Biocompatibility of poly(vinyl alcohol)-hyaluronic acid and poly(vinyl alcohol)-gellan membranes crosslinked by glutaraldehyde vapors

Glutaraldehyde (GTA) solutions are commonly used to crosslink biomolecules and artificial polymers in order to reduce the degradation rate and to avoid the rapid dissolution in biological fluids. The toxicity of these materials is often due to the presence of GTA residuals unremoved by washing procedures. In this study membranes of PVA-hyaluronic acid and PVA-gellan with different composition have been obtained by solution casting technique and crosslinked by exposure to vapors of GTA in acid environment. The harmful effects of GTA residuals released from the membranes have been evaluated by the cytotoxicity and cytocompatibility in vitro tests, based on the cell culture method. The results showed that these materials have no toxic effects: they do not affect cell viability and proliferation, nor exert damages on mithocondrial and lysosomal functions. The poor adhesion of cells seeded directly onto membranes is due to the surface properties of these materials which are completely refractory at cell adhesion and proliferation. The use of GTA in vapor phase as crosslinking agent of natural and artificial polymer blends is demonstrated to be an efficacious procedure that avoids the presence of toxic residuals into materials.