SA/G hydrogel containing hCAP-18/LL-37-engineered WJ-MSCs-derived conditioned medium promoted wound healing in rat model of excision injury

Development and design of efficient wound dressings are subject of intensive investigations either in basic or in clinical researches. Although, hydrogel-based wound dressings have gained increasing attention and showed beneficial results in term of improved wound healing effect, they are not yet able to heal complex wounds. This study was conducted in an attempt to improve wound healing properties and introduce a novel potential wound dressing. Wharton's jelly derived-mesenchymal stem cells (WJ-MSCs) were transfected with a recombinant construct encoding hCAP-18/LL-37 gene which has several important functions in wound healing process. Next, the conditioned medium (CM) of the transfected cells (LL-37-MSCs) was harvested, and its concentrate was formulated in a sodium alginate (SA)/gelatin (G) hydrogel. Finally, the wound healing efficacy of the hydrogel-CM combination was evaluated in an excision wound model in rat. In vitro findings exhibited biocompatibility, biodegradability, acceptable mechanical properties, sustained release, and capacity to absorb wound exudate for the hydrogel. In vivo, the hydrogel effectively accelerated wound contraction and promoted wound healing in comparison to controls. Although further investigations including preclinical and clinical studies are required, our findings strongly suggest that the hydrogel might be considered as a potential novel wound dressing for healing of a variety of wounds.