NEURAL CELL PATTERN-FORMATION ON GLASS AND OXIDIZED SILICON SURFACES MODIFIED WITH POLY(N-ISOPROPYLACRYLAMIDE)

Control over the adsorption of proteins and over the adsorption and sp atial orientation of mammalian cells onto surfaces has been achieved b y modification of glass and other silicon oxide substrates with poly(N -isopropylacrylamide) (PNIPAM). The functionalization of the substrate s was achieved either by a polymeranalogous reaction of aminosilanes w ith reactive N-(isopropylacrylamide) (NIPAM)-copolymers and by copolym erization of NIPAM with surface-bound methacrylsilane. The obtained co atings were characterized by FT-IR, ellipsometry, and surface plasmon resonance measurements. The adsorption of two proteins-fibrinogen and ribonuclease A-on these surfaces was studied in situ by real time surf ace plasmon resonance measurements. The PNIPAM grafted surfaces prepar ed by either chemical procedure inhibited the adsorption of both prote ins. More importantly they prevented the adhesion of neuroblasromaXgli oma hybrid cells cultured either in serum-free medium or in a medium c ontaining serum proteins. Deep-UV irradiation was used to perform abla tion processes and to create patterns permitting the examination of sp atially controlled adhesion and growth of cells. This study showed tha t patterned ultrathin polymer films on glass are suitable substrates f or controlling the interactions of cells with surfaces and are capable of directing the attachment and spreading of cells.