Cancer Thermotherapy Research Articles

Second harmonic generation microscopy from non-centrosymmetric gold half-coated polystyrene spheres

The optical properties of metallic nanoparticles and nano-structures have shown to be of interest to be exploited for a variety of applications in the field of biosensing, photonic devices and in cancer thermotherapy. In this work, the nonlinear optical properties of gold coated polystyrene microspheres are investigated using second harmonic generation microscopy. Polystyrene microspheres coated on half of their surface with a thin layer of gold deposited by electron-beam evaporation form non-centrosymmetric micro-sized objects that are presumably SHG active. The nonlinear second-harmonic signal was collected from isolated particles and was examined under distinct polarization conditions. Upon irradiation using a 800 nm femtosecond laser, the polystyrene spheres are fully ablated due to intense plasmon-enhancement and focusing effect from the gold coating at the center of the sphere producing gold half-shells that are themselves non-centrosymmetric. The residual gold structures were further investigated using second harmonic generation microscopy revealing polarization effects.

Optically Triggered Melting of DNA on Individual Semiconducting Carbon Nanotubes

AbstractOptical excitation of nanostructures is known to induce local heating, a phenomenon that has been intensely exploited for drug release, gene delivery, cancer thermotherapy, and energy harvesting. However, the effect is typically small requiring collective heating of a large concentration or aggregates of particles. Herein, we show that optical excitation of individual semiconducting single‐walled carbon nanotubes triggers strongly localized heating adequate to melt non‐covalently attached double‐stranded oligonucleotides in solution. In contrast to conventional thermal dehybridization, this optically triggered DNA melting occurs at a solution temperature that is 22 °C lower than the DNA melting temperature. This unexpectedly large localized optical heating effect provides important new insights to design selective optical nanoheaters at the single particle level.

Optically Triggered Melting of DNA on Individual Semiconducting Carbon Nanotubes.

Optical excitation of nanostructures is known to induce local heating, a phenomenon that has been intensely exploited for drug release, gene delivery, cancer thermotherapy, and energy harvesting. However, the effect is typically small requiring collective heating of a large concentration or aggregates of particles. Herein, we show that optical excitation of individual semiconducting single-walled carbon nanotubes triggers strongly localized heating adequate to melt non-covalently attached double-stranded oligonucleotides in solution. In contrast to conventional thermal dehybridization, this optically triggered DNA melting occurs at a solution temperature that is 22 °C lower than the DNA melting temperature. This unexpectedly large localized optical heating effect provides important new insights to design selective optical nanoheaters at the single particle level.

In Vivo Magnetic Resonance Imaging and Microwave Thermotherapy of Cancer Using Novel Chitosan Microcapsules.

Herein, we develop a novel integrated strategy for the preparation of theranostic chitosan microcapsules by encapsulating ion liquids (ILs) and Fe3O4 nanoparticles. The as-prepared chitosan/Fe3O4@IL microcapsules exhibit not only significant heating efficacy in vitro under microwave (MW) irradiation but also obvious enhancement of T2-weighted magnetic resonance (MR) imaging, besides the excellent biocompatibility in physiological environments. The chitosan/Fe3O4@IL microcapsules show ideal temperature rise and therapeutic efficiency when applied to microwave thermal therapy in vivo. Complete tumor elimination is realizing after MW irradiation at an ultralow power density (1.8 W/cm2), while neither the MW group nor the chitosan microcapsule group has significant influence on the tumor development. The applicability of the chitosan/Fe3O4@IL microcapsules as an efficient contrast agent for MR imaging is proved in vivo. Moreover, the result of in vivo systematic toxicity shows that chitosan/Fe3O4@IL microcapsules have no acute fatal toxicity. Our study presents an interesting type of multifunctional platform developed by chitosan microcapsule promising for imaging-guided MW thermotherapy.Electronic supplementary materialThe online version of this article (doi:10.1186/s11671-016-1536-0) contains supplementary material, which is available to authorized users.

Cancer Cell Internalization of Gold Nanostars Impacts Their Photothermal Efficiency In Vitro and In Vivo: Toward a Plasmonic Thermal Fingerprint in Tumoral Environment.

