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 liquid being washed out has similar RF heating rates (HRs) as DI water. This purification process also allows for higher concentrations of NPs to be obtained. It is worth noting that although using AuNPs in this example, the fundamental principles can be applied to other NP materials.</li>
	<li>As an example, purify a 500 ml bottle of commercially available AuNPs of diameter 5 nm and then subject them to a 13.56 MHz RF field of electric-field strength 90 kV/m.
	<ol>
		<li>Take ~125 ml from the stock AuNP solution and split between six 50 kDa centrifuge filter tubes. Centrifuge at 3,000 rpm. for 2 min 5 sec. Remove filtered buffer and refill filters with more stock solution. Repeat until all 500 ml has been filtered.</li>
		<li>Replace the filtered buffer with a similar volume of DI water and repeat approximately 8 times (or until the filtered buffer RF HRs are equivalent to DI water). Note, UV-Vis analysis can also be used to monitor contaminant absorption peaks. Once the buffer contaminants have been fully removed, pipette approximately 0.5 ml DI water into each filter and resuspend the AuNPs by repeated pipetting. This should completely remove the AuNPs from the filter and allow for full resuspension. Combine all six suspensions into one 15 ml Eppendorf tube.</li>
		<li>Once the AuNPs have been purified and concentrated, analyze the sample using ICP-OES and/or ICP-MS, UV-vis and Zeta potential for data on concentration and NP stability, respectively. SEM and/or TEM analysis can also be used to obtain morphological data. Detailed sample preparation for these techniques can be found in the literature4.</li>
	</ol>
	</li>
	<li>Using the Kanzius RF system described in previous studies8, or derivations of this system, place a 1.3 ml cylindrical quartz cuvette so that the RF electric-field in air (with no sample present) would be ~90 kV/m inside the cuvette. For a standard saline sample (0.9 % NaCl) the electric-field would be reduced to ~1.1 kV/m. These are the approximate conditions used to allow comparisons to be made between different systems.
	<ol>
		<li>Pipette 1.3 ml of a 1,000 mg/l sample of purified AuNP colloid into the quartz cuvette and introduce this into the RF-field. This can be done by using a custom-built Teflon sample holder. Expose sample to the RF-field for a period of 120 sec or until the sample reaches 70 &deg;C to prevent electrical arcing or rapid boiling. Capture the thermal imaging data (as well as control areas) using an IR camera &amp; associated software. Repeat this procedure three times.</li>
		<li>Filter the sample through another 50 kDa centrifuge filter to extract the AuNPs from the DI water buffer. Re-expose the buffer to the RF-field, again three times. The difference in HRs between the AuNP colloid and the background DI water buffer determines the HR due to the AuNPs themselves. Expect to obtain HRs of ~0.3 &deg;C/sec and 0.05 &deg;C/sec to give an AuNP dependent HR of ~ 0.25 &deg;C/sec. Resuspend the remaining AuNPs from the filter in 1.3 ml water for in vitro/vivo experiments.</li>
	</ol>
	</li>
</ol>
2. Nanoparticle-assisted RF-induced Hyperthermia: In vitro Studies
<ol>
	<li>These in vitro studies can be applied to any type of cancer cell type that form 2D monolayers. In this experiment use human hepatocellular carcinoma derived Hep3B cells.
	<ol>
		<li>Plate ~50,000 cells in the front three wells of a 12-well plate with 1 ml of growth media. Repeat this 6 times (use three plates for NP studies and three plates as controls). Incubate at 37.5 &deg;C for 24 hr before introducing the NPs. Sterilize NPs first using BioSafety Cabinet UV-light exposure for 5 min.</li>
		<li>Into each well introduce 0.1 ml of a 1,000 mg/L AuNP solution and leave for another 24 hr. Add 0.1 ml of water into each well of the three control cell plates and also leave for 24 hr.</li>
		<li>After 24 hr have passed, aspirate the cell media and wash with PBS to remove any surface-bound AuNPs. Replace the cell media. Cells are now ready for RF exposure.</li>
	</ol>
	</li>
