Targeted photothermal therapy of melanoma in C57bl/6 mice using Fe3 O4 @Au core-shell nanoparticles and near-infrared laser

Background: Gold nanoshells can be tuned to absorb a particular wavelength of light. As a result, these tunable nanoparticles (NPs) can efficiently absorb light and convert it to heat. This phenomenon can be used for cancer treatment known as photothermal therapy. In this study, we synthesized Fe3 O4 @Au core-shell NPs, magnetically targeted them towards tumor, and used them for photothermal therapy of cancer. Objective: The main purpose of this research was to synthesize Fe3 O4 @Au coreshell NPs, magnetically target them towards tumor, and use them for photothermal therapy of cancer. Material and Methods: In this experimental study, twenty mice received 2 � 106 B16-F10 melanoma cells subcutaneously. After tumors volume reached 100 mm3,the mice were divided into five groups including a control group, NPs group, laser irradiation group, NPs + laser group and NPs + magnet + laser group. NPs were injected intravenously. After 6 hours, the tumor region was irradiated by laser (808 nm, 2.5 W/cm2, 6 minutes). The tumor volumes were measured every other day. Results: The effective diameter of Fe3 O4 @Au NPs was approximately 37.8 nm. The average tumor volume in control group, NPs group, laser irradiation group, NPs + laser irradiation group and NPs + magnet + laser irradiation group increased to 47.3, 45.3, 32.8, 19.9 and 7.7 times, respectively in 2 weeks. No obvious change in the average body weight for different groups occurred. Conclusion: Results demonstrated that magnetically targeted nano-photothermal therapy of cancer described in this paper holds great promise for the selective destruction of tumors. © 2021, Shriaz University of Medical Sciences. All rights reserved

The effects of folate-conjugated gold nanorods in combination with plasmonic photothermal therapy on mouth epidermal carcinoma cells

The use of lasers has emerged to be highly promising for cancer therapy modalities, most commonly, the photothermal therapy method. Unfortunately, the most common disadvantage of laser therapy is its nonselectivity and requirement of high power density. The use of plasmonic nanoparticles as highly enhanced photoabsorbing agents has thus introduced a much more selective and efficient cancer therapy strategy. In this study, we aimed to demonstrate the selective targeting and destruction of mouth epidermal carcinoma cells (KB cells) using the photothermal therapy of folate-conjugated gold nanorods (F-GNRs). Considering the beneficial characteristics of GNRs and overexpression of the folate receptor by KB cells, we selected F-GNRs as a targeted photothermal therapy agent. Cell viability was evaluated using a 3-(4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide assay. Apoptosis was determined by flow cytometry using an annexin V-fluorescein isothiocyanate/propidium iodide apoptosis detection kit. No cell damage or cytotoxicity from the individual treatment of laser light or F-GNRs was observed. However, a 56 cell lethality was achieved for KB cells using combined plasmonic photothermal therapy of 20 μM F-GNRs with seven pulses of laser light and 6-h incubation periods. Cell lethality strongly depends on the concentration of F-GNRs and the incubation period that is mainly due to the induction of apoptosis. This targeted damage is due to the F-GNRs present in the cancer cells strongly absorbing near-infrared laser light and rapidly converting it to heat. This new therapeutic avenue for cancer therapy merits further investigation using in vivo models for application in humans. © 2013 Springer-Verlag

Radiation dose and risk of exposure-induced death associated with chest CT examination during COVID-19 outbreak

As the use of chest CT examination during the COVID-19 outbreak is increased, patient radiation doses are become a concern. So, this survey was conducted to evaluate the patient radiation dose and estimated the cancer risk of chest CT examination during COVID-19 outbreak. From February 2020 to September 2021, 165 chest CT examination were acquired. For all patients, organ doses and the effective dose were calculated using ImpactDose software. The risk of exposure-induced death (REID) values was estimated by using models developed in the BEIR VII (Biological Effects of Ionizing Radiation VII)-Phase 2 report. Study population included 75 male and 90 female, with an average age of 51 years. The mean effective dose in females were greater than in the males (5.42 mSv versus 4.43 mSv, P < 0.0001). The mean REID values in patients undergoing chest CT examination with a 16-MDCT scanner were 232 per million male and 351.3 per million female. The risk of lung cancer was high for both male and female. According to our study, it is proposed that to use low-dose CT chest protocol, as a reliable tool in detecting COVID-19 pneumonia in daily practice, can reduce radiation dose and estimated cancer risk