Biological characterization of hydrogels of poly(vinyl alcohol) and hyaluronic acid

Hydrogels of hyaluronic acid (HA) and poly(vinyl alcohol) (PVA) were prepared using eight freezing-thawing cycles from HA/PVA blends (10/90, 20/80, 30/70, 40/60, 50/50, and 0/100 (w/w) ratios). The biocompatibility of the hydrogels was tested by means of in vitro cytotoxicity and cytocompatibility tests using cell culture techniques. The release with time of HA and PVA, the two hydrogel components, ion aqueous medium was also monitored and evaluated. The results indicate that all the hydrogels are not cytotoxic, while cell adhesion was very scarce in PVA and was not improved by the addition of HA. The release kinetics of HA and PVA from the hydrogels were different. After 2 h, HA percentages from about 80 (10/90 blend) to 100% (20/80, 40/60 blends) were released from the hydrogels into the aqueous medium. In contrast, the percentages of released PVA remain lower in time compared with HA, reaching a plateau after 24 h and ranging from a maximum of about 13% (0/100 blend) to a minimum of about 6% (10/90, and 20/80 blends).