Ciprofloxacin Release Behaviour From Gamma-irradiated Dextran-poly(Ethylene Glycol) Diacrylate Hydrogel and Its Kinetic Fitting Models

Currently, hydrogels prepared from naturally sourced polymers are frequently utilized as matrices in drug delivery systems, owing to their favorable interaction with biological environments and their ability to encapsulate therapeutic agents effectively. However, these hydrogels often exhibit low mechanical properties, enabling premature degradation and ineffective drug release. In this study, we developed hybrid hydrogels synthesized from dextran, a natural polymer, and poly(ethylene glycol) diacrylate (PEGDA), a synthetic polymer, to create a biocompatible and mechanically stable matrix for controlled drug release. The dextran–PEGDA hydrogels were successfully synthesized using gamma rays at irradiation doses of 15 and 25 kGy. Gel fraction test showed a high gel fraction of more than 90% for both 15 and 25 kGy hydrogels, indicating successful formation of a three-dimensional network within the dextran-PEGDA hydrogel. Fourier transform infrared analysis revealed the disappearance of vinyl groups from PEGDA, further confirming the successful formation of crosslinking between the polymers in the hydrogel. Scanning electron microscope images demonstrated that the 25 kGy hydrogel has denser pore structures compared to the 15 kGy hydrogel. Interestingly, the drug release study showed that the 15 kGy hydrogel can release the ciprofloxacin up to 84% after 24 hours of immersion in phosphate-buffered saline solution. Furthermore, the Korsmeyer-Peppas and first-order kinetic models provided a strong fit to the experimental data for 15 and 25 kGy hydrogels, with the R ² values higher than 0.95, indicating the ciprofloxacin release is mainly determined by the ability of the drug to diffuse through the densely cross-linked polymer network. Antibacterial test showed that both hydrogels exhibited pronounced antibacterial properties toward E. coli and S. aureus , implying that the ciprofloxacin incorporated into the network remained pharmacologically active following crosslinking by gamma radiation. Overall, the study revealed that dextran–PEGDA hydrogels exhibit satisfactory mechanical stability and enable a controlled release pattern, suggesting their suitability for future development of drug delivery systems.