Dual crosslinked poly(vinyl alcohol)/starch/oxidized-cellulose nanofiber hydrogels with self-healing and antibacterial effects

Abstract

Hydrogels composed of polyvinyl alcohol (PVA), Pehuen Starch (PS), and TEMPO-oxidized cellulose nanofibrils (TO-CNF) were prepared by the use of a one-pot method that consisted of sonication and freeze-thawing cycles without intermediate separation. Field Emission Scanning Electron Microscopy (FE-SEM), Atomic Force Microscopy (AFM), and Micro-Computed Tomography (micro-CT) analyses confirmed that PVA/PS/TO-CNF hydrogels had dynamic behavior (reversible ester bonds and hydrogen bonds), resulting in homogeneous porous architectures. FTIR spectra highlighted chemical structure changes because of the dual cross-linking reaction. Along the same line, rheological measurements indicated a predominantly elastic nature and incremented storage modulus by 20–50%, promoted by the addition of 1 wt.% TO-CNF. Light optical microscopy revealed a fast self-healing behavior within 2 min post-incision, and thermal gravimetry (TGA) confirmed that the inclusion of borax improved thermal stability. Biocompatibility tests with MSCs and HepG2 cells showed non-toxicity, with 1:1 mass ratio PVA/PS-TOCNF hydrogels exhibiting superior dimensional stability, viable cell recovery rates (20–40%), and antimicrobial activity against E. coli. These results demonstrates the potential of biobased polymers (PS-TOCNF) to improve the properties of PVA/borax hydrogels for next-generation healthcare applications, offering a promising solution with competitive mechanical strength, biocompatibility, and antibacterial properties.