	<li>Place each 12-well cell pack within the RF-field. Wait until the cells have cooled to 31 &deg;C. Turn on the RF generator and expose for 3.5 min. The final temperature of the cell media will be ~37 &deg;C. Turn off the RF field. Remove the cells and place them in an incubator for 24 hr before analysis.
	<ol>
		<li>Remove cells from the incubator and aspirate cell media. Add 1.6 ml of cell media to each well as well at 0.4 ml of MTT reagent. Incubate cells for 4 hr. Aspirate media and replace with 2 ml of Dimethyl sulfoxide (DMSO). Place the cell plates on a bench rocker and leave for 10 min to allow the DMSO to solubilize the MTT reagents. Finally, pipette 100 &mu;l of each well into a 96-well plate and optically read the well at 570 nm using a plate reader such as the SPECTROstar Nano plate reader.</li>
	</ol>
	</li>
</ol>
3. Nanoparticle-assisted RF-induced Hyperthermia: In vivo Studies
<ol>
	<li>These in vivo studies can be applied to any type of cancer that forms solid tumors in an orthotopic or ectopic murine model. This experiment uses Hep3B liver cancer cells in an ectopic tumor BALB-C Nude mouse model.</li>
	<li>Note: all in vivo experiments are executed in compliance with all relevant guidelines, regulations and regulatory agencies. Also, the protocol being demonstrated was performed under the guidance and approval of University of Texas M.D. Anderson Cancer Centers Institutional Animal Care and Use Committee (IACUC).
	<ol>
		<li>Grow an appropriate number of cells (~100 k) in a tissue culture flask with the appropriate growth medium. Incubate in a 37 &deg;C incubator with 5 % CO2 for the duration of cell culture.</li>
		<li>Treat cells with trypsin (to detach from the flask) and produce a solution of 2 million cells for every 25 &mu;l. Add an equal quantity of Matrigel (on ice) and mix thoroughly to prepare the final injection solution. Inject this solution into the desired position on the mouse's back and wait an appropriate amount of time for the tumors to grow to the desired size (2-4 weeks for most cells). Before RF exposure, BALB-C Nude mice should bear solid ectopic tumors 0.5-1 cm diameter.</li>
	</ol>
	</li>
	<li>
	<ol>
		<li>Prepare the mice to be used (in this case BALB-C Nude mice) by anaesthetizing them with a solution of ketamine and xylazine by IP injection. While the mice are falling asleep, keep them in a temperature controlled chamber at 37 &deg;C. 20 mice in total will be needed, all bearing similar size tumors. Ten mice will be used in conjunction with and without AuNPs (the latter being PBS injections only) while the remaining 10 mice will be split between RF-exposed and non RF-exposed controls: both groups with no AuNP injections.</li>
		<li>Once properly anaesthetized, inject the AuNPs directly into the tumor using a 1-cc syringe with a 27 G needle. The AuNP solution should be at a Au concentration of 200 mg/L in 0.1 ml of PBS. After injection, use a surgical swab to absorb blood and wipe the injection site with an alcohol wipe.</li>
		<li>Then mount the mouse to be treated on the receiving head of the RF generator. The mouse must be positioned so that the tumor is closest to the transmission head. Shield the areas that are not to be treated, as well as sensitive areas such as eyes, ears, and toes, with copper tape. Be sure that the copper tape is appropriately contacting the grounding plane so that no charge buildup occurs. Also, the exposure area must have a gap of at least 1 cm greater than the size of the desired treatment site.</li>
		<li>Position IR thermal camera so that the tumor and treatment area are visible. Turn on RF for 5 min. Record the resulting temperature curve. If therapy achieves temperatures greater than 42 &deg;C stop treatment immediately.</li>
	</ol>
	</li>
	<li>
	<ol>
		<li>After RF exposure recover the mice from anesthesia in a warm chamber until they are conscious.</li>
		<li>Repeat the experiment with the same mice 48 hr later (steps 3.3.1 - 3.4.1).</li>
		<li>After the experiment, euthanize the mice in accordance with institutional protocols and procedures. Record the weight of the tumor. For histological analysis fix the tumors using formalin and embed them in paraffin. Tumor sections are typically stained with hematoxylin and eosin and for targets relevant to gauging therapeutic efficacy, e.g. Ki-67, cleaved caspase-3, etc.</li>
	</ol>
	</li>
</ol>

