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Ultraviolet light and laser irradiation enhances the antibacterial activity of glucosamine-functionalized gold nanoparticles.

Govindaraju S, Ramasamy M, Baskaran R, Ahn SJ, Yun K - Int J Nanomedicine (2015)

Bottom Line: Laser-irradiated GlcN-AuNPs exhibited significant bactericidal activity against E. coli.Flow cytometry and fluorescence microscopic analysis supported the cell death mechanism in the presence of GlcN-AuNP-treated bacteria.The overall results of this study suggest that the prepared nanoparticles have potential as a potent antibacterial agent for the treatment of a wide range of disease-causing bacteria.

View Article: PubMed Central - PubMed

Affiliation: Department of Bionanotechnology, Gachon University, Gyeonggi-do, Republic of Korea ; Centre for Advanced Instrumentation, Korea Research Institute of Standard and Science, University of Science and Technology, Daejeon, Republic of Korea.

ABSTRACT
Here we report a novel method for the synthesis of glucosamine-functionalized gold nanoparticles (GlcN-AuNPs) using biocompatible and biodegradable glucosamine for antibacterial activity. GlcN-AuNPs were prepared using different concentrations of glucosamine. The synthesized AuNPs were characterized for surface plasmon resonance, surface morphology, fluorescence spectroscopy, and antibacterial activity. The minimum inhibitory concentrations (MICs) of the AuNPs, GlcN-AuNPs, and GlcN-AuNPs when irradiated by ultraviolet light and laser were investigated and compared with the MIC of standard kanamycin using Escherichia coli by the microdilution method. Laser-irradiated GlcN-AuNPs exhibited significant bactericidal activity against E. coli. Flow cytometry and fluorescence microscopic analysis supported the cell death mechanism in the presence of GlcN-AuNP-treated bacteria. Further, morphological changes in E. coli after laser treatment were investigated using atomic force microscopy and transmission electron microscopy. The overall results of this study suggest that the prepared nanoparticles have potential as a potent antibacterial agent for the treatment of a wide range of disease-causing bacteria.

No MeSH data available.


Related in: MedlinePlus

Transmission electron micrographs of Escherichia coli before and after treatment with GlcN-AuNPs.Notes: (A) Bacteria before treatment with GlcN-AuNPs showing clear and well structured morphology. (B) Bacteria after treatment with GlcN-AuNPs showing damaged cell membranes and ruptured structures. (B1) Inset image shows nanoparticles attached and surrounding E. coli.Abbreviations: AuNPs, gold nanoparticles; GlcN-AuNPs, glucosamine-functionalized gold nanoparticles.
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f8-ijn-10-067: Transmission electron micrographs of Escherichia coli before and after treatment with GlcN-AuNPs.Notes: (A) Bacteria before treatment with GlcN-AuNPs showing clear and well structured morphology. (B) Bacteria after treatment with GlcN-AuNPs showing damaged cell membranes and ruptured structures. (B1) Inset image shows nanoparticles attached and surrounding E. coli.Abbreviations: AuNPs, gold nanoparticles; GlcN-AuNPs, glucosamine-functionalized gold nanoparticles.

Mentions: Herein, we found out the activation time of the drug into the microbe and demonstrated the morphological changes of E. coli after the intake of preparing GlcN-AuNPs, by using AFM and TEM. In this study, we used only GlcN-AuNPs, based on the MIC result that irradiation-exposed nanoparticles have a potent anti bacterial effect. The nanoparticle-treated bacteria were damaged and their morphology was changed, whereas the untreated bacteria had a well defined structure, were smooth, and generally showed typically rod-shaped cells. The TEM images in Figure 8 show that some of the small AuNPs (those less than 100 nm in size) had entered the bacterial cells. The AFM images in Figure 9 show the time dependence of the morphological changes in the bacteria, with increasing bacterial damage seen with increasing duration of treatment. The AFM images show no change to the outer surface of the membrane at 0 hour and subsequent morphological changes depending on duration of incubation. After 24 hours of incubation, the bacterial morphology was unstructured, indicated that GlcN-AuNPs successfully entered the bacterial cells. With time, the approximate bacterial height decreased from 300 nm to 140 nm, confirming these morphological changes.


