[Show abstract][Hide abstract] ABSTRACT: The myocardial microenvironment plays a decisive role in the survival, migration and differentiation of stem cells. We studied myocardial micro-environmental changes induced by ultrasound-targeted microbubble destruction (UTMD) and their influence on the transplantation of mesenchymal stem cells (MSCs). Various intensities of ultrasound were applied to the anterior chest in canines with myocardial infarction after intravenous injection of microbubbles. The expression of cytokines and adhesion molecules in the infarcted area of the myocardium was detected after three sessions of UTMD in 1 wk. Real-time quantitative reverse transcription polymerase chain reaction (RTQ-PCR) showed that the expression of vascular cell adhesion molecule-1 (VCAM-1), stromal cell-derived factor-1 (SDF-1) and vascular endothelial growth factor (VEGF) in the 1.5 W/cm(2) and 1 W/cm(2) groups was markedly increased compared with the 0.5 W/cm(2) or the control groups (3.8- to 4.7-fold, p < 0.01), and the expression of interleukin-1β (IL-1β) in the 1.5 W/cm(2) group was increased twofold over the 1.0 W/cm(2) group, whereas the 0.5 W/cm(2) group experienced no significant changes. UTMD at 1.0 W/cm(2) was performed as previously described before mesenchymal stem cell (MSC) transplantation. Myocardial perfusion, angiogenesis and heart function were investigated before and 1 month after MSC transplantation. Coronary angiography and 99mTc-tetrofosmin scintigraphy revealed that myocardial perfusion was markedly improved after UTMD + MSCs treatment (p < 0.05). At echocardiographic analysis, heart function and the wall motion score index were significantly improved by UTMD + MSCs treatment compared with MSCs or UTMD alone and the control. In a canine model of myocardial infarction, therapeutic effects were markedly enhanced by MSC transplantation after the myocardial micro-environmental changes induced by UTMD; therefore, this novel method may be useful as an efficient approach for cellular therapy.
Full-text · Article · Aug 2013 · Ultrasound in medicine & biology
[Show abstract][Hide abstract] ABSTRACT: Objectives:
To prospectively assess changes in spleen stiffness and splenoportal venous flow before and after transjugular intrahepatic portosystemic shunt (TIPS) placement.
We prospectively evaluated spleen stiffness measured by the mean shear wave velocity with acoustic radiation force impulse imaging and the splenoportal venous velocity with color Doppler sonography in 12 patients (mean age ± SD, 42.6 ± 11.0 years; range, 29-65 years) who underwent TIPS placement for portal hypertension and gastroesophageal bleeding. The mean shear wave velocity and angle-corrected splenoportal venous velocity at the main portal and splenic veins were measured 1 day before and 3 to 9 days after TIPS placement (mean interval, 6.0 ± 1.95 days; range, 4-10 days) and were compared with portal vein pressure measured during the procedure.
There was a significant difference in portal vein pressure before and after TIPS (25.34 ± 6.21 versus 15.66 ± 6.07 mm Hg; P = .0005). After TIPS, the mean shear wave velocity decreased significantly in all 12 cases (3.50 ± 0.46 versus 3.15 ± 0.39 m/s before and after TIPS; P = .00015). The flow velocity at the main portal vein increased significantly after TIPS (22.21 ± 4.13 versus 47.25 ± 12.37 cm/s; P = .0000051). The splenic vein velocity and spleen index measured 25.57 ± 6.98 cm/s and 55.99 ± 21.27 cm(2), respectively, before TIPS and 35.72 ± 11.10 cm/s and 50.11 ± 21.12 cm(2) after TIPS (P = .0004 and .003).
A significant decrease in the mean shear wave velocity and increase in the splenoportal venous velocity occurred with reduced portal vein pressure after TIPS placement. Hence, both parameters can be used as noninvasive quantitative markers for monitoring TIPS function after placement.