<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. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oops+they+did+it+again!+Carbon+nanotubes+hoax+scientists+in+viability+assays.">Oops they did it again! Carbon nanotubes hoax scientists in viability assays.</a> Nano Lett. 6, 1261 (2006).</li></ol>

We have nothing to disclose.

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...

Watch this Scientific Journal Video about Protocols for Assessing Radiofrequency Interactions with Gold Nanoparticles and Biological Systems for Non-invasive Hyperthermia Cancer Therapy at JoVE.com

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 Views.  University of Texas M.D. Anderson Cancer Center. 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.

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

Staining Protocols for Human Pancreatic Islets

Estimates of islet area and numbers and endocrine cell composition in the adult human pancreas vary from several hundred thousand to several million and beta mass ranges from 500 to 1500 mg 1-3. With this known heterogeneity, a standard processing and staining procedure was developed so that pancreatic regions were clearly defined and islets characterized using rigorous histopathology and immunolocalization examinations. 
Standardized procedures for processing human pancreas recovered from organ donors are described in part 1 of this series. The pancreas is processed into 3 main regions (head, body, tail) followed by transverse sections. Transverse sections from the pancreas head are further divided, as indicated based on size, and numbered alphabetically to denote subsections. This standardization allows for a complete cross sectional analysis of the head region including the uncinate region which contains islets composed primarily of pancreatic polypeptide cells to the tail region.
The current report comprises part 2 of this series and describes the procedures used for serial sectioning and histopathological characterization of the pancreatic paraffin sections with an emphasis on islet endocrine cells, replication, and T-cell infiltrates. Pathology of pancreatic sections is intended to characterize both exocrine, ductular, and endocrine components. The exocrine compartment is evaluated for the presence of pancreatitis (active or chronic), atrophy, fibrosis, and fat, as well as the duct system, particularly in relationship to the presence of pancreatic intraductal neoplasia4. Islets are evaluated for morphology, size, and density, endocrine cells, inflammation, fibrosis, amyloid, and the presence of replicating or apoptotic cells using H&amp;E and IHC stains. 
The final component described in part 2 is the provision of the stained slides as digitized whole slide images. The digitized slides are organized by case and pancreas region in an online pathology database creating a virtual biobank. Access to this online collection is currently provided to over 200 clinicians and scientists involved in type 1 diabetes research. The online database provides a means for rapid and complete data sharing and for investigators to select blocks for paraffin or frozen serial sections.

This video demonstrates procedures for characterization of human pancreatic islets using hematoxylin and eosin (H&E) and immunohistochemistry (IHC). Pancreatic sections from head, body, and tail regions are stained by both H&amp;E and IHC to determine islet endocrine composition (insulin, glucagon, and pancreatic polypeptide), cell replication (Ki67), and inflammatory infiltrates (H&E, CD3). The uncinate region is localized using IHC for pancreatic polypeptide.

Estimates of islet area and numbers and endocrine cell composition in the adult human pancreas vary from several hundred thousand to several million and ...

