Diagnostic ultrasound VFLASH technology to enhance the left ventricular ejection function of acute myocardial ischemia in rats

Department of ultrasound, the second affiliated hospital of the army medical university (the third military medical university), chongqing, 400037, China; Department of ultrasound, wuhan general hospital of the people's liberation army, wuhan 430070, China

Abstract:

Objective to study the diagnostic ultrasound, the diagnostic ultrasound, DUS) VFLASH technology on acute myocardial ischemia model of rats left ventricular ejection function treatment. Methods 6 ~ 8 weeks of 70 healthy male SD rats, by using the random number table method is divided into 5 groups: high mechanical index group (HMI, MI = 1. 4, n = 11), low mechanical index group (LMI, MI = 0. 7, n = 17), HMI joint micro bubble (MB) group (HMB, n = 15) The acute myocardial ischemia model of rats was established by ligating the anterior descending branch of the coronary artery, and ultrasound treatment was performed in groups at 24, 72 and 96 h, respectively. Cardiac ejection fraction (EF) ultrasound was performed on 28 days. 20 Hz 4 MHz frequency, pulse repetition frequency, pulse width in the MI = 1. 4 to 5 cycles, MI = 0. 7 to 18 cycle, pulse duration 1. 2 s, 2 s pulse interval time, duration of 1 200 s. record each rat survival state, with the aim to terminate 28 d, comparison between groups of rat survival. 28 days after comparison between groups rats left ventricular ejection function (EF), take each rat heart tissue and HE staining to observe changes in myocardial tissue. Results (1) survival rate: 72% of the HMI group, 47% of the LMI group, 20% of the HMB group, 50% of the LMB group, 82% of the control group, only the HMI group was higher than the HMB group, the difference was statistically significant (P < 0.05), the difference between the other groups was not statistically significant (P > 0. 05). HMI group (87.71 4.69) %,LMI group (78.04 7.35) %,HMB group (75.09 9.47) %, LMB group (83) 76. 43 + 6. %, the control group (64. 97 + 9.37) %, simple ultrasound group (i.e., HMI and LMI group) and the EF values of LMB group were significantly higher than that of control group, HMI is higher than that of LMI group, the differences were statistically significant (P < 0. 05), there was no statistically significant difference between LMI with LMB (P > 0. 05). (3) the control large cardiac muscle necrosis, fibrosis, and no obvious difference was found between each treatment group fibrosis area. Conclusion ultrasound irradiation VFLASH The technique can effectively improve the cardiac function of acute myocardial ischemia rats, and the simple high mechanical index ultrasound has a better effect and is safer.

Multifunctional hard-shelled microbubbles for differentiating imaging, cavitation and drug release by ultrasound

Waner Chen,‡abc Yan Yang,a Dihua Shangguan, d Yuejing Wue and Zhe Liu Polymeric microbubbles bearing a hard shell exhibit prominent stability and tunable coustical properties that serve the purposes of biomedical imaging and ultrasound (US)-triggered cavitations. It is of great significance to expand the utility scope of hard-shelled microbubbles withmultifunctionality, which will dramatically enhance the efficiency and precision of disease-oriented treatments. To this end, the multifunctional hard-shelled microbubbles (PMBs) for US imaging and US-triggered stimuli-responsive cavitations have been synthesized via a one-step in situ polymerization. Varied parameters including US frequency, acoustical powers and pulse duration time have been screened to optimize the cavitation conditions. It was notable to observe that by use of PMBs, a US-triggered progress of imaging, stable and inertial cavitations could be easily differentiated with an elaborately modulated parameter, which gives a visualizable pathway for imaging, stimuli-responsive cavitation, drug transportation and release at each stage. Meanwhile, commercial US contrast agents (Sonovue and Xueruixin with lipid and protein shell materials) have been compared with PMBs in terms of their cavitation performances. These valuable findings imply a promising perspective to use these multifunctional microbubbles as a novel visualizable theranostic strategy against diseases.