Antibacterial hydrogels based on poly(sodium 2-acrylamido-2-methylpropane sulfonate) and gelatin and incorporating chlorhexidine gluconate (CHG) as a drug were fabricated. The work focused on the effects of varying the CHG concentration. The hydrogel containing 0.02% w/v of CHG was chosen as the drug-loaded hydrogel for comparison with the hydrogel with no drug. From the drug release results, it was found that only 2-5% CHG was released, indicating that the CHG strongly interacted with the hydrogel network. To confirm the antibacterial efficiency of the hydrogels, the shake-flask method and scanning electron microscopy were employed. The antibacterial activity of the drug-loaded hydrogels showed a 7-log reduction for S. aureus gram-positive and a 5-6-log reduction for E. coli gram-negative bacteria. In addition, an MTT assay was performed to evaluate their potential cytotoxicity and showed a percentage cell viability after 24 h of more than 70% which classified them as being non-cytotoxic. In conclusion, the hydrogels containing CHG are considered as one of the interesting candidates for potential biomedical use as antibacterial wound dressings. Further in vivo investigations are planned.

Hydrogel composed of poly(sodium 2-acrylamido-2-methylpropane sulfonate) and gelatin containing different molecular weights of poly(ethylene glycol) (PEG) as a humectant were prepared via UV photopolymerization. The results indicated that the PEG slowed down evaporative water loss and water vapor transmission. Water transport, whether it was absorption, transmission or evaporation, and also tensile properties were found to be dependent to varying extents on the PEG molecular weight. These results could also be related to the amount of non-freezable water, as determined by differential scanning calorimetry. These properties and their relevance to the hydrogel’s potential use as a wound dressing are discussed.