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

Nanotechnology-based radiation therapy to cure cancer and the challenges in its clinical applications

Radiation therapy against cancer frequently fails to attain the desired outcomes because of several restricting aspects. Radiation therapy is not a targeted antitumor treatment, and it poses serious threats to normal tissues as well. In many cases, some inherent features of tumors make them resistant to radiation therapy. Several nanoparticles have shown the capacity to upgrade the viability of radiation treatment because they can directly interact with ionizing radiation to increase cellular radiation sensitivity. Several types of nanomaterials have been investigated as radio-sensitizers, to improve the efficacy of radiotherapy and overcome radio-resistance including, metal-based nanoparticles, quantum dots, silica-based nanoparticles, polymeric nanoparticles, etc. Despite all this research and development, certain challenges associated with the exploitation of nanoparticles to enhance and improve radiation therapy for cancer treatment are encountered. Potential applications of nanoparticles as radiosensitizers is hindered by the difficulties associated with ensuring their production at a large scale with improved characterizations and because of certain biological challenges. By overcoming the shortcomings of nanoparticles like working on the pharmacokinetics, and physical and chemical characterization, the therapy can be improved. It is expected that in the future more knowledge will be available regarding nanoparticles and their clinical efficacy, leading to the successful development of nanotechnology-based radiation therapies for a variety of cancers. This review highlights the limitations of conventional radiotherapy in cancer treatment and explores the potential of nanotechnology, specifically the use of nanomaterials, to overcome these challenges. It discusses the concept of using nanomaterials to enhance the effectiveness of radiation therapy and provides an overview of different types of nanomaterials and their beneficial properties. The review emphasizes the need to address the obstacles and limitations associated with the application of nanotechnology in cancer radiation therapy for successful clinical translation.

Monte Carlo simulation of physical dose enhancement in core-shell magnetic gold nanoparticles with TOPAS

The application of metal nanoparticles (MNPs) as sensitization materials is a common strategy that is used to study dose enhancement in radiotherapy. Recent in vitro tests have revealed that magnetic gold nanoparticles (NPs) can be used in cancer therapy under a magnetic field to enhance the synergistic efficiency in radiotherapy and photothermal therapy. However, magnetic gold NPs have rarely been studied as sensitization materials. In this study, we obtained further results of the sensitization properties of the magnetic gold NPs (Fe3O4@AuNPs) with or without magnetic field using the TOPAS-nBio Monte Carlo (MC) toolkit. We analyzed the properties of Fe3O4@AuNP in a single NP model and in a cell model under monoenergetic photons and brachytherapy, and we investigated whether the magnetic field contributes to the physical sensitization process. Our results revealed that the dose enhancement factor (DEF) of Fe3O4@AuNPs was lower than that of gold nanoparticles (AuNPs) in a single NP and in a cell irradiated by monoenergetic photons. But it’s worth mentioning that under a magnetic field, the DEF of targeted Fe3O4@AuNPs in a cell model with a clinical brachytherapy source was 22.17% (cytoplasm) and 6.89% (nucleus) higher than those of AuNPs (50 mg/mL). The Fe3O4@AuNPs were proved as an effective sensitization materials when combined with the magnetic field in MC simulation for the first time, which contributes to the research on in vitro tests on radiosensitization as well as clinical research in future.

Using Chitosan or Chitosan Derivatives in Cancer Therapy

Cancer is one of the major causes of death worldwide. Chemotherapeutic drugs have become a popular choice as anticancer agents. Despite the therapeutic benefits of chemotherapeutic drugs, patients often experience side effects and drug resistance. Biopolymers could be used to overcome some of the limitations of chemotherapeutic drugs, as well as be used either as anticancer agents or drug delivery vehicles. Chitosan is a biocompatible polymer derived from chitin. Chitosan, chitosan derivatives, or chitosan nanoparticles have shown their promise as an anticancer agent. Additionally, functionally modified chitosan can be used to deliver nucleic acids, chemotherapeutic drugs, and anticancer agents. More importantly, chitosan-based drug delivery systems improved the efficacy, potency, cytotoxicity, or biocompatibility of these anticancer agents. In this review, we will investigate the properties of chitosan and chemically tuned chitosan derivatives, and their application in cancer therapy.