Ultraviolet light and laser irradiation enhances the antibacterial activity of glucosamine-functionalized gold nanoparticles.

Govindaraju S, Ramasamy M, Baskaran R, Ahn SJ, Yun K - Int J Nanomedicine (2015)

Transmission electron micrographs of Escherichia coli before and after treatment with GlcN-AuNPs.Notes: (A) Bacteria before treatment with GlcN-AuNPs showing clear and well structured morphology. (B) Bacteria after treatment with GlcN-AuNPs showing damaged cell membranes and ruptured structures. (B1) Inset image shows nanoparticles attached and surrounding E. coli.Abbreviations: AuNPs, gold nanoparticles; GlcN-AuNPs, glucosamine-functionalized gold nanoparticles.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4554421&req=5

f8-ijn-10-067: Transmission electron micrographs of Escherichia coli before and after treatment with GlcN-AuNPs.Notes: (A) Bacteria before treatment with GlcN-AuNPs showing clear and well structured morphology. (B) Bacteria after treatment with GlcN-AuNPs showing damaged cell membranes and ruptured structures. (B1) Inset image shows nanoparticles attached and surrounding E. coli.Abbreviations: AuNPs, gold nanoparticles; GlcN-AuNPs, glucosamine-functionalized gold nanoparticles.
Mentions: Herein, we found out the activation time of the drug into the microbe and demonstrated the morphological changes of E. coli after the intake of preparing GlcN-AuNPs, by using AFM and TEM. In this study, we used only GlcN-AuNPs, based on the MIC result that irradiation-exposed nanoparticles have a potent anti bacterial effect. The nanoparticle-treated bacteria were damaged and their morphology was changed, whereas the untreated bacteria had a well defined structure, were smooth, and generally showed typically rod-shaped cells. The TEM images in Figure 8 show that some of the small AuNPs (those less than 100 nm in size) had entered the bacterial cells. The AFM images in Figure 9 show the time dependence of the morphological changes in the bacteria, with increasing bacterial damage seen with increasing duration of treatment. The AFM images show no change to the outer surface of the membrane at 0 hour and subsequent morphological changes depending on duration of incubation. After 24 hours of incubation, the bacterial morphology was unstructured, indicated that GlcN-AuNPs successfully entered the bacterial cells. With time, the approximate bacterial height decreased from 300 nm to 140 nm, confirming these morphological changes.

Bottom Line: Laser-irradiated GlcN-AuNPs exhibited significant bactericidal activity against E. coli.Flow cytometry and fluorescence microscopic analysis supported the cell death mechanism in the presence of GlcN-AuNP-treated bacteria.The overall results of this study suggest that the prepared nanoparticles have potential as a potent antibacterial agent for the treatment of a wide range of disease-causing bacteria.

View Article: PubMed Central - PubMed

Affiliation: Department of Bionanotechnology, Gachon University, Gyeonggi-do, Republic of Korea ; Centre for Advanced Instrumentation, Korea Research Institute of Standard and Science, University of Science and Technology, Daejeon, Republic of Korea.

ABSTRACT
Here we report a novel method for the synthesis of glucosamine-functionalized gold nanoparticles (GlcN-AuNPs) using biocompatible and biodegradable glucosamine for antibacterial activity. GlcN-AuNPs were prepared using different concentrations of glucosamine. The synthesized AuNPs were characterized for surface plasmon resonance, surface morphology, fluorescence spectroscopy, and antibacterial activity. The minimum inhibitory concentrations (MICs) of the AuNPs, GlcN-AuNPs, and GlcN-AuNPs when irradiated by ultraviolet light and laser were investigated and compared with the MIC of standard kanamycin using Escherichia coli by the microdilution method. Laser-irradiated GlcN-AuNPs exhibited significant bactericidal activity against E. coli. Flow cytometry and fluorescence microscopic analysis supported the cell death mechanism in the presence of GlcN-AuNP-treated bacteria. Further, morphological changes in E. coli after laser treatment were investigated using atomic force microscopy and transmission electron microscopy. The overall results of this study suggest that the prepared nanoparticles have potential as a potent antibacterial agent for the treatment of a wide range of disease-causing bacteria.

No MeSH data available.


Related in: MedlinePlus