Cerenkov Luminescence Imaging (CLI) for Cancer Therapy Monitoring

In molecular imaging, positron emission tomography (PET) and optical imaging (OI) are two of the most important and thus most widely used modalities1-3. PET is characterized by its excellent sensitivity and quantification ability while OI is notable for non-radiation, relative low cost, short scanning time, high throughput, and wide availability to basic researchers. However, both modalities have their shortcomings as well. PET suffers from poor spatial resolution and high cost, while OI is mostly limited to preclinical applications because of its limited tissue penetration along with prominent scattering optical signals through the thickness of living tissues.
 Recently a bridge between PET and OI has emerged with the discovery of Cerenkov Luminescence Imaging (CLI)4-6. CLI is a new imaging modality that harnesses Cerenkov Radiation (CR) to image radionuclides with OI instruments. Russian Nobel laureate Alekseyevich Cerenkov and his colleagues originally discovered CR in 1934. It is a form of electromagnetic radiation emitted when a charged particle travels at a superluminal speed in a dielectric medium7,8. The charged particle, whether positron or electron, perturbs the electromagnetic field of the medium by displacing the electrons in its atoms. After passing of the disruption photons are emitted as the displaced electrons return to the ground state. For instance, one 18F decay was estimated to produce an average of 3 photons in water5. 
 Since its emergence, CLI has been investigated for its use in a variety of preclinical applications including in vivo tumor imaging, reporter gene imaging, radiotracer development, multimodality imaging, among others4,5,9,10,11. The most important reason why CLI has enjoyed much success so far is that this new technology takes advantage of the low cost and wide availability of OI to image radionuclides, which used to be imaged only by more expensive and less available nuclear imaging modalities such as PET.
 Here, we present the method of using CLI to monitor cancer drug therapy. Our group has recently investigated this new application and validated its feasibility by a proof-of-concept study12. We demonstrated that CLI and PET exhibited excellent correlations across different tumor xenografts and imaging probes. This is consistent with the overarching principle of CR that CLI essentially visualizes the same radionuclides as PET. We selected Bevacizumab (Avastin; Genentech/Roche) as our therapeutic agent because it is a well-known angiogenesis inhibitor13,14. Maturation of this technology in the near future can be envisioned to have a significant impact on preclinical drug development, screening, as well as therapy monitoring of patients receiving treatments.

Cerenkov Luminescence Imaging CLI for Cancer Therapy Monitoring

Use of Cerenkov Luminescence Imaging (CLI) for monitoring preclinical cancer treatment is described here. This method takes advantage of Cerenkov Radiation (CR) and optical imaging (OI) to visualize radiolabeled probes and thus provides an alternative to PET in preclinical therapeutic monitoring and drug screening.

In  molecular imaging, positron emission tomography (PET) and optical imaging (OI)  are two of the most important and thus most widely used modalities1-3. ...

Non-invasive Optical Measurement of Cerebral Metabolism and Hemodynamics in Infants

Perinatal brain injury remains a significant cause of infant mortality and morbidity, but there is not yet an effective bedside tool that can accurately screen for brain injury, monitor injury evolution, or assess response to therapy. The energy used by neurons is derived largely from tissue oxidative metabolism, and neural hyperactivity and cell death are reflected by corresponding changes in cerebral oxygen metabolism (CMRO2). Thus, measures of CMRO2 are reflective of neuronal viability and provide critical diagnostic information, making CMRO2 an ideal target for bedside measurement of brain health.
Brain-imaging techniques such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT) yield measures of cerebral glucose and oxygen metabolism, but these techniques require the administration of radionucleotides, so they are used in only the most acute cases.
Continuous-wave near-infrared spectroscopy (CWNIRS) provides non-invasive and non-ionizing radiation measures of hemoglobin oxygen saturation (SO2) as a surrogate for cerebral oxygen consumption. However, SO2 is less than ideal as a surrogate for cerebral oxygen metabolism as it is influenced by both oxygen delivery and consumption. Furthermore, measurements of SO2 are not sensitive enough to detect brain injury hours after the insult 1,2, because oxygen consumption and delivery reach equilibrium after acute transients 3. We investigated the possibility of using more sophisticated NIRS optical methods to quantify cerebral oxygen metabolism at the bedside in healthy and brain-injured newborns. More specifically, we combined the frequency-domain NIRS (FDNIRS) measure of SO2 with the diffuse correlation spectroscopy (DCS) measure of blood flow index (CBFi) to yield an index of CMRO2 (CMRO2i) 4,5.
With the combined FDNIRS/DCS system we are able to quantify cerebral metabolism and hemodynamics. This represents an improvement over CWNIRS for detecting brain health, brain development, and response to therapy in neonates. Moreover, this method adheres to all neonatal intensive care unit (NICU) policies on infection control and institutional policies on laser safety. Future work will seek to integrate the two instruments to reduce acquisition time at the bedside and to implement real-time feedback on data quality to reduce the rate of data rejection.

