Evaluation of an Ultrasonic Insulin Delivery System in Hyperglycemic Rabbits

Introduction: Sonophoresis has been assessed as a novel approach to create skin permeability and drug delivery using low frequencies of ultrasound waves in the range of 20 kHz to 3 MHz. In this study, a system including seven 40 kHz piezoelectric transducers and an insulin chamber designed by the Medical Physics Research Center has been evaluated on hyperglycemic rabbits. Materials and Methods: Thirty five rabbits became hyperglycemic through Alloxan monohydrate injection and were divided into five groups. The rabbits were treated in two main groups (with insulin and ultrasound radiation in two radiation periods), one main control group and two further control groups (one group with ultrasound radiation with longer radiation period in absence of insulin and presence of normal saline; and the other group without ultrasound radiation in presence of insulin). By filling the system chamber with insulin and placing it on the skin of the abdomen and activating the piezoelectric transducers, blood samples were drawn from the animals before ultrasound irradiation and after it in specified intervals. The glucose level was measured using a glucometer and the serum insulin level was determined using a radioimmunoassay method. Results: Maximum decrease in glucose level was recorded for a 20 minute irradiation in a 180 minute period, and the highest increase in insulin level was recorded for the10 minute radiation group in a 60 minute period. Discussion and Conclusion: Because rapid uptake and reaching a peak in a short time and its swift decrease make a good scheme for controlling glucose level after meals, the 10 minute radiation seems to be more suitable. Also, it is predicted that irradiation time in the interval between food consumption and use of the instrument is critical

Hyperthermia Effects in the Presence of Gold Nanoparticles Together with Chemotherapy on Saos-2 Cell Line

Introduction: Hyperthermia created by microwave (MW), infrared, ultrasound and other methods, is often utilized as an adjuvant to sensitize cancer cells to the effects of chemotherapy and radiation therapy. We investigated the efficacy of hyperthermia using MW in synergy with chemotherapy in the presence and absence and gold nanoparticles (GNPs). Material and Methods: After culturing and proliferation of the Saos-2 cell line derived from human osteogenic sarcoma, the cells were incubated at two concentrations of GNPs in two diameters of 20 and 40 nm and in the absence and presence of doxorubicin in different groups. Forty eight hours after irradiating the cells with MW up to a temperature of 42°C, cell survival rate was determined using the MTT method, in order to study the effectiveness of the therapeutic parameters. Results: Cell survival in the presence of GNPs was greater than 95%. After chemotherapy by doxorubicin with and without 40 nm GNPs, cell survival rates were determined as 62.8% and 37.1%, declining down to 17% and 4.1% respectively following the combined treatment with MW and chemotherapy in the presence of 20 and 40 nm GNPs. Discussion and Conclusions: GNPs did not induce any cytotoxicity by themselves; their presence along with MW provided a reduction in survival rate that was comparable in severity with the lethal effects of doxorubicin. MW hyperthermia with GNPs produced a higher treatment efficiency in comparison to similar groups in which GNPs were absent. The synergism observed between hyperthermia and chemotherapy was dependent in GNPs' size and concentration. This finding could be caused by increased uptake of doxorubicin by the cells in the presence of GNPs