RESUMEN

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: 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 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.

RESUMEN

OBJECTIVES: To investigate the effects of Au@Fe2O3 core-shell nanoparticle (NP), with and without conjugation to folic acid (FA) as a targeting ligand, on radiosensitization of both cancer and healthy cells. METHODS: Au@Fe2O3 NPs were first synthesized, then modified with FA, and finally characterized. Radiation dose enhancement studies were performed on KB cancer cells and L929 healthy cells. NPs at the concentration of 20 µg/ml were first incubated with both cell lines and then different doses of 6 MV X-ray radiation were examined. The end effects were evaluated via MTT assay and flow cytometry using AnnexinV/PI kit. RESULTS: It was indicated that viability of KB cells has a much lower rate than L929 cells when the cells were treated by {(FA-Au@Fe2O3) + (X-ray)} regimen. Cell viability was even decreased significantly when X-ray dose increased. Moreover, flow cytometry studies revealed that FA-targeted NPs induced higher level of apoptosis for KB cancer cells than L929 healthy cells. CONCLUSION: Our findings provide a new perspective on high ability of the synthesized FA-targeted Au@Fe2O3 NPs which may be considered as an efficient radiosensitizer in the process of targeted radiation therapy of cancer.

Asunto(s)

Sistemas de Liberación de Medicamentos , Ácido Fólico/química , Oro/química , Nanopartículas de Magnetita/química , Fármacos Sensibilizantes a Radiaciones/farmacología , Animales , Apoptosis/efectos de los fármacos , Apoptosis/efectos de la radiación , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/efectos de la radiación , Humanos , Células KB , Células L , Ratones , Dosis de Radiación , Fármacos Sensibilizantes a Radiaciones/química , Fármacos Sensibilizantes a Radiaciones/toxicidad , Radioterapia , Rayos X

RESUMEN

BACKGROUND: Hemodialysis is a process of removing waste and excess fluid from blood when kidneys cannot function efficiently. It often involves diverting blood to the filter of the dialysis machin to be cleared of toxic substances. Fouling of pores in dialysis membrane caused by adhesion of plasma protein and other toxins will reduce the efficacy of the filtre. OBJECTIVE: In This study, the influence of pulsed ultrasound waves on diffusion and the prevention of fouling in the filter membrane were investigated. MATERIAL AND METHODS: Pulsed ultrasound waves with frequency of 1 MHz at an intensity of 1 W/cm2 was applied to the high flux (PES 130) filter. Blood and blood equivalent solutions were passed through the filter in separate experimental setups. The amount of Creatinine, Urea and Inulin cleared from both blood equvalent solution and human whole blood passed through High Flux (PES 130) filter were measured in the presence and absence of ultrasound irradiation. Samples were taken from the outlet of the dialyzer every five minutes and the clearance of each constituent was calculated. RESULTS: Statistical analysis of the blood equvalent solution and whole blood indicated the clearance of Urea and Inulin in the presence of ultrasound increased (p<0.05), while no significant effects were observed for Creatinine. CONCLUSION: It may be concluded that ultrasound, as a mechanical force, can increase the rate of clearance of some toxins (such as middle and large molecules) in the hemodialysis process.

RESUMEN

BACKGROUND: Drug nano-carriers are one of the most important tools for targeted cancer therapy so that undesired side effects of chemotherapy drugs are minimized. In this area, the use of ultrasound can be helpful in controlling drug release from nanoparticles to achieve higher treatment efficiency. OBJECTIVE: Here, we studies the effects of ultrasound irradiation on the release profile of 5-fluorouracil (5-Fu) loaded magnetic poly lactic co-glycolic acid (PLGA) nanocapsules. METHODS: 5-Fu loaded magnetic PLGA nanocapsules were synthesized by multiple emulsification method. Particle size was measured by dynamic light scattering (DLS) and transmission electron microscope (TEM). The pattern of drug release was assessed with and without 3 MHz ultrasound waves at intensities of 0.3, 0.5 and 1 w/cm2 for exposure time of 5 and 10 min in phosphate-buffered saline (PBS). RESULTS: The size of nanoparticles was about 70 nm. Electron microscope images revealed the spherical shape of nanoparticles. The results demonstrated that the intensity and exposure time of ultrasound irradiation have significant effects on the profile of drug release from nanoparticles. CONCLUSION: It may be concluded that the application of ultrasound to control the release profile of drug loaded nanocapsules would be a promising method to develop a controlled drug delivery strategy in cancer therapy.

RESUMEN

BACKGROUND: Low intensity ultrasound (US) has some well-known bio-effects which are of great importance to be considered. Objective: We conducted the present study to investigate the effects of low intensity continuous ultrasound on blood cells count in rat. METHODS: Rats were anesthetized and blood samples were collected before US exposure. Then, they were exposed to US with nominal intensity of 0.2 W/cm2 at frequency of 3 MHz for a period of 10 minutes and this protocol was repeated for 7 days. Twenty four hours after the last US exposure, secondary blood samples were collected and the changes in blood parameters were evaluated. RESULTS: Analysis revealed that platelets, hematocrit (HCT) and hemoglobin (HGB) were significantly different between experimental and sham groups but no difference between sham and control groups was observed. The results show that HCT and HGB of exposed rats were significantly reduced. Conclusion: This study shows that low intensity US may lead to side effects for hematological parameters such as reduction in the levels of HGB and HCT.