Enhancement of the effect of novel targeted 5-aminolevulinic acid conjugated bismuth oxide nanoparticles-based photodynamic therapy by simultaneous radiotherapy on KB cells

BACKGROUND

Selective accumulation of photosensitizers into cancerous cells is one of the most important factors affecting photodynamic therapy (PDT) efficacy. 5-aminolevulinic acid (5-ALA) is the precursor of a strong photosensitizer, protoporphyrin-IX; but it has poor permeability into the cells. Folate receptors are overexpressed on the surface of many tumor cells. In the present study, folic acid (FA) and 5-ALA conjugated bismuth oxide nanoparticles were synthesized; and used in PDT, radiotherapy (RT), and concurrent PDT & RT against nasopharyngeal carcinoma (KB cell line).

METHODS

The KB cells were incubated with the synthesized nanoparticles (NPs) for 2 h; then illuminated using a custom-made LED lamp at the light dose of 26 J/cm2. Irradiation of the cells was carried out using X-ray 6 MV (2 Gy); and synergistic effect of the simultaneous RT and PDT treatments was evaluated using fractional product values. Efficacy of the treatments was determined using MTT and Caspase-3 enzyme activity assays.

RESULTS

Targeting of folic acid receptors enables the selective endocytosis of the conjugated NPs. RT results in the presence of Bi2O3 NPs showed a significant radiosensitizer potential of these NPs. Fractional product values of 1.49±0.05, 1.36±0.06, and 1.05±0.06 obtained in the presence of FA-5-ALA conjugated NPs, 5-ALA conjugated NPs, and in the absence of the NPs, respectively. Therefore, simultaneous RT and PDT in the presence of these conjugated NPs is superior to RT in the presence of the NPs.

CONCLUSION

Simultaneous PDT and RT in the presence of FA-5-ALA conjugated bismuth oxide NPs can be introduced as a promising therapeutic approach in controlling KB cancer cells.

Review of nanomaterial advances for ionizing radiation dosimetry

There are a wide range of applications with ionizing radiation and a common theme throughout these is that accurate dosimetry is usually required, although many newer demands are provided by improved features in higher range, multi-spectral and particle type detected. Today, the array of dosimeters includes both offline and online tools, such as gel dosimeters, thermoluminescence (TL), scintillators, optically stimulated luminescence (OSL), radiochromic polymeric films, gels, ionization chambers, colorimetry, and electron spin resonance (ESR) measurement systems. Several future nanocomposite features and interpretation of their substantial behaviors are discussed that can lead to improvements in specific features, such as (1) lower sensitivity range, (2) less saturation at high range, (3) overall increased dynamic range, (4) superior linearity, (5) linear energy transfer and energy independence, (6) lower cost, (7) higher ease of use, and (8) improved tissue equivalence. Nanophase versions of TL and ESR dosimeters and scintillators each have potential for higher range of linearity, sometimes due to superior charge transfer to the trapping center. Both OSL and ESR detection of nanomaterials can have increased dose sensitivity because of their higher readout sensitivity with nanoscale sensing. New nanocrystalline scintillators, such as perovskite, have fundamentally important advantages in sensitivity and purposeful design for key new applications. Nanoparticle plasmon coupled sensors doped within a lower Zeff material have been an effective way to achieve enhanced sensitivity of many dosimetry systems while still achieving tissue equivalency. These nanomaterial processing techniques and unique combinations of them are key steps that lead to the advanced features. Each must be realized through industrial production and quality control with packaging into dosimetry systems that maximize stability and reproducibility. Ultimately, recommendations for future work in this field of radiation dosimetry were summarized throughout the review.

