Browsing by Author "Curley, Steven A."
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Item A New Imaging Platform for Visualizing Biological Effects of Non-Invasive Radiofrequency Electric-Field Cancer Hyperthermia(Public Library of Science, 2015) Corr, Stuart J.; Shamsudeen, Sabeel; Vergara, Leoncio A.; Ho, Jason Chak-Shing; Ware, Matthew J.; Keshishian, Vazrik; Yokoi, Kenji; Savage, David J.; Meraz, Ismail M.; Kaluarachchi, Warna; Cisneros, Brandon T.; Raoof, Mustafa; Nguyen, Duy Trac; Zhang, Yingchun; Wilson, Lon J.; Summers, Huw; Rees, Paul; Curley, Steven A.; Serda, Rita E.Herein, we present a novel imaging platform to study the biological effects of non-invasive radiofrequency (RF) electric field cancer hyperthermia. This system allows for real-time in vivointravital microscopy (IVM) imaging of radiofrequency-induced biological alterations such as changes in vessel structure and drug perfusion. Our results indicate that the IVM system is able to handle exposure to high-power electric-fields without inducing significant hardware damage or imaging artifacts. Furthermore, short durations of low-power (< 200 W) radiofrequency exposure increased transport and perfusion of fluorescent tracers into the tumors at temperatures below 41°C. Vessel deformations and blood coagulation were seen for tumor temperatures around 44°C. These results highlight the use of our integrated IVM-RF imaging platform as a powerful new tool to visualize the dynamics and interplay between radiofrequency energy and biological tissues, organs, and tumors.Item Biotransport kinetics and intratumoral biodistribution of malonodiserinolamide-derivatized [60]fullerene in a murine model of breast adenocarcinoma(Dove Press, 2017) Lapin, Norman A.; Vergara, Leoncio A.; Mackeyev, Yuri; Newton, Jared M.; Dilliard, Sean A.; Wilson, Lon J.; Curley, Steven A.; Serda, Rita E.; The Smalley-Curl Institute for Nanoscale Science and Technology[60]Fullerene is a highly versatile nanoparticle (NP) platform for drug delivery to sites of pathology owing to its small size and both ease and versatility of chemical functionalization, facilitating multisite drug conjugation, drug targeting, and modulation of its physicochemical properties. The prominent and well-characterized role of the enhanced permeation and retention (EPR) effect in facilitating NP delivery to tumors motivated us to explore vascular transport kinetics of a water-soluble [60]fullerene derivatives using intravital microscopy in an immune competent murine model of breast adenocarcinoma. Herein, we present a novel local and global image analysis of vascular transport kinetics at the level of individual tumor blood vessels on the micron scale and across whole images, respectively. Similar to larger nanomaterials, [60]fullerenes displayed rapid extravasation from tumor vasculature, distinct from that in normal microvasculature. Temporal heterogeneity in fullerene delivery to tumors was observed, demonstrating the issue of nonuniform delivery beyond spatial dimensions. Trends in local region analysis of fullerene biokinetics by fluorescence quantification were in agreement with global image analysis. Further analysis of intratumoral vascular clearance rates suggested a possible enhanced penetration and retention effect of the fullerene compared to a 70 kDa vascular tracer. Overall, this study demonstrates the feasibility of tracking and quantifying the delivery kinetics and intratumoral biodistribution of fullerene-based drug delivery platforms, consistent with the EPR effect on short timescales and passive transport to tumors.Item Citrate-Capped Gold Nanoparticle Electrophoretic Heat Production in Response to a Time-Varying Radio-Frequency Electric Field(American Chemical Society, 2012) Corr, Stuart J.; Raoof, Mustafa; Mackeyev, Yuri; Phounsavath, Sophia; Cheney, Matthew A.; Cisneros, Brandon T.; Shur, Michael; Gozin, Michael; McNally, Patrick J.; Wilson, Lon J.; Curley, Steven A.; Smalley Institute for Nanoscale Science and TechnologyThe evaluation of heat production from gold nanoparticles (AuNPs) irradiated with radio-frequency (RF) energy has been problematic due to Joule heating of their background ionic buffer suspensions. Insights into the physical heating mechanism of nanomaterials under RF excitations must be obtained if they are to have applications in fields such as nanoparticle-targeted hyperthermia for cancer therapy. By developing a purification protocol that allows for highly stable and concentrated solutions of citrate-capped AuNPs to be suspended in high-resistivity water, we show herein, for the first time, that heat production is only evident for AuNPs of diameters ≤10 nm, indicating a unique size-dependent heating behavior not previously observed. Heat production has also shown to be linearly dependent on both AuNP concentration and total surface area and