Non-Crosslinked And Near-Neutral Chitosan-Based Bioactive Mouthwash

To develop a chitosan (CS)-based drug-free mouthwash and investigate its antibacterial and antioxidant activities under near-neutral conditions. The study prepared a near-neutral CS mouthwash and evaluated its antibacterial activity against P. gingivalis and S. mutans via inhibition rate and SEM. Antibacterial stability was assessed after 3 months. Cytotoxicity and antioxidant effects were tested on human oral keratinocytes (HOK). The CS mouthwash containing 100 μg/mL CS showed the pH value of 6.0 and the great antibacterial activity against both Gram-negative Porphyromonas gingivalis and Gram-positive Streptococcus mutans (almost 100% inhibition rate at 3 h). The antibacterial effects of CS mouthwash after 3 months show no significant differences compared to that three months ago, indicating the consistent and enduring antibacterial property of CS mouthwash. In addition, CS mouthwash caused no cytotoxicity to HOK and could protect HOK from damage under H2O2-induced oxidative stress, demonstrating the great capacity of intracellular ROS scavenging. This is the first report regarding the antibacterial and antioxidant activity of the drug-free and near-neutral CS solution-based mouthwash. The oral-tolerated pH and the multiple functions of the CS mouthwash allow it to have great potentials for the clinical use.