Gold nanoparticles are prime candidates for cancer thermotherapy. However, while the ultimate target for nanoparticle-mediated photothermal therapy is the cancer cell, heating performance has not previously been evaluated in the tumoral environment. A systematic investigation of gold nanostar heat-generating efficiency in situ is presented: not only in cancer cells in vitro but also after intratumoral injection in vivo. It is demonstrated that (i) in aqueous dispersion, heat generation is governed by particle size and exciting laser wavelength; (ii) in cancer cells in vitro, heat generation is still very efficient, but irrespective of both particle size and laser wavelength; and (iii) heat generation by nanostars injected into tumors in vivo evolves with time, as the nanostars are trafficked from the extracellular matrix into endosomes. The plasmonic heating response thus serves as a signature of nanoparticle internalization in cells, bringing the ultimate goal of nanoparticle-mediated photothermal therapy a step closer.

Nanodrug-Mediated Thermotherapy of Cancer Stem-Like Cells

Cancer stem-like cells (CSCs) are rare subpopulations of cancer cells that are resistant to conventional chemotherapy and radiotherapy and contribute to cancer metastases and tumor recurrence. Therefore, it is of significance to develop an effective therapy to eliminate the CSCs. Cancer thermotherapy realized by depositing heat into tumor in a minimally invasive way is a promising alternative to the conventional therapies for cancer treatment. However, this method is limited by its inability to target CSCs, potentially allowing the CSCs to survive and re-initiate tumor growth. More recently, nanodrug-mediated thermotherapy has been explored to selectively eliminate CSCs and specifically deposit heat in tumor to spare healthy tissue. Here, we provide a brief overview of the targeting moieties and nanoplatforms used in developing nanodrug-mediated thermotherapy of cancer with particular emphasis on the CSCs, as well as the challenges and potential directions for future research in this emerging field.

Superparamagnetic iron oxide nanocargoes for combined cancer thermotherapy and MRI applications.

Nanoparticle-based cancer diagnosis-therapy integrative systems (cancer theranostics) represent an emerging approach in oncology. To address this issue in the present work iron oxide (γ-Fe2O3-maghemite) nanoparticles (IONPs) were encapsulated within the matrix of (bis(p-sulfonatophenyl)phenylphosphine)-methoxypolyethylene glycol-thiol (mPEG) polymer vesicles using a two-step process for active chemotherapeutic cargo loading in cancer theranostics. This formation method gives simple access to highly reactive surface groups present on IONPs together with good control over the vesicle size (50-100 nm). The simultaneous loading of a chemotherapeutic drug cargo (doxorubicin) and its in vitro release in cancer cells was achieved. The feasibility of controlled drug release under different pH conditions was demonstrated in the case of encapsulated doxorubicin molecules, showing the viability of the concept of stimulated drug delivery for magneto-chemotherapy. These polymer-magnetic nanocargoes (PMNCs) exhibit enhanced contrast properties that open potential applications for magnetic resonance imaging. These self-assembled magnetic polymersomes can be used as efficient multifunctional nanocarriers for combined therapy and imaging.

DNA-Hybrid-Gated Photothermal Mesoporous Silica Nanoparticles for NIR-Responsive and Aptamer-Targeted Drug Delivery.

Near-infrared light is an attractive stimulus due to its noninvasive and deep tissue penetration. Particularly, NIR light is utilized for cancer thermotherapy and on-demand release of drugs by the disruption of the delivery carriers. Here we have prepared a novel NIR-responsive DNA-hybrid-gated nanocarrier based on mesoporous silica-coated Cu1.8S nanoparticles. Cu1.8S nanoparticles, possessing high photothermal conversion efficiency under a 980 nm laser, were chosen as photothermal agents. The mesoporous silica structure could be used for drug storage/delivery and modified with aptamer-modified GC-rich DNA-helix as gatekeepers, drug vectors, and targeting ligand. Simultaneously, the as-produced photothermal effect caused denaturation of DNA double strands, which triggered the drug release of the DNA-helix-loaded hydrophilic drug doxorubicin and mesopore-loaded hydrophobic drug curcumin, resulting in a synergistic therapeutic effect. The Cu1.8S@mSiO2 nanocomposites endocytosed by cancer cells through the aptamer-mediated mode are able to generate rational release of doxorubicin/curcumin under NIR irradiation, strongly enhancing the synergistic growth-inhibitory effect of curcumin against doxorubicin in MCF-7 cells, which is associated with a strong mitochondrial-mediated cell apoptosis progression. The underlying mechanism of apoptosis showed a strong synergistic inhibitory effect both on the expression of Bcl-2, Bcl-xL, Mcl-1, and upregulated caspase 3/9 activity and on the expression level of Bak and Bax. Therefore, Cu1.8S@mSiO2 with efficient synergistic therapeutic efficiency is a potential multifunctional cancer therapy nanoplatform.

