Chitosan Schiff base electrospun fabrication and molecular docking assessment for nonleaching antibacterial nanocomposite production

In this work, new chitosan derivative nanofibers that exhibit antibacterial properties were successfully fabricated. The two CS Schiff base derivatives (CS-APC and CS-2APC) were prepared by incorporating 4-amino antipyrine moiety in two different ratios, followed by a reductive amination to obtain the corresponding derivatives CS-APCR and CS-2APCR. Spectral analyses were used to confirm the chemical structure. The molecular docking evaluation of CS-APC, CS-APCR, and CS was conducted on DNA topoisomerase IV, thymidylate kinase and SARS-CoV-2 main protease (3CL(pro)) active sites. CS-APCR showed a well-fitting into the three enzyme active sites with docking score values of - 32.76, - 35.43 and - 30.12 kcal/mol, respectively. The nanocomposites of CS derivatives were obtained by electrospinning the blends of CS-2APC and CS-2APCR with polyvinyl pyrrolidone (PVP) at 20 kV. The morphology of the nanofibers was investigated by scanning electron microscopy (SEM). It was found that fiber diameters were significantly decreased when CS-2APC and CS-2APCR were incorporated into pure PVP to reach 206-296 nm and 146-170 nm, respectively, compared to 224-332 nm for pure PVP. The derivatives of CS and their nanofibers with PVP were found to have antibacterial activities against two strains of Staphylococcus aureus and Escherichia coli. Data revealed that CS-2APC nanofibers showed antibacterial activity to the two strains of E. coli less than CS-2APCR nanofibers.

Automated summary

New chitosan derivative nanofibers with antibacterial properties were successfully produced in this study. Two CS Schiff base derivatives (CS-APC and CS-2APC) were prepared by incorporating 4-amino antipyrine moiety in different ratios, and further modified to obtain CS-APCR and CS-2APCR. The chemical structure was confirmed using spectral analyses. Molecular docking evaluation showed that CS-APCR has good fitting in the active sites of three enzymes with docking score values of - 32.76, - 35.43, and - 30.12 kcal/mol, respectively. CS derivative nanofibers were obtained by blending CS-2APC and CS-2APCR with PVP, resulting in decreased fiber diameters compared to pure PVP. The CS derivatives and their nanofibers exhibited antibacterial activities against Staphylococcus aureus and Escherichia coli, with CS-2APCR nanofibers showing stronger activity against E. coli strains than CS-2APC nanofibers.