Encapsulating an agro-industrial waste into liposomal systems enhances safety and therapeutic properties for skin applications

Cashew nutshell liquid (CNSL), an abundant agro-industrial by-product of the cashew industry, represents a sustainable source of bioactive phenolic lipids with promising antioxidant and anti-inflammatory properties. In this study, technical CNSL (tCNSL) was incorporated directly into soybean lecithin liposomes (CNSL-LP) without prior purification, following a green, waste-to-value approach. The resulting formulations exhibited suitable physicochemical properties, including mean diameters of 552-624 nm, low polydispersity (PDI ≈ 0.3), high encapsulation efficiencies (79.5-88.0%), sustained release over 48 h, and good storage stability. CNSL-LP protected liposomal polyunsaturated fatty acids from oxidative damage and showed no cytotoxicity up to 50 μM in keratinocytes, fibroblasts, and monocytes, whereas free CNSL was significantly more toxic. Moreover, CNSL-LP reduced oxidative stress-induced cell death, modulated inflammatory cytokine expression, promoted a pro-regenerative COL1A1/MMP1 profile, and restored keratinocyte migration under oxidative conditions. In the nematode Caenorhabditis elegans, reduced toxicity was revealed with the liposomal formulation of CNSL with regard to pharyngeal pumping rate. These findings demonstrate that liposomal encapsulation influences safety, stability, and biological efficacy of CNSL, allowing its valorisation as a sustainable ingredient for topical skin-care and wound-healing applications.