Multifunctional polysaccharides for skin health: A review in antioxidant, anti-inflammatory, and regenerative mechanisms.

Natural polysaccharides derived from algae, fungi, plants, and bacteria have emerged as multifunctional biopolymers with significant potential for dermatological and cosmetic applications. Their biological performance is strongly influenced by structural parameters, including molecular weight, sulfation degree, branching pattern, charge density, and conformational organization. This review critically discusses the relationships between structural characteristics and the antioxidant, anti-inflammatory, moisturizing, and regenerative activities of polysaccharides involved in skin homeostasis. Sulfated and uronic acid-rich polysaccharides exhibit antioxidant effects through reactive oxygen species scavenging and modulation of redox-sensitive signaling pathways, while anti-inflammatory activities are associated with regulation of NF-κB and MAPK cascades. Hydrating properties are related to hydrophilicity, film-forming ability, and hydrogel network formation, contributing to water retention, barrier reinforcement, and reduction of transepidermal water loss. Regenerative effects involve extracellular matrix remodeling, angiogenesis, and stimulation of fibroblast and keratinocyte proliferation. This review further addresses the influence of extraction methods, chemical modifications, and advanced delivery systems on polysaccharide bioactivity and translational performance, as well as current challenges related to structural heterogeneity, safety, standardization, and clinical validation. Collectively, polysaccharides represent promising multifunctional platforms for next-generation dermatological and cosmetic applications.