Synthesis of novel chitosan-PVC conjugates encompassing Ag nanoparticles as antibacterial polymers for biomedical...

We herein describe the synthesis of four Cs-PVC conjugates three of them were functionalized with benzothiazole (BTh) derivative as an antibacterial agent. Two of these BTh-functionalized conjugates, namely Cs2 and Cs3, comprise silver nanoparticles (AgNPs) and Ag/TiO₂ NPs, respectively. The structures were characterized via FTIR spectroscopic analysis, morphological investigation such as scanning (SEM) and transmission (TEM) electron microscopy, and thermal gravimetric analysis (TGA). Spectral data confirmed the introduction of the BTh to the Cs backbone as well as the coupling between the two polymers. SEM data showed homogenous polymer surfaces with well-distributed Ag nanoparticles. The Ag contents in the prepared samples Cs2 and Cs3 were, respectively, 0.61 and 0.21%, however, TEM analysis showed that the sizes of AgNPs and Ag/TiO₂ NPs were in the range of 3-7 nm and 15-22 nm for the prepared conjugates, respectively. The antibacterial activity of the synthesized conjugates was investigated against two Gram-negative (E. coli, and S. typhimurium) and two Gram-positive (S. aureus, and L. monocytogenes) bacteria. The antibacterial assay showed that all three Cs-PVC (Cs1, Cs2, and Cs3) conjugates modified with BTh exhibited excellent bacterial inhibition after 30, 60, and 120 min.