This work was funded by the NIH (U54CA143837), the NIH M.D. Anderson Cancer Center Support Grants (CA016672), the V Foundation (SAC), and an unrestricted research grant from the Kanzius Research Foundation (SAC, Erie, PA). We thank Kristine Ash from the Department of Surgical Oncology, M.D. Anderson Cancer Center, for administrative assistance.

A complete experimental overview is depicted in Figure 1.
Further details are depicted in steps 1-3 below.
1. Assessing RF Heating of NP Colloids: AuNPs as an Example
<ol>
	<li>In general, for each NP sample being investigated, first wash the sample several times through a centrifugation filter with deionized (DI) water to remove background ions and contaminants. All ions and contaminants will have been removed from the AuNP suspension when the li...

<ol>
	<li>Gannon, C. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Carbon+nanotube-enhanced+thermal+destruction+of+cancer+cells+in+a+noninvasive+radiofrequency+field.">Carbon nanotube-enhanced thermal destruction of cancer cells in a noninvasive radiofrequency field.</a> Cancer. 110, 2654 (2007).</li><li>Curley, S. A., Cherukuri, P., Briggs, K., Patra, C. R., Upton, M., Dolson, E., Mukherjee, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Noninvasive+radiofrequency+field-induced+hyperthermic+cytotoxicity+in+human+cancer+cells+using+cetuximab-targeted+gold+nanoparticles.">Noninvasive radiofrequency field-induced hyperthermic cytotoxicity in human cancer cells using cetuximab-targeted gold nanoparticles.</a> J. Exp. Ther. Oncol. 7, 313 (2008).</li><li>Gannon, C. J., Patra, C. R., Bhattacharya, R., Mukherjee, P., Curley, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intracellular+gold+nanoparticles+enhance+non-invasive+radiofrequency+thermal+destruction+of+human+gastrointestinal+cancer+cells.">Intracellular gold nanoparticles enhance non-invasive radiofrequency thermal destruction of human gastrointestinal cancer cells.</a> Journal of Nanobiotechnology. 6, 2 (2008).</li><li>Raoof, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stability+of+antibody-conjugated+gold+nanoparticles+in+the+endolysosomal+nanoenvironment:+implications+for+noninvasive+radiofrequency-based+cancer+therapy.">Stability of antibody-conjugated gold nanoparticles in the endolysosomal nanoenvironment: implications for noninvasive radiofrequency-based cancer therapy.</a> Nanomedicine. 8, 1096 (2012).</li><li>Glazer, E. S., Massey, K. L., Zhu, C., Curley, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pancreatic+carcinoma+cells+are+susceptible+to+noninvasive+radio+frequency+fields+after+treatment+with+targeted+gold+nanoparticles.">Pancreatic carcinoma cells are susceptible to noninvasive radio frequency fields after treatment with targeted gold nanoparticles.</a> Surgery. 148, 319 (2010).</li><li>Glazer, E. S., Curley, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Radiofrequency+field-induced+thermal+cytotoxicity+in+cancer+cells+treated+with+fluorescent+nanoparticles.">Radiofrequency field-induced thermal cytotoxicity in cancer cells treated with fluorescent nanoparticles.</a> Cancer. 116, 3285 (2010).</li><li>Glazer, E. S., Curley, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Non-invasive+radiofrequency+ablation+of+malignancies+mediated+by+quantum+dots,+gold+nanoparticles+and+carbon+nanotubes.">Non-invasive radiofrequency ablation of malignancies mediated by quantum dots, gold nanoparticles and carbon nanotubes.</a> Therapeutic Delivery. 2, 1325 (2011).</li><li>Corr, S. J., Raoof, M., Mackeyev, Y., Phounsavath, S., Cheney, M. A., Cisneros, B. T., Shur, M., Gozin, M., McNally, P. J., Wilson, L. J., Curley, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Citrate-Capped+Gold+Nanoparticle+Electrophoretic+Heat+Production+in+Response+to+a+Time-Varying+Radiofrequency+Electric-Field.">Citrate-Capped Gold Nanoparticle Electrophoretic Heat Production in Response to a Time-Varying Radiofrequency Electric-Field.</a> J. Phys. Chem. C. 116, 24380 (2012).</li><li>Kruse, D. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Radio-Frequency+Coupling+Network+for+Heating+of+Citrate-Coated+Gold+Nanoparticles+for+Cancer+Therapy:+Design+and+Analysis.">A Radio-Frequency Coupling Network for Heating of Citrate-Coated Gold Nanoparticles for Cancer Therapy: Design and Analysis.</a> IEEE Transactions on Biomedical Engineering. 58, 10 (2011).</li><li>Li, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Negligible+absorption+of+radiofrequency+radiation+by+colloidal+gold+nanoparticles.">Negligible absorption of radiofrequency radiation by colloidal gold nanoparticles.</a> J. Colloid Interf. Sci. 358, 47 (2011).</li><li>Liu, X., Chen, H. J., Chen, X., Parini, C., Wen, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Low+frequency+heating+of+gold+nanoparticle+dispersions+for+non-invasive+thermal+therapies.">Low frequency heating of gold nanoparticle dispersions for non-invasive thermal therapies.</a> Nanoscale. , (2012).</li><li>Sassaroli, E., Li, K. C. P., O'Neill, B. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Radio+frequency+absorption+in+gold+nanoparticle+suspensions:+a+phenomenological+study.">Radio frequency absorption in gold nanoparticle suspensions: a phenomenological study.</a> J. Phys. D App. Phys. 45, 075303 (2012).</li><li>Worle-Knirsch, J. M., Pulskamp, K., Krug, H. 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These protocols allow the experimentalist to fully analyze the extent to which nanomaterials (in this case AuNPs) can increase RF-induced hyperthermia for cancer treatment. The first protocol specifically deals with analyzing heat production from highly-concentrated and purified AuNP samples. Although other groups have reported heat production primarily from the buffers which the AuNPs are suspended in and not the AuNPs themselves9-11, their RF systems used lower concentrations of AuNPs with diameters &gt;10 n...

