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.

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 Fe3O4@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 Fe3O4@Au core-shell NPs, magnetically target them towards tumor, and use them for photothermal therapy of cancer.Material and Methods: 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 Fe3O4@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.

Background The concept of diagnostic reference level (DRL) is considered a regular method to optimize radiation protection in diagnostic imaging system. The objective of implementing a reference level for dose is to produce high-quality images by applying a minimum dose of radiation based on the As Low As Reasonably Achievable (ALARA) principle. Therefore, this study aimed to evaluate the status of radiation protection in diagnostic radiology wards of educational hospitals affiliated with Birjand University of Medical Sciences. Methods This study was performed during a period of 11-months in the radiology center of the teaching hospital of Birjand University of Medical Sciences. The studied population included 477 patients who were referred to as clinically indicated x-ray radiography. In order to calculate local DRLs, dose area product (DAP) was measured by a DAP-meter (KERMAX-plus SPD, model 120–131 HS) for 11 devices at educational hospitals affiliated with Birjand University of Medical Sciences. The local DRL values was calculated as 75% of the mean DAP distribution for a specific patient trial at each center. Results DAP for Chest PA examination was gained to be in the range from 0.12 Gy.cm2 to 0.42 Gy.cm2 with an average value of 0.23 Gy.cm2 which is above the value of the reference level (0.12 Gy.cm2) for Chest PA. For Chest lateral the observed DAP was found to be in the range from 0.18 Gy.cm2 to 1.48 Gy.cm2 with an average value of 0.65 Gy.cm2 and are therefore twice the reference value (0.3 Gy.cm2). The higher DRL values (average = 2.73) are for lumbar spine lateral radiography. It is observed that the DRL values of chest PA, abdomen AP and Lumbar spine AP are much lower with the earlier studies. Conclusions The DRLs helps in understanding the current practices in radiographic examinations. Comparison with other hospitals, the scope of dose optimization and ultimately patient dose reduction in hospitals affiliated with Birjand University of Medical Sciences needs further investigation.

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