A review of bismuth-based nanoparticles and their applications in radiosensitising and dose enhancement for cancer radiation therapy

About 50% of cancer patients receive radiation therapy. Despite the therapeutic benefits of this method, the toxicity of radiation in the normal tissues is unavoidable To improve the quality of radiation therapy, in addition to other methods such as IMRT, IGRT, and high radiation dose, nanoparticles have shown excellent potential when ionising radiation is applied to the target volume. Recently, bismuth-based nanoparticles (BiNPs) have become particularly popular in radiation therapy due to their high atomic numbers (Z), high X-ray attenuation coefficient, low toxicity, and low cost. Moreover, it is easy to synthesise in a variety of sizes and shapes. This study aimed to review the effects of the bismuth-based NP and its combination with other compounds, and their potential synergies in radiotherapy, discussed based on their physical, chemical, and biological interactions. Targeted and non-targeted bismuth-based NPs used in radiotherapy as radiosensitizers and dose enhancement effects are described. The results reported in the literature were categorised into various groups. Also, this review has highlighted the importance of bismuth-based NPs in different forms of cancer treatment to find the highest efficiency for applying them as a suitable candidate for various cancer therapy and future clinical applications.

Natural Baicalein-Rich Fraction as Radiosensitizer in Combination with Bismuth Oxide Nanoparticles and Cisplatin for Clinical Radiotherapy

Purpose

Methods

Results

Conclusion

Monte Carlo-based calculation of nano-scale dose enhancement factor and relative biological effectiveness in using different nanoparticles as a radiosensitizer

INTRODUCTION

Nowadays, some nanoparticles (NPs) are known and used as radiosensitizers in radiotherapy and radiobiology, due to their desired biological, physical, and chemical effects on cells. This study aimed to evaluate and compare the dose enhancement factor (DEF) and the biological effectiveness of some common NPs through EGSnrc and MCDS Monte Carlo (MC) simulation codes.

MATERIALS AND METHODS

To evaluate considered NPs' DEF, a single NP with 50 nm diameter was simulated at the center of concentric spheres. NP irradiations were done with 30, 60, and 100 keV photon energies. The secondary electron spectra were scored at the surface of considered NPs, and the dose values were scored at surrounding water-filled spherical shells which were distributed up to 4000 nm from the NP surface. The electron spectra were used in the MCDS code to obtain different initial DNA damages for the calculation of enhanced relative biological effectiveness (eRBE).

RESULTS

By decreasing the photon energy, an increment of DEF was seen for all studied NPs. The maximum DEF at 30, 60, and 100 keV photon energies were respectively related to silver (Ag), gadolinium (Gd), and bismuth (Bi) NPs. The maximum double-strand break (DSB) related (eRBEDSB) values for the 30 keV photon belonged to Ag, while BiNPs showed the maximum values at other photon energies. The minimum eRBEDSB values were also related to iron (Fe) NPs at the entire range of studied photon energies.

CONCLUSIONS

The compared nanoscale physical and biological results of our study can be helpful in the selection of optimum NP as a radiosensitizer in future radiobiological studies. Bi, gold (Au), Ag, and platinum (Pt) NPs had great potential, respectively, as radiosensitizers relative to the other studied NPs.

Bismuth oxide nanoparticles as agents of radiation dose enhancement in intraoperative radiotherapy

PURPOSE

Intraoperative radiotherapy (IORT) technique is an advanced radio therapeutic method used for delivery of a single high-dose radiation during surgery while removing healthy tissues from the radiation field. Nowadays, growing attention is being paid to IORT for its low-energy (kilovoltage) delivery as it requires less radiation protection, but suffers several disadvantages, including high-dose delivery and prolonged treatment time. The application of nanoparticles with high atomic number and high attenuation coefficients in kilovoltage energy may help overcome the mentioned shortcomings. This study was designed to investigate and quantify the mean dose enhancement factor (DEF) in the presence of nanoparticles using IORT method.

METHODS

Bismuth oxide nanoparticles (Bi₂ O₃ NPs), both in sheet and spherical formats, were synthesized using a novel hydrothermal method and characterized with x-ray diffraction (XRD), transmission electron microscopy (TEM), and Brunauer-Emmett-Teller (BET) analysis. Genipin-gelatin gel dosimeter (GENIPIN) was produced in three batches of pure with sheet and with spherical nanoparticles in concentration of 46.596 µg/ml, and irradiated with 50 kV x-rays.

RESULTS

Samples were scanned by a spectrophotometer, which indicated a DEF of 3.28  ±  0.37 and 2.50  ±  0.23 for sheet and spherical NPs, respectively. According to the results of this study, GENIPIN is a suitable dosimeter for the evaluation of three-dimensional dose distribution in the presence Bi₂ O₃ NPs.