Caveolin-1 and CDC42 mediated endocytosis of silica-coated iron oxide nanoparticles in HeLa cells.

Nanomedicine is a rapidly growing field in nanotechnology, which has great potential in the development of new therapies for numerous diseases. For example iron oxide nanoparticles are in clinical use already in the thermotherapy of brain cancer. Although it has been shown, that tumor cells take up these particles in vitro, little is known about the internalization routes. Understanding of the underlying uptake mechanisms would be very useful for faster and precise development of nanoparticles for clinical applications. This study aims at the identification of key proteins, which are crucial for the active uptake of iron oxide nanoparticles by HeLa cells (human cervical cancer) as a model cell line. Cells were transfected with specific siRNAs against Caveolin-1, Dynamin 2, Flotillin-1, Clathrin, PIP5Kα and CDC42. Knockdown of Caveolin-1 reduces endocytosis of superparamagnetic iron oxide nanoparticles (SPIONs) and silica-coated iron oxide nanoparticles (SCIONs) between 23 and 41%, depending on the surface characteristics of the nanoparticles and the experimental design. Knockdown of CDC42 showed a 46% decrease of the internalization of PEGylated SPIONs within 24 h incubation time. Knockdown of Dynamin 2, Flotillin-1, Clathrin and PIP5Kα caused no or only minor effects. Hence endocytosis in HeLa cells of iron oxide nanoparticles, used in this study, is mainly mediated by Caveolin-1 and CDC42. It is shown here for the first time, which proteins of the endocytotic pathway mediate the endocytosis of silica-coated iron oxide nanoparticles in HeLa cells in vitro. In future studies more experiments should be carried out with different cell lines and other well-defined nanoparticle species to elucidate possible general principles.

Au@Ag/Au nanoparticles assembled with activatable aptamer probes as smart "nano-doctors" for image-guided cancer thermotherapy.

Although nanomaterial-based theranostics have increased positive expectations from cancer treatment, it remains challenging to develop in vivo "nano-doctors" that provide high-contrast image-guided site-specific therapy. Here we designed an activatable theranostic nanoprobe (ATNP) via self-assembly of activatable aptamer probes (AAPs) on Au@Ag/Au nanoparticles (NPs). As both quenchers and heaters, novel Au@Ag/Au NPs were prepared, showing excellent fluorescence quenching and more effective near-infrared photothermal therapy than Au nanorods. The AAP comprised a thiolated aptamer and a fluorophore-labeled complementary DNA; thus, the ATNP with quenched fluorescence in the free state could realize signal activation through target binding-induced conformational change of the AAP, and then achieve on-demand treatment under image-guided irradiation. By using S6 aptamer as the model, in vitro and in vivo studies of A549 lung cancer verified that the ATNP greatly improved imaging contrast and specific destruction, suggesting a robust and versatile theranostic strategy for personalized medicine in future.

SU-E-T-558: An Exploratory RF Pulse Sequence Technique Used to Induce Differential Heating in Tissues Containing Iron Oxide Nanoparticles for a Possible Hyperthermic Adjuvant Effect to Radiotherapy

Purpose: In pre-clinical trials of cancer thermotherapy, hyperthermia can be induced by exposing localized super-paramagnetic iron oxide nanoparticles (SPION) to external alternating magnetic fields generated by a solenoid electrical circuit (Zhao et al., Theranostics 2012). Alternatively, an RF pulse technique implemented in a regular MRI system is explored as a possible hyperthermia induction technique . Methods: A new thermal RF pulse sequence was developed using the Philips pulse programming tool for the 3T Ingenia MRI system to provide a sinusoidal magnetic field alternating at the frequency of 1.43 kHz (multiples of sine waves of 0.7 ms period) before each excitation RF pulse for imaging. The duration of each thermal RF pulse routine was approximately 3 min, and the thermal pulse was applied multiple times to a phantom that contains different concentrations (high, medium and low) of SPION samples. After applying the thermal pulse each time, the temperature change was estimated by measuring the phase changes in the T1-weighted inversion-prepared multi-shot turbo field echo (TFE) sequence (TR=5.5 ms, TE=2.7 ms, inversion time=200 ms). Results: The phase values and relative differences among them changed as the number of applied thermal RF pulses increased. After the 5th application of the thermal RF pulse, the relative phase differences increased significantly, suggesting the thermal activation of the SPION. The increase of the phase difference was approximately linear with the SPION concentration. Conclusion: A sinusoidal RF pulse from the MRI system may be utilized to selectively thermally activate tissues containing super-paramagnetic iron oxide nanoparticles.

