Bystander Effect of Therapeutic Ultrasound in the Presence of Cisplatin: An in Vitro Study on Human Melanoma Cells.

Background: In the bystander effect, non-irradiated cells receive biological signals from adjacent irradiated cells and undergo a variety of alterations, considered recently in non-ionizing irradiation like ultrasound waves. In this study, the bystander effect of therapeutic ultrasound exposure alone and in combination with cisplatin was determined. Objective: This study aims to determine the bystander effect caused by ultrasound and cisplatin. Material and Methods: This experimental study was conducted on the human melanoma cell line including two groups of target and bystander cells. The target cell group was divided into three sub-groups of ultrasound irradiation alone, cisplatin alone, and ultrasound irradiation in the presence of cisplatin that the culture medium of these three groups of cells was transferred to the bystander cell group using the medium transfer technique. Then, apoptotic bystander cells and the expression of P53 and HO-1 in target and bystander groups were measured. Results: The results of the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and apoptosis assay showed that cell death in target and bystander groups receiving the ultrasound with cisplatin is higher than in the ultrasound without cisplatin. PCR (the polymerase chain reaction) results in the target and bystander groups receiving treatments with increased expression of the P53 gene. Target and bystander groups receiving the ultrasound without cisplatin showed a decrease in HO-1 gene expression, while the ultrasound with cisplatin showed an increase in the HO-1 gene compared to the control group. Conclusion: Combining ultrasound with ultrasound and without it can transfer bystander signals to the cells that are not directly treated.

Increased radiosensitivity of melanoma cells through cold plasma pretreatment mediated by ICG.

Radiation therapy (RT) is the primary treatment for many cancers, but its effectiveness is reduced due to radioresistance and side effects. The study aims to investigate an emerging treatment for cancer, cold atmospheric plasma (CAP), as a selectable treatment between cancerous and healthy cells and its role in the occurrence of photodynamic therapy (PDT) utilizing indocyanine green (ICG) as a photosensitizer. We examined whether the efficiency of radiotherapy could be improved by combining CAP with ICG. The PDT effect induced by cold plasma irradiation and the radiosensitivity of ICG were investigated on DFW and HFF cell lines. Then, for combined treatment, ICG was introduced to the cells and treated with radiotherapy, followed by cold plasma treatment simultaneously and 24-h intervals. MTT and colony assays were used to determine the survival of treated cells, and flow cytometry was used to identify apoptotic cells. Despite a decrease in the survival of melanoma cells in CAP, ICG did not affect RT. Comparing the ICG + CAP group with CAP, a significant reduction in cell survival was observed, confirming the photodynamic properties of plasma utilizing ICG. The treatment outcome depends on the duration of CAP. The results for healthy and cancer cells also confirmed the selectivity of plasma function. Moreover, cold plasma sensitized melanoma cells to radiotherapy, increasing treatment efficiency. Treatment of CAP with RT can be effective in treating melanoma. The inclusion of ICG results in plasma treatment enhancement. These findings help to select an optimal strategy for a combination of plasma and radiotherapy.

The Synergistic Effect of Cold Atmospheric Plasma Mediated Gold Nanoparticles Conjugated with Indocyanine Green as An Innovative Approach to Cooperation with Radiotherapy.

OBJECTIVE: The multimodality treatment of cancer provides a secure and effective approach to improve the outcome of treatments. Cold atmospheric plasma (CAP) has got attention because of selectively target and kills cancer cells. Likewise, gold nanoparticles (GNP) have been introduced as a radiosensitizer and drug delivery with high efficacy and low toxicity in cancer treatment. Conjugating GNP with indocyanine green (ICG) can develop a multifunctional drug to enhance radio and photosensitivity. The purpose of this study is to evaluate the anticancer effects of GNP@ICG in radiotherapy (RT) and CAP on DFW melanoma cancer and HFF fibroblast normal cell lines. MATERIALS AND METHODS: In this experimental study, the cells were irradiated to RT and CAP, alone and in combination with or without GNP@ICG at various time sequences between RT and CAP. Apoptosis Annexin V/PI, MTT, and colony formation assays evaluated the therapeutic effect. Finally, the index of synergism was calculated to compare the results. RESULTS: Most crucially, the cell viability assay showed that RT was less toxic to tumors and normal cells, but CAP showed a significant anti-tumor effect on melanoma cells with selective toxicity. In addition, cold plasma sensitized melanoma cells to radiotherapy so increasing treatment efficiency. This effect is enhanced with GNP@ICG. In comparison to RT alone, the data showed that combination treatment greatly decreased monolayer cell colonization and boosted apoptotic induction. CONCLUSION: The results provide new insights into the development of better approaches in radiotherapy of melanoma cells assisted plasma and nanomedicine.

