the efficiency and cell selective properties of the substrate in isolation of multi-potent progenitor/MSC from adult human whole blood. Incorporation of optimised –CH3 groups is a cost effective route for producing substrates that significantly enhance MSC isolation and expansion, highlighting the potential of the optimised substrates to replace RGD and fibronectin modifications in selected applications.