Modulating fibroblast adhesion, spreading, and proliferation using self-assembled monolayer films of alkylthiolates on gold

Ultrathin, highly organized functionalized alkylthiol monolayers were appli ed as model substrates for cell growth and protein adsorption studies. The aim of this approach was to improve the understanding of molecular surface determinants required for adhesion-dependent cell growth and proliferation using well-controlled surface chemistry. Carboxyl- and methyl-terminated al kylthiol monolayers on gold were used to monitor Swiss 3T3 fibroblast adhes ion, spreading, and growth. Stress fiber and focal contact formation were d etermined by immunostaining of actin filaments and paxillin. Fibronectin de position and conformation on these surface chemistries in the presence and absence of competing proteins were also determined. The relative levels of adsorbed fibronectin were assessed using radiolabeled proteins Exposure of the 10th type III cell integrin binding domain of fibronectin was assessed using a radiolabeled monoclonal antibody. Distinct alkylthiol substrate che mistry-dependent differences were observed in fibroblast adhesion, spreadin g, and growth. The formation of focal contacts and stress fibers was enhanc ed on the carboxyl-terminated surface relative to the methyl surface. Relat ive deposition and conformations of adsorbed fibronectin were shown to he d ependent on surface chemistry in both the presence and absence of competing proteins. The results indicated that well-controlled culture surfaces modu late differential cell adhesion, spreading, and growth through modulations of the amounts and conformations of adsorbed extracellular matrix molecules (e.g., fibronectin). (C) 2000 John Wiley & Sons, Inc.