Shielding performance of multi-metal nanoparticle composites for diagnostic radiology: an MCNPX and Geant4 study.

Lead-free polymer composite shields are used in diagnostic radiology to protect patients from unnecessary radiation exposure. This study aimed to examine and introduce the radiation-shielding properties of single- and multi-metal nanoparticle (NP)-based composites containing Bi, W, and Sn using Geant4, MCNPX, and XCom for radiological applications. The mass attenuation coefficients and effective atomic numbers of single- and multi-metal NP-loaded polymer composites were calculated using the Geant4 and MCNPX simulation codes for X-ray energies of 20-140 keV. The nano-sized fillers inside the polydimethylsiloxane (PDMS:C2H6SiO) matrix included W (K = 69.5 keV), Bi (K = 90.5 keV), and Sn (K = 29.20 keV). For single-metal shields, one filler was used, while in multi-metal shields, two fillers were required. The MCNPX and Geant4 simulation results were compared with the XCom results. The multi-metal NP composites exhibited higher attenuation over a larger energy range owing to their attenuation windows. In addition, Bi2O3 + WO3 NPs showed a 39% higher attenuation at 100-140 keV, and that of Bi2O3 + SnO2 NPs was higher at 40-60 keV. Meanwhile, the WO3 + SnO2 NPs exhibited lower attenuation. The difference between the results obtained using Geant4 and XCom was less than 2%, because these codes have similar simulation structures. The results show that the shielding performance of the Bi2O3 + WO3 filler is better than that of the other single- and multi-metal fillers. In addition, it was found that the Geant4 code was more accurate for simulating radiation composites.

Ultrasound responsive Gd-DOTA/doxorubicin-loaded nanodroplet as a theranostic agent for magnetic resonance image-guided controlled release drug delivery of melanoma cancer.

Theranostic agents use simultaneous for diagnostic and therapeutic procedures. In the present study, the effect of Gd-DOTA/doxorubicin-loaded perfluorohexane nanodroplets as a theranostic nanoparticle for control released drug delivery and ultrasound/MR imaging was investigated on B16F10 melanoma cancer cells. The intracellular uptake was performed by inductively coupled plasma optical emission spectrometry (ICP-OES) that indicated sonicated Gd-DOTA/DOX@PFH NDs uptake by cancer cells was approximately 1.5 times more than the non-sonicated nanodroplets after 12 h. In vitro and in vivo toxicity assays revealed that synthesized NDs are biocompatible and do not have organ toxicity. Ultrasound exposure significantly enhanced the release of doxorubicin from NDs (P-value< 0.05). Ultrasound echogenicity and T1-MRI relaxometry indicated that synthesized NDs have strong ultrasound signal intensity and high r1 relaxivity (6.34 mM-1 S-1). The concentration of DOX in mice vital organs for Gd-DOTA/DOX NDs was significantly lower than that of free DOX. Doxorubicin concentration after 150 min in the tumor region for the DOX-loaded Gd-NDs+US group reached 14.8 µg/g followed by sonication, which was 2.3 fold higher than that of the non-sonicated group. According to the obtained results, the synthesized nanodroplets, with excellent diagnostic (ultrasound/MRI) and therapeutic properties, could be promising theranostic agents in cancer imaging and drug delivery for chemotherapeutic application.

Sonodynamic Therapy Using Dacarbazine-Loaded AuSiO2 Nanoparticles for Melanoma Treatment: An In-Vitro Study on the B16F10 Murine Melanoma Cell Line.

