ABSTRACT
Objective:To evaluate the right ventricular(RV) function by two-dimensional speckle tracking echocardiography(2D-STE) in heart failure patients with different left ventricle diastolic dysfunction grade.Methods:Twenty-nine healthy volunteers(control group), sixteen heart failure patients with reduced ejection fraction(HFrEF group) and eighty-six heart failure patients with preserved ejection fraction(HFpEF group) were enrolled in the Second Affiliated Hospital of Chongqing Medical University from October 2018 to September 2019. HFpEF patients were further divided into four subgroups according to recommendations of the American Society of Echocardiography in 2016: normal left ventricular diastolic function group and left ventricular diastolic dysfunction groups with grade 1, 2, 3 (LVDD1, LVDD2, LVDD3). Conventional ultrasonic parameters were obtained in apical four-chamber images, including RV basal diameter(RVD1), RV middle diameter(RVD2) and RV longitudinal diameter(RVD3), RV end diastolic area(EDA), end systolic area(ESA) and fractional area change(FAC), peak systolic velocity(S′), myocardial performance index(MPI), tricuspid annular plane systolic excursion(TAPSE). 2D-STE was performed to observe strain parameters, including basal, middle, apical and the whole longitudinal peak systolic strain of RV free wall respectively (RVLSbas, RVLSmid, RVLSapi and RVLSfw). Then 2D strain parameters were compared among these groups, and the correlation between 2D strain parameters and conventional ultrasonic parameters were analyzed.Results:①TAPSE and S′ gradually decreased in normal group, HFpEF group and HFrEF group(all P<0.05). For the four subgroups of HFpEF, compared to LVDD3, TAPSE、S′ increased significantly in normal group, LVDD1 and LVDD2(all P<0.05). ②RVLSbas, RVLSmid, RVLSfw gradually increased in control group, HFpEF group and HFrEF group(all P<0.05). The same trend appeared in group LVDD1, LVDD2 and LVDD3(all P<0.05). ③In control group, HFpEF group and HFrEF group, RVLSfw showed strong correlation with LVEF( r=0.77, P<0.01) and middle correlation with age, TAPSE, and S′( r=0.41, -0.48, -0.40, P<0.01). In the subgroups of HFpEF, RVLSfw had middle correlation with LV diastolic function( r=0.59, P<0.01), and weak correlation with age( r=0.21, P<0.01), and the same correlations with B-type natriuretic peptide(BNP), FAC, TAPSE( r=0.28, -0.29, -0.29; all P<0.01). Conclusions:2D-STE can detect the early subtle impairment of RV systolic function in HFpEF patients.
ABSTRACT
ObjectiveTo evaluate the accuracy and reproducibility of three‐dimensional echocardiographic( 3DE) automated quantification technique for assessment of left heart chamber volumes and function in consecutive patients . Methods One hundred and fifty consecutive patients underwent 3DE were enrolled in the cross‐sectional study . According to image quality , the patients were divided into satisfactory group ( n ＝ 102 ) and unsatisfactory group ( n ＝ 33 ) . T he accuracy and reproducibility of automated 3DE for measuring left ventricular end‐diastolic volume ( LVEDV ) , left ventricular end‐systolicvolume ( LVESV ) ,left atrial volume ( LAV ) and left ventricular ejection fraction ( LVEF ) were evaluated by the traditional manual 3DE as the relative standard . Among those with satisfactory image quality ,the effects of cardiac cycle selection on automatic 3DE were analyzed . In addition ,according to LVEDV index and LAV index ,the patients were grouped as enlargement group and normal group ,and the significance of editing the endocardial boundaries for both groups were analyzed . Results ① One hundred and thirty‐five patients were successfully analyzed by the automated 3DE . T he inter‐technique comparisons showed good correlations ( r‐values :LVEDV 0 .90 ,LVESV 0 .87 ,LAV 0 .86 ,LVEF 0 .67 ;all P ＜ 0 .01 ) and small biases( LVEDV 11 .9 ml ,LVESV 6 .4 ml ,LAV 9 .0 ml ,LVEF －0 .4% ) for all measurements in all patients . ② T he various parameters in satisfactory group had better correlations and consistency than those in the unsatisfactory group( all P ＜0 .05) . ③Between the two different cardiac cycles ,the automated 3DE measurements showed good correlations( r‐values :EDV 0 .96 ,ESV 0 .96 ,LAV 0 .95 ,LVEF 0 .80 ;all P＜ 0 .01 ) . ④ After optimized boundary of the automated 3DE ,LVEDV ,LVESV increased and LVEF decreased in the left chamber enlargement group( all P ＜0 .05) . ⑤All automated measurements were more reproducible than conventional manual measurements in both intra‐/inter‐observer studies . Conclusions Since automated 3DE is accurate and reproducible for the assessment of left heart chamber volumes and function ,it can be widely used in clinical practice as a feasible and objective ultrasound technique .
