Synthesis Of A New NaHoF₄@CeO₂ Nanoparticles Dual Mode Imaging Agents And In Vitro Experimental Study On Its Radiation Sensitization Of Pancreatic Cancer

Objective:(1)To study the synthesis of Na Ho F4@Ce O2 Nanoparticles(NPs)which had double modal imaging and radiotherapy sensitization of pancreatic cancer in vitro,and identify the physical and chemical characteristics and physiological toxicity in vivo and in vitro of the NPs.(2)To research the Computed Tomography(CT)and Magnetic Resonance Imaging(MRI)dual mode imaging efficacy of new Na Ho F4 @Ce O2 NPs in vitro;(3)To study the radiotherapy sensitization effect of Na Ho F4 @Ce O2 NPs on human pancreatic cancer cells(panc-1)in vitro.Methods:(1)Synthesize of Na Ho F4@Ce O2 NPs used six chloride holmium(Ho Cl3·6H2O),ammonium fluoride(NH4F)and cerium nitrate hexahydrate(Ce(NO3)3·6H2O)as main material,use Transmission Electron Microscope(TEM),Dynamic Light Scattering instrument(DSL),Inductively Coupled Plam Optical Emission Spectrometer(ICP-OES)to measure the particle size,dispersion and main contents of elements;(2)Use MTT experiment to determine different concentrations(0,50,100,200,400,and 800 μg/l)NPs effect on cell survival of human aortic endothelial(HAEC)and Panc-1 cells;In vivo biological toxicity: mice tail vein injection of different concentration(0,5,10 and 20 mg/kg)NPs,detection of blood routine,liver and kidney function and major organs(heart,liver,spleen,kidney,lung,pancreas)HE staining to assess the effect of NPs on main organs after 15 days.(3)Evaluate the effect of the NPs in vitro CT imaging in different concentrations(0,1,2,4 g/l),and compare with the commonly used contrast agent Iopamidol;The T2 relaxation time of different concentrations(0、0.2、0.4、0.6、0.8m M)of the NPs was determined by the MRI,and the MRI imaging effect was verified.(4)MTT and cell cloning experiments were performed to verify the effect of radiotherapy on panc-1 in the pure NPs group,Radiation therapy(RI)group and RI+NPs group.Each experiment was conducted three times independently.Double-tailed t test was used for single treatment group experiments.Two-anova test was used for two treatment groups.Results :(1)The successful synthesis NPs was consistent with the experimental requirements.TEM showed that synthesis NPs was round,diameter of about 16 nm,DLS showed normally distributed particle size,the median size of 17 ± 0.8 nm,ICP-OES measurement showed that Ho and Ce are contained in synthesis NPs.(2)In vitro toxicity MTT assay showed that the cell survival rate of the experimental group was slightly lower than that in the control group,but there was no statistically significant difference(P > 0.05).After the injection of NPs 15 days later,there was no significant difference between the blood laboratory related indexes and the control group(P >0.05),and the main organs(heart,liver,spleen,kidney,lung,pancreas)HE staining was not a significant tissue damage.(3)The CT values of Iopamidol and NPs at different concentrations increased significantly with the increase of concentration,and the CT value of NPs group was higher than Iopamidol group at the same concentration,with significant difference(p<0.001).With the increase of NPs concentrations,MRI T2 time was significantly shortened and the signal intensity decreased,and the difference was statistically significant(P < 0.05).(4)Radiation MTT experiment result showed that RI+NPs group survival rate(63.21%),significantly lower than the pure RI(84.58%)and pure NPs group(93.58%),the differences between groups have obvious statistics meaning(p<0.001).Cell cloning experiments showed that the cell survival scores of panc-1 cells were significantly reduced with different doses of radiation after NPs culture(P < 0.001).Conclusion:(1)Using a variety of physical and chemical characterization appraisal indicated the successful synthesis of a good dispersion Na Ho F4@Ce O2 NPs,and through in vitro and in vivo toxicity experiments showed that the NPs with smaller biological toxicity which conform to the requirements of the experiments.(2)By means of in vitro double modal CT and MRI imaging and compare with Iopamidol(CT contrast agent)and measure MRI T2 relaxation time suggested Na Ho F4@Ce O2 NPs can perform as double modal CT and MRI imaging(3)MTT and cell cloning experiments show that NPs can improve sensitivity on Panc-1 cell to radiotherapy,increase Panc-1 celd death,and realize the effect of radiotherapy sensitization.