The use of nanoparticles as a sonosensitizer in cancer sonodynamic therapy has been gaining attention because of their great advantages in drug delivery applications. By conjugating chemotherapy agents with nanoparticles, we can develop a drug delivery platform, control drug release and improve the outcome of treatments. The in-vitro study described here evaluates the combination of AuSiO2 nanoparticles and dacarbazine (DTIC@AuSiO2) as a sonosensitizer for sonodynamic therapy of melanoma. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry assays revealed that the viability of B16F10 melanoma cells was significantly inhibited by the increase in apoptosis induction in treatment with DTIC@AuSiO2 nanoparticles under ultrasound exposure compared with treatment with the free DTIC or AuSiO2 nanoparticles. The sonosensitization activity of AuSiO2 nanoparticles and greater uptake of DTIC by tumor cells after loading in DTIC@AuSiO2 nanoparticles inhibited the proliferation of melanoma tumor cells effectively. In conclusion, the DTIC@AuSiO2 nanoparticles established in this study could represent a good drug delivery and sonosensitizer platform for use in melanoma sonodynamic therapy.

Investigating the number of radiation fields in intensity-modulated radiotherapy plans of optic nerve sheath meningioma patients using dose gradient index.

Purpose: In optic nerve radiotherapy, vital organs are very close to the target volume, they are highly sensitive to radiation and have low dose tolerance. In this regard, evaluating dose fall-off steepness around the target volume is required to assess various intensity-modulated radiation therapy (IMRT) plans in the treatment of the optic nerve sheath meningioma (ONSM) patients.Materials and Methods: Thirteen ONSM patients were analyzed with three IMRT techniques, including three (IMRT-3F), five (IMRT-5F), and seven fields (IMRT-7F). These plans were studied using Dmean, Dmax, D2%, D98%, V100%, uniformity index (UI), homogeneity index (HI), conformity index (CI), and specifically the dose gradient indices (DGIs).Results: The values of Dmaxand Dmeanfor IMRT-3F, IMRT-5F and IMRT-7F were (5637.42 ± 57.08, 5322.84 ± 83.86), (5670.51 ± 67.87, 5383.00 ± 58.45), and (5692.99 ± 31.65, 5405.72 ± 51.73), respectively, which were increased with increment in the number of IMRT fields from 3 to 7. The UI and HI indices were significantly different between IMRT-3F and IMRT-7F (p = 0.010 and p = 0.005, respectively), and CI was close to the ideal value (0.99 ± 0.01) in IMRT-7F. The significant findings of the dose gradient indices represented smaller values in IMRT-7F, which led to a faster dose fall-off, particularly at the 70%-85% isodose levels around the target.Conclusion: Increasing the number of radiation fields in IMRT treatment plans of ONSM patients had a considerable difference in both the dosimetric parameters of the target volume and at-risk organs, as well as the dose gradient indices. Overall, IMRT-7F could be considered as a preferred technique in the treatment of this meningioma.

DETERMINATION OF THE NEUTRON CONTAMINATION DURING BRAIN RADIOTHERAPY USING A MODERATED-BORON TRIFLUORIDE DETECTOR AND THE MCNP MONTE CARLO CODE.

This study aimed to determine the neutron dose equivalent to the thyroid gland and eye lens in brain tumor radiation therapy with 15- and 18-MV three-dimensional conformal methods (3D-CRT). A Monte Carlo simulation was performed using the Monte Carlo N-particle transport code to calculate neutron fluence and ambient dose equivalent (H*(10)). Afterward, these parameters were measured using a model NRD roentgen equivalent in man (REM) neutron detector (Thermo Electron Corporation, USA) equipped with Eberline's ASP-2e rate meter. Finally, the organ neutron dose equivalent was obtained by applying depth corrections to the measured ambient dose equivalent at the distance of the organ center from the central beam axis. The ratio of the out-of-field photon dose equivalent, measured previously, to the neutron dose equivalent in the eye lens was high due to its proximity to the radiation field. In contrast, this ratio remained unexpectedly high in the thyroid gland that is far from the central beam axis (about 15 cm). The calculated neutron parameters agreed with the measurements. The present study findings indicate that external field photon dose is the main source of thyroid gland biological effects in radiotherapy of brain tumors. In addition, it is appropriate to apply the model NRD REM neutron detector for measuring neutron contamination from high-energy linear accelerators inside and outside the treatment field.

