| Part Ⅰ The basic physicochemical properties and biological of properties manganese hexacyanoferrate potassium potassium nanoparticlesObjective: To analyse of potassium manganese hexacyanoferrate nanoparticles basic characterization,stability,uniformity,magnetic characteristics and biological toxicity,exploring its feasibility and advantage of MR contrast agents.Methods: The application of high resolution transmission electron microscopy(TEM)observation and analysis of manganese hexacyanoferrate potassium nanoparticle size,particle size distribution,morphology and characterization;determination of manganese potassium hexacyanoferrate nanoparticles using X-ray powder diffraction of mesoporous structure and phase structure;transverse relaxation using 0.5T MR analyzer determination of manganese hexacyanoferrate potassium nanoparticles longitudinal relaxation rate of R1 and the transverse relaxation rate of R2;according to different concentration(concentration were 0.96,1.92,3.83,7.67 mmol/L)of the manganese hexacyanoferrate potassium potassium solution in vitro MR imaging,correlation analysis between the concentration and the magnetic resonance signal intensity changes.The ICR mice were randomly divided into 6 groups(5 groups for injection group,the 1 group was control group),intravenous injection of different concentrations of iron and manganese potassium hydride nano contrast agent(410.4mg/kg,482.22mg/kg,513mg/kg,567.38mg/kg,615.6mg/kg),the control group were injected with saline,observe all mice were administered for 14 days about the poisoning and death.Results : Manganese potassium hexacyanoferrate nanoparticles prepared by cube in high resolution transmission electron microscope,uniform particle size,a diameter of about 30 nm.The molecular formula KMn[Fe(CN)6]2H2O was determined by X ray powder diffraction and electron microscope.The particle size distribution of potassium manganese hexacyanoferrate nanoparticles is narrow and the peak value is about 90 nm.The transverse relaxation rate of 1.2074 m M-1s-1 was determined by 0.5T magnetic resonance analyzer,and longitudinal relaxation rate was0.7599 m M-1s-1.The signal intensity of T1 and T2 weighted images of different concentrations of potassium hexacyanoferrate nanoparticles was very obvious,and the concentration of contrast medium was positively correlated with the intensity of the signal.The median lethal dose(501.1mg/kg)of mice was 102 times that of the best effective dose(4.9mg/kg),and the safe dose range was wide.Conclusions: The surface structure of manganese hexacyanoferrate potassium nanoparticles stable,uniform particle size,good dispersibility and good biocompatibility.Manganese potassium hexacyanoferrate nanoparticles with high R1 relaxivity and R2 relaxation rate,with its concentration and the magnetic resonance signal intensity of image correlation,which can be used as T1 and T2 contrast agent.With safe enough to use potassium manganese hexacyanoferrate nanoparticles dose,good biocompatibility.Part Ⅱ MR T2 WI enhancement effect in different organs of the rat with different concentration of manganese hexacyanoferrate potassium nanoparticles contrast agentObjective: After injecting 45mmol/L manganese potassium hexacyanoferrate nanoparticles contrast agent through the tail vein of the rats at different time points,MRI enhanced scan in rats in different organs(heart,liver and kidney),then analyzing the biological distribution relationships between injection concentration and the degree of enhancement in different organs of the rat.Methods: 16 healthy male SD rats were randomly divided into 2 groups,one group with 8 rats for injecting,the other group with 8 rat for blank control group.The TSE-T1 WI and TSE-T2 WI sequences of each rats in the scanning group were scanned,and the scanning organs included the myocardium,liver and kidney.Start MR scanning in different organs of the rat(heart,liver and kidney)after injecting 45mmol/L manganese potassium hexacyanoferrate nanoparticles contrast agent(dose weight ratio 1ml/300g)through the tail vein of the rats on 5min、30min、1h、2h、3h、4.5h、6h、10h。