No preview · Article · Feb 2013 · Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine
[Show abstract][Hide abstract] ABSTRACT: Gene therapy holds great promise for the treatment of diseases. The key problem of gene therapy is the choice of an effective vector. Ultrasound-mediated microbubble technique (UMMT) has already shown promising applications in numerous types of tumors apart from cervical carcinoma. In the present study, according to the results of an MTT assay, we initially chose an ultrasound intensity of 0.5 W/cm(2), an ultrasound exposure time of 30 sec and a microbubble concentration of 10% as the optimum experimental condition for wtp53 plasmid transfection into HeLa cells. To further investigate the transfection efficiency of ultrasound combined with microbubbles, RT-PCR analysis was used to examine the mRNA level of p53. The transfection efficiency in the plasmid plus microbubbles and ultrasound group was significantly higher than that of the other groups. Following transfection of the wtp53 gene, flow cytometric analysis showed that the cell cycle of HeLa cells was arrested in the G1 phase. The results of the present study suggest that UMMT, a new gene delivery system, increases the transfection efficiency of the wtp53 gene. Moreover, the growth of HeLa cells was arrested by introducing wtp53. This study may afford a new trend for the gene therapy of cervical carcinoma.
Preview · Article · Jun 2012 · Experimental and therapeutic medicine
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study was to explore the transfection of the recombinant expression plasmid pEGFP-C1/RB94 into human retinoblastoma cells (HXO-Rb44) using ultrasound-targeted microbubble destruction (UTMD). pEGFP-C1/RB94 was transfected into HXO-Rb44 in vitro by UTMD, with liposome as the positive control. After 24 to 72 h, the expression of the reporter gene enhanced green fluorescent protein (EGFP) was observed using fluorescent microscopy and flow cytometry. The cell viability of HXO-Rb44 was measured by a MTT assay. The mRNA and proteins of RB94, caspase-3 and Bax were analyzed by reverse transcription polymerase chain reaction (RT-PCR) and Western blot. Moreover, the apoptosis rate and cell cycle progression of the cells were detected by flow cytometry. This study demonstrated that UTMD can enhance the transfection efficiency of RB94, which has an obvious impact on the inhibition of the growth process of retinoblastoma cells, suggesting that the combination of UTMD and RB94 compounds might be a useful tool for use in the gene therapy of retinoblastoma.
No preview · Article · Apr 2012 · Ultrasound in medicine & biology
[Show abstract][Hide abstract] ABSTRACT: The aim of the present study was to explore whether ultrasound microbubble destruction augments site-targeted engraftment of bone marrow mesenchymal stem cells (BM-MSCs) to kidney tissue and promotes recovery of the kidney in acute kidney injury (AKI) in rats. AKI was induced by the subcutaneous injection of mercuric chloride (HgCl₂). Forty Sprague-Dawley (SD) rats were randomly divided into the following groups after the establishment of rat models of AKI (n = 10): (1) Model group alone (control group); (2) 1.0 W/cm² ultrasound (US) + microbubble (MB) (US/MB group); (3) MSCs group; and (4) 1.0 W/cm² US+MB + MSCs group (US/MB + MSCs group). The number of 4',6-diamidino-2-phenylindole (DAPI) labelled MSCs was evaluated by fluorescence microscopy and real-time polymerase chain reaction (RT-PCR) and Western blotting and histological examination were performed 7 days after MSCs transplantation. It was observed via fluorescence microscopy that the number of DAPI-labelled MSCs in the kidney for the US/MB + MSCs group was significantly more than the MSCs group (p < 0.05). The results from RT-PCR revealed that the US/MB and US/MB + MSCs groups markedly increased the level of inter-cellular adhesion molecule 1 (ICAM-1) messenger ribonucleic acid (mRNA) compared with the control group and the MSCs group (p < 0.05). Western blot analysis showed that the expression of hepatocyte growth factor (HGF) and epidermal growth factor (EGF) in the US/MB + MSCs group were markedly increased compared with the all other groups (p < 0.01). The extent of tubular necrosis and dilation was significantly milder in the US/MB + MSCs group (acoustic exposure conditions: 5s at 1 MHz and 1.0 W/cm² with a 5s pause, totalling 60 s) than the all other groups (p < 0.05). Microbubble destruction by 1.0 W/cm² ultrasound can promote both the homing of BM-MSCs to kidney tissue and the recovery of the kidney in AKI in rats.