Evaluation of Pulsed Electromagnetic Field Effects: A Systematic Review and Meta-Analysis on Highlights of Two Decades of Research In Vitro Studies.

Pulsed electromagnetic field (PEMF) therapy is a type of physical stimulation that affects biological systems by producing interfering or coherent fields. Given that cell types are significantly distinct, which represents an important factor in stimulation, and that PEMFs can have different effects in terms of frequency and intensity, time of exposure, and waveform. This study is aimed at investigating if distinct positive and negative responses would correspond to specific characteristics of cells, frequency and flux density, time of exposure, and waveform. Necessary data were abstracted from the experimental observations of cell-based in vitro models. The observations were obtained from 92 publications between the years 1999 and 2019, which are available on PubMed and Web of Science databases. From each of the included studies, type of cells, pulse frequency of exposure, exposure flux density, and assayed cell responses were extracted. According to the obtained data, most of the experiments were carried out on human cells, and out of 2421 human cell experiments, cell changes were observed only in 51.05% of the data. In addition, the results pointed out the potential effects of PEMFs on some human cell types such as MG-63 human osteosarcoma cells (p value < 0.001) and bone marrow mesenchymal stem cells. However, human osteogenic sarcoma SaOS-2 (p < 0.001) and human adipose-derived mesenchymal stem cells (AD-MSCs) showed less sensitivity to PEMFs. Nevertheless, the evidence suggests that frequencies higher than 100 Hz, flux densities between 1 and 10 mT, and chronic exposure more than 10 days would be more effective in establishing a cellular response. This study successfully reported useful information about the role of cell type and signal characteristic parameters, which were of high importance for targeted therapies using PEMFs. Our findings would provide a deeper understanding about the effect of PEMFs in vitro, which could be useful as a reference for many in vivo experiments or preclinical trials.

The Radioprotective Effect of Ascorbic Acid and Kefir against Genotoxicity Induced by Exposure in Mice Blood Lymphocytes.

The aim of this research was to determine how coadministration of ascorbic acid prior to the beginning of X-irradiation influences the lymphocyte DNA damage and also if the kefir supplementation to irradiated mice may alter the recovery procedure of lymphocyte genetic material injury. Following treatment of animals with these agents, the whole-body of mice were irradiated to 6 MV X-rays, then genotoxicity activity was investigated by comet assay. Our results show that the Total Comet Score (TCS) value was 1.39 and 1.5 fold less in the kefir and ascorbic acid groups respectively the following irradiation than in the irradiated mice only. Coadministration of ascorbic acid and kefir with 2 h, before relatively to 2 Gy radiation decreased DNA damage in lymphocyte blood cells. The antioxidant strength of ascorbic acid and kefir were investigated by the study of the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging properties and also ferric reducing antioxidant power (FRAP) assay. Our results revealed that ascorbic acid and kefir show strong antioxidant activity by these methods. According to these results, it seems that ascorbic acid and kefir, as a free radical scavenging capacitiy, protect animal lymphocyte blood cells from radiation-induced DNA injury and genotoxicity.

Effect of targeted gold nanoparticles size on acoustic cavitation: An in vitro study on melanoma cells.

