Evaluation of Acoustic Cavitation in Terephthalic Acid Solutions Containing Gold Nanoparticles by the Spectrofluorometry Method

Background. When a liquid is irradiated with high intensity and low-frequency ultrasound, acoustic cavitation occurs. The existence of particles in a liquid provides nucleation sites for cavitation bubbles and leads to a decrease in the ultrasonic intensity threshold needed for cavitation onset. Materials and Methods. The study was designed to measure hydroxyl radicals in terephthalic acid solutions containing gold nanoparticles in a near field of a 1 MHz sonotherapy probe. The effect of ultrasound irradiation parameters containing mode of sonication and ultrasound intensity in hydroxyl radicals production have been investigated by the spectrofluorometry method. Results. Recorded fluorescence signal in terephthalic acid solution containing gold nanoparticles was higher than the terephthalic acid solution without gold nanoparticles. Also, the results showed that any increase in intensity of the sonication would be associated with an increase in the fluorescence intensity. Conclusion. Acoustic cavitation in the presence of gold nanoparticles has been introduced as a way for improving therapeutic effects on the tumors in sonodynamic therapy. Also, the terephthalic acid dosimetry is suitable for detecting and quantifying free hydroxyl radicals as a criterion of cavitation production over a certain range of conditions in medical ultrasound fields

Modified Photochemical Properties of Mitoxantrone by Plasmonic Photothermal Response of Hollow Gold Nanoshells

Introduction: Mitoxantrone (MX) has been introduced as a photosensitizer drug. However, due to some side effects, the widespread use of this drug has been confronted with some limitations. Hollow gold nanoshells (HGN) have attracted considerable attention due to their interesting photochemical features that can use as nanocarrier. In this paper, the thermal response of MX and the use of this property for thermal effects during the photodynamic process by MX-conjugated HGN were investigated. Material and Methods: After optimizing the synthesis of ultimate nanostructure, the characteristics of pharmacological agents including MX, HGN, methoxy polyethylene glycol (mPEG)-HGN, and MX-mPEG-HGN were determined. Then, the thermal response of MX was determined at 0-50°C. Finally, by applying light irradiation with a non-coherent source at a wavelength of 670 nm and exposures of 0 to 50 j/cm2, the profile release and temperature variation in MX-mPEG-HGN were determined. Results: The zeta potentials of HGN and MX were negative, which resulted in electrostatic repulsion between them. In order to solve this challenge, the surface modification of HGN with mPEG was performed, resulting in the chemical bonding of the drug with the nanostructures and increasing the stability of the final nanostructure. With increasing temperature, the optical density of the drug at 660 nm significantly increased, which is an effective induction of photodynamic effect. Conclusion: In this study, we used mPEG-HGN as the nanocarrier for MX. Also, the thermal behavior of MX was recognized as an important factor in increasing temperature that could improve the photodynamic process

The Role of Crocetin-Loaded PLGA Nanoparticles as a Pre-Treatment Agent on Indocyanine-Photodynamic Therapy of Breast Cancer Cell

Introduction: Photodynamic therapy (PDT) can be considered as a non-invasive method for cancer treatment. One of the most commonly of a water-soluble dye photosensitizer (PS) used in photothermal therapy (PTT) and PDT is Indocyanine Green (ICG). However, high ‎cytotoxicity in high concentration and instability in aqueous media were limited its application. ‎It was shown that using nanoparticles or plant extracts in combination with PS could improve PDT efficiency. In this study, anti-cancer properties of crocetin (Crt) loaded PLGA (Poly lactic-co-glycolic acid) nanoparticles (NPs) were utilized to increase the PDT efficacy with ICG on the MCF-7 cells. Material and Methods: Crt was encapsulated into PLGA NPs and its particle size distribution and encapsulation efficiency were evaluated. IC10 of Crt, PLGA-Crt NPs and ICG was determined by MTT assay in MCF-7 cancer cells. At these concentrations, the cells were pre-treated with Crt or PLG-Crt, then treated with ICG and finally exposure to near infrared (NIR) laser with 2.5 W powers at different times. The cells viability was evaluated by the MTT assay. Results: The findings showed no dark cytotoxicity due to ICG (12.9 μM), Crt or PLGA-Crt alone. But NIR laser irradiation in the presence of ICG after cells pre-treatment by the Crt or PLGA-Crt NPs leads to induce cell death to (61.6 ±7) % and (75.5 ±5) %, respectively (P<0.05). Conclusion: The results demonstrated that PLGA-Crt NPs in combination with ICG could improve PDT outcomes more efficiently in comparison with Crt and ICG. Therefore, this method could be effective in breast cancer therapy with low cytotoxicity

