Stimuli-Responsive Crosslinked Chitosan/PVP/PEG Hydrogel Networks for Targeted Drug Delivery and Antimicrobial...

In this study, a unique pH-sensitive PEG/C/PVA hydrogel based on chitosan (C), polyvinyl propylene (PVP) and polyethylenglycol (PEG) crosslinked with tetraethyl orthosilicate (TEOS) was fabricated. This PEG/C/PVA hydrogel was designed to deliver different drugs with distinct release profiles, including diclofenac sodium and ciprofloxacin, and to exhibit antimicrobial activity. As a result of crosslinking with TEOS, the PEG/C/PVA hydrogel exhibits improved swelling characteristics, enabling pH-dependent drug release. In the characterization study, SEM analysis showed a smooth, porous surface, whereas FTIR confirmed the presence of the amine group of chitosan at 3432.4 cm^-1, Si─N at 1211.1 cm^-1 and Si─O─Si at 620.2 cm^-1, indicating the presence of TEOS. Thermogravimetric analysis (TGA) showed that the synthesized PEG/C/PVA hydrogel exhibits excellent thermal stability. In the swelling study, the maximum swelling (g/g) in water was 25.1, in acidic pH (pH = 2) was 27.57 and at a lower electrolyte concentration, it was 21.3 and 20.6 in NaCl and CaCl₂, respectively. Based on the release kinetics of diclofenac sodium and ciprofloxacin, we evaluated the performance of the PEG/C/PVA hydrogel and demonstrated good antimicrobial activity. The PEG/C/PVA hydrogel's potential for use in drug delivery systems where precise control over drug release is required is shown by its varied release behaviour. It might be invaluable in situations where drug absorption depends on pH fluctuations or where site-specific administration is required. This work offers promising results for targeted drug delivery systems by demonstrating the adaptability of a pH-sensitive chitosan-based PEG/C/PVA hydrogel crosslinked with TEOS. Subsequent investigations will examine the potential uses and long-term durability of these PEG/C/PVA hydrogels across diverse biological environments.