Self-healing hydrogels of oxidized pullulan and poly(vinyl alcohol)

Composite hydrogels of poly(vinyl alcohol) (PVA) and C-6-fully oxidized pullulan (OxP) were prepared and investigated. Hydrogels with different content of OxP into the PVA matrix were prepared by freezing/thawing method. FTIR and NMR were used to assess the degree of interaction between the two polymers into the physical network. The morphology analysis has shown an excellent distribution of the OxP inside the PVA matrix. The effect of polymer composition on the diffractogram patterns and viscoelastic parameters was examined and an optimum composition of 7.5% OxP in the PVA hydrogel was identified, being characterized by high crystallinity and gel strength. The self-healing ability of the hydrogels was revealed, after submitting the sample to a large deformation it recovers very fast the initial structure. The cell viability was tested and promising results were obtained for PVA/OxP hydrogels. The synergism between PVA and OxP into the physical network recommends these hydrogels for biomedical applications.