SPATIAL CONTROL OF NEURONAL CELL ATTACHMENT AND DIFFERENTIATION ON COVALENTLY PATTERNED LAMININ OLIGOPEPTIDE SUBSTRATES

The spatial control of neuronal cell attachment and differentiation vi a specific receptor mediated interactions, may provide an effective me ans for the in vitro reconstruction of neuronal cell architecture. In this study, receptor-specific oligopeptide sequences derived from the extracellular matrix (ECM) molecule laminin, a potent neural cell atta chment and differentiation promoter were covalently bound on fluorinat ed ethylene propylene (FEP) films. The degree of receptor-specific cel l attachment and the ability to spatially control neurite outgrowth by covalently patterning the oligopeptide sequences on the FEP film surf ace were assessed. FEP films were first chemically activated with a Ra dio Frequency Glow Discharge (RFGD) process that covalently replaces t he surface fluorine atoms with reactive hydroxyl groups. Oligopeptides containing the YIGSR sequence from the B1 chain of laminin and the wa ter soluble oligopeptide containing the IKVAV sequence (CSRARKQAASIKVA VSADR) from the A chain were covalently bound to the hydroxylated FEP films. Electron Spectroscopy for Chemical Analysis (ESCA) verified the covalent attachment of the oligopeptides to the material surface. The degree of receptor mediated NG108-15 call attachment on immobilized C DPGYIGSR films was determined using competitive binding media. A 78% r eduction in cell attachment was observed on films containing CDPGYIGSR in the cell plating medium. Only a 23% reduction in cell attachment w as noted on films plated in medium containing a mock CDPGYIGSK sequenc e. FEP films immobilized with the IKVAV oligopeptide sequence were sho wn to mediate PC12 cell attachment and a competitive binding medium al so significantly attenuated cell attachment on the immobilized films. The spatial patterning of these oligopeptide sequences to the FEP surf ace was shown to localize cell attachment and neurite extension on the patterned pathways. The surrounding unmodified FEP surface was inhibi tory in serum containing medium and prevented cellular interactions ou tside the oligopeptide modifications. The spatial immobilization of la minin oligopeptides on FEP films provides a means to organize the atta chment and differentiation of neuronal cells in a receptor-specific ma nner.