The absorption of RF energy by biological tissue (due to their inherent electrical permittivity) results in elevated tissue temperatures as a function of time, which eventually leads to cell death by hyperthermia. It is hypothesized that cancer hyperthermia can be optimized through the use of targeted nanomaterials that internalize within the cancer cell and act as RF-thermal transducers, leaving the neighboring healthy, normal cells intact. Several reports have already shown that a variety of NPs can act as effective RF heat sources which aid in cancer necrosis1-4.
In these regards, gold NPs (AuNPs)3-5, carbon nanotubes1, and quantum dots6, 7 have exhibited exciting characteristics when used in both in vitro and in vivo RF experiments. Although the exact nature of the heating mechanism of these NPs when exposed to an RF-field is still being debated, a series of fundamental experiments using AuNPs has placed great significance on both NP size and aggregation states. It was shown that only AuNPs with diameters &lt;10 nm will heat when exposed to an RF-field8. Also, this heating mechanism is significantly attenuated when the AuNPs are aggregated. This aggregation condition was also validated within in vitro models that placed importance upon optimizing AuNP colloidal stability within endolysomal intracellular compartments for efficacious RF therapy4. However, the techniques and experimental principles used to collect and assess this data can be problematic, especially in the case of validating RF heat profiles from NP colloids.
Several reports have shown that Joule heating of the background ionic suspension that the NPs are suspended in can be the main source of RF heat production and not the NPs themselves9-12. Although our recent paper8 has validated the use of RF interactions in generating heat from AuNPs of diameters less than 10 nm, we aim to describe these protocols in more detail throughout this article.
We also demonstrate the protocols and techniques needed to evaluate the effectiveness of AuNPs as hyperthermic thermal agents in both in vitro and in vivo experiments for liver cancer models. Although we focus primarily on simple colloids of citrate-capped AuNPs, the same techniques can be applied to other AuNP hybrids such as antibody- and chemotherapy-conjugated complexes. By adhering to these principles the experimentalist should hopefully be able to rapidly evaluate the potential for any nanomaterial to be an effective RF-induced thermal hyperthermic agent.