ABSTRACT
Purpose To develop the folate-targeted theranostic nanoprobe, investigate the active targeting behavior of nanoprobes to hepatocellular carcinoma(HCC)in vitro,and discuss the effect of enhanced US/MRI dual-mode imaging in vitro and the synergistic effect of high intensity focused ultrasound on HCC killing. Materials and Methods The folate-targeted nanoprobe loaded with iron oxide nanoparticles (Fe3O4) and phase-shift material perfluorohexane (PFH) was prepared by double emulsion method and carbodiimide method. The average particle size, morphological structure and the ability of liquid-gas phase transition were detected. The active targeting ability of the nanoprobe to HCC BEL-7402 was observed in vitro.The ultrasonic imaging effect of nanoprobe was observed by HIFU irradiation in vitro.MRI was performed on the Fe3O4nanoprobe with different content of magnetic particles.The synergistic killing ability of the nanoprobe combined with HIFU on liver cancer cells was detected with in vitro apoptosis experiment. Results The folate-targeted nanoprobe loading iron oxide nanoparticles (Fe3O4) and phase-shift material PFH was prepared, with the average size of (402.50±66.43) nm. It was in the shape of regular sphere with the magnetic particle Fe3O4scattered inside. The HIFU irradiation caused liquid and gas phase transition.In vitro targeting experiments showed that BEL-7402 cells were surrounded by a large number of nanoscale probes.In vitro dual mode imaging showed that the ultrasonic echo intensity was obviously enhanced after HIFU irradiates nanoscale probes. The MR negative imaging ability of the nanoprobe was also enhanced with the enhancement of Fe3O4concentration in nanoparticles. In vitro apoptosis experiments showed that the nanoscale probe had the ability to significantly enhance the effect of HIFU on the killing of HCC. Conclusion The prepared folate-targeted theranostic nanoprobes exhibit the excellent capability for in vitro targeting.They can be used for ultrasound and MRI as multimodal imaging agents and coordinates with HIFU to enhance the effect on killing HCC, which realizes the early diagnosis of tumor and targeted precision therapy.
ABSTRACT
Speckle tracking imaging (STI) has been used to evaluate the changes in cardiac function through quantifying myocardial deformation,which can accurately quantify right ventricular function and improve the diagnostic efficacy,early detect the right ventricular dysfunction of cardiopulmonary diseases.The progresses of STI in the evaluation on right ventricular function were reviewed in this article.
