Camellia Oleifera oil-loaded chitosan nanoparticles embedded in hydrogels as cosmeceutical products with improved biological properties and sustained drug release.

Hydrogels based on poly(vinyl alcohol), silk sericin, and gelatin containing Camellia oleifera oil (CO)-loaded chitosan nanoparticles (CSNPs) were fabricated. The loading of CO into CSNPs was achieved by a two-step procedure, which included an oil-in-water emulsion and an ionic gelation method. SEM images of CO-loaded CSNPs illustrated the spherical shape with aggregation of the nanoparticles. The particle size and polydispersity index were 541-1089 nm and 0.39-0.65, respectively. The encapsulation efficiency and loading capacity were 3-16 % and 4-6 %, respectively. The gelatin/poly(vinyl alcohol)/sericin hydrogels were fabricated and incorporated with CO or CO-loaded CSNPs with different concentrations of CO-loaded CSNPs. All hydrogels demonstrated a porous structure. Besides, the hydrogels containing CO-loaded CSNPs showed a more controlled and sustained release profile than the hydrogels containing CO. Moreover, the hydrogels showed tyrosinase inhibition (9-13 %) and antioxidant activity (37-60 %). Finally, the hydrogels containing CO-loaded CSNPs were non-toxic to the Normal Human Dermal Fibroblasts and NCTC clone 929 cells, even at a high dosage of 50 mg/mL. As a result, these hydrogels exhibited excellent potential for use in cosmeceutical industries.