Alginate-hyaluronan hybrid hydrogels for wound healing

tIn this paper we propose polysaccharide hydrogels combining alginate (ALG) and hyaluronan (HA) asbiofunctional platform for dermal wound repair. Hydrogels produced by internal gelation were homo-geneous and easy to handle. Rheological evaluation of gelation kinetics of ALG/HA mixtures at differentratios allowed understanding the HA effect on ALG cross-linking process. Disk-shaped hydrogels, at differ-ent ALG/HA ratio, were characterized for morphology, homogeneity and mechanical properties. Resultssuggest that, although the presence of HA does significantly slow down gelation kinetics, the concen-tration of cross-links reached at the end of gelation is scarcely affected. The in vitro activity of ALG/HAdressings was tested on adipose derived multipotent adult stem cells (Ad-MSC) and an immortalizedkeratinocyte cell line (HaCaT). Hydrogels did not interfere with cell viability in both cells lines, but sig-nificantly promoted gap closure in a scratch assay at early (1 day) and late (5 days) stages as comparedto hydrogels made of ALG alone (p < 0.01 and 0.001 for Ad-MSC and HaCaT, respectively). In vivo woundhealing studies, conducted on a rat model of excised wound indicated that after 5 days ALG/HA hydrogelssignificantly promoted wound closure as compared to ALG ones (p < 0.001). Overall results demonstratethat the integration of HA in a physically cross-linked ALG hydrogel can be a versatile strategy to promotewound healing that can be easily translated in a clinical setting.