Photosensitivity and Radiosensitivity of Methylene Blue (MB) With Gold Nanoparticles Coated By Thioglucose (Gnps-Tio): An In Vitro Study

Introduction: Multifunctional of cancer-specific tumor biomarkers is a potent therapeutic approach to treat cancer diseases with high efficacy. Among these methods that can be mentioned are the composition and design of nanoparticles and photosensitizers (PS). The purpose of this study is to investigate the effect of gold nanoparticles (GNPs) coated thioglucose (Tio) combined with methylene blue photosensitizer to enhance the efficacy of hybrid therapy (photodynamic and radiation therapy).Material and Methods: First, GNPs-Tio was synthesized. Next, the toxicity of GNPs-Tio, MB, and their combinations was determined on the MCF-7 cell line to achieve their optimal concentrations. In the next step, the efficacy of combination therapy was evaluated using hybrid therapy. For this purpose, an optical dose of 15.6 J/cm2 and 2 Gy for radiation therapy were delivered. Cell viability was evaluated using MTT and colony assays.Results: According to the MTT assay, the combined photodynamic and radiation treatment of GNPs-Tio did not cause significant cell death. But this induced significant cell death by using GNPs-Tio + MB while the cell survival rate was almost zero. Combined therapy caused significant cell death in the presence of each of the pharmacological agents alone and their combination in colony assay.Conclusion: The difference in treatment results between the MTT and the colony assay can be due to the more accurate colony assay for cell death detection. Significant cell death was achieved in the combination of photodynamic and radiotherapy in the presence of MB and MB + GNP-Tio

Effect of Silver Nanoparticles on Improving the Efficacy of 5-Aminolevulinic Acid-Induced Photodynamic Therapy

Introduction: The most important limitation of 5-aminolevulinic acid (5-ALA)-induced photodynamic therapy (PDT) is the efficacy of the cells in converting 5-ALA to protoporphyrin IX. The present study aimed to investigate the effectiveness of silver nanoparticles (AgNPs) with the photosensitivity at the surface plasmon resonance wavelength on 5-ALA-mediated PDT. Material and Methods: First of all, the toxicity of 5-ALA, AgNPs, and combined 5-ALA and AgNPs was evaluated on DFW cell line derived from melanoma. After choosing the optimal concentration, both pulsed and continuous light irradiations were conducted at different doses using a light‑emitting diode source in the groups receiving 5-ALA, AgNPs, as well as 5-ALA and AgNPs combination, and the controls. The cell survival was evaluated 24 h after irradiation using MTT assay. Results: According to the results, light exposure did not significantly change cell survival in the absence or presence of AgNPs. However, light exposure in the presence of 5-ALA and AgNPs/5-ALA combination caused a significant reduction in the cell survival. The necessary light exposure to induce 50% cell death (ED50) in the presence of 5-ALA was 1280 mJ/cm2; however, this value was 280 mJ /cm2 in the presence of combined AgNPs and 5-ALA. Conclusion: As the findings indicated, PDT had a higher efficacy in the presence of combined 5-ALA and AgNPs than in the sole 5-ALA presence. Nonetheless, further studies are required to evaluate the definitive mechanism of these findings

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 outcomeof 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 andlow toxicity in cancer treatment. Conjugating GNP with indocyanine green (ICG) can develop a multifunctional drugto enhance radio and photosensitivity. The purpose of this study is to evaluate the anticancer effects of GNP@ICG inradiotherapy (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 combinationwith or without GNP@ICG at various time sequences between RT and CAP. Apoptosis Annexin V/PI, MTT, and colonyformation 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 CAPshowed a significant anti-tumor effect on melanoma cells with selective toxicity. In addition, cold plasma sensitizedmelanoma cells to radiotherapy so increasing treatment efficiency. This effect is enhanced with GNP@ICG. Incomparison to RT alone, the data showed that combination treatment greatly decreased monolayer cell colonizationand boosted apoptotic induction. Conclusion: The results provide new insights into the development of better approaches in radiotherapy of melanomacells assisted plasma and nanomedicine

The effect of fasting on Positron Emission Tomography (PET) imaging (ahead of publication)

