Surface modification of electrospun fibers with polyelectrolyte multilayer thin films to improve animal-tissue cell adhesion

Abstract

The adhesion of L929 cells from mouse fibroblast on poly ε-caprolactone (PCL) nanofibrous scaffolds was successfully improved by coating the scaffolds with polyelectrolyte multilayer thin films (PEMs) prepared by the layer-by-layer deposition method. Initially, three PEMs were constructed from poly(diallydimethyl ammonium chloride) (PDADMAC) and poly(sodium 4-styrene sulfonate) (PSS), PDADMAC/gelatin and chitosan/gelatin on glass slides, silicon wafers and PCL films. Their thickness and hydrophobic/hydrophilic property were investigated. Being constructed by two strong polyelectrolytes, PDADMAC/PSS was the thickest among the three, at the same number of layers. In addition, it was found that, in culture medium solution, the stability of PDADMAC/gelatin was unsurpassed by that of chitosan/gelatin. The in vitro L929 cell behaviors on glass cover slips coated with PDADMAC/PSS as the primer and PDADMAC/gelatin and chitosan/gelatin as the top coats were evaluated by the MTT assay and a microscope. The results indicated that, although the cells were able to grow on all prepared PEMs, those with negatively charged gelatin at the outermost layer were the most effective in terms of cell viability, proliferation and spreading. Cell adhesion, as considered by cell viability, proliferation and spreading, on PDADMAC/gelatin was better than that on chitosan/gelatin. Eventually, PCL was electrospun into nanofibrous scaffolds before coating with PDADMAC/PSS as the primer and PDADMAC/gelatin as the top coat. The results as revealed by the MTT assay and a scanning electron microscope suggested that use of PDADMAC/gelatin as the top coat significantly enhanced cell viability, proliferation as well as spreading comparing with the uncoated scaffolds and scaffolds coated with PDADMAC/PSS.