Surface-initiated ATRP modification of tissue culture substrates: poly(glycerol monomethacrylate) as an antifouling surface.

Surface-initiated atom transfer radical polymerization (SI-ATRP) can be used to produce conformal coatings of controlled thickness on virtually any surface, providing to it specific physico-chemical and biological properties. Here we have tackled the problem of modulating cell adhesion on typical culture substrates; tissue culture polystyrene (TCPS) offers a number of favorable properties (optical transparency, chemical stability, sterilizability, availability in a wide variety of shapes) but somehow limited biological function. A fine tuning of cell adhesion can, on the contrary, allow better control cell phenotype during cell expansion or, by using responsive polymers, allow attachment/detachment cycles with reduced cell damage. Here we have optimized a procedure of TCPS surface oxidation to allow the adsorption of cationic macroinitiators and the successive growth of surface-born polymer chains, producing films with controlled thickness. We have specifically focused our attention on the preparation of films containing poly(glycerol monomethacrylate) (PGMMA), showing that PGMMA is nontoxic but nonadhesive to cells, possibly providing "stealth" surfaces. Cell adhesion can be reinstated by copolymerizing GMMA with other monomers: films containing N,N-dimethylamino ethyl methacrylate (DMAEMA; in the surface-grown films this monomer is substantially hydrophobic at physiological pH) together with GMMA provided cell attachment and spreading to comparable to TCPS. Last, cell circularity was here shown to be a valid reporter for the assessment of cell spreading.