Zosterin

Zosterin is a natural polymeric substance reported to be extracted from eelgrass, primarily Zostera marina, a seagrass that grows in coastal marine environments. Descriptions in historical pharmacology literature characterize zosterin as a water‑soluble, high molecular weight polysaccharide‑rich colloid that can form gels and hydrogels, giving it notable water‑absorption and rheological properties.

Composition and properties are variable by source and preparation, but zosterin is generally described as a carbohydrate‑based biopolymer with uronic acids and associated glycoproteins. It exhibits high water binding and the ability to form semi‑solid gels under appropriate conditions, including changes in temperature, pH, or the presence of multivalent ions. The material can be obtained as a dry powder, a viscous gel, or a hydrogel suitable for topical applications.

Extraction and preparation typically involve aqueous extraction of dried plant material, clarification, and precipitation or concentration steps, followed by drying or formulation into gels. The resulting product is marketed and studied in various purer or less-purified forms, with quality and composition varying according to source material and processing.

Applications reported in the literature include topical wound care, hemostatic and protective dressings, thickening agents in pharmaceutical and cosmetic formulations, and exploratory work in drug delivery and tissue engineering. In modern mainstream medicine, zosterin is not a standard, widely adopted therapeutic; its use tends to be in niche or historical contexts, with attention to purity, safety, and regulatory considerations.

Safety and regulation information is variable, but zosterin is generally described as non‑toxic in topical contexts, provided that appropriate quality controls are applied. As with many natural polymers, user outcomes depend on the source material, extraction method, and formulation.