<table border="1">
	<tbody>
		<tr>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>Reagent/Material</td>
		</tr>
		<tr>
			<td>500 ml gold nanoparticles (5 nm)</td>
			<td>Ted Pella, INC</td>
			<td>15702-5</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Amicon Ultra-4/-15 Centrifugal Filter Units (50 kDa)</td>
			<td>Millipore</td>
			<td>UFC805024/UFC910096</td>
			<td>(4 ml and 15 ml volumes)</td>
		</tr>
		<tr>
			<td>MEM X1 Cell Culture Media</td>
			<td>Cellgro</td>
			<td>10-101-CV</td>
			<td>(add extra nutrients as necessary)</td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum</td>
			<td>Sigma</td>
			<td>F4135-500 ml</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Copper Tape</td>
			<td>Ted Pella</td>
			<td>16072</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>Equipment</td>
		</tr>
		<tr>
			<td>Kanzius RF System (13.56 MHZ)</td>
			<td>ThermMed, LLC, Inc. (Erie, PA, USA)</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>IR Camera</td>
			<td>FLIR SC 6000, FLIR Systems, Inc. (Boston, MA, USA)</td>
			<td>Contact FLIR</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>1.3 ml Quartz Cuvette</td>
			<td>ThermMed, LLC, Inc. (Erie, PA, USA)</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Teflon Sample holder with Rotary Stage</td>
			<td>ThermMed, LLC, Inc. (Erie, PA, USA)</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>SPECTROstar Nano Microplate reader</td>
			<td>BGM Labtech</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>UV-Vis spectrometer</td>
			<td>Applied Nanofluorescence, Houston, TX)</td>
			<td>NS1 NanoSpectralyzer</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>ICP-OES</td>
			<td>PerkinElmer</td>
			<td>Optima 4300 DV</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Zetasizer</td>
			<td>Malvern</td>
			<td>Zen 3600 Zetasizer</td>
			<td>&nbsp;</td>
		</tr>
	</tbody>
</table>

protocols for assessing radiofrequency interactions with gold nanoparticles and biological systems for non-invasive hyperthermia cancer therapy

Cancer therapies which are less toxic and invasive than their existing counterparts are highly desirable. The use of RF electric-fields that penetrate deep into the body, causing minimal toxicity, are currently being studied as a viable means of non-invasive cancer therapy. It is envisioned that the interactions of RF energy with internalized nanoparticles (NPs) can liberate heat which can then cause overheating (hyperthermia) of the cell, ultimately ending in cell necrosis.
In the case of non-biological systems, we present detailed protocols relating to quantifying the heat liberated by highly-concentrated NP colloids. For biological systems, in the case of in vitro experiments, we describe the techniques and conditions which must be adhered to in order to effectively expose cancer cells to RF energy without bulk media heating artifacts significantly obscuring the data. Finally, we give a detailed methodology for in vivo mouse models with ectopic hepatic cancer tumors.

1. Assessing RF heating of NP colloids: AuNPs as an example.
After following section 1.1 - 1.2.3 expect to have a highly concentrated, stable, and purified solution of 5 nm and 10 nm diameter AuNPs. From the 500 ml as-purchased stock solution, expect to obtain at least 4 ml of solution at a concentration of 1,000 mg/L. The difference in HRs between the AuNPs and the background DI water buffer solution at this concentration should be ~0.25 &deg;C/sec and 0.1 &deg;C/sec for 5 nm and 10 nm AuNPs, re...

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Protocols for Assessing Radiofrequency Interactions with Gold Nanoparticles and Biological Systems for Non-invasive Hyperthermia Cancer Therapy

We describe the protocols used to investigate the interactions of 13.56 MHz radiofrequency (RF) electric-fields with gold nanoparticle colloids in both non-biological and biological systems (in vitro/vivo). These interactions are being investigated for applications in cancer therapy.

Cancer therapies  which are less toxic and invasive than their existing counterparts are highly  desirable. The use of RF electric-fields that penetrate ...

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10.7K vistas.  University of Texas M.D. Anderson Cancer Center.  Se describen los protocolos que se utilizan para investigar las interacciones de 13.56 MHz de radiofrecuencia (RF) de electricidad-los campos con coloides de nanopartículas de oro en ambos sistemas no biológicos y biológicos (in vitro / in vivo). Estas interacciones están siendo investigados para su aplicación en la terapia del cáncer. 