نبذة مختصرة : This study aims to investigate the oxidative degradation of chitosan to produce chitooligosaccharides (CHOS) as a potential bioagent for biomaterials engineering. CHOS was produced via microwaved-assisted oxidative degradation of chitosan by using hydrogen peroxide in an acidic aqueous solution. The effects of the H2O2 concentration, reaction time, microwave power, and reaction temperature on the degradation of chitosan were investigated. Following optimization of these parameters, three soluble CHOS fractions CHOS 1 (4-8 kDa), CHOS 2 (3-5 kDa), and CHOS 3 (1-3 kDa) were synthesized and the physicochemical, structural, thermal properties and water solubility were investigated. No significant structure alteration of the initial chitosan was detected by Fourier transform infrared spectroscopy (FTIR), UV–vis, and nuclear magnetic resonance (NMR) analyses, making our microwave-assisted oxidative degradation a valuable method for the production of CHOS. Interestingly, CHOS fractions exhibited improved radical scavenging activities and antibacterial activities compared to the initial chitosan. The half maximal effective concentration (EC50) of the CHOS fractions were found to be in the range of 2.69–0.724 mg/mL significantly lower than the chitosan (7.75, mg/mL). Besides, the CHOS fractions exhibited lower minimum inhibitory concentration (MIC; in the range of 62.5–500 µg/mL) compared to the initial chitosan (>1000 µg/mL). Moreover, the 3T3-Ll fibroblast cells treated with CHOS fractions exhibited more than 95% viability after 48 h of culture. Cell migration and collagen production assays also showed the positive effect of CHOS fractions, particularly CHOS 3. These results indicate that CHOS can be a promising bioactive agent in biomedical applications, in particular for wound healing applications.
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