ABSTRACT
Objective To investigate the targeting ability and photoacoustic imaging of novel nanoparticle probe loaded with ZnPc and docetaxel.Methods The polymeric nanoparticles probe loaded with ZnPc and docetaxel were fabricated using double emulsion method.RGDfK was modified on the surface for breast carcinoma targeting by carbodiimide method.The encapsulating ratio (ER) and drug loading (DL) of ZnPc and docetaxel were assessed.The modification rate and targeting ability of molecular probe were tested in vitro,and the photoacoustic imaging and drug release profiles were observed.Results The probes were loaded with ZnPc and docetaxel efficiently and successfully.The size of novel nanoparticle loaded with ZnPc and docetaxel was (266.00 ± 65.85)nm,and the surface potential was (-29.20± 6.27)mV.ER and DL of docetaxel was (88.00±0.32)％ and (34.92±0.02)μg/mg,of ZnPc was (97.25±0.22)％ and (30.87±0.11)μg/mg,respectively.The probes had certain sustained slow release effect and showed obvious photoacoustic signals,which enhanced with the increase of the content of ZnPc.Flow cytometry detection results showed that the RGDfk modification rate was 89.19％.The apoptotic rate of novel nanoparticle loaded with ZnPc and docetaxel targeting breast carcinoma increased after the laser irradiation in vitro.Conclusion The new polymeric multifunctional nanoparticles probe has an ideal size and good photoacoustic signals,also the ability to target breast carcinoma cells and inhibit the proliferation of breast carcinoma cells efficiently.
ABSTRACT
Nowadays,breast imaging-reporting and data system for ultrasound (BI-RADS-US) is widely used in the clinic.With the rapid development of ultrasound technology,such as elastography,CEUS,three-dimensional ultrasonography and MicroPure technology,the combination of new ultrasonic technology with BI-RADS-US plays a more important role in improving the ability of ultrasound in diagnosis of small breast lesions and the diagnosis efficiency for breast cancer.The status of new ultrasonic technology combined with BI-RADS-US in evaluating benign and malignant breast lesions were reviewed in this article.
ABSTRACT
Carotid artery vulnerable plaque is prone to rupture and thrombosis,which is closely related to the occurrence of stroke.The detection of carotid plaque vulnerability is particularly important for early risk assessment of cerebrovascular disease.Carotid ultrasound is noninvasive,less expensive and with high reproducibility,therefore has become the important method for detecting the vulnerability of carotid artery plaque.The progresses of ultrasound technique for detection of carotid vulnerable plaque in recent years were reviewed in this article.
ABSTRACT
Purpose To compare the diagnostic value of thyroid imaging reporting and data system (TI-RADS) made out by American College of Radiology (ACR TI-RADS) and Kwak (Kwak TI-RADS) on thyroid nodules.Materials and Methods Clinical data and preoperative ultrasound images of 920 patients with thyroid nodules (in total 1130 nodules) were retrospectively analyzed.The nodules were classified according to two TI-RADS standards and performance curves of the subjects were constructed with surgical pathological results as golden standards.Diagnostic value of two TI-RADS on thyroid nodules was analyzed and diagnostic efficiency was compared.Results For the 1130 thyroid nodules,malignant rate for 1-5 category patients classified by ACR TI-RADS was 0,0,8.4％,50.9％ and 88.4％,respectively;and that for 2-5 category patients (2,3,4a,4b,4c,5) classified by Kwak TI-RADS was 0,1.2％,9.1％,50.0％,87.8％ and 89.5％,respectively.Susceptibility,specificity,positive predictive value (PPV) negative predictive value (NPV) accuracy and area under curve (AUC) of benign and malignant thyroid nodules diagnosed by Kwak TI-RADS were 95.7％,77.9％,75.5％,96.3％,85.3％ and 0.925,respectively.Susceptibility,specificity,PPV,NPV,accuracy and AUC of benign and malignant thyroid nodules diagnosed by ACR TI-RADS were 97.0％,73.2％,72.0％,97.2％,83.1％ and 0.918,respectively.A statistical difference in specificity was shown between ACR TI-RADS and Kwak TI-RADS (P＜0.05).but no statistical difference in susceptibility,PPV,NPV,acuracy or AUC was found between the two groups (P＞0.05).Conclusion The two TI-RADS were of quite high value in diagnosing benign and malignant thyroid nodules.Kwak TI-RADS was of higher specificity compared with ACR TI-RADS.
