A nanoemulgel formulation of acetylated Crataegus pinnatifida polysaccharide for the treatment of skin photoaging in mice

Ultraviolet (UV) radiation is a primary factor contributing to photoaging, a form of premature skin aging characterized by the appearance of wrinkles, fine lines, uneven pigmentation, and reduced skin elasticity. Plant-derived polysaccharides exhibit notable antioxidant and anti-inflammatory properties, making them promising candidates for the management of skin photoaging. Nevertheless, the hydrophilic nature and large molecular size of polysaccharides make them less effective for topical application. This study aimed to develop a method to increase polysaccharide transdermal absorption, using Crataegus pinnatifida polysaccharide (CPP) as a model. Acetylation was employed to modify the CPP, yielding three derivatives with varying degrees of substitution (DS): 0.16 (Ace-CPP 1 ), 0.43 (Ace-CPP 2 ), and 0.56 (Ace-CPP 3 ). The in vitro antioxidant activity increased with increasing degree of substitution. A nanoemulgel formulation was developed, achieving approximately 72 % permeation of the native CPP. Furthermore, the acetylated CPP derivatives demonstrated enhanced permeation, exceeding 92 % within 4 h. In vivo studies revealed that the Ace-CPP 3 -based nanoemulgel significantly outperformed the native CPP in alleviating UVB-induced photoaging. This was evidenced by reduced oxidative stress, suppression of tissue inflammation, and promotion of collagen deposition. These findings underscore the potential of nanoemulgel formulation of acetylated CPP derivatives to advance applications in dermatology and cosmeceuticals.