CONCLUSION

As a result, IORT along with Bi₂ O₃ NPs has the potential to reduce treatment time and/or normal tissue dose; moreover, it could provide localized dose enhancement.

Iron oxide and gold bimetallic radiosensitizers for synchronous tumor chemoradiation therapy in 4T1 breast cancer murine model

The development of highly integrated multifunctional nanomaterials with a superadditive therapeutic effect and good safety is an urgent but challenging task in cancer therapy research. The present study aims to design a nanoplatform that offers the opportunity to enhance antitumor activity while minimizing side effects. Given the Au-mediated X-ray radiation enhancement and the ability of Fe-based nanomaterials to create reactive oxygen species (ROS) and DNA damage, we anticipated that bimetallic Fe3O4-Au heterodimer would bring strong radiosensitizing capacity. Fe3O4-Au heterodimer surface was covered with bovine serum albumin (BSA) to achieve good surface functionality, stability and prolonged blood circulation. Folic acid (FA) moieties were added to the nanoformulation to increase tumor-homing, specificity and uptake. Finally, curcumin (CUR) was incorporated into the nanoparticle to function as a natural anticancer agent. The integration of all these components has yielded a single nanoplatform, Fe3O4-Au-BSA-FA-CUR, capable of successfully fulfilling the mission of superadditive cancer therapy to avoid the risks of organ removal surgery. The efficacy of the proposed nanoplatform was investigated in vitro and in vivo. High radiosensitizing ability, X-ray-induced ROS generation and DNA damage, and good biocompatibility were demonstrated through in vitro experiments. Also, the administration of Fe3O4-Au-BSA-FA-CUR with X-ray irradiation completely eradicated the tumor without any mortality and toxicity in healthy tissues in vivo. Our results highlight the potential of CUR-loaded Fe3O4-Au-BSA-FA heteronanostructure to enable synergistic localized radiochemotherapy and open up a new door to attractive possibilities that warrant further exploration.

Nanoparticle dose enhancement of synchrotron radiation in PRESAGE dosimeters

The physical absorbed dose enhancement by the inclusion of gold and bismuth nanoparticles fabricated into water-equivalent PRESAGE dosimeters was investigated. Nanoparticle-loaded water-equivalent PRESAGE dosimeters were irradiated with superficial, synchrotron and megavoltage X-ray beams. The change in optical density of the dosimeters was measured using UV-Vis spectrophotometry pre- and post-irradiation using a wavelength of 630 nm. Dose enhancement was measured for 5 nm and 50 nm monodispersed gold nanoparticles, 5-50 nm polydispersed bismuth nanoparticles, and 80 nm monodispersed bismuth nanoparticles at concentrations from 0.25 mM to 2 mM. The dose enhancement was highest for the 95.3 keV mean energy synchrotron beam (16-32%) followed by the 150 kVp superficial beam (12-21%) then the 6 MV beam (2-5%). The bismuth nanoparticle-loaded dosimeters produced a larger dose enhancement than the gold nanoparticle-loaded dosimeters in the synchrotron beam for the same concentration. For the superficial and megavoltage beams the dose enhancement was similar for both species of nanoparticles. The dose enhancement increased with nanoparticle concentration in the dosimeters; however, there was no observed nanoparticle size dependence on the dose enhancement.

Synergetic Influence of Bismuth Oxide Nanoparticles, Cisplatin and Baicalein-Rich Fraction on Reactive Oxygen Species Generation and Radiosensitization Effects for Clinical Radiotherapy Beams

Purpose

This study aimed to quantify synergetic effects induced by bismuth oxide nanoparticles (BiONPs), cisplatin (Cis) and baicalein-rich fraction (BRF) natural-based agent on the reactive oxygen species (ROS) generation and radiosensitization effects under irradiation of clinical radiotherapy beams of photon, electron and HDR-brachytherapy. The combined therapeutic responses of each compound and clinical radiotherapy beam were evaluated on breast cancer and normal fibroblast cell line.

