Development of pH-responsive and antibacterial semi-IPN hydrogel films based on carboxymethylcellulose and tetraethyl orthosilicate

Abstract

Multifunctional hydrogel films which could combine pH responsiveness, antibacterial activity, and cytocompatibility are attractive for advanced biomedical and functional applications. In this study, semiinterpenetrating polymer network (semi-IPN) hydrogel films were fabricated from sodium carboxymethyl cellulose (CMC) and tetraethyl orthosilicate (TEOS), followed by the incorporation of silver chloride (AgCl) to introduce antibacterial functionality. The structure, morphology, and thermal properties of the films were investigated using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The developed hydrogels exhibited reversible pH-dependent swelling, reaching approximately 850 +/- 34 in alkaline media while shrinking under acidic conditions. Ag-containing films inhibited the growth of both Escherichia coli and Bacillus subtilis, producing inhibition zones of 9.5 mm for each strain. Cytocompatibility evaluation using the MTT assay demonstrated excellent fibroblast viability after 7 days, with cell viabilities of 97.49 +/- 0.85 for CMC films and 93.68 +/- 2.40 for Ag-containing films, satisfying ISO 10993-5 requirements. The combination of simple processing, inexpensive raw materials, pH-responsive behavior, antibacterial performance, and cytocompatibility highlights the potential of these semi-IPN hydrogel films for applications including wound dressing, controlled drug delivery, active food packaging, biosensing, and agricultural technologies.