When a liquid is irradiated with high intensities of ultrasound irradiation, acoustic cavitation occurs. Since cavitation can be fatal to cells, it is utilized to destroy cancer tumors. Considering cavitation onset and bubbles collapse, the required ultrasonic intensity threshold can be significantly decreased in the presence of nanoparticles in a liquid. The effects of gold nanoparticles size on acoustic cavitation were investigated in this in vitro study. For this purpose, ultrasonic waves were used at intensities of 0.5, 1 and 2 W/cm2 and frequency of 1 MHz in the presence of F-Cys-GNPs with 15, 23 and 79 nm sizes and different concentrations (0.2, 1 and 5 µg/ml) in order to determine their effects on the viability of melanoma cells. This was performed at different incubation times 12, 24 and 36 h. The viability of melanoma cells decreased at higher concentrations and sizes of F-Cys-GNPs. The lowest viability of melanoma cells was seen in those containing 79, 23, and 15 nm F-Cys-GNPs. This finding could be explained from the concept that the nucleation sites on the surface of GNPs increase with an increase in size of GNPs, which results in an increase in the number of cavitation bubbles. Acoustic cavitation in the presence of gold nanoparticles can be used as a way for improving therapeutic effects on the tumors.

Dose perturbation due to dental amalgam in the head and neck radiotherapy: A phantom study.

Dental amalgam, causes perturbation in photon dose distribution of head and neck (H&N) radiotherapy. The aim of this study was to evaluate the effects of dental amalgam on dose distribution of H&N radiotherapy and accuracy of dose calculations algorithm of commercial treatment planning system (TPS). In this study, the measurements were performed using a constructed H&N anthropomorphic. The sample of healthy teeth and teeth filled by amalgam inserted in the desired segment of the phantom in turn. After scanning and organs segmentation of phantom, intensity-modulated radiation therapy (IMRT) plan including 7 fields in the absence (plan 1) and presence (plan 2) of dental amalgam were created separately. Phantom was irradiated using 6 MV linear accelerator (SIMENS-ARTISTE, 5918). Assessment of the effects of dental amalgam on dose distribution and the accuracy of dose calculation algorithm of TPS was done by measurement and comparing of organ's received dose using thermoluminescent dosimeter (TLDs), placed on a phantom and TPS calculations. The scattering and attenuation due to the presence of dental amalgam led to an increase in parotid glands received dose (up to 24.38%) and a decrease in mean dose (up to -6.25%) PTV70. Results of this study revealed that discrepancies between the collapsed cone convolution (CCC) algorithm calculations Prowess Panther TPS and TLD measurements were -19.77% to 27.49% in presence of amalgam and -1.09% to 5.03% in presence of healthy teeth in phantoms. Attenuation and scattering due to amalgam in IMRT of H&N cancer may lead to a significant dose perturbation which is not predictable by dose calculation of TPS.

An overview of therapeutic applications of ultrasound based on synergetic effects with gold nanoparticles and laser excitation.

Acoustic cavitation which occurs at high intensities of ultrasound waves can be fatal for tumor cells. The existence of dissolved gases and also the presence of nanoparticles (NPs) in a liquid, irradiated by ultrasound, decrease the acoustic cavitation onset threshold and the resulting bubbles collapse. On the other hand, due to unique capabilities and optical properties of gold nanoparticles (GNPs), they have been emphasized as effective NPs in the field of tumor therapy. Absorption of the laser light by GNPs causes the water molecules around the NPs to evaporate and produces vapor cavities. In this paper, we have reviewed published studies in the fields of ultrasound therapy, sonodynamic therapy (SDT) and synergism of low-level ultrasound and also laser radiation in the presence of GNPs.

Investigating the Sonodynamic-Radiosensitivity Effect of Gold Nanoparticles on HeLa Cervical Cancer Cells.

BACKGROUND: In this article, we estimated the combined effect of radiotherapy (RT) with ultrasound (US) wave and the ability of gold nanoparticles (GNPs) to improve their combined therapeutic effects. METHODS: At first, HeLa cells received the various treatment modalities: RT (6 MV; 0.5, 1, and 2 Gy), US irradiation (1 MHz; 0.5, 1, and 1.5 W/cm², 1 minute), and RT+US. Afterwards, the enhanced effect of US on RT was evaluated. Then, the effect of the synthesized GNPs at different concentrations (0.2, 1, and 5 µg/mL, 24 hours) was evaluated to assess the effect on HeLa cells combined with RT+US. Cell survival rates in the different treatment groups at 24, 48, and 72 hours post-treatment were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and trypan blue assays. RESULTS: Our results show US irradiation could enhance the effect of RT at the same radiation dose and could be utilized as a sensitizer agent for RT. Moreover, our findings indicate RT+US in combination with different nanoparticle concentrations could enhance the effect of RT+US so that they can improve the treatment results up to 9.93 times and act as sonodynamic-radiosensitivity. These results also indicate that the combination of RT with US along with GNPs has synergistic effects compared to RT or US alone. Cell survival results show that combining the low US waves (1.5 W/cm²), GNPs (5 µ/mL), and X-rays (2 Gy) increase the cytotoxicity on HeLa cell up to 95.8%. CONCLUSION: We concluded that GNPs could act as a good sensitizing agent in RT+US irradiation and could result in the synergistic effects.

