Experimental Study On Ferroso-Ferric Oxide Nanoparticles In Rdiogrequency Ablation

Purpose:To synthesize and characterize of Ferriso-ferro oxide nanoparticles (FFO-NPs).Materials and Methods:FFO-NPs were synthesized under alkaline conditions, while maintaining a molar ratio of Fe2+:Fe3+=1:2 in nitrogen. FeCl2·4H2O and FeCl3·6H2O were dissolved under a nitrogen atmosphere in 50ml of 5% polyethylene glycol (PEG) solution with vigorous stirring at 800-1000 rpm. The solution was purged with nitrogen (2L/min) for 30 min to remove any oxygen present in a 250ml three-mouth lagena. After the addition of NH3·H2O to maintain the pH of the mixture was at 10-12, a black precipitate was formed 30min later. Then the mixture was heated to 80℃and kept stirring for 50min. Separate the precipitate by Fe-Rb-B magnet and washed with 5% PEG solution (50℃) for seven times to remove unreacted chemicals and decrease the pH of the solution to 7.3-7.5.100ml deionized water, which contain 1.5g Sodium Oleate (SO), was added to the black precipitate. After kept into the pressure cooker in 150℃for 2 hours, the mixture cooled down to room temperature and the process was finished.Results:The final concentration was 4.5% (0.195mol/L). The black precipitate was Ferroso-Ferric Oxide, which confirme by X-Ray diffraction. The shape of the particles is global and well-distributed under the visual field of a transmission electron microscope.A Brookhaven Zeta PALS revealed the FFO-NPs zeta potential was -52.35±2.14mV and the mean diameter were 12.35±5.41nm. The black suspension was stable and well-distibute in four months.Conlusion:The self-made FFO-NPs are suitable for experiment study.Purpose:To evaluate influence on celluar proliferation, acute toxicology and distribution of Ferroso-ferric oxide nanoparticles.Materials and Methods:MTT method to evaluate influence on proliferation of cell line of HepG2. The acute toxic reaction, the main organs distribution and pathological morphology of mice were evaluated after given FFO-NPs by oral administration, intravenous and intraperitoneal injection with different doses respectively. Detect the distribution of nanoparticles by Prussian blue stain and analyze the size change in different groups by immunohistochemistry stain diagnostic method.Results:FFO-NPs did not restrain the proliferation of HepG2. It were taken up and distributed into spleens and livers mostly and the quantized dates was better than the grade dates to evaluate the distribution and metabolism of FFO-NPs. LD50 (median lethal dose) was> 6000.0 mg/kg, EDo (maximum non-effect dose)=750.0 mg/kg by oral administration; LD50 was>1250.0 mg/kg, EDo=750.0 mg/kg by intravenous injection; And LD50 was> 4500.0mg/kg, EDo=1250.0 mg/kg by intraperitonealinjection. Histomorphology was not changed as observed by high resolutionmicroscope in five main organs of each group mice. Conclusion: FFO-NPs have little influence on proliferation of cell line of HepG2, of whichacute toxicity of is very low, to be taken up and distributed into spleens and livers alsodemonstrates feasibility of macrophage-targeted distributions for diagnostic and drugtherapy., of which acute toxicity of is very low, to be taken up and distributed intospleens and livers also demonstrates feasibility of macrophage-targeted distributionsfor diagnostic and drug therapy. Purpose:To determine whether self-made ferroso-ferric oxide nanoparticles (FFO-NPs) enhanced radio frequency (RF) related temperature distribution in agar phantoms and in a vivo rabbit liver model.Materials and methods:Standardized 1-L 5% agar phantoms were constructed with varying FFO-NPs concentration, RF was applied with simultaneous measuring temperature of different distance from electrode in the same transverse plane. In vivo experiment, RF ablation was performed in the liver of seven rabbits after the transcathater arterial administration of FFO-NPs (0.28ml, per kilogram of body weight) 30 minutes prior to ablation (FFO-NPs group) and in seven rabbits without prior FFO-NPs administration (control group). Coagulation diameter and area of necrosis section were evaluated on the basis of postprocedural MR imaging and subsequent gross pathologic findings. Statistical analysis was performed with the analysis of variance in vitro experiment and the student t test in vivo experiment.Results:In the in vitro experiment, FFO-NPs concentration had significant effects on RF-generated heating of the agar phantoms (p<0.05). In the rabbit liver model, FFO-NPs at physiologic content significantly increased coagulation diameter and area on the basis of MR imaging or subsequent gross pathologic findings. Additionally, no significant differences were seen in other RF induced parameters including impedance, voltage and current.Conclusion:Transcathater arterial administration of FFO-NPs in combination with RF ablation of focal liver lesions is feasible and safe, and significantly enlarged coagulation as expected.