was severely attenuated upon AuNP aggregation. These relationships have been further validated using permittivity analysis across a frequency range of 10 MHz–3 GHz as well as static conductivity measurements. Theoretical evaluations suggest that the heating mechanism can be modeled by the electrophoretic oscillation of charged AuNPs across finite length scales in response to a time-varying electric field. It is anticipated these results will assist future development of nanoparticle-assisted heat production by RF fields for applications such as targeted cancer hyperthermia.Item Cytotoxicity and variant cellular internalization behavior of water-soluble sulfonated nanographene sheets in liver cancer cells(Springer, 2013) Corr, Stuart J.; Raoof, Mustafa; Cisneros, Brandon T.; Kuznetsov, Oleksandr; Massey, Katheryn; Kaluarachchi, Warna D.; Cheney, Matthew A.; Billups, Edward W.; Wilson, Lon J.; Curley, Steven A.; Richard E. Smalley Institute for Nanoscale Science and TechnologyHighly exfoliated sulfonated graphene sheets (SGSs), an alternative to graphene oxide and graphene derivatives, were synthesized, characterized, and applied to liver cancer cells in vitro. Cytotoxicity profiles were obtained using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, WST-1[2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, and lactate dehydrogenase release colorimetric assays. These particles were found to be non-toxic across the concentration range of 0.1 to 10 μg/ml. Internalization of SGSs was also studied by means of optical and electron microscopy. Although not conclusive, high-resolution transmission and scanning electron microscopy revealed variant internalization behaviors where some of the SGS became folded and compartmentalized into tight bundles within cellular organelles. The ability for liver cancer cells to internalize, fold, and compartmentalize graphene structures is a phenomenon not previously documented for graphene cell biology and should be further investigated.Item Gold nanoparticles and radiofrequency in experimental models for hepatocellular carcinoma(Elsevier, 2014) Raoof, Mustafa; Corr, Stuart J.; Zhu, Cihui; Cisneros, Brandon T.; Kaluarachchi, Warna D.; Phounsavath, Sophia; Wilson, Lon J.; Curley, Steven A.; Richard E. Smalley Institute for Nanoscale Science & TechnologyHepatocellular carcinoma (HCC) is one of the most lethal and chemo-refractory cancers, clearly, alternative treatment strategies are needed. We utilized 10 nm gold nanoparticles as a scaffold to synthesize nanoconjugates bearing a targeting antibody (cetuximab, C225) and gemcitabine. Loading efficiency of gemcitabine on the gold nanoconjugates was 30%. Targeted gold nanoconjugates in combination with RF were selectively cytotoxic to EGFR expressing Hep3B and SNU449 cells when compared to isotype particles with/without RF (P < 0.05). In animal experiments, targeted gold nanoconjugates halted the growth of subcutaneous Hep3B xenografts in combination with RF exposure (P < 0.05). These xenografts also demonstrated increased apoptosis, necrosis and decreased proliferation compared to controls. Normal tissues were unharmed. We have demonstrated that non-invasive RF-induced hyperthermia when combined with targeted delivery of gemcitabine is more effective and safe at dosages ~ 275-fold lower than the current clinically-delivered systemic dose of gemcitabine.Item Gold Nanoparticles Stabilized with MPEG-Grafted Poly(l-lysine): in Vitro and in Vivo Evaluation of a Potential Theranostic Agent(American Chemical Society, 2015) Bogdanov, Alexei A. Jr.; Gupta, Suresh; Koshkina, Nadezhda; Corr, Stuart J.; Zhang, Surong; Curley, Steven A.; Han, GangAs the number of diagnostic and therapeutic applications utilizing gold nanoparticles (AuNPs) increases, so does the need for AuNPs that are stable in vivo, biocompatible, and suitable for bioconjugation. We investigated a strategy for AuNP stabilization that uses methoxypolyethylene glycol-graft-poly(l-lysine) copolymer (MPEG-gPLL) bearing free amino groups as a stabilizing molecule. MPEG-gPLL injected into water solutions of HAuCl4 with or without trisodium citrate resulted in spherical (Zav = 36 nm), monodisperse (PDI = 0.27), weakly positively charged nanoparticles (AuNP3) with electron-dense cores (diameter: 10.4 ± 2.5 nm) and surface amino groups that were amenable to covalent modification. The AuNP3 were stable against aggregation in the presence of phosphate and serum proteins and remained dispersed after their uptake into endosomes. MPEG-gPLL-stabilized AuNP3 exhibited high uptake and very low toxicity in human endothelial cells, but showed a high dose-dependent toxicity in epithelioid cancer cells. Highly stable radioactive labeling of AuNP3 with 99mTc allowed imaging of AuNP3 biodistribution and revealed dose-dependent long circulation in the blood. The minor fraction of