Low-frequency Ultrasound Homemade Microbubble Thrombolysis As Well As Non-invasive And Open The Blood-brain Barrier, A Preliminary Study

Objective To make a new ultrasound contrast agent of surfactant fluorocarbon-filled which has stable quality and is umharmful to human body, to observe the thrombolysis effect of low-frequency external therapeutic ultrasound(ETUS) with self-made microbubbles and urokinase to aged thrombus and the relationship between thrombotic age and thrombolysis effect, to contrast the different thrombolysis effects between self-made microbubbles and SonoVue microbubbles and to assess the feasibility of non-invasive thrombolysis by low-frequency ETUS plus self-made microbubble and urokinase for the animal experiment.Methods Mix span-60 and tween-80,and make the ultrasound contrast agent of surfactant fluorocarbon-filled with sound-shaking machine. Detect the microbubbles' quales by Coulter II particle counting measurement.Drew blood from 10 healthy volunteers' ulnar veins, and made 8-hour age thrombuses. According to the matching principle, divided all thrombuses into six groups :(1)NS(control group), (2)UK, (3)ETUS, (4) ETUS+UK, (5)ETUS+MB, (6) ETUS+UK+MB. After irradiated by ultrasound according to the experimental operating methods for 20 minutes, the thrombuses were weighed and counted weight loss rates. Contrast the rates among different groups and assess the thrombolysis effect by various methods.Drew blood from 10 healthy volunteers' ulnar veins, and divided the thrombuses into 3 groups by age:(1) 4h(4-hour age), (2)8h (8-hour age), and (3) 12h( 12-hour age). Each group was dealt with two methods, only by urokinase and by ultrasound plus urokinase and microbubbles. Contrast the thrombolysis effect to different age thrombuses by two methods.Drew blood from 10 healthy volunteers' ulnar veins, and made 8-hour age thrombuses. According to the matching principle, divided all thrombuses into 3 groups:(1)thrombolysis using urokinase for 20 minutes; (2) thrombolysis using ultrasound with urokinase and self-made microbubbles for 20 minutes; and (3)thrombolysis using ultrasound with urokinase and SonoVue microbubbles for 20 minutes. Contrast the thrombolysis effect by three methods.Results We made the ultrasound contrast agent of surfactant fluorocarbon-filled successfully, whose qualities were stable and whose sizes were even.These microbubbles' particle diameters range from 0.8urn to 4.0um, and 95 percent were below 2.0um. The density was 7.2x109 /ml.We got the weight loss rates in groups, which were 7.0750±3.0491% in group NS; 15.6610±4.6009% in group UK; 8.0000±2.7907% in group ETUS; 18.5420±4.2393% in group ETUS+UK; 29.0430±7.0044% in group ETUS+MB (compared with group UK, P < 0.01);50.0810±6.9949% in group ETUS+UK+MB (compared with every group, P < 0.01).There were significant differences in weight loss rates among different aged thrombus groups dealt with only urokinase (P<0.01), and the same to the groups dealt with ultrasound plus urokinase and microbubbles (P<0.01). Compared with two different thrombolytic methods to same age thrombus, the weight loss rate in the groups dealt with ultrasound plus urokinase and microbubbles was more than the groups dealt with only urokinase (P<0.01).While in the same thrombolytic conditions, compared with the group dealt with SonoVue microbubbles, the weight loss rate of thrombus in group dealt with self-made microbubbles was non-significant difference.Conclusion The self-made ultrasound contrast agent of surfactant fluorocarbon-filled has stable and safe quality. Low-frequency ETUS with self-made microbubbles and urokinase can obviously enhance the thrombolytic rate in vitro, and the rate is depressing as the age of thrombus increases. The thrombolytic effects between self-made microbubbles and SonoVue microbubbles are similar.Objective To detect the hypothesis that noninvasive defining parameters ultrasound can open the blood-brain barrier (BBB) in presence of ultrasound contrast agent. To find out the conditions and phases of BBB disruption induced by low-frecency ETUS plus self-made ultrasound contrast agent. And to explore the mode and mechanism of BBB disruption.Methods Divide 50 healthy ripe Wistar rats without sex restriction into 4 groups: ?NS(control group), (2)UK, (3)UK+MB, and(4)MB. Inject the microbubbles into femoral vein, and then make ultrasound wave irradiation on head. Some time later, make the heart perfusing and get the brain by decapitation. Observe the opening condition of BBB after HE staining and the effusion of Evans Blue in the Evans blue/fluorescence microscopy method. Observe the changes after the lanthanum trace labeling with electron microscopy.Result The brain tissues of group MB had not been changed obviously. The tissues of group US was not found evident damage. While by transmission electron microscope, It seemed to be fluidify around micrangium and could not find severe hurt in BBB. We found the ultrasound with microbubbles hurt the vessel wall mildly ,opened BBB and made light brain tissue damage,there was peripheral nerve cells being dropsical gently.