As a nuclear approach, Positron Emission Tomography (PET) is a functional imaging technique which is based on the detection of gamma ray pairs emitted by a positron-emitting radionuclide. There are certain limitations to this technique such as normal tissue uptake. Therefore, it has been recommended that patients prepare before scanning. Fasting for a short while before PET imaging is an example of such preparation. In this paper, we attempted to collect the studies evaluating the effects of fasting in the three sections of cardiac, brain and abdominal PET imaging. Conclusively, we found that the effects of fasting on PET imaging can be different depending on the type of PET scanning, radiotracer, patient’s diseases, fasting duration and in case of any additional dietary plans. It is proposed that further study be conducted on this subject in order to determine such effects in more detail

In Vitro Investigation into Plasmonic Photothermal Effect of Hollow Gold Nanoshell Irradiated with Incoherent Light

Introduction: Hollow gold nanoshells (HAuNS) are one of the most attractive nanostructures for biomedical applications due to their interesting physicochemical properties. This study sought to evaluate the plasmonic photothermal effect of HAuNS irradiated with incoherent light on melanoma cell line. Materials and Methods: After the synthesis of nanostructures, the temperature changes of HAuNS and polyethylene glycol stabilized HAuNS (HAuNS-PEG) were evaluated at different irradiation dose levels. After determining the potential cytotoxicity of the agents, the DFW cells were irradiated by incoherent light with and without the nanostructures at different exposure doses with two spectral bands of 670±25 nm and 730±25 nm. Finally, the rate of the cell survival was determined by 1-Methyltetrazole-5-Thiol assay 24 h after irradiating. Results: The HAuNS, HAuNS-PEG, and light exposure did not have any significant effect on the cell survival, individually. Stabilizing with PEG led to an increase in size and decreased their polydispersity index, zeta potential, and conductivity. The slopes of temperature and cell death caused by 730 nm were greater than 670 nm when the cells were irradiated in the presence of nanostructures. These changes became more significant with increasing the dose of exposure and HAuNS (or HAuNS-PEG) concentration. The lowest cell survival occurred in the concentration of 250 μg/ml of nanostructures and an exposure dose of 9 min (

A physicochemical model of X-ray induced photodynamic therapy (X-PDT) with an emphasis on tissue oxygen concentration and oxygenation

Abstract X-PDT is one of the novel cancer treatment approaches that uses high penetration X-ray radiation to activate photosensitizers (PSs) placed in deep seated tumors. After PS activation, some reactive oxygen species (ROS) like singlet oxygen (1O2) are produced that are very toxic for adjacent cells. Efficiency of X-PDT depends on 1O2 quantum yield as well as X-ray mortality rate. Despite many studies have been modeled X-PDT, little is known about the investigation of tissue oxygen content in treatment outcome. In the present study, we predicted X-PDT efficiency through a feedback of physiological parameters of tumor microenvironment includes tissue oxygen and oxygenation properties. The introduced physicochemical model of X-PDT estimates 1O2 production in a vascularized and non-vascularized tumor under different tissue oxygen levels to predict cell death probability in tumor and adjacent normal tissue. The results emphasized the importance of molecular oxygen and the presence of a vascular network in predicting X-PDT efficiency

Ultraviolet B efficacy in improving antileishmanial effects of silver nanoparticles

Objective(s):Cutaneous Leishmaniasis (CL) is a parasitic disease caused by various species of the flagellated protozoan, Leishmania. Regardless of the numerous studies, there are still serious challenges in the treatment of CL. This study aimed at evaluating the influence of a low dose ultraviolet B (UVB) radiation along with silver nanoparticles (AgNPs) on a mouse model of CL induced by Leishmania major[m1] . Materials and Methods: L. major promastigotes (MRHO/IR/75/ER) were extracted from infected mice spleens. Two months after subcutaneous injection of 2×106 promastigotes into the footpad of BALB/c mice, when the lesions were developed, the animals were divided into 4 groups including one control group and three study groups: AgNPs, UVB and UVB plus AgNPs. Spleen parasite burden was assessed on day 40 after the first treatment. The data were analyzed by Instat, Elidaand SPSS16 software programs. Results:  The results showed the highest pronounced inhibitory effect in the group receiving AgNPs plus UVB. In addition, a significant difference was obtained between the group receiving AgNPs alone and the one with combinational therapy. The findings on parasite burden showed a significant difference between the control group and other treatment groups. Conclusion:It could be suggested that UVB in the presence of AgNPs, by inhibiting the spread of CL lesions and reducing the rate of visceral progression of the disease, provides a serious anti-leishmanial effect