A pH-responsive chitosan/sodium polyaspartate/alginate hydrogel platform for coumarin-6 encapsulation

Zegarra-Urquia C.L.; Angeles-Boza A.; Santiago-Contreras J.; Zhang D.; Zaragoza-Contreras E.A. · Polymer Bulletin (2026) · DOI: 10.1007/s00289-025-06257-6

Resumen

Hydrogels were synthesized via ionic crosslinking between chitosan (CS), a cationic polymer, and the anionic polymers sodium polyaspartate (NaPAsp), and alginate (AG), using the semi-dissolution/acidification/sol–gel transition method. The resulting pH-responsive CS/NaPAsp/AG hydrogel exhibits an average pore diameter of 200–300 µm and a water absorption capacity ranging from 900 to 2000%. FTIR, XRD, and TGA analyses confirmed the formation of a polyelectrolyte network and SEM images showed a highly porous structure whose morphology varied with pH. Rheological studies revealed gel-like behavior and structural integrity over a wide pH range. CS-g-OA micelles exhibited spherical morphology and efficiently encapsulated coumarin-6 (~ 30%), employed as a hydrophobic fluorophore, while the hydrogel loaded with the micellar system achieved higher flourophore encapsulation efficiency (~ 53%), indicating synergistic retention of hydrophobic cargo. These properties suggest the hydrogel is well-suited for encapsulating and transporting coumarin derivatives and other hydrophobic drugs. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2026.

Instituciones: Universidad Nacional Mayor de San Marcos