Methods

In this study, individual BiONPs, Cis, and BRF, as well as combinations of BiONPs-Cis (BC), BiONPs-BRF (BB) and BiONPs-Cis-BRF (BCB) were treated to the cells before irradiation using HDR brachytherapy with 0.38 MeV iridium-192 source, 6 MV photon beam and 6 MeV electron beam. The individual or synergetic effects from the application of the treatment components during the radiotherapy were elucidated by quantifying the ROS generation and radiosensitization effects on MCF-7 and MDA-MB-231 breast cancer cell lines as well as NIH/3T3 normal cell line.

Results

The ROS generated in the presence of Cis stimulated the most substantial amount of ROS compared to the BiONPs and BRF. Meanwhile, the combination of the components had induced the higher ROS levels for photon beam than the brachytherapy and electron beam. The highest ROS enhancement relative to the control is attributable to the presence of BC combination in MDA-MB-231 cells, in comparison to the BB and BCB combinations. The radiosensitization effects which were quantified using the sensitization enhancement ratio (SER) indicate the highest value by BC in MCF-7 cells, followed by BCB and BB treatment. The radiosensitization effects are found to be more prominent for brachytherapy in comparison to photon and electron beam.

Conclusion

The BiONPs, Cis and BRF are the potential radiosensitizers that could improve the efficiency of radiotherapy to eradicate the cancer cells. The combination of these potent radiosensitizers might produce multiple effects when applied in radiotherapy. The BC combination is found to have the highest SER, followed by the BCB combination. This study is also the first to investigate the effect of BRF in combination with BiONPs (BB) and BC (BCB) treatments.

Main Approaches to Enhance Radiosensitization in Cancer Cells by Nanoparticles: A Systematic Review

In recent years, high atomic number nanoparticles (NPs) have emerged as promising radio-enhancer agents for cancer radiation therapy due to their unique properties. Multi-disciplinary studies have demonstrated the potential of NPs-based radio-sensitizers to improve cancer therapy and tumor control at cellular and molecular levels. However, studies have shown that the dose enhancement effect of the NPs depends on the beam energy, NPs type, NPs size, NPs concentration, cell lines, and NPs delivery system. It has been believed that radiation dose enhancement of NPs is due to the three main mechanisms, but the results of some simulation studies failed to comply well with the experimental findings. Thus, this study aimed to quantitatively evaluate the physical, chemical, and biological factors of the NPs. An organized search of PubMed/Medline, Embase, ProQuest, Scopus, Cochrane and Google Scholar was performed. In total, 77 articles were thoroughly reviewed and analyzed. The studies investigated 44 different cell lines through 70 in-vitro and 4 in-vivo studies. A total of 32 different types of single or core-shell NPs in different sizes and concentrations have been used in the studies.

Radiosensitization Effects by Bismuth Oxide Nanoparticles in Combination with Cisplatin for High Dose Rate Brachytherapy

Purpose

The aim of this study was to investigate the potential of the synergetic triple therapeutic combination encompassing bismuth oxide nanoparticles (BiONPs), cisplatin (Cis), and high dose rate (HDR) brachytherapy with Ir-192 source in breast cancer and normal fibroblast cell line.

Methods

In vitro models of breast cancer cell lines (MCF-7, MDA-MB-231) and normal fibroblast cell line (NIH/3T3) were employed. Cellular localization and cytotoxicity studies were conducted prior to inspection on the radiosensitization effects and generation of reactive oxygen species (ROS) on three proposed radiosensitizers: BiONPs, Cis, and BiONPs-Cis combination (BC). The optimal, non-cytotoxic concentration of BiONPs (0.5 mM) and the 25% inhibitory concentration of Cis (1.30 µM) were applied. The radiosensitization effects were evaluated by using a 0.38 MeV Iridium-192 HDR brachytherapy source over a prescribed dose range of 0 Gy to 4 Gy.

Results

The cellular localization of BiONPs was visualized by light microscopy and accumulation of the BiONPs within the vicinity of the nuclear membrane was observed. Quantification of the sensitization enhancement ratio extrapolated from the survival curves indicates radiosensitization effects for MCF-7 and MDA-MB-231 when treated with BiONPs, Cis, and BC. However, NIH/3T3 cells exhibited contradictive behavior as it only reacted towards the BC combination. Nonetheless, the MCF-7 cell line loaded with BC shows the highest SER of 4.29. ROS production analysis, on the other hand, shows that Cis and BC radiosensitizers generated the highest free radicals in comparison to BiONPs alone.