Applicator modeling for electromagnetic thermotherapy of cervix cancer

This report proposes an induction heating coil design that can be used for producing strong magnetic fields around ferromagnetic implants located in the cervix of uterus. The effect of coil design on the uniformity and extent of heat generation ability is inspected. Also, a numerical model of the applicator is developed that includes the ferromagnetic implants, and is coupled to the bioheat transfer model of the body tissue. Then, the ability of the proposed applicator for electromagnetic thermotherapy is investigated.

Preparation of monodisperse biodegradable magnetic microspheres using a T-shaped microchannel reactor

Monodisperse magnetic microspheres with biodegradability and biocompatibility were successfully prepared using a T-shaped microchannel reactor instead of the traditional three-necked flask equipped with the mechanical stirrer. Solvothermal was adopted to produce hydrophilic ferriferrous oxide (Fe3O4) nanoparticles with high magnetic responsiveness, which was subsequently emulsified with a dichloromethane solution of polylactic acid (PLA) in the presence of a gelatin stabilizer. This water-in-oil (W/O) emulsion and an additional aqueous phase, namely an aqueous polyvinyl alcohol (PVA) solution, were injected into the T-shaped microchannel reactor and converged at the joint to yield a W/O/W composite emulsion. Evaporation of the solvent in the microchannel gave rise to the target magnetic microspheres. The results show that the magnetic microspheres have a uniform particle size and good magnetic responsiveness, indicating their potential use in targeted drug delivery for cancer treatment and thermotherapy.

Vaccinia virus-mediated melanin production allows MR and optoacoustic deep tissue imaging and laser-induced thermotherapy of cancer

We reported earlier the delivery of antiangiogenic single chain antibodies by using oncolytic vaccinia virus strains to enhance their therapeutic efficacy. Here, we provide evidence that gene-evoked production of melanin can be used as a therapeutic and diagnostic mediator, as exemplified by insertion of only one or two genes into the genome of an oncolytic vaccinia virus strain. We found that produced melanin is an excellent reporter for optical imaging without addition of substrate. Melanin production also facilitated deep tissue optoacoustic imaging as well as MRI. In addition, melanin was shown to be a suitable target for laser-induced thermotherapy and enhanced oncolytic viral therapy. In conclusion, melanin as a mediator for thermotherapy and reporter for different imaging modalities may soon become a versatile alternative to replace fluorescent proteins also in other biological systems. After ongoing extensive preclinical studies, melanin overproducing oncolytic virus strains might be used in clinical trials in patients with cancer.

Investigation of Sub-100 nm Gold Nanoparticles for Laser-Induced Thermotherapy of Cancer.

Specialized gold nanostructures are of interest for the development of alternative treatment methods in medicine. Photothermal therapy combined with gene therapy that supports hyperthermia is proposed as a novel multimodal treatment method for prostate cancer. In this work, photothermal therapy using small (<100 nm) gold nanoparticles and near-infrared (NIR) laser irradiation combined with gene therapy targeting heat shock protein (HSP) 27 was investigated. A series of nanoparticles: nanoshells, nanorods, core-corona nanoparticles and hollow nanoshells, were synthesized and examined to compare their properties and suitability as photothermal agents. In vitro cellular uptake studies of the nanoparticles into prostate cancer cell lines were performed using light scattering microscopy to provide three-dimensional (3D) imaging. Small gold nanoshells (40 nm) displayed the greatest cellular uptake of the nanoparticles studied and were used in photothermal studies. Photothermal treatment of the cancer cell lines with laser irradiation at 800 nm at 4 W on a spot size of 4 mm (FWHM) for 6 or 10 min resulted in an increase in temperature of ~12 °C and decrease in cell viability of up to 70%. However, in vitro studies combining photothermal therapy with gene therapy targeting HSP27 did not result in additional sensitization of the prostate cancer cells to hyperthermia.

