Pristine carbon nanotubes are efficient absorbers at radio frequencies
Year: 2022
Type: article
Abstract: Radio frequency ablation and microwave hyperthermia are powerful tools for destroying dysfunctional biological tissues. However, wireless application of these techniques is hindered by their inability to focus the electromagnetic energy to small targets. The use of locally injected radio frequency- or microwave-absorbing nanomaterials can help to overcome this challenge by confining heat production to the injected region. Previous theoretical work suggests that high-aspect-ratio conducting nanomaterials, such as carbon nanotubes, offer powerful radio frequency and microwave absorption. While carbon nanotubes have been demonstrated as radiothermal agents, common solubilization methods may reduce their absorption efficiency, yielding undesirable nonspecific heating in the biological tissue background. In this manuscript, we hypothesize that pristine carbon nanotubes can act as efficient absorbers at radio frequencies, thus providing differential heating over the tissue background. Specifically, we use a sonication-free preparation technique to preserve both the high aspect ratio and local concentration of pristine carbon nanotubes. We validate the differential heating of these samples by 4.5-fold at 2 GHz compared to the heating of saline at a physiological concentration using infrared thermography. In addition, we successfully achieved local heating of pristine carbon nanotubes within a three-dimensional biological tissue phantom. Numerical simulations further aid in producing a temperature map within the phantom and confirming localized heating. Due to their significant differential and local heating, we believe that pristine carbon nanotubes may facilitate region-specific radio frequency ablation and microwave hyperthermia while keeping nonspecific heating to a low level in the normal tissue background.
Source: Nanotechnology
Authors: Nicholas J Rommelfanger, Kenneth Brinson, John E Bailey, Analiese M Bancroft, Zihao Ou, Guosong Hong
Institution: Stanford University
Language: English
Subfield: Biomedical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, Spinal Muscular Atrophy Foundation, Rita Allen Foundation, Focused Ultrasound Foundation, National Institutes of Health, Wu Tsai Neurosciences Institute, Stanford University, National Institute on Aging, National Institute of Neurological Disorders and Stroke, National Science Foundation Graduate Research Fellowship Program
Awards: Mesh electronics for understanding space encoding in the amphibian brain, G2000443604, Brain Aging Studies with Single-Neuron Resolution Using Syringe-Injectable Electronics, CAREER: Sculpting light in biological tissue: an ultrasound-mediated traveling light source for spatiotemporally precise in vivo gene editing, G5130526148, G880926405
OpenAlex ID: W4229039363