We combined frequency-domain near-infrared spectroscopy measures of cerebral hemoglobin oxygenation with diffuse correlation spectroscopy measures of cerebral blood flow index to estimate an index of oxygen metabolism. We tested the utility of this measure as a bedside screening tool to evaluate the health and development of the newborn brain.

Perinatal brain injury remains a significant cause of infant mortality  and morbidity, but there is not yet an effective bedside tool that can  accurately ...

Non-invasive Assessment of Microvascular and Endothelial Function

The authors have utilized capillaroscopy and forearm blood flow techniques to investigate the role of microvascular dysfunction in pathogenesis of cardiovascular disease. Capillaroscopy is a non-invasive, relatively inexpensive methodology for directly visualizing the microcirculation. Percent capillary recruitment is assessed by dividing the increase in capillary density induced by postocclusive reactive hyperemia (postocclusive reactive hyperemia capillary density minus baseline capillary density), by the maximal capillary density (observed during passive venous occlusion). Percent perfused capillaries represents the proportion of all capillaries present that are perfused (functionally active), and is calculated by dividing postocclusive reactive hyperemia capillary density by the maximal capillary density. Both percent capillary recruitment and percent perfused capillaries reflect the number of functional capillaries. The forearm blood flow (FBF) technique provides accepted non-invasive measures of endothelial function: The ratio FBFmax/FBFbase is computed as an estimate of vasodilation, by dividing the mean of the four FBFmax values by the mean of the four FBFbase values. Forearm vascular resistance at maximal vasodilation (FVRmax) is calculated as the mean arterial pressure (MAP) divided by FBFmax. Both the capillaroscopy and forearm techniques are readily acceptable to patients and can be learned quickly.
The microvascular and endothelial function measures obtained using the methodologies described in this paper may have future utility in clinical patient cardiovascular risk-reduction strategies. As we have published reports demonstrating that microvascular and endothelial dysfunction are found in initial stages of hypertension including prehypertension, microvascular and endothelial function measures may eventually aid in early identification, risk-stratification and prevention of end-stage vascular pathology, with its potentially fatal consequences.

Capillaroscopy is a non-invasive, relatively inexpensive methodology for directly visualizing the microcirculation. The forearm blood flow technique provides accepted non-invasive measures of endothelial function.

The authors have utilized capillaroscopy and forearm blood flow techniques to investigate the role of microvascular dysfunction in pathogenesis of ...

Transplantation into the Anterior Chamber of the Eye for Longitudinal, Non-invasive In vivo Imaging with Single-cell Resolution in Real-time

Intravital imaging has emerged as an indispensable tool in biological research. In the process, many imaging techniques have been developed to study different biological processes in animals non-invasively. However, a major technical limitation in existing intravital imaging modalities is the inability to combine non-invasive, longitudinal imaging with single-cell resolution capabilities. We show here how transplantation into the anterior chamber of the eye circumvents such significant limitation offering a versatile experimental platform that enables non-invasive, longitudinal imaging with cellular resolution in vivo. We demonstrate the transplantation procedure in the mouse and provide representative results using a model with clinical relevance, namely pancreatic islet transplantation. In addition to enabling direct visualization in a variety of tissues transplanted into the anterior chamber of the eye, this approach provides a platform to screen drugs by performing long-term follow up and monitoring in target tissues. Because of its versatility, tissue/cell transplantation into the anterior chamber of the eye not only benefits transplantation therapies, it extends to other in vivo applications to study physiological and pathophysiological processes such as signal transduction and cancer or autoimmune disease development.

Transplantation into the Anterior Chamber of the Eye for Longitudinal, Non-invasive In vivo Imaging with Single-cell Resolution in Real-time

A new approach combining intraocular transplantation and confocal microscopy enables longitudinal, non-invasive real-time imaging with single-cell resolution within grafted tissues in vivo. We demonstrate how to transplant pancreatic islets into the anterior chamber of the mouse eye.

Intravital imaging has emerged as an indispensable tool in biological research.  In the process, many imaging techniques have been developed to study ...