Advances in Nanomaterial-Mediated Photothermal Cancer Therapies: Toward Clinical Applications

Photothermal therapy (PTT) has attracted extensive research attention as a noninvasive and selective treatment strategy for numerous cancers. PTT functions via photothermal effects induced by converting light energy into heat on near-infrared laser irradiation. Despite the great advances in PTT for cancer treatment, the photothermal therapeutics using laser devise only or non-specific small molecule PTT agents has been limited because of its low photothermal conversion efficiency, concerns about the biosafety of the photothermal agents, their low tumor accumulation, and a heat resistance of specific types of cancer. Using nanomaterials as PTT agents themselves, or for delivery of PTT agents, offers improved therapeutic outcomes with fewer side effects through enhanced photothermal conversion efficiency, accumulation of the PTT agent in the tumor tissue, and, by extension, through combination with other therapies. Herein, we review PTT’s current clinical progress and present the future outlooks for clinical applications. To better understand clinical PTT applications, we describe nanomaterial-mediated photothermal effects and their mechanism of action in the tumor microenvironment. This review also summarizes recent studies of PTT alone or in combination with other therapies. Overall, innovative and strategically designed PTT platforms are promising next-generation noninvasive cancer treatments to move closer toward clinical applications.

Studies on the Exposure of Gadolinium Containing Nanoparticles with Monochromatic X-rays Drive Advances in Radiation Therapy

While conventional radiation therapy uses white X-rays that consist of a mixture of X-ray waves with various energy levels, a monochromatic X-ray (monoenergetic X-ray) has a single energy level. Irradiation of high-Z elements such as gold, silver or gadolinium with a synchrotron-generated monochromatic X-rays with the energy at or higher than their K-edge energy causes a photoelectric effect that includes release of the Auger electrons that induce DNA damage—leading to cell killing. Delivery of high-Z elements into cancer cells and tumor mass can be facilitated by the use of nanoparticles. Various types of nanoparticles containing high-Z elements have been developed. A recent addition to this growing list of nanoparticles is mesoporous silica-based nanoparticles (MSNs) containing gadolinium (Gd–MSN). The ability of Gd–MSN to inhibit tumor growth was demonstrated by evaluating effects of irradiating tumor spheroids with a precisely tuned monochromatic X-ray.

Study of absorption of radio frequency field by gold nanoparticles and nanoclusters in biological medium

Gold nanoparticles (AuNPs) and gold nanoclusters (AuNCs) are gaining interest in medical diagnosis and therapy as they are bio-compatible and are easy to functionalize. Their interaction with radiofrequency (RF) field for hyperthermia treatment is ambiguous and needs further investigation. A systematic study of the absorption of capacitive RF field by AuNPs and AuNCs dispersed in phosphate-buffered saline (PBS) is reported here in tissue mimicking phantom. The stability of AuNPs and AuNCs dispersed in PBS was confirmed for a range of pH and temperature expected during RF hyperthermia treatment. Colloidal gold solutions with AuNPs (10 nm) and AuNCs (2 nm), and control, i.e. PBS without nanogold, were loaded individually in 3 ml wells in a tissue phantom. Phantom heating was carried out using 27 MHz short-wave diathermy equipment at 200 and 400 W for control and colloidal gold solutions. Experiments were conducted for colloidal gold at varying gold concentrations (10-100 µg/ml). Temperature rise measured in the phantom wells did not show dependence on the concentration and size of the AuNPs. Furthermore, temperature rise recorded in the control was comparable with the measurements recorded in both nanogold suspensions (2, 10 nm). Dielectric property measurements of control and colloidal gold showed <3% difference in electrical conductivity between the control and colloidal gold for both nanoparticle sizes. From the measurements, it is concluded that AuNPs and AuNCs do not enhance the absorption of RF-capacitive field and power absorption observed in the biological medium is due to the ions present in the medium.

