Disruption of bacterial biofilms by a green synthesized artemisinin nano-copper nanomaterial.

Bacterial biofilms are associated with antibiotic resistance and account for ∼80% of all bacterial infections. In this study, we explored novel nanomaterials for combating bacteria and their biofilms. Artemisinin nano-copper (ANC) was synthesized using a green synthesis strategy, and its shape, size, structure, elemental composition, chemical valence, zeta potential, and conductivity were characterized using transmission electron microscopy, X-ray diffractometer, X-ray photoelectron spectroscopy, zeta potential, and dynamic light scattering. The results showed that ANC was successfully synthesized utilizing a liquid phase chemical reduction method using chitosan as a modified protectant and l-ascorbic acid as a green reducing agent. The stability of ANC was evaluated using dynamic light scattering. The results showed that the particle size of ANC at different concentrations was comparable to that of the original solution after 7 days of storage, and there was no significant change in the polydispersity index (P > 0.05). The antibacterial effects of ANC on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were determined by disc diffusion and broth dilution methods. The results demonstrated that ANC inhibited and killed E. coli and S. aureus. The effect of ANC on bacterial biofilms was investigated using crystal violet staining, scanning electron microscopy, laser confocal microscopy, and quantitative polymerase chain reaction. The results showed that ANC treatment was able to destroy bacterial biofilms and downregulate biofilm- and virulence-related genes in E. coli (HlyA, gyrA, and F17) and S. aureus (cna, PVL, ClfA, and femB). Green-synthesized ANC possesses excellent antibiofilm properties and is expected to exhibit antibacterial and antibiofilm properties.

Green synthesis and characterization of an orally bioactive artemisinin-zinc nanoparticle with enhanced bactericidal activity.

The occurrence of multidrug-resistant bacteria necessitates the development of new antibacterial agents. This study synthesized artemisinin-zinc nanoparticles (AZ NPs) using a simple green method and investigated their physicochemical properties, antibacterial activity, and oral biological activity. A spherical shape morphology of AZ NPs was observed by scanning and transmission electron microscopy, with a particle size of 73 ± 2.604 nm. Energy dispersive spectrometry analysis showed that the AZ NPs consisted mainly of Zn, C, N, and O elements. According to differential scanning calorimeter analysis, the AZ NPs were stable up to 450 °C. Fourier-transform infrared spectroscopy revealed that artemisinin successfully bound to zinc acetate. The AZ NPs showed antibacterial activity against Salmonella and Escherichia coli, with a minimum inhibitory concentration of 0.056 mg/mL for both and minimum bactericidal concentrations of 0.21 and 0.11 mg/mL, respectively. The mechanisms by which AZ NPs mediate membrane damage were revealed by the downregulation of gene expression, and potassium ion and protein leakage. In vivo safety trials of these drugs revealed low toxicity. After AZ NPs were administered to infected mice, the intestinal bacteria decreased significantly, liver and kidney function were restored, histopathological damage to the liver and spleen were reduced, and the expression of inflammatory cytokines decreased. Therefore, AZ NPs have the potential as an oral antibacterial agent and can be used in antibiotic development and in the pharmaceutical industry.