ABSTRACT
Objective To prepare a kind of Gelsolin-targeted ultrasound contrast agent (GSN-PLGA) and to explore its targeting and imaging effection in vitro.Methods The high molecular PLGA-COOH ultrasound contrast agents were prepared by a modified double emulsion technique and then conjugated with Gelsolin monoclonal antibody by carbodiimide technique.The physical property of contrast agent was determined.And the connectivity condition of ultrasound contrast agent with Gelsolin monoclonal antibody was estimated.The targeting ability and the effect of enhancing ultrasound imaging in vitro were explored.Results The average diameter of GSN-PLGA was (575.67 ± 4.71) nm.The potential was (-11.46±1.19) mV.And the binding rate of Gelsolin monoclonal antibody was 96.93％.In vitro experimentshowed more GSN-PLGA could be intaked by Hca-F cells and the ultrasound imaging cloud be enhanced greatly.Conclusion The GSN-PLGA nanoparticle can bind to Hca-F cells specifically and can enhance the ultrasound imaging greatly.
ABSTRACT
Objective To investigate distribution of carotid plaques,degree of stenosis and risk factors of unstable plaques in patients with acute ischemic stroke.Methods Totally 909 patients with acute ischemic stroke (AIS group) confirmed with head MRI were enrolled,while 885 patients without stroke in the same period hospitalization were selected as controls (control group).The distribution of carotid plaques and the degree of stenosis were compared between the 2 groups.Patients in AIS group were divided into stenosis rate ≥50％ subgroup and ＜50％ subgroup according to the degree of carotid artery stenosis,and the detectable rate of stable plaques and unstable plaques were compared between the 2 groups.Clinical data of patients with unstable plaques and non-unstable plaques in AIS group were compared.Logistic regression models were established with parameters with significantly differences among those features.Results The detectable rates of multiple plaques and unstable plaques of carotid artery and the degree of stenosis in AIS group were statistically higher than those in control group (all P＜0.001).The detectable rate of unstable plaque in carotid artery stenosis rate ≥50％ group was statistically higher than that in stenosis rate ＜50％ group (P＜0.001).Age,male,diabetes,dyslipidemia,smoking and drinking were significantly risk factors (all P＜0.05).Age,diabetes,dyslipidemia and smoking were independent risk factors (all P＜0.05).Conclusion Carotid unstable plaque and stenosis are closely related to the occurrence of AIS.Age,diabetes,dyslipidemia and smoking are independent risk factors for carotid artery plaque.
ABSTRACT
Ultrasonography is considered as the preferred imaging method in diagnosis of thyroid nodules,which can quickly locate thyroid nodules and assess the size,shape,internal structure,echo level of thyroid nodules and surrounding lymph nodes.New technology of elasticity imaging and CEUS can respectively evaluate the hardness and blood supply of thyroid nodules,being helpful to nature diagnose of nodules.The progresses of ultrasound in diagnosis of benign and malignant thyroid nodules were reviewed in this article.
ABSTRACT
Objective To evaluate the intra- and interatrial synchronization before and after pacemaker implantation in patients with sick sinus syndrome ( SSS) by tissue Doppler imaging ( TDI) . Methods Thirty-eight patients with SSS ( SSS group ) underwent pacemaker implantation . Echocardiography was performed before and after operation . Twenty-five volunteers were chosen as control group . Routine measurement of left and right atrial diameter by echocardiography . In apical four chamber view ,the sample volume of TDI was located at right atrial lateral wall at tricuspid annulus ,interatrial septum and left atrial lateral wall at mitral annulus . The interval time between the early diastolic wave ( E wave) and the late diastolic wave (A wave) (E-AR ,E-AI ,E-AL ) ,and the duration of A wave (AR ,AI ,AL ) were measured . At the same time ,the electromechanical coupling time was measured ,namely the initiation of the P wave of the synchronous electrocardiogram to the starting point of A wave ( P-A0R ,P-A0I ,P-A0L ) , and the starting point of the P wave to the peak point of the A wave ( P-AR ,P-AI ,P-AL ) . And the right atrial electromechanical delay time ,P-A0I and P-A0R value ( T0IR ) ,P-AI value and P-AR value ( TIR ) were recorded .Other parameters include left atrial electromechanical delay time:P-A0L and P-A0I value ( T0LI ) , and P-AL and P-AI value ( TLI ) ;interatrial electromechanical delay time:P-A0L and P-A0R value ( T0LR ) ,P-AL and P-AR ( TLR ) were recorded . Results Compared with the control group ,left atrium and right atrium in SSS group enlarged before operation , E-AR ,E-AI ,E-AL ,P-A0R ,P-A0I ,P-AR ,P-AL prolonged ,while T0LR and T0LI were shortened ( all P < 0 .05 ) . Postoperative changes in SSS group patients included shortened E-AR ,E-AI and E-AL ,and prolonged T0LI and T0LR ( all P <0 .05) . Compared with the control group ,the size of left atriums and right atriums in SSS group still increased postoperation ,and the P-A0I 、P-AR and P-AL remained longer (all P <0 .05) . The same as the control group ,the postoperative AR ,AI and AL in SSS group were decreased successively ( all P < 0 .05 ) . Conclusions In SSS patients , electromechanical asynchrony exists in different part of atrium and between left atrium and right atrium . Pacemaker therapy can improve atrial electromechanical synchronicity .