Mn-doped ZnS quantum dots-chlorin e6 shows potential as a treatment for chondrosarcoma: an in vitro study.

Chondrosarcoma is the second-most malignant cancer of the bone and routine treatments such as chemotherapy and radiotherapy have not responded to the treatment of this cancer. Due to the resistance of chondrosarcoma to radiotherapy, the combination of therapeutic methods has been considered in recent years. In this study, a novel combination approach is used that allows photodynamic therapy to be activated by X-rays. The synthesis of Mn-doped zinc sulphide (ZnS) quantum dots was carried out and chlorin e6 photosensitiser attached by covalent and non-covalent methods and their application as an intracellular light source for photodynamic activation was investigated. The toxicity of each nanoparticles was evaluated on chondrosarcoma cancer cells (SW1353) before and after radiation. Also, the effect nanoparticle-photosensitiser conjugated type was investigated in the therapeutic efficacy. The characterisation test (SEM, TEM, EDS, TGA, XRD and ICP analyses) was shown successful synthesis of Mn-doped ZnS quantum dots. Chondrosarcoma cancer cell viability was significantly reduced when cells were treated with MPA-capped Mn-doped ZnS quantum dots-chlorin e6 with spermine linker and with covalent attachment (P ≤ 0.001). These results indicate that X-ray can activate the quantum dot complexes for cancer treatment, which can be a novel method for treatment of chondrosarcoma.

Assessment of Imprecise Small Photon Beam Modeling by Two Treatment Planning System Algorithms.

BACKGROUND: Dosimetric accuracy in intensity-modulated radiation therapy (IMRT) is the main part of quality assurance program. Improper beam modeling of small fields by treatment planning system (TPS) can lead to inaccuracy in treatment delivery. This study aimed to evaluate of the dose delivery accuracy at small segments of IMRT technique using two-dimensional (2D) array as well as evaluate the capability of two TPSs algorithm in modeling of small fields. METHODS: Irradiation were performed using 6 MV photon beam of Siemens Artiste linear accelerator. Dosimetric behaviors of two dose calculation algorithms, namely, collapsed cone convolution/superposition (CCCS) and full scatter convolution (FSC) in small segments of IMRT plans were analyzed using a 2D diode array and gamma evaluation. RESULTS: Comparisons of measurements against TPSs calculations showed that percentage difference of output factors of small fields were 2% and 15% for CCCS and FSC algorithm, respectively. Gamma analysis of calculated dose distributions by TPSs against those measured by 2D array showed that in passing criteria of 3 mm/3%, the mean pass rate for all segment sizes is higher than 95% except for segment sizes below 3 cm × 3 cm optimized by TiGRT TPS. CONCLUSIONS: High pass rate of gamma index (95%) achieved in planned small segments by Prowess relative to results obtained with TiGRT. This study showed that the accuracy of small field modeling differs between two dose calculation algorithms.

