Development of sericin-elastin nanoblends containing resveratrol for cosmeceutical applications.

Resveratrol (RSV), a high-value phytocompound upcycled from winemaking byproducts, is highly promising for cosmeceutical applications against oxidative stress due to its extraordinary antioxidant, anti-inflammatory and cytoprotective properties. However, its topical application is severely limited by chemical instability, poor aqueous solubility, and rapid degradation by light and oxygen. To overcome these limitations and maximize epidermal efficacy, a biocompatible nanoblend composed of sericin and elastin was developed. The sericin (4 mg/mL)/elastin (2 mg/mL) nanoblends showed an average diameter of 140 nm, a narrow size distribution, a Zeta potential of -35 mV and high stability at pH 7 and 10, as well as at temperatures between 32 °C and 37 °C. The encapsulation of RSV (0.4 mg/mL) did not affect the mean diameter and polydispersity index of the systems, allowing an entrapment efficiency of ∼30% (drug content of 0.12 mg/mL). The release profile showed a biphasic kinetic trend over time. When tested on HaCaT human keratinocytes, both single polymers and blend nanosystems demonstrated excellent tolerability, confirming the high biocompatibility of the formulation. Furthermore, RSV-loaded blend nanoparticles showed a superior cytoprotective effect compared to the free drug, a trend confirmed by DPPH, CellROX and MitoSOX assays. Finally, CompuSyn analysis validated a strong synergy between the carrier and RSV (CI < 1) with a synergistic effect at 10 µg/mL with a Dose Reduction Index (DRI) of 3.00. In conclusion, the developed sericin-elastin nanoblends containing RSV represent innovative cosmeceuticals characterized by strong antioxidant activity able to be employed for the topical treatment of skin disorders.