AuGNP3 was found in major organs and at sites of experimentally induced inflammation. Gold analysis showed evidence of a partial degradation of the MPEG-gPLL layer in AuNP3 particles accumulated in major organs. Radiofrequency-mediated heating of AuNP3 solutions showed that AuNP3 exhibited heating behavior consistent with 10 nm core nanoparticles. We conclude that PEG-pPLL coating of AuNPs confers “stealth” properties that enable these particles to exist in vivo in a nonaggregating, biocompatible state making them suitable for potential use in biomedical applications such as noninvasive radiofrequency cancer therapy.Item Intravital microscopy for evaluating tumor perfusion of nanoparticles exposed to non-invasive radiofrequency electric fields(Springer, 2016) Lapin, Norman A.; Krzykawska-Serda, Martyna; Ware, Matthew J.; Curley, Steven A.; Corr, Stuart J.Poor biodistribution and accumulation of chemotherapeutics in tumors due to limitations on diffusive transport and high intra-tumoral pressures (Jain RK, Nat Med. 7(9):987–989, 2001) have prompted the investigation of adjunctive therapies to improve treatment outcomes. Hyperthermia has been widely applied in attempts to meet this need, but it is limited in its ability to reach tumors in deeply located body regions. High-intensity radiofrequency (RF) electric fields have the potential to overcome such barriers enhancing delivery and extravasation of chemotherapeutics. However, due to factors, including tumor heterogeneity and lack of kinetic information, there is insufficient understanding of time-resolved interaction between RF fields and tumor vasculature, drug molecules and nanoparticle (NP) vectors. Intravital microscopy (IVM) provides time-resolved high-definition images of specific tumor microenvironments, overcoming heterogeneity issues, and can be integrated with a portable RF device to enable detailed observation over time of the effects of the RF field on kinetics and biodistribution at the microvascular level. Herein, we provide a protocol describing the safe integration of IVM with a high-powered non-invasive RF field applied to 4T1 orthotopic breast tumors in live mice. Results show increased perfusion of NPs in microvasculature upon RF hyperthermia treatment and increased perfusion, release and spreading of injected reagents preferentially in irregular vessels during RF exposure.Item Radiofrequency-induced Cellular Hyperthermia: Water-soluble Fullerene as a New Cancer Therapeutic Agent(2014-09-08) Cheney, Matthew Andrade; Wilson, Lon J.; Curley, Steven A.; Billups, W. Edward; Jacot, Jeffrey G.Due to the susceptibility of cancer to hyperthermia, abundant biomedical research is being conducted for the development of therapies using nanotechnology for noninvasive cancer hyperthermia. In this work, the water-soluble and neutrally-charged C60 fullerene, C60-ser, is presented as a new cancer therapeutic agent for the hyperthermia of liver cancer using radiofrequency (RF) energy. With liver cancer being the second leading cause of death in men and the sixth most in women worldwide, new and improved therapies are needed to combat the limitations associated with current cancer treatments. Using a RF generator operating at 13.56 MHz, aqueous heating of purified C60-ser within the RF field has been observed in a concentration- and aggregation-dependent manner. These findings now lay the foundation for a new cancer hyperthermia therapy using C60 fullerene. Though the exact mechanism of C60-ser heating within the RF field is still uncertain, evidence has shown that the six serinol malonate (ser) groups of C60-ser must be attached to C60 to produce any significant heating. C60 is known to play numerous roles in the biomedical field, including drug delivery, active cancer cell targeting, bone therapy, gene therapy, X-ray contrast enhancement, and now, through the present work, as a potential new cancer therapy by RF-induced hyperthermia. By attaching a fluorescent tag (PF) to C60-ser to form C60-serPF, passive and active internalization into Hep3B and Huh7 liver cancer cells has been observed, with evidence of internalization within the cytoplasm and, more surprisingly, the nucleus. Very few nanomaterials have been definitively proven to internalize within the nucleus of cells, raising the potential for both C60-ser and C60-serPF to be used for other biomedical purposes and not just solely for RF-induced hyperthermia effects on cellular DNA. In vivo biodistribution studies of C60-serPF also has showed its presence in all major organs, including the brain. Since C60-ser was shown to inhibit the internalization of C60-serPF in vitro, uptake by liver cancer cells of both nanomaterials proceed by similar pathways. Therefore, the ability of C60-serPF to traverse the blood brain barrier of mice suggests an array of opportunities for brain-related