早期前立腺癌に対するアンドロゲン除去療法併用高温度療法における温熱増感薬パルテノライドの効果 : 病理組織の変性を主眼として

パルテノライド (parthenolide : PTL) はNF-κB阻害剤として温熱による癌細胞死を誘導する増感作用があることが知られている. 本研究においては早期前立腺癌に対する経尿道的マイクロ波高温度療法 (TUMT) の治療効果を高める目的で, その前後にPTLの投与を行い, その病理組織所見をPTL使用前の症例のものと比較検討した. 対照群と同じくTUMTに先だって3か月間のアンドロゲン除去療法 (ADT) を施行して前立腺体積の縮小を図った. PTLは1日量0.5 mg (2回分服) の服用をTUMTの, 当初は30日前, 次いで15日前より開始し, 45日間の連続投与を行った. PTL投与を行った45例の臨床病期はT1-2N0M0, TUMT施行前の前立腺体積の縮小度は34.6%であった. TUMT施行後3か月を経過下した後に経尿道的前立腺切除術 (TURP) を施行し, その全切片の病理組織学的検索を施行した結果, 45例中41例において癌細胞は消滅していた. TURP切片中に癌細胞の遺残を認めた4例のいずれにも退行変性が認められ, 内3例は癌細胞として生存が可能と判定されたが, 残りの1例の癌細胞はいずれ消滅するであろうと判定された. PTL使用前の75例 (癌細胞の遺残16例, 生存可能6例) と比較すると, いまだ症例数は少ないが, PTLの癌細胞に対する温熱増感効果は顕著であった.

DNA Self‐Assembly of Targeted Near‐Infrared‐Responsive Gold Nanoparticles for Cancer Thermo‐Chemotherapy

The development of external stimulus-responsive nanoparticle (NP) systems for cancer therapy has received considerable attention in recent years, as these systems can differentially increase drug accumulation at target cancer cells/tissues, drastically decrease systemic toxicity, and potentially avoid underor over-dosing. External stimuli that have been exploited for such applications include light, magnetic field, ultrasound, and electricity. Among them, nearinfrared (NIR) light (650–900 nm) has recently become an attractive stimulus because of its minimal absorbance by skin and tissue, thus allowing for noninvasive and deep tissue penetration. In particular, NIR light can be effectively converted into heat by using photothermal NPs, such as gold nanorods (NRs), gold nanoshells, hollow gold nanospheres, and carbon nanotubes. As such, NIR-responsive NP platforms offer several important benefits for cancer therapy. For example, NIR-induced local heating can be used for cancer thermotherapy. In addition, NIR-responsive NP delivery systems enable on-demand release of drugs for cancer chemotherapy, presumably by heat-induced disruption of the delivery vehicles. Furthermore, the combination of NIR-based thermotherapy and triggered chemotherapy (thermo-chemotherapy) could provide higher therapeutic efficacy than respective monotherapies. In addition to these advantages, investigators are exploring the possibility of integrating active targeting ligands in NIR-responsive NP platforms for targeted cancer thermochemotherapy. This triple combination of thermotherapy, triggered drug release, and targeted delivery, would achieve optimal therapeutic efficacy in cancer treatment, relative to pairwise combinations. For example, Lee et al. have designed folate-conjugated, doxorubicin (Dox) loaded poly(lactic-co-glycolic acid) (PLGA)–gold half-shell NPs, and this combination led to effective tumor elimination in target tissues in a NIR-responsive manner. A current strategy in formulating this targeted NIR-responsive NP requires multiple steps, including 1) the synthesis of drug-loaded NPs, 2) deposition of gold compositions on NPs, and 3) postconjugation with targeting ligands followed by purification. However, these complex processes could increase the difficulty of adjusting bio-physicochemical properties of NPs in a reproducible manner, and could contribute to unintended drug release from NPs, thereby resulting in unfavorable batch-to-batch variability in the characteristics of drug loading. Alternatively, using pre-functionalized components to self-assemble into targeted NPs would eliminate the need for post-modification of NPs and is amenable to being scaledup with little batch-to-batch variability. This self-assembly strategy has led to the clinical translation of first-in-man targeted cyclodextrin-based NPs for small interfering RNA (siRNA) delivery, and targeted PLGA-based NPs for docetaxel delivery. Nevertheless, use of such a self-assembly strategy in the design of targeted NIR-responsive NPs has not been reported to date. Inspired by nature and the ability of complimentary strands of DNA to hybridize, we designed a DNA-based platform that can self-assemble into targeted NIR-responsive NPs for cancer therapy. As illustrated in Figure 1, this platform comprises three distinct functional components: complementary DNA strands, the gold NR (50 nm 10 nm), and a polyethylene glycol (PEG) layer. The DNA strands, which consist of sequential CG base pairs, provide loading sites for Dox, a model chemotherapeutic drug. By changing the number of CG base pairs, drug loading can be precisely tuned. In addition to serving as drug-loading scaffold, one strand of the DNA (termed capture strand) is thiolated for gold NR capture, and the complementary strand (termed targeting strand) is pre-conjugated with ligands for cellspecific targeting. Gold NRs serve as the model NIR light-to[*] Dr. Z. Xiao, Dr. C. Ji, Dr. J. Shi, J. Frieder, Dr. J. Wu, Prof. O. C. Farokhzad Laboratory of Nanomedicine and Biomaterials Department of Anesthesiology, Brigham and Women’s Hospital Harvard Medical School, Boston, MA, 02115 (USA) E-mail: ofarokhzad@zeus.bwh.harvard.edu

