Glutaraldehyde-crosslinked chitosan-graft-poly(N-hydroxyethyl acrylamide) films: Synthesis, characterization, and application as Fe3+adsorbent

Abstract

This study aimed to develop CS-g-PHEAA-GA films (G1-G9) by grafting poly(N-hydroxyethyl acrylamide) (PHEAA) onto chitosan (CS) and crosslinking with glutaraldehyde (GA), in order to investigate their Fe3+binding capacity and hemocompatibility. The resulting films were evaluated for grafting yield (G%), pHdependent swelling kinetic (at pH 3.2, 5, 7.4), Fe3+ adsorption capacity at varying FeCl3 concentrations (250, 375, 500 mg/L), prothrombin time (PT/INR) of blood plasma, and hemocompatibility. The successful crosslinking and grafting of CS-g-PHEAA-GA films were confirmed by SEM, FTIR, and XRD. Among films, G5 with the highest crosslinking, exhibited a G% of 633 % and an equilibrium swelling capacity of 270-300 %, representing an optimal balance of functional properties. Crosslinked films demonstrated stable swelling behavior, mechanical integrity, safe coagulation response (PT, PTT, INR, PT%), and a hemocompatibility within clinical reference ranges. In vitro adsorption assays confirmed that the GA-crosslinked films containing PHEAA as a monomer (G2, G5) adsorbed 45.85 and 37.25 mg/g of Fe3+, respectively, at 500 mg/L FeCl3 and pH 1.2, within 120-180 min. Among them, G5 exhibited the most stable adsorption profile. Comparative analysis demonstrates that these films outperform many reported CS-based adsorbents, highlighting their strong potential for Fe3+ chelation therapies.