This research aims to fabricate a potent pH‐sensitive double network sodium alginate/chitosan hydrogel cross‐linked by calcium chloride (CaCl2) and glutaraldehyde for the controlled release of amoxicillin (AMX) to mitigate gastrointestinal tract bacterial infection. The effect of polymer ratios and CaCl2 concentration is investigated by the developing porosity, gel fraction, and swelling ratios in simulated physiological fluids of different pH and in vitro biodegradation at pH 7.4. Interaction between the polymers with the formation of cross‐linked structures, amorphous phase nature, good thermal stability, and transition from porous, fibrous structures to highly densified structures of the hydrogels is revealed by scanning electron microscopy, Fourier‐transform infrared spectroscopy, x‐ray diffraction, and thermogravimetric analysis. Based on structure–property relationships, a sodium alginate/chitosan hydrogel (weight ratio 75:25) cross‐linked with 2% CaCl2 and soaked in 2% (25 wt/v% solutions) glutaraldehyde is chosen for the incorporation of 200 mg of the drug. The percent cumulative AMX release in physiological fluids and the drug release kinetics using different models reveal that the most appropriate Korsmeyer–Peppas model suggests AMX release from the matrix follows diffusion coupled with swelling‐regulated time‐dependent non‐Fickian transport process related to hydrogel erosion. Excellent antibacterial against Streptococcus pyogenes and Escherichia coli is exhibited by this composition.

This research focused on preparing hydrogels with controlled drug release properties to control gastrointestinal tract bacterial infection. Chitosan (CS) and polyvinylpyrrolidone (PVP) were used as the base polymers, with the CS component crosslinked by glutaraldehyde for hydrogel preparation using the solution casting technique. The effect of varying glutaraldehyde content in the hydrogels was characterized by the extent of swelling in simulated physiological fluids of pH 1.2, 6.8, and 7.4; the development of porosity; and gel fraction. Functional groups and covalent and hydrogen bonds formed, thermal stability, phase structure, and morphology were characterized by Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, and scanning electron microscopy. The results show that the components in the hydrogels have good compatibility and formed honeycomb-like structures. In vitro studies confirmed that the hydrogels have good biodegradability at pH 7.4. Based on these properties, a CS/PVP hydrogel of the ratio of 60 : 40 crosslinked with 600 μL glutaraldehyde was selected for the in-situ loading of 200 mg of the drug metronidazole (MTZ). The hydrogel was characterized for cumulative drug release in the simulated physiological fluids and drug release kinetics using different models and for its antibacterial activity. The best-fit Korsmeyer–Peppas model suggests that MTZ release followed diffusion and swelling-controlled time-dependent non-Fickian transport related to hydrogel erosion. This hydrogel displays enhanced antimicrobial activity against Staphylococcus aureus, and Escherichia coli showed substantial inhibition zones indicating the produced CS/PVP hydrogels are promising candidates for controlled drug release applications.

In this research work, we explore the UV-protection and antibacterial activity of cotton fabric functionalized with copper oxide- titanium oxide nano composites (CuO@TiO2 NCs). The cotton fabrics based textile modified with L-methionine as cross-linking agents, by padding and rolling technique at higher temperature, and after, in situ synthesis and immobilization of the CuO@TiO2 NCs carried out using cupper nitrate (Cu(NO3)2 and titanium isopropoxide (TIP) as a source of Cu(OH)2 and TiO2 colloid which further converting into CuO and TiO2 nanoparticles (NPs) respectively to prepare UV-protective and antibacterial cotton fabrics. By this method 18.09 nm CuO and 32.5 nm TiO2 NPs of average crystal size were prepared respectively. The morphology and structure of the textile samples were characterized using FTIR, Raman Spectroscopy, High resolution scanning electron microscopy (HR-SEM), Energy-dispersive X-ray spectroscopy (EDS), X-ray photo spectroscopy (XPS), thermal gravimetric analysis (TGA) and XRD. The optical properties of the cotton fabric based textile samples were discussed using UV-vis diffuse reflectance spectrum (UV-DRS), and the antibacterial activity, ultraviolet protection performance, water absorption and vapor permeability of the cotton fabric based textile samples were analyzed. The results showed that the carboxyl groups of L-methionine were esterified with hydroxyl groups of the cotton fabric and the amine and the thiol ether group formed on the surface of the cotton fabrics which further enhance the binding of NPs. CuO@TiO2 NCs were successfully loaded onto the cotton fabrics by strong electrostatic interaction, causing the outstanding antibacterial activity against gram positive bacterial Staphylococcus aureus and gram negative bacteria E.coli. In addition, compared with the unfunctionalized cotton fabrics, the UV protection factor reached 50+, thus, multifunctional cotton fabrics with excellent antibacterial and anti-ultraviolet properties were obtained.