The measurement of each organ about signal intensity(SI)and background noise signal intensity,standard deviation(SD)at each time point after enhancement,calculating the organ signal-to-noise ratio(SNR)and signal enhancement ratio(SER),rendering the organs of signal-to-noise ratio(SNR)-time and signal enhancement ratio(SER)-time curve,compared with one factor analysis of variance increased at each time point about heart,liver and kidney SI,SNR and SER have no significant difference.Results : Manganese potassium hexacyanoferrate nanoparticles contrast agent before and after injection of 5min、30min、1h、2h、3h、4.5h、6h、10h,myocardial SI were :253.21±33.17、152.19±15.46、153.96±11.66、146.61±10.19、116.32±9.74、111.23±6.61、124.17±11.48、147.48±13.27、200.19±28.82;SNR were:10.09±1.60、6.22±1.88、5.90±0.59、5.90±1.06、4.96±0.98、5.47±0.89、5.59±1.01、8.09±1.88、9.79±1.65;after injection 5min to 10 h at each time point,the myocardial SER: 0.37±0.23、0.40±0.10、0.39±0.17 、 0.49±0.12 、 0.44±0.17 、 0.43±0.13 、 0.21±0.17,0.16±0.14.Injection of manganese hexacyanoferrate nanoparticles enhanced myocardial potassium after contrast,SI,SNR and SER reached the peak at 1h,1h ~ 4.5h to strengthen the basic smooth,thenthe enhancement degree decreased gradually,gradually recovered after 10 h.SI,SNR and SER in the myocardium after 10 h were 200.19±28.82、9.79±1.65、0.16±0.14,compared with the myocardial SI and SNR,there was statistical difference.The difference of myocardial SNR between 5min-6h and plain scan was statistically significant(P < 0.05).The difference of 10 h time between Duan Xinji SNR and plain scan was not statistically significant(P > 0.05).5min-4.5h myocardial SER at each time point compared with 6h,P < 0.05,the difference was statistically significant.5min-6h myocardial SER at each time point compared with 10 h,P < 0.05,the difference was statistically significant.Manganese potassium hexacyanoferrate nanoparticles contrast agent before and after injection of 5min、30min、1h、2h、3h、4.5h、6h、10h,rat renal cortex SI were757.46±144.47 、 560.26±100.74 、 506.60±98.87 、 531.50±106.54 、 363.36±145.11 、413.86±170.66、529.67±157.21、443.49±58.46、512.34±44.51;SNR were 35.42±4.62、29.54±10.77、18.42±3.48、17.40±2.92、15.71±6.13、15.85±3.99、18.37±5.17、16.78±7.43、16.66±5.26;SER were 0.25±0.18 、 0.30±0.23 、 0.28±0.08 、 0.50±0.09 、 0.42±0.15 、0.34±0.15、0.36±0.16、0.29±0.17.Manganese potassium hexacyanoferrate nanoparticles contrast agent before and after injection of 5min、30min、1h、2h、3h、4.5h、6h、10h,renal medulla SI were 876.48±71.93 、 622.45±156.38 、 512.84±165.74 、 560.46±131.09 、484.84±138.80、520.22±56.74、464.24±56.74、546.62±96.25、692.64±114.00;SNR were43.15±5.24、23.16±5.93、18.58±7.67、18.15±6.30、16.75±3.54、20.68±4.81、22.81±4.50、21.50±5.95、26.21±5.02;SER were 0.44±0.16、0.57±0.08、0.58±0.08、0.61±0.17、0.58±0.15 、 0.57±0.04 、 0.56±0.19 、 0.56±0.16.Injection of manganese potassium hexacyanoferrate nanoparticles contrast agent kidney after signal intensity decreased gradually,the enhancement degree gradually increased,the renal cortex in 2h enhanced to peak,2 hours after the renal cortex enhancement degree decreased gradually.10 hours later,the SI,SNR and SER of renal cortex were 512.34±44.51 、 16.66±5.26 、 0.29±0.17,respectively,but there was significant difference between the two groups.The renal medulla increased to the peak after 2h,and there was no significant decrease in the degree of renal enhancement in the 2h-10 h period.10 hours later,the SI,SNR and SER of renalmedulla were 692.64±114.00、26.21±5.02、0.56±0.16,and the difference was significant between the plain and the medulla of kidney.2h renal cortex SER,respectively,compared with 5min,30 min,1H,3h,4.5H,6h,10 h,renal cortex compared with P<0.05,the difference was statistically significant.2H renal medulla SER were compared with 5min,30 min,4.5H,6h,10 h renal cortex,P<0.05,the difference was statistically significant.4.5H renal medulla SER compared with 6h、10h,kidney,medulla,SER,P>0.05,the difference was not statistically significant.Manganese potassium hexacyanoferrate nanoparticles contrast agent before and after injection of 5min、30min、1h、2h、3h、4.5h、6h、10h,liver SI were 305.70±75.81、104.54±23.84、93.70±14.99、85.46±17.84、104.22±16.02、116.45±23.43、126.51±14.08、139.91±27.36、156.95±28.57;SNR were 