Synthesis and physicochemical properties of an aromatic chitosan derivative: In vitro antibacterial, antioxidant, and anticancer evaluations, and in silico studies.

This study was designed to synthesize a functionalized chitosan by coupling the amine groups of chitosan with 2,4,6-Trimethoxybenzaldehyde, producing a chitosan Schiff base (Cs-TMB). The development of Cs-TMB was verified employing FT-IR, 1H NMR, the electronic spectrum, and elemental analysis. Antioxidant assays exhibited significant ameliorations of Cs-TMB, reporting scavenging activities of 69.67 ± 3.48 % and 39.65 ± 1.98 % for ABTS•+ and DPPH, respectively, while native chitosan showed scavenging ratios of 22.69 ± 1.13 % and 8.24 ± 0.4.1 % toward ABTS•+ and DPPH, respectively. Besides, Cs-TMB exerted significant antibacterial activity up to 90 % with remarkable bactericidal capacity against virulent gram-negative and gram-positive bacteria compared to the original chitosan. Furthermore, Cs-TMB exhibited a safe profile against normal fibroblast cells (HFB4). Interestingly, flow cytometric analysis showed that Cs-TMB demonstrated prominent anticancer properties of 52.35 ± 2.99 % against human skin cancer cells (A375), compared to 10.66 ± 0.55 % for Cs-treated cells. Moreover, Python and PyMOL in-house scripts were used to predict the interaction of Cs-TMB with the adenosine A1 receptor and visualized as a protein-ligand system submerged in a lipid membrane. Overall, these findings accentuate that Cs-TMB could be a favorable representative for wound dressing formulations and skin cancer treatment.

Enhancement of Antioxidant and Hydrophobic Properties of Alginate via Aromatic Derivatization: Preparation, Characterization, and Evaluation.

The preparation of bioactive polymeric molecules requires the attention of scientists as it has a potential function in biomedical applications. In the current study, functional substitution of alginate with a benzoyl group was prepared via coupling its hydroxyl group with benzoyl chloride. Fourier transform infrared spectroscopy indicated the characteristic peaks of aromatic C=C in alginate derivative at 1431 cm-1. HNMR analysis demonstrated the aromatic protons at 7.5 ppm assigned to benzoyl groups attached to alginate hydroxyl groups. Wetting analysis showed a decrease in hydrophilicity in the new alginate derivative. Differential scanning calorimetry and thermal gravimetric analysis showed that the designed aromatic alginate derivative demonstrated higher thermo-stability than alginates. The aromatic alginate derivative displayed high anti-inflammatory properties compared to alginate. Finally, the in vitro antioxidant evaluation of the aromatic alginate derivative showed a significant increase in free radical scavenging activity compared to neat alginate against DPPH (2,2-diphenyll-picrylhydrazyl) and ABTS free radicals. The obtained results proposed that the new alginate derivative could be employed for gene and drug delivery applications.