Modeling and experimental data of zirconium-89 production yield

The radionuclide zirconium-89 can be employed for the positron emission tomography (PET). In this study ⁸⁹Zr excitation function via ⁸⁹Y(p,n)⁸⁹Zr reaction was calculated by the TALYS-1.8 code based on microscopic level density model. The formation of ⁸⁹Zr was simulated using the Monte Carlo simulation code MCNPX to calculate the integral yield in the ⁸⁹Y target body for threshold up to 40MeV incident-proton energy. The target thickness was based on calculation of the stopping power using the SRIM-2013 code matched to any incident-proton energy. The production yield of the ⁸⁹Zr simulated with the Monte Carlo method for the ⁸⁹Y(p,n)⁸⁹Zr, ⁸⁹Y(d,2n)⁸⁹Zr, ^natSr(α,xn)⁸⁹Zr and ^natZr(p,pxn)⁸⁹Zr reactions and the results were in good agreement with published experimental results for the optimum energy range. An experimental yield of 53.1MB/µA for the 15MeV proton-induced on Y₂O₃ powder as a disk-target obtained for 1h irradiation at the AMIRS cyclotron.

Theoretical assessment and targeted modeling of TiO2 in reactor towards the scandium radioisotopes estimation

⁴⁷Sc radioisotope with beta particle emission can be used for targeted radionuclide therapy in nuclear medicine and can be produced by nuclear reactor (with high activities) and accelerator. In this work, the specific activity of ⁴⁷Sc with the isotopic impurities produced through irradiating the enriched ⁴⁷Tio₂ and natural TiO₂ targets have been calculated by the MCNPX-2.6 and the TALYS-1.8 codes and also theoretical approach in a fast neutron flux 3×10¹³ncm^-2s^-1 in the reactor. In addition, the cross sections of ⁴⁶Ti(n,p)⁴⁶Sc reaction have been interpolated in the 1-10MeV energy range and compared with the corresponding experimental data, as well. Moreover, the average cross sections of ⁴⁶Ti(n,p)⁴⁶Sc, ⁴⁷Ti(n,p)⁴⁷Sc and ⁴⁸Ti(n,p)⁴⁸Sc reactions were reproduced. Acceptable agreement between the experimental data and calculated results confirms the ability of the used methods to design and predict the production process in reactor.

Assessment and estimation of 67Cu production yield via deuteron induced reactions on natZn and 70Zn

⁶⁷Cu radioisotope is a beta particle-emitting nuclide used in radioimmunotherapy (RIT) as well as for imaging, tracer kinetic studies and dosimetry. ⁶⁷Cu can be produced by bombarding ^natZn with deuterons. In this study, the physical yields of ⁶⁷Cu via ^natZn(d,x)⁶⁷Cu reaction channel as well as via subreactions of ⁶⁸Zn(d,2pn)⁶⁷Cu, ⁶⁷Zn(d,2p)⁶⁷Cu, ⁷⁰Zn(d,2p3n)⁶⁷Cu, ⁶⁸Zn(d,x)⁶⁷Ni(T_1/2=21s)→⁶⁷Cu and ⁷⁰Zn(d,x)⁶⁷Ni(T_1/2=21s)→⁶⁷Cu in the ^natZn target have been calculated by using the MCNPX-2.6, TALYS-1.8 and SRIM codes. Also, the total cross sections for production of ⁶⁷Cu from ^natZn(d,x)⁶⁷Cu reaction channel in the energy range of 15-45MeV have been estimated by TALYS code. The best reaction to produce ⁶⁷Cu radionuclide in a carrier free form was chosen with deuteron energy around 30MeV on ⁷⁰Zn thick target. Good agreement between the calculated results and the experimental values shows that the employed methods can be used for prediction and production estimation in cyclotron.

Thermohydrogel Containing Melanin for Photothermal Cancer Therapy

Melanin is an effective absorber of light and can extend to near infrared (NIR) regions. In this study, a natural melanin is presented as a photothermal therapeutic agent (PTA) because it provides a good photothermal conversion efficiency, shows biodegradability, and does not induce long-term toxicity during retention in vivo. Poloxamer solution containing melanin (Pol-Mel) does not show any precipitation and shows sol-gel transition at body temperature. After irradiation from 808 nm NIR laser at 1.5 W cm^-2 for 3 min, the photothermal conversion efficiency of Pol-Mel is enough to kill cancer cells in vitro and in vivo. The tumor growth of mice bearing CT26 tumors treated with Pol-Mel injection and laser irradiation is suppressed completely without recurrence postirradiation. All these results indicate that Pol-Mel can become an attractive PTA for photothermal cancer therapy.

