Preparation, properties, and cell attachment/growth behavior of PVA/chitosan-blended hydrogels

Hydrogels were prepared from blends of poly(vinyl alcohol) and chitosan in various ratios. Electron spectroscopy for chemical analysis of the resulting hydrogel membranes showed that the chitosan component was concentrated on the air-surface side of cast membranes, at a nearly constant concentration over the range 10 wt.% to 40 wt.% of chitosan content of the blends. Two-dimensional distribution of the chitosan component in the air-surface side of the sample with 40 wt.% chitosan was uniform, while that with 15 wt.% chitosan was heterogeneous and localized in high-density islands. Although the zeta-potential on the air-surface side of the hydrogels increased to a constant value with increasing chitosan content at pH 7.2, the zeta-potential values in all the hydrogels were negative. The attachment and growth of fibroblast cells (L-929) on the hydrogels was studied by cell culture. On hydrogels with more than 15 wt.% chitosan content, the attached cells were able not only to remain viable, but also to proliferate. The relative cell attachment after incubation for 30 h increased with increasing chitosan content in the hydrogels. The hydrogel with 40 wt.% chitosan content was superior to collagen, a widely-used mammalian cell-culture substrate, for cell attachment and growth. This cell attachment/growth behavior appears to be due not only to the interaction between chitosan molecules and cells, but also to the nature of the two-dimensional distribution of chitosan components on the surface of the hydrogels.