TEM Studies on Antibacterial Mechanisms of Black Phosphorous Nanosheets
| Autor: | Surya Narayanan, Ramasubramonian Deivanayagam, David J. Banner, Tara Foroozan, Emre Firlar, Boao Song, Tolou Shokuhfar, Laura Alzate, Ramin Rojaee, Abhijit H. Phakatkar, Reza Shahbazian-Yassar |
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| Rok vydání: | 2020 |
| Předmět: |
Chemistry
Organic Chemistry Biophysics Pharmaceutical Science Bioengineering 02 engineering and technology General Medicine 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Bacterial cell structure 0104 chemical sciences Nanomaterials Biomaterials Cell membrane medicine.anatomical_structure Membrane Transmission electron microscopy Elemental analysis Drug Discovery medicine 0210 nano-technology Lipid bilayer Antibacterial activity |
| Zdroj: | International Journal of Nanomedicine. 15:3071-3085 |
| ISSN: | 1178-2013 |
| DOI: | 10.2147/ijn.s237816 |
| Popis: | Purpose Recently, two-dimensional (2D) nanomaterials are gaining tremendous attention as novel antibacterial platforms to combat against continuously evolving antimicrobial resistance levels. Among the family of 2D nanomaterials, black phosphorus (BP) nanosheets have demonstrated promising potential for biomedical applications. However, there is a need to gain nanoscale insights of the antibacterial activity of BP nanosheets which lies at the center of technical challenges. Methods Ultra-large BP nanosheets were synthesized by liquid-exfoliation method in the eco-friendly deoxygenated water. Synthesized BP nanosheets were characterized by TEM, AFM, and Raman spectroscopy techniques and their chemical stability was evaluated by EDS and EELS elemental analysis. The antibacterial activity of BP nanosheets was evaluated at nanoscale by the ultramicrotome TEM technique. Further, HAADF-STEM image and EDS elemental line map of the damaged bacterium were utilized to analyze the presence of diagnostic ions. Supportive SEM and ATR-FTIR studies were carried out to confirm the bacterial cell wall damage. In vitro colony counting method was utilized to evaluate the antibacterial performance of ultra-large BP nanosheets. Results Elemental EELS and EDS analysis of BP nanosheets stored in deoxygenated water confirmed the absence of oxygen peak. TEM studies indicate the various events of bacterial cell damage with the lost cellular metabolism and structural integrity. Colony counting test results show that as-synthesized BP nanosheets (100 μg/mL) can kill ~95% bacteria within 12 hours. Conclusion TEM studies demonstrate the various events of E. coli membrane damage and the loss of structural integrity. These events include the BP nanosheets interaction with the bacterial cell wall, cytoplasmic leakage, detachment of cytoplasm from the cell membrane, reduced density of lipid bilayer and agglomerated DNA structure. The EDS elemental line mapping of the damaged bacterium confirms the disrupted cell membrane permeability and the lost cellular metabolism. SEM micrographs and ATR-FTIR supportive results confirm the bacterial cell wall damage. |
| Databáze: | OpenAIRE |
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