Relationship between the structure of a highly regular fucoidan from Fucus evanescens and its ability to form nanoparticles

• Published in: International journal of biological macromolecules 2021-08, Vol.185, p.679-687
• Main Authors: Rasin, Anton B., Shevchenko, Natalia M., Silchenko, Artem S., Kusaykin, Mikhail I., Likhatskaya, Galina N., Zvyagintsevа, Tatyana N., Ermakova, Svetlana P.
• Format: Article
• Language: English
• Subjects: Carbohydrate Conformation; Carbohydrate Sequence; Chitosan; Chitosan - chemistry; Fucoidan; Fucus - chemistry; Molecular Docking Simulation; Nanoparticles; Particle Size; Polysaccharides - chemistry; Regular polysaccharide; Water - chemistry
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2021.06.180

Chitosan/fucoidan nanoparticles were created using two fucoidans from the Fucus evanescens algae. One of them was a regular fucoidan obtained for the first time from the alga harvested at the reproductive growth stage, using only standard extraction methods, without additional modifications. Its structure was established via NMR spectroscopy to consist of the repeating →3)-α-L-Fucp-(2,4SO3−)-(1 → 4)-α-L-Fucp-(2SO3−)-(1→ fragment. Such fragment also coustituted 55% of the other fucoidan's structure, however it also included long sequences of α-L-fucopyranose residues sulfated only at C2. The nanoparticles were re-dispersed in water and the influence of fucoidan/chitosan mass ratio on the nanoparticles' size and zeta potential was investigated. 3D models of the regular fucoidan and chitosan's sections were created and their molecular docking was performed, showing that either polymer could occupy the exterior of the complex, depending on their ratio. Thermodynamic parameters of fucoidan-chitosan binding process were accessed, with the results indicating that significant conformational changes of fucoidan and chitosan molecules take place during the interaction, presumably to allow for more effective binding. •A regular fucoidan from Fucus evanescens was used for nanoparticle creation.•A fucoidan’s ability to form nanoparticles is related to its structure and molecular weight.•Fucoidan-chitosan binding process involves two binding events.•Thermodynamic parameters of fucoidan-chitosan binding depend on the fucoidan’s structural characteristics.