No preview · Article · Apr 2012 · Ultrasound in medicine & biology
[Show abstract][Hide abstract] ABSTRACT: To prospectively assess the stiffness of the liver and spleen with acoustic radiation force impulse (ARFI) imaging pre and post transjugular intrahepatic portosystemic shunt (TIPS) placement.
Between February, 2011 and September, 2011, we prospectively measured stiffness of the liver and spleen with mean shear wave velocity (MSV, m/s) on ARFI imaging in 10 healthy volunteers (mean age 32.2 ± 10.3 years, age range 23-53 years) and 10 patients (mean age, 38.6 ± 6.4 years, age range 30-48 years) who underwent TIPS placement for treatment of portal hypertension (PHTN). The portal vein pressure was measured while placing the TIPS. To assess the changes in the stiffness of the liver and spleen following TIPS placement, we measured MSV of the liver and spleen one day before TIPS insertion and 4-9 days after TIPS placement (mean interval 5.9 ± 2.0 days, interval range 5 to 10 days).
There was significant difference in portal vein pressure pre (27.67 ± 5.86 mmHg) and post (18.00 ± 6.93 mmHg) TIPS insertion (P<.01). The MSV of the liver in healthy subjects, patients with PHTN pre TIPS and patients with PHTN post TIPS measured 1.16 ± 0.06 m/s, 2.48 ± 0.39 m/s, and 2.37 ± 0.28 m/s, respectively. The MSV of the spleen in healthy subjects, patients with PHTN pre TIPS and patients with PHTN post TIPS measured 2.22 ± 0.22 m/s, 3.65 ± 0.32 m/s, and 3.27 ± 0.30 m/s, respectively. There were significant differences in MSV of the liver and spleen between healthy subjects and patients with PHTN (all P<.001). There was no significant difference in MSV of the liver pre and post TIPS placement (P>.05). However, a statistically significant difference in MSV of the spleen pre and Post TIPS placement (P<.001) was demonstrated. In addition, we observed a significant difference in spleen index between healthy subjects and patients with PHTN (P<.001), as well as between pre and post TIPS placement (P<.01).
The MSV of the spleen measured with ARFI correlates well with portal vein pressure. Hence, the spleen stiffness by means of MSV on ARFI imaging can be used as a quantitative marker in monitoring the portal vein pressure as the function of the TIPS.
No preview · Article · Mar 2012 · Clinical imaging
[Show abstract][Hide abstract] ABSTRACT: Laser-mediated gene transfection has received much attention as a new method for targeted gene therapy because of the high controllability of laser energy and direction. In this report, we describe a combination laser-microbubble system that enables membrane-impermeable molecules to penetrate cell membranes. The main theories we apply are optical breakdown and photoacoustic generation, which are induced by laser irradiation. Firstly, different types of laser light (Ar-green, Novus Varia poly-wavelength and Nd:YAG laser) were adopted to blast liposome microbubble contrast medium; subsequently, the Nd:YAG laser (1064 nm, 4 ns), which could successfully blast microbubbles, and ultrasound were used in combination to irradiate a mixture of liposome microbubbles and retinoblastoma (Rb) cells. After irradiation, membrane permeability was evaluated by flow cytometric assay using propidium iodide (PI) and fluorescein diacetate (FDA). The proportion of permeabilized resealed cells was affected by changes in the light energy. All of the Nd:YAG laser, Nd:YAG combination laser-microbubble and combination ultrasound-microbubble systems were able to permeabilize the Rb cells. These results suggest that this combination laser-microbubble system is a new means of delivering exogenous materials into living cells.
No preview · Article · Mar 2010 · Lasers in Medical Science
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study was to explore the feasibility of using ultrasound-targeted microbubble destruction to treat liver fibrosis induced by hepatocyte growth factor (HGF).