Non-invasive Imaging and Analysis of Cerebral Ischemia in Living Rats Using Positron Emission Tomography with 18F-FDG

Stroke is the third leading cause of death among Americans 65 years of age or older1. The quality of life for patients who suffer from a stroke fails to return to normal in a large majority of patients2, which is mainly due to current lack of clinical treatment for acute stroke. This necessitates understanding the physiological effects of cerebral ischemia on brain tissue over time and is a major area of active research. Towards this end, experimental progress has been made using rats as a preclinical model for stroke, particularly, using non-invasive methods such as 18F-fluorodeoxyglucose (FDG) coupled with Positron Emission Tomography (PET) imaging3,10,17. Here we present a strategy for inducing cerebral ischemia in rats by middle cerebral artery occlusion (MCAO) that mimics focal cerebral ischemia in humans, and imaging its effects over 24 hr using FDG-PET coupled with X-ray computed tomography (CT) with an Albira PET-CT instrument. A VOI template atlas was subsequently fused to the cerebral rat data to enable a unbiased analysis of the brain and its sub-regions4. In addition, a method for 3D visualization of the FDG-PET-CT time course is presented. In summary, we present a detailed protocol for initiating, quantifying, and visualizing an induced ischemic stroke event in a living Sprague-Dawley rat in three dimensions using FDG-PET.

Non-invasive Imaging and Analysis of Cerebral Ischemia in Living Rats Using Positron Emission Tomography with 18F-FDG

Brain damage resulting from cerebral ischemia may be non-invasively imaged and studied in rats using pre-clinical positron emission tomography coupled with the injectable radioactive probe, 18F-fluorodeoxyglucose. Further, the use of modern software tools that include volume of interest (VOI) brain templates dramatically increase the quantitative information gleaned from these studies.

Stroke is the third leading cause of death among Americans 65 years of age or older1. The quality of life for patients who suffer from a stroke fails to ...

Murine Model for Non-invasive Imaging to Detect and Monitor Ovarian Cancer Recurrence

Epithelial ovarian cancer is the most lethal gynecologic malignancy in the United States. Although patients initially respond to the current standard of care consisting of surgical debulking and combination chemotherapy consisting of platinum and taxane compounds, almost 90% of patients recur within a few years. In these patients the development of chemoresistant disease limits the efficacy of currently available chemotherapy agents and therefore contributes to the high mortality. To discover novel therapy options that can target recurrent disease, appropriate animal models that closely mimic the clinical profile of patients with recurrent ovarian cancer are required. The challenge in monitoring intra-peritoneal (i.p.) disease limits the use of i.p. models and thus most xenografts are established subcutaneously. We have developed a sensitive optical imaging platform that allows the detection and anatomical location of i.p. tumor mass. The platform includes the use of optical reporters that extend from the visible light range to near infrared, which in combination with 2-dimensional X-ray co-registration can provide anatomical location of molecular signals. Detection is significantly improved by the use of a rotation system that drives the animal to multiple angular positions for 360 degree imaging, allowing the identification of tumors that are not visible in single orientation. This platform provides a unique model to non-invasively monitor tumor growth and evaluate the efficacy of new therapies for the prevention or treatment of recurrent ovarian cancer.

We describe a non-invasive animal imaging platform that allows the detection, quantification, and monitoring of ovarian cancer growth and recurrence. This intra-peritoneal xenograft model mimics the clinical profile of patients with ovarian cancer.

Epithelial ovarian cancer is the most lethal gynecologic malignancy in the United States. Although patients initially respond to the current standard of ...

Non-invasive Assessment of the Efficacy of New Therapeutics for Intestinal Pathologies Using Serial Endoscopic Imaging of Live Mice

Animal models of inflammatory bowel disease (IBD) and colorectal cancer (CRC) have provided significant insight into the cell intrinsic and extrinsic mechanisms that contribute to the onset and progression of intestinal diseases. The identification of new molecules that promote these pathologies has led to a flurry of activity focused on the development of potential new therapies to inhibit their function. As a result, various pre-clinical mouse models with an intact immune system and stromal microenvironment are now heavily used. Here we describe three experimental protocols to test the efficacy of new therapeutics in pre-clinical models of (1) acute mucosal damage, (2) chronic colitis and/or colitis-associated colon cancer, and (3) sporadic colorectal cancer. We also outline procedures for serial endoscopic examination that can be used to document the therapeutic response of an individual tumor and to monitor the health of individual mice. These protocols provide complementary experimental platforms to test the effectiveness of therapeutic compounds shown to be well tolerated by mice.

