Plant-Based, Hydrogel-like Microfibers as an Antioxidant Platform for Skin Burn Healing

Natural polymers from organic wastes have gained increasingattentionin the biomedical field as resourceful second raw materials for thedesign of biomedical devices which can perform a specific bioactivefunction and eventually degrade without liberating toxic residuesin the surroundings. In this context, patches and bandages, that needto support the skin wound healing process for a short amount of timeto be then discarded, certainly constitute good candidates in ourquest for a more environmentally friendly management. Here, we proposea plant-based microfibrous scaffold, loaded with vitamin C (VitC),a bioactive molecule which acts as a protecting agent against UV damagesand as a wound healing promoter. Fibers were fabricated via electrospinningfrom various zein/pectin formulations, and subsequently cross-linkedin the presence of Ca2+ to confer them a hydrogel-likebehavior, which we exploited to tune both the drug release profileand the scaffold degradation. A comprehensive characterization ofthe physico-chemical properties of the zein/pectin/VitC scaffolds,either pristine or cross-linked, has been carried out, together withthe bioactivity assessment with two representative skin cell populations(human dermal fibroblast cells and skin keratinocytes, HaCaT cells).Interestingly, col-1a gene expression of dermal fibroblasts increasedafter 3 days of growth in the presence of the microfiber extractionmedia, indicating that the released VitC was able to stimulate collagenmRNA production overtime. Antioxidant activity was analyzed on HaCaTcells via DCFH-DA assay, highlighting a fluorescence intensity decreaseproportional to the amount of loaded VitC (down to 50 and 30%), confirmingthe protective effect of the matrices against oxidative stress. Finally,the most performing samples were selected for the in vivo test ona skin UVB-burn mouse model, where our constructs demonstrated tosignificantly reduce the inflammatory cytokines expression in theinjured area (50% lower than the control), thus constituting a promising,environmentally sustainable alternative to skin patches.