14.25±7.70、4.91±1.96、3.76±0.92、3.30±0.71、4.37±1.54、4.69±2.51、6.25±2.21、5.34±1.95、7.04±2.50;SER were 0.64±0.19、0.71±0.12、0.75±0.15、0.67±0.16、0.69±0.22、0.56±0.22、0.60±0.20、0.51±0.25.After injection of nanoparticles contrast agent,the liver was enhanced rapidly and obviously,the SI of liver was significantly reduced after 5min,SER was 0.64±0.19,the difference was statistically significant.1h after liver enhancement intensity to the peak,then began to strengthen,4.5h decreased significantly after 10 h,SNR,SER,SI in liver were 156.95±28.57、7.04±2.50、0.51±0.25,and the scan of liver SI,SNR still has a statistically significant difference with enhancement.Intravenous injection of nanoparticles contrast agent after 5min,compared with plain,liver SER was 0.64±0.19,30 min after the liver signal continues to rise,1h after liver enhancement peak was 0.75±0.15,SER,3h after liver SER decreased significantly.Comparison SNR between 5min and 30 min in liver after injection contrast agent.After injection of contrast agents,liver SNR at each time point of 5min-10 h compared with plain scan,P<0.05,the difference was statistically significant,P<0.05.5min-6h each time point liver SER and 10 h comparison,30min-3h each time point liver SER and 4.5H compare,P< 0.05,the difference has statistical significance.Conclusions: Manganese potassium hexacyanoferrate nanoparticles contrast agent on rat liver T2 negative significantly enhance the effect of imaging a longer time window,the liver in 5min T2 initial negative enhancement effect,after 1h reached the peak enhancement,and to keep the platform enhanced to 3h.Manganese hexacyanoferratenanoparticles can be used as potassium contrast agent liver T2 negative contrast agent.The myocardial enhancement effect was the second;the renal enhancement effect was relatively slow,and the renal cortex and medulla reached the peak value at 2h,and the renal medulla was enhanced by about 5h.Part Ⅲ Analysis of pathological basis of enhanced liver contrast with manganese hexacyanoferrate potassium nanoparticles in ratsObjective: Injecting manganese hexacyanoferrate potassium nanoparticles contrast agent by the optimal concentration(45mmol/L)in different time.The liver of rats was examined by light microscopy and electron microscopy,and discussing nanoparticles contrast agent in rat liver biological distribution(subcellular level),distribution characteristics,the time point of contact and enhance principle.Methods: 22 healthy male SD rats were randomly divided into 2 groups,one group with 11 rats for injecting,the other group with 11 rat for blank control group.On experimental group,after injecting 45mmol/L manganese potassium hexacyanoferrate nanoparticles contrast agent(dose weight ratio 1ml/300g)through the tail vein of the rats than sampling liver tissue.The blank group was randomly selected one SD rat as a blank control group.The 12 SD rats were numbered as 1-12 in chronological order.Each SD rats were performed with light and electron microscopy were fixed after sectioning,observed and study the distribution of nanoparticles contrast agent in SD rats’ liver.Results :HE staining method was used to stain the normal rat liver,which showed that the morphology of liver cells was complete and the nucleus was clear.Staining of normal rat liver by Prussian blue,liver sinus visible blue particles,the numbers of blue dye nanoparticles in 1-2 hours of hepatic sinus were most,nearly invisible disappearance in16 hours,24 hours.,The results of electron microscope showed that nanoparticles in the hepatic sinus Kupffer cells were clusted aggregation,which were accord with manganese hexacyanoferrate potassium potassium chemical formula KMn[Fe(CN)6] by element analysis of electron microscopy.Conclusions: After intravenous injection of manganese potassium hexacyanoferrate nanoparticles,contrast agents is liver specific uptake,mainly masslike accumulation in the hepatic sinus Kupffer cells.The quantity of manganese hexacyanoferrate nanoparticles uptaked by liver had correlation with time.The highest intake was after 1 hour,the characteristics match manganese potassium hexacyanoferrate in the SD rats vivo MR imaging features. |
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