Abstract
A simple and economical method for polyvinyl alcohol/polyvinylpyrrolidone/citric acid (PVA/PVP/CA) hydrogel preparation using microwave-assisted irradiation was presented. The synthesized hydrogels embedded with berberine or chlorogenic acid were investigated as a wound dressing agent. This study showed that the optimum condition for the hydrogel synthesis based on gel fraction and a degree of swelling values was 6:6:3% (w/v) of PVA/PVP/CA under 600 W at 120 °C for 3 min of microwave irradiation. Herbal active compounds, berberine and chlorogenic acid, were loaded onto the hydrogel (4% (w/v)), and both were able to inhibit the growth of Staphylococcus aureus. Additionally, the anti-inflammatory study revealed that 700 μg/mL berberine and 2500 μg/mL chlorogenic acid could inhibit protein degradation equivalent to a 200 μg/mL aspirin solution. The drug release study demonstrated that both compounds showed a more sustained release into PBS than water. The mechanism for the three-dimensional network formation based on esterification and the hydrogen-bonding interaction was also proposed. The ionic liquid-like structure of PVP-CA possibly played an important role in the cross-linking process. In addition, sodium bicarbonate applied to the synthesized hydrogel also had a significant effect in enhancing gel formation. The proposed approach showed a potential of the loaded hydrogels to protect wounds from infection and enhance the healing process.
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