Production and purification of Scandium-47: A potential radioisotope for cancer theranostics

In this study, production of ⁴⁷Sc radionuclide by irradiating the natural titanium dioxide powder (TiO₂) in the fast neutron flux (~3*10¹³ncm^-2s^-1) for 4 days in Tehran Research Reactor (TRR, Iran) and separation from titanium target was investigated. The study showed the feasibility of production ⁴⁷Sc by TRR. The separation efficiency and radiochemical purity (ScCl₃) of radio-scandium, ⁴⁷Sc radionuclide purity were obtained 98%, 99% and 88% respectively.

Theranostics for hepatocellular carcinoma with Fe3O4@ZnO nanocomposites

An Fe₃O₄@ZnO/Dox/TfR Ab was designed and synthesized as a theranostic agent for hepatocellular carcinoma, allowing for a targeted drug delivery with concurrent chemoradiotherapy and visual MRI evaluation of the therapeutic effect.

Nanomedicine applied to translational oncology: A future perspective on cancer treatment

The high global incidence of cancer is associated with high rates of mortality and morbidity worldwide. By taking advantage of the properties of matter at the nanoscale, nanomedicine promises to develop innovative drugs with greater efficacy and less side effects than standard therapies. Here, we discuss both clinically available anti-cancer nanomedicines and those en route to future clinical application. The properties, therapeutic value, advantages and limitations of these nanomedicine products are highlighted, with a focus on their increased performance versus conventional molecular anticancer therapies. The main regulatory challenges toward the translation of innovative, clinically effective nanotherapeutics are discussed, with a view to improving current approaches to the clinical management of cancer. Ultimately, it becomes clear that the critical steps for clinical translation of nanotherapeutics require further interdisciplinary and international effort, where the whole stakeholder community is involved from bench to bedside. From the Clinical Editor: Cancer is a leading cause of mortality worldwide and finding a cure remains the holy-grail for many researchers and clinicians. The advance in nanotechnology has enabled novel strategies to develop in terms of cancer diagnosis and therapy. In this concise review article, the authors described current capabilities in this field and outlined comparisons with existing drugs. The difficulties in bringing new drugs to the clinics were also discussed.

Photo-thermal effect enhances the efficiency of radiotherapy using Arg-Gly-Asp peptides-conjugated gold nanorods that target αvβ3 in melanoma cancer cells

BACKGROUND

Thermotherapy has been known to be one of the most effective adjuvants to radiotherapy (RT) in cancer treatment, but it is not widely implemented clinically due to some limitations, such as, inadequate temperature concentrations to the tumor tissue, nonspecific and non-uniform distribution of heat. So we constructed arginine-glycine-aspartate peptides-conjugated gold nanorods (RGD-GNRs) that target the alpha(v) beta(3) Integrin (αvβ3) and investigate whether the photo-thermal effect of RGD-GNRs by near infrared radiation (NIR) could enhance the efficiency of RT in melanoma cancer cells.

RESULTS

RGD-GNRs could be seen both on the surface of the cell membranes and cytoplasm of A375 cells with high expression of αvβ3. After exposed to 808 nm NIR, RGD-GNRs with various concentrations could be rapidly heated up. Compared to other treatments, flow cytometric analysis indicated that RT + NIR + RGD-GNRs increased apoptosis (p < 0.001) and decreased the proportion of cells in the more radioresistant S phase (p = 0.014). Treated with NIR + RGD-GNRs, the radiosensitivity was also significantly enhanced (DMFSF2: 1.41).

CONCLUSION

Results of the current study showed the feasibility of using RGD-GNRs for synergetic RT with photo-thermal therapy. And it would greatly benefit the therapeutic effects of refractory or recurrent malignant cancers.

Targeting and noninvasive treatment of hepatocellular carcinoma in situ by ZnO nanorod-mediated concurrent chemoradiotherapy

TfR Ab/Dox/ZnO nanocomposites, in which transferrin receptor antibody (TfR Ab) functionalized ZnO nanorods, loaded with doxorubicin (Dox), were prepared to mediate concurrent chemoradiotherapy for the treatment of hepatocellular carcinoma.

