PHYSICAL AND BIOLOGICAL STABILITY OF DEHYDRO-THERMALLY CROSS-LINKED COLLAGEN POLY(VINYL ALCOHOL) BLENDS

Dehydro-thermal treatments for 3, 24 and 72 h were used to crosslink b lends of collagen and poly(vinyl alcohol) with various compositions. T his crosslinking method increases the biological stability in vitro of collagen, as was established by an enzymatic test. When the poly(viny l alcohol) content is not more than 20% the resistance of collagen to enzymatic digestion is not affected by the presence of the synthetic c omponent. A higher content of poly(vinyl alcohol) produces a steric hi ndrance screening that enhances the resistance of collagen to the coll agenase. Dehydro-thermal treatment performed for 24 and 72 h increases the crystallinity of poly(vinyl alcohol), thus reducing the solubilit y of this component of the blend. Calorimetric analysis was carried ou t by differential scanning calorimetry to investigate the structure an d the thermal stability of the blends. Dehydro-thermal treatments carr ied out for 24 and 72 h induce high degrees of crosslinking in collage n and high crystallinity in poly(vinyl alcohol). The two components of the blend seem to create independent structures and the blend can sho w interpentrating-network-like behaviour.