Scope of Nanotechnology-based Radiation Therapy and Thermotherapy Methods in Cancer Treatment

The main aim of nanomedicine is to revolutionize the health care system and find effective approaches to fighting fatal diseases. Therapeutic beams, which are employed in radiation therapy, do not discriminate between normal and cancerous cells and must rely on targeting the radiation beams to specific cells. Interestingly, the application of nanoscale particles in radiation therapy has aimed to improve outcomes in radiation therapy by increasing toxicity in tumors and reducing it in normal tissues. This review focuses on approaches to nanotechnology-based cancer radiation therapy methods such as radionuclide therapy, photodynamic therapy, and neutron capture therapy. Moreover, we have investigated nanotechnology-based thermotherapy methods, including hyperthermia and thermoablation, as non-ionizing modalities of treatment using thermal radiation. The results strongly demonstrate that nanotechnology-based cancer radiation therapy and thermotherapy methods hold substantial potential to improve the efficacy of anticancer radiation and thermotherapy modalities.

Photothermal Properties of Inorganic Nanomaterials as Therapeutic Agents for Cancer Thermotherapy

In recent years, gold (Au) nanoparticles (NPs) and single-walled carbon nanotubes (SWCNTs) have attracted significant attention as potent therapeutic agents for cancer thermotherapy. In this paper the photothermal properties of inorganic nanomaterials including porous silicon (PSi), titania (TiO2) nanotubes (NTs), TiO2 NPs, and multiwalled carbon nanotubes (MWCNTs), Au NPs and SWCNTs have been systematically investigated. PSi shows by far the largest temperature rise (deltaT), TiO2 NTs the second largest deltaT, and MWCNTs the smallest deltaT upon exposure to near-infrared (NIR) laser. The high photothermal effect of PSi has been found to be attributed to the high absorbance and the high surface-to-volume ratio due to the numerous micropores in PSi In addition, the factors affecting the photothermal effects of nanomaterials have been discussed. Our results suggest that PSi and TiO2 NTs are also potential therapeutic agents for cancer thermotherapy with excellent photothermal properties as well as high biocompatibility.

Decoration of carbon nanotubes with iron–cobalt (FeCo) alloy using polymer-stabilization and electroless deposition techniques for thermotherapy applications

FeCo nanoparticles were successfully plated onto the surface of CNTs via a one-step catalyzation method for electroless deposition. The FeCo plated CNTs were studied using X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray (EDX) analysis and vibrating sample magnetometry (VSM). FeCo deposition and plating uniformity were also characterized. The results show the approach as a feasible means of decorating CNTs with metal nanoparticles without the use of Sn sensitization solution. The CNT–FeCo composite easily heated to the desired temperature range of 43–46 °C required to inhibit thermotolerance development in cancer thermotherapy. Using the elemental mappings of the deposited nanoparticles, a quantitative distribution index is defined and it is used to quantitatively characterize the influence of catalyst on the deposit uniformity on the CNTs. Pd distribution appears to control the plating uniformity and hence has significant influence on the magnetic properties of the deposit.