Dual Function of Gold Nanoparticles in Synergism with Mitoxantrone and Microwave Hyperthermia Against Melanoma Cells

Background: This study was performed to evaluate any synergetic effects of mitoxantrone (MX) and gold nanoparticles (GNPs) as dual therapeutic approach, along with microwave (MW) hyperthermia for melanoma cancer. Methods: Various tests were performed on the DFW melanoma cell line in the presence of MX and different concentrations of GNPs, with and without MW irradiation. MTT [3-(4,5-dimethylthiazol­2-yl)-2,5-iphenyltetrazolium bromide] assays were conducted to evaluate the effectiveness of the used therapeutic methods in terms of cell survival. Relative lethal synergism (RLS) was calculated as the ratio of cell death following hyperthermia in the presence of a treatment agent to that after applying hyperthermia in the absence of the same treatment agent. Results: Results showed MX and GNPs under MW irradiation to provide maximum cell death (P < 0.001 compared to the other groups). The mean RLS for MW hyperthermia along with the MX-GNP combination was 4.14, whereas in the absence of GNP the value for MX chemotherapy was 0.94. Conclusion: MX chemotherapy in the presence of different concentrations of GNP did not alter cell survival as compared to in its absence.

The Radioprotective Effect of Resveratrol Against Genotoxicity Induced by γ-Irradiation in Mice Blood Lymphocytes.

In this study, we evaluated whether the protective potential of resveratrol (RSV; 3,5,4'-trihydroxy-trans-stilbene) against γ-radiation caused damages in peripheral blood lymphocyte of mice. Resveratrol as a polyphenolic compound scavenges free radicals. Various doses of RSV were administered intraperitoneally 2 hours to adult male mice before a single dose of whole-body γ-irradiation (2 Gy). To assess the protective ability of RSV, the alkaline comet assay in blood lymphocyte of mice was performed and the total comet score was evaluated. The results of the alkaline comet assay showed that RSV significantly inhibited radiation-induced DNA damage. We observed that RSV protects blood lymphocyte against radiation-induced damage in mice.

Effect of gold nanoparticle size on acoustic cavitation using chemical dosimetry method.

When a liquid is irradiated with high intensities of ultrasound irradiation, acoustic cavitation occurs. Acoustic cavitation generates free radicals from the breakdown of water and other molecules. Cavitation can be fatal to cells and is utilized to destroy cancer tumors. The existence of particles in liquid provides nucleation sites for cavitation bubbles and leads to decrease the ultrasonic intensity threshold needed for cavitation onset. In the present investigation, the effect of gold nanoparticles with appropriate amount and size on the acoustic cavitation activity has been shown by determining hydroxyl radicals in terephthalic acid solutions containing 15, 20, 28 and 35nm gold nanoparticles sizes by using 1MHz low level ultrasound. The effect of sonication intensity in hydroxyl radical production was considered. The recorded fluorescence signal in terephthalic acid solutions containing gold nanoparticles was considerably higher than the terephthalic acid solutions without gold nanoparticles at different intensities of ultrasound irradiation. Also, the results showed that the recorded fluorescence signal intensity in terephthalic acid solution containing finer size of gold nanoparticles was lower than the terephthalic acid solutions containing larger size of gold nanoparticles. Acoustic cavitation in the presence of gold nanoparticles can be used as a way for improving therapeutic effects on the tumors.

Comparison of the Absorbed Dose for (99m)Tc-Diethylenetriaminepentaacetic Acid and (99m)Tc-Ethylenedicysteine Radiopharmaceuticals using Medical Internal Radiation Dosimetry.

The aim of this study was the investigation of absorbed dose to the kidneys, spleen, and liver during technetium-99 m ethylene dicysteine and technetium-99 m diethylenetriaminepentaacetic acid ((99m)Tc-EC and (99m)Tc-DTPA) kidney scan. Patients who had been prepared for the kidney scan, were divided into two groups (Groups 1 and 2). The first group (Group 1) and the second group (Group 2) received intravenous injection of (99m)Tc-EC and (99m)Tc-DTP, respectively. A certain amount of radiopharmaceuticals was injected into each patient and was immediately imaged with dual-head gamma camera to calculate the activity through the conjugated view method. Then, the doses of kidney, liver, and spleen were measured using medical internal radiation dosimetry method. Finally, absorbed dose of these organs was compared. Based on these different results (P < 0.05), organs absorbed dose was significantly less with radiopharmaceutical (99m)Tc-EC as compared with (99m)Tc-DTPA.