Isolation of alginate from drifting Seaweed and its application in the preparation of bioactive hemostatic beads

Abstract

The increasing accumulation of drifting seaweed along Vietnam’s coastal regions poses significant environmental and economic challenges. Utilizing this abundant biomass to produce high-value products represents a sustainable approach to environmental management and circular economy development. This study focuses on the isolation of alginate from drifting seaweed (Sargassum) collected from the coastal area of Quang Ninh, and its application in the preparation of bioactive hemostatic beads. After cleaning and removing impurities, the seaweed was extracted with sodium carbonate solution, followed by ethanol precipitation and drying. The alginate yield reached approximately 36,2 % relative to the dry seaweed mass. FTIR analysis confirmed the presence of characteristic alginate functional groups (O-H, COO⁻, C-O-C), consistent with commercial alginate. The extracted alginate was used to fabricate hemostatic beads via gelation and cross-linking with Ca²⁺ ions. In vitro tests in animal blood models showed that the hemostatic particles were able to form gel after 45 ± 5 seconds when in contact with blood fluid, with no cytotoxicity observed in MTT assays on fibroblast cell lines. These findings indicate that alginate from drifting seaweed has potential as a safe biomedical material and contributes to the treatment of coastal waste.