Synthesis and characterization of functionalized chitosan coupled with phenolic aldehyde to thwart antibiotics-resistant bacteria with antioxidant and anti-inflammatory properties: In vitro evaluations and computational investigations.

This research aims to synthesize a functionalized chitosan derivative (Cs-Ph) to impede the proliferation of clinical antibiotics-resistant bacteria through conjugating carbonyl group of phloretin (Ph) as a bioactive agent with -NH2 along the chitosan (Cs) chain. The synthesis of Cs-Ph was substantiated using elemental, 1H NMR, FT-IR, SEM, and UV-vis spectra analyses. Elemental analysis findings demonstrated that the deacetylation and substitution degrees were 75.4 % and 15.8 %, respectively. The antibacterial results revealed substantial augmentations of Cs-Ph toward clinical antibiotics-resistant Gram-positive and Gram-negative bacteria previously obtained from infected injuries compared to the Cs. Interestingly, molecular docking findings demonstrated remarkable bindings of Cs-Ph to different proteins in pathogenic bacteria. Additionally, Cs exerted antioxidant capacities of 35.6 ± 2.8 % and 9.38 ± 1.4 % against ABTS•+ and DPPH radicals, respectively. Importantly, Cs-Ph revealed substantial augmentations against ABTS•+ and DPPH radicals, reporting 43.23 ± 2.16 % and 33.06 ± 1.65 %, respectively. Significantly, Cs-Ph manifested outstanding efficiency in suppressing TNF-α level, implying its anti-inflammatory activity. Beyond that, scratch wound healing evaluation in vitro exposed that the wound healing properties of Cs-Ph were increased by 2.2 fold compared to unmodified chitosan. Overall, these findings accentuate that Cs-Ph could be utilized in formulating multifunctional wound dressings.