Radio-thermo-sensitivity Induced by Gold Magnetic Nanoparticles in the Monolayer Culture of Human Prostate Carcinoma Cell Line DU145

BACKGROUND AND OBJECTIVE

Prostate cancer is the second cause of death in men worldwide. In this study, the cytotoxic effects of PLGA polymer-coated gold Magnetic Nanoparticles (MGNPs), as a novel treatment to enhance radiation and thermal sensitivity in the presence of hyperthermia (43°C) and electron beam, on DU145 prostate cancer cells were investigated.

METHODS

Nanoparticles were characterized using TEM, DLS, XRD and SAED methods. MGNPs entrance into the cells was determined using Prussian blue staining and TEM. Furthermore, the cytotoxic effects of combinatorial treatment modalities were assessed by applying colony and sphere formation assay.

RESULTS

Our results revealed that the decrease of colony and sphere numbers after combinatorial treatment of hyperthermia and radiation in the presence of nanoparticles was significantly higher than the other treatment groups (P<0.05). This treatment method proved that it has the capability of eliminating most of the DU145 cells (80-100%), and increased the value of the linear parameter (α) to 4.86 times.

CONCLUSION

According to the study, magnetic gold nanoparticles, in addition to having a high atomic number, can effectively transmit heat produced inside them to the adjacent regions under hyperthermia, which increases the effects of radio-thermosensitivity, respectively.

Effects of Ultrasound Irradiation on the Release Profile of 5-fluorouracil from Magnetic Polylactic co-glycolic Acid Nanocapsules

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.

Synergistic effects of magnetic drug targeting using a newly developed nanocapsule and tumor irradiation by ultrasound on CT26 tumors in BALB/c mice

The aim of the current study was to magnetically target the 5-fluorouracil (5-Fu) loaded magnetic poly lactic-co-glycolic acid (PLGA) nanocapsules towards CT26 colon tumor model in BALB/c mice. In addition, we ultrasonicated the tumors impregnated by nanocapsules with the goal of aiding them in magnetic drug targeting (MDT) procedure. Newly synthesized 5-Fu-loaded PLGA magnetic nanocapsules were characterized. Various treatment modalities with the use of nanocapsules, magnetic fields, and ultrasound were applied to the tumors and appropriate controls were considered. Magnetic resonance imaging (MRI) and Prussian blue (PB) staining were performed to analyze the distribution of nanocapsules within the CT26 tumor. Finally, anti-tumor and pro-apoptotic effects of each treatment modality on CT26 tumors were investigated. The effective diameter of nanocapsules was approximately 70 nm. The histological staining of the tumor tissue with PB as well as MRI revealed a broad distribution of magnetic nanocapsules within the tumor and confirmed the targeting of nanocapsules to the tumors. Anti-tumor studies demonstrated that the combination of nanocapsules-MDT-ultrasound effectively inhibits the growth of CT26 tumors compared with injection of 5-Fu alone (P < 0.01). The present study exhibits potentials of the newly synthesized magnetic nanocapsule and suggests that the combination of MDT and ultrasound might help this new nanotechnology-based cancer chemotherapy agent in vivo.