Forty Wistar rats were divided into five groups after the models of liver fibrosis were prepared: (1) HGF, ultrasound, and microbubbles (HGF+US/MB); (2) HGF and ultrasound (HGF+US); (3) HGF and microbubbles (HGF+MB); (4) HGF (HGF); and (5) model alone (MA). All rats were killed after being transfected for 14 days. Recovery of the liver was detect by diffusion-weighted imaging (DWI) and pathological methods. Collagen I expression was detected by immunohistochemistry. Hepatocyte growth factor expression in the liver was detect by western blotting.
The results of DWI and pathological examination showed the recovery of liver in HGF+US/MB group were better than those of other groups. In HGF+US/MB group, collagen I expression was less, and HGF protein was the highest among all the groups.
Ultrasound-targeted microbubble destruction could deliver HGF into the fibrotic liver and produce an antifibrosis effect, which could provide a novel strategy for gene therapy of liver fibrosis.
No preview · Article · Nov 2009 · Clinical imaging
[Show abstract][Hide abstract] ABSTRACT: Many studies have suggested that the imbalance of angiogenic factor and anti-angiogenic factor expression contributes significantly to the development of choroidal neovascularization (CNV), and ultrasound microbubble combination system can increase the gene transfection efficiency successfully. This study was designed to investigate whether ultrasound-mediated microbubble destruction could effectively deliver therapeutic plasmid into the retina of rat, and whether gene transfer of pigment epithelium-derived factor (PEDF) could inhibit CNV.
Human retinal pigment epithelial cells were isolated and treated either with ultrasound or plasmid alone, or with a combination of plasmid, ultrasound and microbubbles to approach feasibility of microbubble-enhanced ultrasound enhance PEDF gene expression; For in vivo animal studies, CNV was induced by argon lasgon laser in rats. These rats were randomly assigned to five groups and were treated by infusing microbubbles attached with the naked plasmid DNA of PEDF into the vitreous of rats followed by immediate ultrasound exposure (intravitreal injection); infusing liposomes with the naked plasmid DNA of PEDF into the vitreous (lipofectamine + PEDF); infusing microbubbles attached with PEDF into the orbit of rats with ultrasound irradiation immediately (retrobular injection); infusing microbubbles attached with PEDF into the femoral vein of rats with exposed to ultrasound immediately (vein injection). The CNV rats without any treatment served as control. Rats were sacrificed and eyes were enucleated at 7, 14, and 28 days after treatment. Gene and protein expression of PEDF was detected by quantitative real-time RT-PCR, Western blotting and immunofluorescence staining, respectively. The effect of PEDF gene transfer on CNV was examined by fluorescein fundus angiography.
In vitro cell experiments showed that microbubbles with ultrasound irradiation could significantly enhance PEDF delivery as compared with microbubbles or ultrasound alone. In the rat CNV model, transfection efficiency mediated by ultrasound/microbubbles was significantly higher than that by lipofectamine-mediated gene transfer at 28 days after treatment. The study also showed that with the administration of ultrasound-mediated microbubbles destruction, the CNV of rats was inhibited effectively.
Ultrasound-microbubble technique could increase PEDF gene transfer into rats' retina and chorioid, in association with a significant inhibition of the development of CNV, suggesting that this noninvasive gene transfer method may provide a useful tool for clinical gene therapy.
