SURFACE DETERMINANTS OF NEURONAL SURVIVAL AND GROWTH ON SELF-ASSEMBLED MONOLAYERS IN CULTURE

We have studied the modulation of hippocampal neuron morphological dev elopment in vitro using surfaces derivatized with aminosilane self-ass embled monolayers (SAMs). The efficacies of model SAMs. alone, or in c ombination with adsorbed heparan sulfate glycosaminoglycan (HS), are r elated to the physical and chemical properties of the surfaces. These properties are determined using X-ray photoelectron spectroscopy (XPS) , optical ellipsometry, and wettability measurements. The ability of s urfaces to promote somal adhesion and the maintenance of discrete neur ites appears to be sensitive to the density and accessibility of posit ively charged amine or amide groups, and has less of an apparent relat ionship to the surface density of uncharged amines. Aromatic ring-cont aining aminosilanes are ineffective in promoting neuron growth, while adsorbed HS augments the neurite-promoting capacity of one marginally adhesive SAM. These results are relevant to an improved understanding of the 'non-specific' contributions of the substrate in affecting neur onal development and the rational design of model surface coatings for neuronal culture.