Conclusion

A BiONPs-Cis combination was unveiled as a novel approach that offers promising radiosensitization enhancement that will increase the efficiency of tumor control while preserving the normal tissue at a reduced dose. This data is the first precedent to prove the synergetic implication of BiONPs, Cis, and HDR brachytherapy that will be beneficial for future chemoradiotherapy strategies in cancer care.

Fluorescent Radiosensitizing Gold Nanoparticles

Ultrasmall polyaminocarboxylate-coated gold nanoparticles (NPs), Au@DTDTPA and Au@TADOTAGA, that have been recently developed exhibit a promising potential for image-guided radiotherapy. In order to render the radiosensitizing effect of these gold nanoparticles even more efficient, the study of their localization in cells is required to better understand the relation between the radiosensitizing properties of the agents and their localization in cells and in tumors. To achieve this goal, post-functionalization of Au@DTDTPA nanoparticles by near-infrared (NIF) organic dyes (aminated derivative of cyanine 5, Cy5-NH₂) was performed. The immobilization of organic Cy5-NH₂ dyes onto the gold nanoparticles confers to these radiosensitizers fluorescence properties which can be exploited for monitoring their internalization in cancerous cells, for determining their localization in cells by fluorescence microscopy (a common and powerful imaging tool in biology), and for following up on their accumulation in tumors after intravenous injection.

Recent Research Trends on Bismuth Compounds in Cancer Chemoand Radiotherapy

Background:

Application of coordination chemistry in nanotechnology is a rapidly developing research field in medicine. Bismuth complexes have been widely used in biomedicine with satisfactory therapeutic effects, mostly in Helicobacter pylori eradication, but also as potential antimicrobial and anti-leishmanial agents. Additionally, in recent years, application of bismuth-based compounds as potent anticancer drugs has been studied extensively.

Methods:

Search for data connected with recent trends on bismuth compounds in cancer chemo- and radiotherapy was carried out using web-based literature searching tools such as ScienceDirect, Springer, Royal Society of Chemistry, American Chemical Society and Wiley. Pertinent literature is covered up to 2016.

Results:

In this review, based on 213 papers, we highlighted a number of current problems connected with: (i) characterization of bismuth complexes with selected thiosemicarbazone, hydrazone, and dithiocarbamate classes of ligands as potential chemotherapeutics. Literature results derived from 50 papers show that almost all bismuth compounds inhibit growth and proliferation of breast, colon, ovarian, lung, and other tumours; (ii) pioneering research on application of bismuth-based nanoparticles and nanodots for radiosensitization. Results show great promise for improvement in therapeutic efficacy of ionizing radiation in advanced radiotherapy (described in 36 papers); and (iii) research challenges in using bismuth radionuclides in targeted radioimmunotherapy, connected with choice of adequate radionuclide, targeting vector, proper bifunctional ligand and problems with 213Bi recoil daughters toxicity (derived from 92 papers).

Conclusion:

This review presents recent research trends on bismuth compounds in cancer chemo- and radiotherapy, suggesting directions for future research.

Investigating the Cytotoxicity of Folate-Conjugated Bismuth Oxide Nanoparticles on KB and A549 Cell Lines

Purpose: Lately, bismuth-based nanomaterials have been widely utilized in medical researches such as imaging, drug delivery and radio-sensitization. Despite their advantages, bismuth-based compounds have shown toxic effects in humans. There are few studies on cytotoxicity effects of bismuth oxide (Bi2O3) nanoparticles (NPs) in-vitro. In this study, we aimed to investigate cytotoxicity of bare and also folate and 5-aminolevulinic acid (5-ALA)-conjugated Bi2O3 NPs on nasopharyngeal carcinoma (KB) and lung cancer (A549) cell lines.

Methods: B_i2O₃ NPs were synthesized and conjugated with folate and 5-ALA. KB and A549 cells were cultured and incubated with 10, 20, 50 and 100 μg/ml concentrations of bare and folate-5-ALA-conjugated NPs. The survival rates were obtained after 2 and 24 hours incubation of the cells with NPs using MTT assay. Also, apoptosis and ROS generation induced by the NPs in the treated cells were obtained using Caspases-3 activity assay and flow cytometry analysis, respectively.

