Collaborative cell-resistant properties of polyelectrolyte multilayer films and surface PEGylation on reducing cell adhesion to cytophilic surfaces.

Both poly(ethylene glycol) (PEG) grafting and layer-by-layer polyelectrolyte multilayer (PEM) deposition for surface modification of biomaterials have been shown to decrease cell adhesion. The aim of this study was to investigate the synergic efficacy of PEGylated PEM films on reducing cell adhesion. PEG grafted to poly(ethylene imine) (PEI) was deposited onto the top of PEI/PAA (poly(acrylic acid)) multilayer films which were deposited onto cytophilic substrates, including tissue culture polystyrene and collagen-based substrate. The efficacy of the PEGylated PEM films in blocking adhesion of L929 cells was investigated by varying the amount of conjugated PEG and the layer numbers of PEM films. We found that cell adhesion was reduced on the swollen PEM films and further decreased by deposition of PEI-g-PEG as the topmost layer. The ability in cell resistance was enhanced with increasing PEG contents of PEGylated PEM films. PEGylated PEM films were stable for long-term incubation in phosphate-buffered saline. We demonstrated that cell affinity of cytophilic surfaces could be depressed by deposition of PEGylated PEM films.