Agarose/k-Carrageenan-based hydrogel films enriched with natural extracts for wound healing applications

Hydrogels are 3D hydrophilic networks that can hold significant amounts of water within their structure, without dissolving in water. They can offer a combination of favorable properties, including high absorbency of biological fluids, biocompatibility, biodegradability, stimuli-responsiveness, high storage capacity and release ability of small and large therapeutic molecules. The hydrogel films designed for wound dressing may accomplish several functions, playing an important role in the healing processes. They can absorb and retain the wound exudates, stimulating fibroblast proliferation and keratinocyte migration and promoting re-epithelialization. Furthermore, they can incorporate and release bioactive molecules allowing a faster healing process. In the past years, materials used to make hydrogel films for wound dressing were synthetic polymers, but more recently natural polymers have been employed as main components of hydrogel dressings for their active involvement in the wound healing process and new tissue regeneration. The main components of the films here proposed are agarose (2.0% w/w) and increasing amount of k-carrageenan (0.5, 1.0 and 1.5% w/w) mixed with glycerol 5% and 10% w/w used as plasticizer agent, in order to obtain an optimal combination of softness and conformability. During preparation, the polymers were added of natural extracts obtained by Cryphaea heteromalla (Hedw.) D. Mohr, a bryophyte species living in the Mediterranean area and possessing a strong antioxidant machinery that makes it able to survive in unfavorable environments. All the films have been characterized in terms of dynamic rheological properties and ability to absorb fluids. Furthermore, their biocompatibility has been tested in vitro in NIH 3T3 cell model.