Photothermal antimicrobial nanotherapy and nanodiagnostics with self-assembling carbon nanotube clusters
Article first published online: 14 SEP 2007
Copyright © 2007 Wiley-Liss, Inc.
Lasers in Surgery and Medicine
Volume 39, Issue 7, pages 622–634, August 2007
How to Cite
Kim, J.-W., Shashkov, E. V., Galanzha, E. I., Kotagiri, N. and Zharov, V. P. (2007), Photothermal antimicrobial nanotherapy and nanodiagnostics with self-assembling carbon nanotube clusters. Lasers Surg. Med., 39: 622–634. doi: 10.1002/lsm.20534
- Issue published online: 14 SEP 2007
- Article first published online: 14 SEP 2007
- Manuscript Accepted: 18 JUL 2007
- The National Research Initiative (NRI) of the USDA-CSREES. Grant Number: 2005-35603-15902
- The National Institute of Biomedical Imaging and Bioengineering. Grant Numbers: R01 EB000873, R01 EB005123
- antimicrobial therapy and diagnostics;
- carbon nanotube;
- near-infrared pulse laser;
Background and Objectives
Unique properties of carbon nanotubes (CNTs) would open new avenues for addressing challenges to realize rapid and sensitive antimicrobial diagnostics and therapy for human pathogens. In this study, new CNTs' capabilities for photothermal (PT) antimicrobial nanotherapy were explored in vitro using Escherichia coli as a model bacterium.
Study Design/Materials and Methods
Single-walled carbon nanotubes (SWNTs) and multi-walled carbon nanotubes (MWNTs) were incubated with E. coli K12 strain. CNTs' locations in bacteria and laser-induced thermal and accompanied effects around CNTs were estimated with TEM and PT microscopy, respectively. Multi-pulse lasers at 532 and 1064 nm with 12-ns pulse duration were used for irradiating sample mixtures at different laser fluences. Cell viability was evaluated using a bacterial viability test kit and epi-fluorescence microscopy.
This study revealed CNTs' high binding affinity to bacteria, their capability to self-assemble as clusters at bacteria surfaces, and their inherent near-infrared (NIR) laser responsiveness. Cell viability was affected neither by CNTs alone nor by NIR irradiations alone. Notable changes in bacteria viability, caused by local thermal and accompanied bubble-formation phenomena, were observed starting at laser fluences of 0.1–0.5 J/cm2 with complete bacteria disintegration at 2–3 J/cm2 at both wavelengths. Furthermore, ethanol in reaction mixtures significantly (more than one order) enhanced bubble formation phenomena.
This first application of laser-activated CNTs as PT contrast antimicrobial agents demonstrated its great potential to cause irreparable damages to disease-causing pathogens as well as to detect the pathogens at single bacterium level. This unique integration of laser and nanotechnology may also be used for drinking water treatment, food processing, disinfection of medical instrumentation, and purification of grafts and implants. Furthermore, the significant ethanol-induced enhancement of bubble formation provides another unique possibility to improve the efficiency of selective nanophotothermolysis for treating cancers, wounds, and vascular legions. Lesers Surg. Med. 39:622–634, 2007. © 2007 Wiley-Liss, Inc.