treatments and therapies using both C60-serPF and C60-ser. Taken together, the materials provide simultaneous diagnostic and therapeutic capabilities, making them a new class of theranostic agent. In vitro studies of C60-ser have shown that it is non-toxic at up to 1.0 mg/mL to liver cancer cells (Hep3B, SNU449, and HepG2), that it modulates cellular metabolic activity, that it negligibly influences the cell cycle, but that it does not promote radiofrequency-induced hyperthermia of individual liver cancer cells. However, when injected intratumorally in mice, C60-ser enhanced the RF heating of liver tumors by 89% and 26% when compared to PBS and water controls alone, respectively. This observed increase in heating led to significant necrosis for the C60-ser treated groups, while necrosis for the control groups was nonexistent. This work has shown in vivo efficacy of an RF/C60-ser combination therapy by hyperthermia for the treatment of liver cancer for the first time. Future directions must involve the incorporation of biological targeting groups conjugated to the C60 moiety to realize the full potential of a noninvasive and targeted approach to cancer cell hyperthermia for liver cancer and other types of cancer, as well.Item Remotely triggered cisplatin release from carbon nanocapsules by radiofrequency fields(Elsevier, 2013) Raoof, Mustafa; Cisneros, Brandon T.; Guven, Adem; Corr, Stuart J.; Wilson, Lon J.; Curley, Steven A.; Richard E. Smalley Institute for Nanoscale Science & TechnologyThe efficacy of nanoparticle-mediated drug delivery is limited by its peri-vascular sequestration, thus necessitating a strategy to trigger drug release from such intra-tumoral nanocarrier-drug depots. In our efforts to explore remotely-activated nanocarriers, we have developed carbon nanocapsules comprised of an ultra-short carbon nanotube shell (US-tubes) loaded with cisplatin (CDDP@US-tubes) and covered with a Pluronic surfactant wrapping to minimize passive release. We demonstrate here that non-invasive radiofrequency (RF) field activation of the CDDP@US-tubes produces heat that causes Pluronic disruption which triggers cisplatin release in an RF-dependent manner. Furthermore, release-dependent cytotoxicity is demonstrated in human hepatocellular carcinoma cell lines.Item RF heating of ultra-short single-walled carbon nanotubes and gadonanotubes for non-invasive cancer hyperthermia(2014-01-30) Phounsavath, Sophia; Wilson, Lon J.; Marti, Angel A.; Grande-Allen, K. Jane; Curley, Steven A.An emerging field of nanoparticle-mediated cancer therapy is based on the interaction of nanoparticles with radiofrequency (RF) energy to induce hyperthermia or thermal cytotoxicity within cancer cells. In this work, the heating properties of ultra-short single-walled carbon nanotubes (US-tubes) and gadonanotubes (GNTs) were assessed in an external radiofrequency field (900 W, 13.56 MHz). Surfactant (Pluronic F-108) suspensions of US-tubes (carbon-based nanocapsules that are 20-80 nm in length and 1.4 nm in diameter) and GNTs (US-tubes loaded internally with Gd3+ ions) heated in a concentration dependent manner when the RF field was applied. The observed bulk heating of the sample suspensions have been attributed to the nanomaterial itself and not the background surfactant solution. The efficacy of these remotely triggered heating agents to produce thermal cytotoxicity was then investigated in vitro in three different hepatocellular cancer cell lines (Hep3B, HepG2, and Snu449). In all cases, cancer cells that were treated with either US-tubes or GNTs in conjunction with RF had lower viabilities than those treated with RF alone. The ability of GNTs to induce thermal cytotoxicity in vivo was then investigated using subcutaneous tumor models in nude mice. Histopathological analysis of treated tumors demonstrated more pronounced and widespread cell damage in tumors treated with GNTs and RF than in the control tumors. It is anticipated that these results will aid in the future development of nanoparticle-mediated cancer therapy by hyperthermia.Item Water-structuring molecules and nanomaterials enhance radiofrequency heating in biologically relevant solutions(Royal Society of Chemistry, 2016) Lara, Nadia C.; Haider, Asad A.; Ho, Jason C.; Wilson, Lon J.; Barron, Andrew R.; Curley, Steven A.; Corr, Stuart J.For potential applications in nano-mediated radiofrequency cancer hyperthermia, the nanomaterial under investigation must increase the heating of any aqueous solution in which it is suspended when exposed to radiofrequency electric fields. This should also be true for a broad range of solution conductivities, especially those that artificially mimic the ionic environment of biological systems. Herein we demonstrate enhanced heating of biologically relevant aqueous solutions using kosmotropes and a hexamalonoserinolamide fullerene.