Preview · Article · Nov 2009 · Chinese medical journal
[Show abstract][Hide abstract] ABSTRACT: The aim of the present study was to explore the gene transfection efficiency of Tat peptide/plasmid DNA/ liposome (TDL) compound combined with ultrasound-targeted microbubble destruction (UTMD) in human umbilical vein endothelial cell (HUVEC). Tat peptide, plasmid DNA (pIRES2-EGFP-HGF) and Lipofectamine™ 2000 were used to prepare the TDL compound. Microbubbles were prepared using mechanic vibration. The expression of the report gene enhanced green fluorescent protein (EGFP) was observed using fluorescent microscopy and flow cytometry. The viability of HUVEC was measured by MTT assay. mRNA and protein of HGF was analyzed by reverse transcription-polymerase chain reaction and Western Blot. The intensity of green fluorescence and the gene transfection efficiency of TDL compound + microbubbles + ultrasound group were higher than those of other groups, and no significantly different viability was found between TDL compound + microbubbles + ultrasound group and the other groups. The HGF mRNA and HGF protein of TDL compound + microbubbles + ultrasound group were higher than those of other groups. Our finding demonstrated that UTMD could enhance the transfection efficiency of TDL compound without obvious effects on the cell viability of HUVEC, suggesting that the combination of UTMD and TDL compound might be a useful tool for the gene therapy of ischemic heart disease. (E-mail: [email protected]
No preview · Article · Nov 2008 · Ultrasound in medicine & biology
[Show abstract][Hide abstract] ABSTRACT: To investigate the effects of paclitaxel loaded ultrasound contrast agents on cell cycles and ultrastructural features of HepG2 cells.
HepG2 cells were cultured, and divided into a blank control group, a paclitaxel group, an ultrasound contrast agents group, and a paclitaxel loaded ultrasound contrast agents group. Cell cycles of the four groups were detected by flow cytometry, and the ultrastructural changes of the cells were observed under a transmission electron microscope.
Paclitaxel loaded ultrasound contrast agents blocked the HepG2 cells at their G2/M phases, and it also induced more apoptosis of the HepG2 cells.
Paclitaxel loaded ultrasound contrast agents can block HepG2 cells at the G2/M phase and induce apoptosis of the cells.
No preview · Article · Jun 2008 · Zhonghua gan zang bing za zhi = Zhonghua ganzangbing zazhi = Chinese journal of hepatology
[Show abstract][Hide abstract] ABSTRACT: Objective To study the effects on human glioma cell line CHG-5 by ultrasonic microbubble intensifier with survivin antisense oligonucleotides
Methods Antisense oligonucleotides targeting survivin mRNA was designed and synthesized. Four regimen groups were designed, group
A: survivin antisense oligonucleotides transfected with ultrasonic microbubble intensifier combined with ultrasound irradiation,
group B: survivin antisense oligonucleotides transfected with lipofectamine combined with ultrasound irradiation, group C:
survivin antisense oligonucleotides with lipofectamine transfection, group D: blank control. The expression changes of surviving
protein were measured by immunohistochemical staining and Western blotting, and MTT assay was used to measure the changes
Results Survivin protein expression in group A was decreased significantly in human glioma cell line CHG-5 than other groups(PP
No preview · Article · Jun 2008 · Chinese Journal of Cancer Research
[Show abstract][Hide abstract] ABSTRACT: The objective of this study was to noninvasively evaluate the severity of renal ischemia-reperfusion (I-R) injury in rabbits with microbubbles targeted to activated neutrophils [phosphatidylserine-conjugated surfactant perfluoropropane-filled microbubbles (SPMB-PS)].
Microbubbles targeted to activated neutrophils (SPMB-PS) were prepared by conjugating phosphatidylserine (PS) to self-assembling surfactant perfluoropropane-filled microbubbles (SPMB). Flow cytometry was performed to assess the presence of PS in SPMB. A renal I-R injury model was established in 18 rabbits for contrast-enhanced ultrasonography. Examination of ultrasonography with SPMB-PS and SPMB was performed on 12 rabbits before and after I-R injury. The time-intensity curve (TIC) was generated from a selected region of interest. Another six rabbits with renal I-R injury underwent contrast-enhanced ultrasonography for 15 min after intravenous injection of SPMB-PS. The renal tissues were immediately excised for immunohistochemical staining and myeloperoxidase (MPO) activity analysis. The correlation between MPO activity and echo intensity (VI) was analyzed.
