The Characteristics Of New Nanoscale Microbubble Contrast Agent And Experimental Research In Vivo Of Nude

Objective:This study discuss the Physical properties of homemade nanoscale ultrasound contrast agent in vitro and in vivo.Methods:Nanoscale bubbles were prepared by mechanical vibration,observe the morphology,distribution,size range and concentration,save 2 weeks in the sterile environment,observe the properties such as particle size have any change;Establish bladder cancer transplantation tumor moder,inject nanoscale contrast agent a 150?l through the tail vein,two hours later injection the Sonovue contrast agent in the same way,stroage the dynamic angiogram.Befor-and-after statistical methods are used to observe the two contrast agents in vivo imaging characteristics and the differences of quantitative results.Results:(1)Microscopically Nanoscale bubbles with spherical shape,symmetrical distribution,without obvious aggregation.Particle of the bubble range between 418-490 nm,the average particle of size was 463.20±27.69nm(n=5),average zeta potential was-14.80±1.26 mV,concentration was(2.42±0.12)x108/ml.After being preserved at four temperature of one week,the nanoscale bubbles was stable.The average particle of size was 525.80±18.08nm(n=5),concentration was(2.23±0.10)x108/ml;Ten days later,the average zeta potential was-13.94±0.23 mV,there was no significant difference with the time of preparation(P>0.05).(2)Nanoscale Ultrasound contrast agents can siginificant enhance the gray-scale imaging,the initiation time(0.90±0.42s)and tmax(24.01±5.83s)is later than Sonovue(0.35±0.15 s ?2.91±0.93s),duration of peak value(111.65±20.87s)is longer than Sonovue(58.59±10.49s),but the peak intensity(14.18±3.45dB)is lower than Sonovue(19.36±3.72dB),the Ascending slope(1.37 + 0.15)is lower than Sonovue(6.16 + 0.54),there was no significant differencebetween the Areas under ascending curve of Nanoscale(59.58±14.67)and Sonovue(52.52±15.93)(P=0.443).(3)The elimination rate of two contrast agwnts is(-1.60±0.36dB/s ?-3.42±0.21dB/s),the ratio of two groups(decay-slope ratio,DSR),DSR =2.14,this means that microbubbles dissolved 2.14 times faster than nanobubbles,there was significant difference between the two contrast agents(P<0.05).The corresponding gray-scale was significant difference between the two contrast agents in 10 s,20s,90 s,2min,4min,8min(P<0.05),two time intencity curve have crossed in about 50 s.Conclusion:The characteristics of nanoscale bubbles of smaller size,symmetrical distribution,better discretion and the stable properties in vitro,which characteristics will provide a basis specification for the preparation of the bubble;Homemade nanoscale contrast agent compared with the conventional contrast agent,the effect was obvious,and has certain clinical application value,which will laid a certain foundation for further target material preparation.