Glycosaminoglycan hydrogel films as bio-interactive dressings for wound healing

Chemically-crosslinked glycosaminoglycan (GAG) hydrogel films were prepared and evaluated as bio-interactive wound dressings. Hyaluronan (HA) and chondroitin sulfate (CS) were first converted to the adipic dihydrazide derivatives and then crosslinked with poly(ethylene glycol) propiondialdehyde to give a polymer network. The crosslinking occurred at neutral pH in minutes at room temperature to give clear, soft hydrogels. After gelation, a solvent-casting method was used to obtain a GAG hydrogel film. A mouse model was used to evaluate the efficacy of these GAG films in facilitating wound healing. Full-thickness wounds were created on the dorsal side of Balb/c mice and were dressed with a GAG film plus Tegaderm™ or Tegaderm™ alone. A significant increase in re-epithelialization was observed on day 5 (p<0.001) and day 7 (p<0.05) for wounds treated with a GAG film plus Tegaderm™ versus those treated with Tegaderm™ alone. While no significant differences in wound contraction or inflammatory response were found, wounds treated with either HA or CS films showed more fibro-vascular tissue by day 10. The GAG hydrogel films provide a highly hydrated, peri-cellular environment in which assembly of other matrix components, presentation of growth and differentiation factors, and cell migration can readily occur.