Results: B_i2O₃ NPs were successfully synthesized with average size of 19.2 ± 6.5 nm, then conjugated with 5-ALA and folate. Either naked or folate-conjugated NPs were easily taken up by the cells in a concentration-dependent manner and showed cytotoxic effects. The significant cell death was noted at the concentrations more than 50 μg/ml for both compounds.

Conclusion: Results indicated low cytotoxicity of the prepared NPs at lower incubation periods, which is very important for their further applications. However, 24 hours incubation of the cells with both forms of NPs caused more cell killing and the cytotoxicity increased with increasing concentrations of the NPs.

Metal-based NanoEnhancers for Future Radiotherapy: Radiosensitizing and Synergistic Effects on Tumor Cells

Radiotherapy is one of the major therapeutic strategies for cancer treatment. In the past decade, there has been growing interest in using high Z (atomic number) elements (materials) as radiosensitizers. New strategies in nanomedicine could help to improve cancer diagnosis and therapy at cellular and molecular levels. Metal-based nanoparticles usually exhibit chemical inertness in cellular and subcellular systems and may play a role in radiosensitization and synergistic cell-killing effects for radiation therapy. This review summarizes the efficacy of metal-based NanoEnhancers against cancers in both in vitro and in vivo systems for a range of ionizing radiations including gamma-rays, X-rays, and charged particles. The potential of translating preclinical studies on metal-based nanoparticles-enhanced radiation therapy into clinical practice is also discussed using examples of several metal-based NanoEnhancers (such as CYT-6091, AGuIX, and NBTXR3). Also, a few general examples of theranostic multimetallic nanocomposites are presented, and the related biological mechanisms are discussed.

Emerging Nanotechnology and Advanced Materials for Cancer Radiation Therapy

Radiation therapy (RT) including external beam radiotherapy (EBRT) and internal radioisotope therapy (RIT) has been widely used for clinical cancer treatment. However, owing to the low radiation absorption of tumors, high doses of ionizing radiations are often needed during RT, leading to severe damages to normal tissues adjacent to tumors. Meanwhile, the RT efficacies are limited by different mechanisms, among which the tumor hypoxia-associated radiation resistance is a well-known one, as there exists hypoxia inside most solid tumors while oxygen is essential to enhance radiation-induced DNA damages. With the development in nanotechnology, there have been great interests in using nanomedicine strategies to enhance radiation responses of tumors. Nanomaterials containing high-Z elements to absorb radiation rays (e.g. X-ray) can act as radio-sensitizers to deposit radiation energy within tumors and promote treatment efficacy. Nanoscale carriers are able to deliver therapeutic radioisotopes into tumors for internal RIT, or chemotherapeutic drugs for synergistically combined chemo-radiotherapy. As uncovered in recent studies, the tumor microenvironment could be modulated by various nanomedicine approaches to overcome hypoxia-associated radiation resistance. Herein, the authors will summarize the applications of nanomedicine for RT cancer treatment, and pay particular attention to the latest development of 'advanced materials' for enhanced cancer RT.

Ultrasmall Silica-Based Bismuth Gadolinium Nanoparticles for Dual Magnetic Resonance-Computed Tomography Image Guided Radiation Therapy

Selective killing of cancer cells while minimizing damage to healthy tissues is the goal of clinical radiation therapy. This therapeutic ratio can be improved by image-guided radiation delivery and selective radiosensitization of cancer cells. Here, we have designed and tested a novel trimodal theranostic nanoparticle made of bismuth and gadolinium for on-site radiosensitization and image contrast enhancement to improve the efficacy and accuracy of radiation therapy. We demonstrate in vivo magnetic resonance (MR), computed tomography (CT) contrast enhancement, and tumor suppression with prolonged survival in a non-small cell lung carcinoma model during clinical radiation therapy. Histological studies show minimal off-target toxicities due to the nanoparticles or radiation. By mimicking existing clinical workflows, we show that the bismuth-gadolinium nanoparticles are highly compatible with current CT-guided radiation therapy and emerging MR-guided approaches. This study reports the first in vivo proof-of-principle for image-guided radiation therapy with a new class of theranostic nanoparticles.