Substrate hydroxylation and cell adhesion

Adhesion of BHK cells to a variety of polymer surfaces carrying measured densities of hydroxyl and carboxyl groups was studied. The effects on cell adhesion of blocking hydroxyl groups by acetylation and carboxyl groups with diazomethane were measured. Hydroxyl groups were required for cell adhesion, though the very high surface densities of these groups diminished cell adhesion. The optimal surface density of OH groups for BHK adhesion was 2000 per 1 × 10−11cm2. Carboxyl groups slightly inhibit cell adhesion, since blocking of these groups by methylation increased adhesion. The role of oxidizing systems of cellular origin in conditioning of the substrate, in serum-free conditions, was demonstrated for leucocytes and BHK cells, in particular by the result that oxidizable substrates such as phytane and poly(1,2-butadiene) could be made suitable for cell adhesion by contact with cells.