Flow cytometry demonstrated that PS was located on the surface of SPMB. TIC showed that the time at which the maximum VI was reached and the time needed for the microbubbles to wash out were the same in the normal kidneys injected with SPMB-PS or SPMB, while there was an obvious delay in emptying time with SPMB-PS compared with SPMB after I-R injury. Fifteen minutes after the injection of SPMB-PS and SPMB, VI was not remarkably different (P>.05) in the normal kidneys, while it was significantly higher (P<.01) in the I-R-injured kidneys. There was a strong correlation between MPO activity and VI 15 min after the injection of SPMB-PS (r=.933, P<.01). Immunohistochemistry showed that most of the inflammatory cells in the I-R-injured kidneys were neutrophils.
A delayed emptying phenomenon was observed during contrast-enhanced ultrasonography in the I-R-injured kidneys, with SPMB-PS targeted to activated neutrophils. Therefore, contrast-enhanced ultrasonography with SPMB-PS may noninvasively evaluate the severity of ischemia-reperfusion injury to the kidneys.
No preview · Article · May 2008 · Clinical imaging
[Show abstract][Hide abstract] ABSTRACT: To explore the feasibility of therapeutic angiogenesis in myocardial infarction induced by hepatocyte growth factor (HGF) mediated by ultrasound-targeted microbubble destruction.
Forty Wistar rats were divided into 4 groups after the models of myocardial infarction were established: HGF + ultrasound + microbubble (HGF + US/MB) groups, HGF and ultrasound (HGF + US) group, HGF and microbubble (HGF + MB) group, and surgery alone (SA) group. Ultrasound-targeted destruction microbubble loaded with HGF gene with ECG trigger was performed in HGF + US group. Microbubble loaded with HGF gene was infused intravenously in HGF + MB group, and normal saline were infused in SA group. All rats were killed 14 days after transfection. The CD34 expression was detected by immunohistochemistry (IHC), and microvessel density (MVD) was counted in high power field. The HGF expression on myocardium was detected by ELISA, and the correlation between the contents of HGF and MVD in myocardium was analyzed.
IHC results showed that CD34 expressions, shown as brown granules, were located on the membrane and endochylema of vascular endothelial cells. The MVD in HGF + US/MB group [ (266.9 +/- 39.8) /HPF] were highest among all the groups. The contents of HGF in myocardium were highest in HGF + US/MB group [(5.54 +/- 0.81) ng/g], and the contents of HGF in anterior wall were significantly higher than those in posterior wall (P < 0.05); the difference was also significant when compared with others groups (P < 0.01). The correlation analysis showed the contents of HGF was positively correlated with MVD in myocardium.
Ultrasound-targeted microbubble destruction can effectively deliver HGF into the infracted myocardium and facilitate angiogenesis, which provides a novel way in the gene therapy of myocardial infarction.
No preview · Article · Mar 2008 · Zhongguo yi xue ke xue yuan xue bao. Acta Academiae Medicinae Sinicae
[Show abstract][Hide abstract] ABSTRACT: To study whether antisense oligonucleotides and ultrasonic microbubble intensifier transfection combined with ultrasound irradiation is an effective and directional way in reversing multidrug resistance (MDR) in tumors.
Mdr1, mrp, and lrp genes antisense oligonucleotides on the ultrasound microbubble intensifier were transfected for the human HepG2/ADM cell lines and then the cells were radiated with low intensity ultrasound. The effects of the reversion of carcinoma cells' MDR and the reduction of their malignancy and growth capability in vitro and in vivo were assessed using RT-PCR, Western blot and MTT.
The treatment restrained the multiplication of the human HepG2/AMD cell lines. The levels of their mRNA and protein of cells' mdr1 and mrp genes dropped significantly. Growth of the subcutaneous transplanted tumors in the nude mice decreased.
Transfection of MDR genes antisense oligonucleotides on the ultrasonic microbubble intensifier combined with low intensity ultrasound radiation may serve as a new treatment method for hepatocellular carcinoma.
No preview · Article · Jun 2006 · Zhonghua gan zang bing za zhi = Zhonghua ganzangbing zazhi = Chinese journal of hepatology