Controlled synthesis of Mn ₂O ₃ nanowires by hydrothermal method and their bactericidal and cytotoxic impact: A promising future material

Mn ₂O ₃ nanowires with diameter ∼70 nm were synthesized by a simple hydrothermal method using Mn(II) nitrate as precursor. X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy techniques were employed to study structural features and chemical composition of the synthesized nanowires. A biological evaluation of the antimicrobial activity and cytotoxicity of Mn ₂O ₃ nanowires was carried out using Escherichia coli and mouse myoblast C ₂C ₁₂ cells as model organism and cell lines, respectively. The antibacterial activity and the acting mechanism of Mn ₂O ₃ nanowires were investigated by using growth inhibition studies and analyzing the morphology of the bacterial cells following the treatment with nanowires. These results suggest that the pH is critical factor affecting the morphology and production of the Mn ₂O ₃ nanowires. Method developed in the present study provided optimum production of Mn ₂O ₃ nanowires at pH∼9. The Mn ₂O ₃ nanowires showed significant antibacterial activity against the E. coli strain, and the lowest concentration of Mn ₂O ₃ nanowires solution inhibiting the growth of E. coli was found to be 12.5 μg/ml. TEM analysis demonstrated that the exposure of the selected microbial strains to the nanowires led to disruption of the cell membranes and leakage of the internal contents. Furthermore, the cytotoxicity results showed that the inhibition of C ₂C ₁₂ increases with the increase in concentration of Mn ₂O ₃ nanowires. Our results for the first time highlight the cytotoxic and bactericidal potential of Mn ₂O ₃ nanowires which can be utilized for various biomedical applications.