Natural extracts and nanomaterials: innovative approaches for skin aging and wound healing

The skin is the primary tissue affected by wounds and aging, compromising its barrier function. Natural products, including Helichrysum italicum oil (HO), are widely applied in dermatology for their antioxidant and regenerative properties. This study evaluated the protective and regenerative effects of HO encapsulated in electrospun nanofibers composed of biodegradable polymers: polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP). These nanofibers, characterized by SEM, were tested on human skin stem cells (SSCs), BJ fibroblasts, and keratinocytes (HaCaT). The treatment improved cell viability and proliferation, even under UV-induced stress. Gene expression analysis revealed activation of stemness markers (SOX2, OCT4, NANOG) and downregulation of senescence-associated genes. In wound healing models, confocal microscopy indicated increased Occludin (OCLN) expression, reflecting enhanced tight junction integrity. AFM analysis confirmed improved cell elasticity after treatment. Additionally, Helichrysum italicum hydrolate (HH), a byproduct of essential oil extraction, was tested in a dynamic bioreactor simulating physiological interactions between SSCs and fibroblasts. HH stimulated type I collagen production and activated regenerative molecular pathways. These findings support the use of plant-based compounds and nanomaterials as a promising strategy for non-invasive topical therapies to promote skin regeneration.