We describe methods for longitudinal monitoring of the efficacy of therapeutics for the treatment of colonic pathologies in mice using a rigid endoscope. This protocol can be readily used for the characterization of the therapeutic response of an individual tumor in live mice and also for monitoring potential disease relapse.

Animal models of inflammatory bowel disease (IBD) and colorectal cancer (CRC) have provided significant insight into the cell intrinsic and extrinsic ...

Non-invasive Assessment of Dorsiflexor Muscle Function in Mice

Assessment of skeletal muscle contractile function is an important measurement for both clinical and research purposes. Numerous conditions can negatively affect skeletal muscle. This can result in a loss of muscle mass (atrophy) and/or loss of muscle quality (reduced force per unit of muscle mass), both of which are prevalent in chronic disease, muscle-specific disease, immobilization, and aging (sarcopenia). Skeletal muscle function in animals can be evaluated by a range of different tests. All tests have limitations related to the physiological testing environment, and the selection of a specific test often depends on the nature of the experiments. Here, we describe an in vivo, non-invasive technique involving a helpful and easy assessment of force frequency-curve (FFC) in mice that can be performed on the same animal over time. This permits monitoring of disease progression and/or efficacy&#160;of a potential therapeutic treatment.

Measurement of rodent skeletal muscle contractile function is a useful tool that can be used to track disease progression as well as efficacy of therapeutic intervention. We describe here the non-invasive, in vivo assessment of the dorsiflexor muscles that can be repeated over time in the same mouse.

Assessment of skeletal muscle contractile function is an important measurement for both clinical and research purposes. Numerous conditions can negatively ...

Oxygenation-sensitive Cardiac MRI with Vasoactive Breathing Maneuvers for the Non-invasive Assessment of Coronary Microvascular Dysfunction

Oxygenation-sensitive cardiac magnetic resonance imaging (OS-CMR) is a diagnostic technique that uses the inherent paramagnetic properties of deoxyhemoglobin as an endogenous source of tissue contrast. Used in combination with standardized vasoactive breathing maneuvers (hyperventilation and apnea) as a potent non-pharmacologic vasomotor stimulus, OS-CMR can monitor changes in myocardial oxygenation. Quantifying such changes during the cardiac cycle and throughout vasoactive maneuvers can provide markers for coronary macro- and microvascular function and thereby circumvent the need for any extrinsic, intravenous contrast or pharmacologic stress agents.
OS-CMR uses the well-known sensitivity of T2*-weighted images to blood oxygenation. Oxygenation-sensitive images can be acquired on any cardiac MRI scanner using a modified standard clinical steady-state free precession (SSFP) cine sequence, making this technique vendor-agnostic and easily implemented. As a vasoactive breathing maneuver, we apply a 4-min breathing protocol of 120 s of free breathing, 60 s of paced hyperventilation, followed by an expiratory breath-hold of at least 30 s. The regional and global response of myocardial tissue oxygenation to this maneuver can be assessed by tracking the signal intensity change. The change over the initial 30 s of the post-hyperventilation breath-hold, referred to as the breathing-induced myocardial oxygenation reserve (B-MORE) has been studied in healthy people and various pathologies. A detailed protocol for performing oxygen-sensitive CMR scans with vasoactive maneuvers is provided.
As demonstrated in patients with microvascular dysfunction in yet incompletely understood conditions, such as inducible ischemia with no obstructive coronary artery stenosis (INOCA), heart failure with preserved ejection fraction (HFpEF), or microvascular dysfunction after heart transplantation, this approach provides unique, clinically important, and complementary information on coronary vascular function.

The assessment of microvascular function by oxygenation-sensitive cardiac magnetic resonance imaging in combination with vasoactive breathing maneuvers is unique in its ability to assess rapid dynamic changes in myocardial oxygenation in vivo and, thus, may serve as a critically important diagnostic technique for coronary vascular function.