Preparation of radioactive praseodymium oxide as a multifunctional agent in nuclear medicine: expanding the horizons of cancer therapy using nanosized neodymium oxide

OBJECTIVE

Many studies have attempted to assess the significance of the use of the β(-)particle emitter praseodymium-142 ((142)Pr) in cancer treatment. As praseodymium oxide (Pr(2)O(3)) powder is not water soluble, it was dissolved in HCl solution and the resultant solution had to be pH adjusted to be in an injectable radiopharmaceutical form. Moreover, it was shown that the nanosized neodymium oxide (Nd(2)O(3)) induced massive vacuolization and cell death in non-small-cell lung cancer. In this work, the production of (142)Pr was studied and water-dispersible nanosized Pr(2)O(3) was proposed to improve the application of (142)Pr in nuclear medicine.

MATERIALS AND METHODS

Data from different databases pertaining to the production of (142)Pr were compared to evaluate the accuracy of the theoretical calculations. Water-dispersible nanosized Pr(2)O(3) was prepared using a poly(ethylene glycol) (PEG) coating or PEGylation method as a successful mode of drug delivery. Radioactive (142)Pr(2)O(3) was produced via a (142)Pr(n,γ)(142)Pr reaction by thermal neutron bombardment of the prepared sample.

RESULTS

There was good agreement between the reported experimental data and the data based on nuclear model calculations. In addition, a small part of nano-Pr(2)O(3) particles remained in suspension and most of them settled out of the water. Interestingly, the PEGylated Pr(2)O(3) nanoparticles were water dispersible. After neutron bombardment of the sample, a stable colloidal (142)Pr(2)O(3) was formed.

CONCLUSION

The radioactive (142)Pr(2)O(3) decays to the stable (142)Nd(2)O(3). The suggested colloidal (142)Pr(2)O(3) as a multifunctional therapeutic agent could have dual roles in cancer treatment as a radiotherapeutic agent using nanosized (142)Pr(2)O(3) and as an autophagy-inducing agent using nanosized (142)Nd(2)O(3).

The anti-hepatoma effect of nanosized Mn-Zn ferrite magnetic fluid hyperthermia associated with radiation in vitro and in vivo

Joint therapy is a promising area of study in cancer treatment. In this paper, we prepared Mn-Zn ferrite (Mn0.5Zn0.5Fe2O4) magnetofluid using PEI as a surfactant, and investigated the anticancer effect of Mn0.5Zn0.5Fe2O4 magnetic fluid hyperthermia (MFH) combined with radiotherapy on hepatocellular carcinoma. Both in vitro and in vivo results suggest that this combined treatment with MFH and radiation has a better therapeutic effect than either of them alone. The apoptotic rate and necrotic rate of the combined treatment group was 38.80 and 25.20%, respectively. In contrast, it was only 7.49 and 3.62% in the radiation-alone group, 15.23 and 7.90% in the MFH-alone group, only 3.52 and 2.16% in the blank control group, and 23.56 and 27.56% in the adriamycin group. The cell proliferation inhibition rate of the combined treatment group (88.5%) was significantly higher than that of the radiation-alone group (37.5%), MFH-alone group (60.6%) and adriamycin group (70.6%). The tumor volume inhibition and mass inhibition rate of the combined treatment group was 87.62 and 88.62%, respectively, obviously higher than the 41.04 and 34.20% of the radiation-alone group, 79.87 and 77.92% of the MFH-alone group and 71.76 and 66.87% of the adriamycin group. It is therefore concluded that this combined application of MFH and radiation can give good synergistic and complementary effects, which offers a viable approach for treatment of cancer.

Calculation of beta induced Bremsstrahlung exposure from therapeutic radionuclide 198Au in tissues, DNA and RNA

Gold-198 (βmax=0.96MeV (98.6%), γmax=0.412MeV (95.5%) and T1/2=2.7 days) is a well-known therapeutic beta emitter in the field of nuclear medicine, and is being used for the treatment of many different cancers. In the present study, the Bremsstrahlung exposure induced by 198Au in different human tissues, DNA and RNA has been calculated. The specific Bremsstrahlung constant (ΓBr), Probability of energy loss by beta during Bremsstrahlung emission (PBr) and Bremsstrahlung activity (Arelease)Br were estimated. We strongly recommend these parameters should be considered in absorbed dose calculations of radionuclide therapy via 198Au.