Surface modification of closed plastic bags for adherent cell cultivation

In modern human mesenchymal stem cells are gaining increasing importance. Usein helium-based gas mixtures (He+N2+H2) as well as helium enriched with suitable film- forming agents the inner surface of polymer bags can be modified with a plasma process development at Fraunhofer IST. The effect of plasma treatment in investigated by FTIR-ATR spectroscopy as well as surface tension determination based on contact angle measurements. Plasma treatment in nominally pure helium increases the surface tension of the polymer foil due to the presence of oxygen traces in the gas and oxygen diffusing through the gas-permeable foil, resp., reacting with surface radical centres formed in the discharge. For the same reason the area density of primary amino groups on the surface obtained by treatment in mixtures with nitrogen is comparably small. With regard to their applicability in cell cultivation three different coatings (bases on APTMS, DACH and TMOS) were tested. It is shown that primary amino groups play an important role in cell cultivation of adherent growing bone marrow mesenchymal stem cells.