Detection of hepatic VX2 carcinomas with ferucarbotran-enhanced magnetic resonance imaging in rabbits: Comparison of nine pulse sequences

Experimental study on ablation of leiomyoma by combination high-intensity focused ultrasound and iodized oil in vitro

AIM

The aim of the current study was to investigate whether iodized oil (IO) enhances high-intensity focused ultrasound (HIFU) ablation of uterine leiomyoma and to determine the features of hyperechoic changes in the target region.

METHODS

Forty samples of uterine leiomyoma were randomly divided into an experimental group and a control group. In the experimental group, the leiomyoma was ablated by HIFU 30 min after 1 mL of iodized oil had been injected into the center of the myoma. The hyperechoic values and areas in the target region were observed by B-modal ultrasound after HIFU ablation. The samples were cut successively into slices and stained by triphenyltetrazolium chloride (TTC) solution within 1 h after HIFU ablation. The diameters of TTC-non-stained areas were measured and tissues in the borderline of the TTC-stained and -non-stained areas were observed pathologically. All procedures in the control group were the same as those in the experimental group except IO was replaced by physiological saline.

RESULTS

The hyperechoic value in the target region in the experimental group was higher than that in the control group 4 min after HIFU ablation (P < 0.05). Hyperechoic areas in the target region as well as TTC-non-stained volumes in the experimental group were greater than those in the control group (P < 0.05). Routine pathologic observation showed that coagulation necrosis of leiomyoma occurred in the target region in both groups.

CONCLUSION

IO causes coagulation necrosis, enlarges tissue damage, and postpones the attenuation of hyperechoic changes in the target region when HIFU ablation is carried out for leiomyoma in vitro.

Dextran-coated superparamagnetic nanoparticles as potential cancer drug carriers in vivo

Dextran-coated superparamagnetic iron oxide nanoparticles (DSPIONs) have gained considerable interest, because of their biocompatibility and biosafety in clinics. Doxorubicin (Dox), a widely used chemotherapeutic drug, always has limited applications in clinical therapy due to its serious side effects of dose-limiting irreversible cardiotoxicity and myelo suppression. Herein, DSPIONs were synthesized and developed as magnetic carriers for doxorubicin. The Dox-DSPION conjugates were evaluated in the in vitro test of Dox release, which showed pH-dependence with the highest release percentage of 50.3% at pH 5.0 and the lowest release percentage of 11.8% in a physiological environment. The cytotoxicity of DSPIONs and Dox-DSPIONs evaluated by the MTT assay indicated that DSPIONs had no cytotoxicity and the conjugates had significantly reduced the toxicity (IC50 = 1.36 μg mL(-1)) compared to free Dox (IC50 = 0.533 μg mL(-1)). Furthermore, confocal microscopic data of cell uptake suggest that less cytotoxicity of Dox-DSPIONs may be attributed to the cellular internalization of the conjugates and sustainable release of Dox from the formulation in the cytoplasm. More importantly, the results from the rabbit VX2 liver tumor model test under an external magnetic field showed that the conjugates had approximately twice the anti-tumor activity and two and a half times the animal survival rate, respectively, compared to free Dox. Collectively, our data have demonstrated that Dox-DSPIONs have less toxicity with better antitumor effectiveness in in vitro and in vivo applications, suggesting that the conjugates have potential to be developed into chemo-therapeutic formulations.