ABSTRACT
Objective To investigate the ability of targeting in vitro breast carcinoma and photoacoustic-mediate apoptosis of breast carcinoma of the nanoparticle probe loaded with Fe3O4 and observe its consequence of photoacoustic imaging in vitro.Methods The polymeric multifunctional nanoparticles probe that was loaded with Fe3O4 and connected with Herceptin targeting breast carcinoma was prepared in the use of double emulsion method and carbodiimide method.General physical property,the condition of Herceptin connected with nanoparticles and the ability of targeting of the probe were tested.The different concentration of nanoparticles was imaged by photoacoustic.The inhibiting effect of targeting nanoparticles on breast carcinoma cells was evaluated in vitro.Results The targeting polymeric multifunctional nanoparticles probes loaded with Fe3O,were prepared successfully with average particle diameter of (235.4± 53.75)nm and Zeta potential (-13.4 ± 4.7)mV.Fe3O4 particles dispersed on the shell of the probes.Antibody Hereeptin was successfully connected with the surface of the nanoprobes.There were massive targeting nanoprobes surround the breast carcinoma cell strains SKBR3 in the targeting group in vitro.The photoascoustic signal of the nanoprobes enhanced with the increase of Fe3O4 concentration in photoacoustic experiment in vitro.The apoptotic rate of breast carcinoma increased after the laser irradiation in the cell inhibition experiment in vitro.That proved the obvious inhibition of breast carcinoma cells was caused by photothermal effect of the prepared nanoprobes.Conclusions The prepared polymeric multifunctional nanoparticles probe that was loaded with Fe3O4 and connected with Herceptin targeting breast carcinoma can be used as a photoacoustic contrast agent,which can inhibit the proliferation of breast carcinoma by targeting photoacoustic therapy.
ABSTRACT
Objective To study the targeting ability of aptamer-modified PLGA nanoparticle encapsulated with gold nanorod and liquid perflurocarbon,and observe its mediated ultrasound/photoacoustic dual-modality imaging in vitro.Methods PLGA nanoparticle was prepared using double emulsion technique.Aptamer-modified PLGA nanoparticle was obtained by connecting,then PLGA nanoparticle was conjugated with MUC1 aptamer carbodiimide technique aimed to obtain aptamer-modified PLGA nanoparticle.Targeting ability of aptamer-modified PLGA nanoparticle to MCF-7 tumor cells in vitro was tested by fluorescence microscope.Besides,there were three control groups including PLGA nanoparticle group,aptamer group and HELA cell group.A commercial photoacoustic instrument was used to detect ultrasound/photoacoustic signal.Results A significant number of aptamer-modified PLGA nanoparticles gathered around the MCF-7 cells,however,the specific binding can not be observed in control groups.Both ultrasound and photoacoustic signal intensity of the aptamer-modified PLGA nanoparticles increased significantly when excited with laser.Conclusions The aptamer-modified PLGA nanoparticle was successfully prepared,and had superior targeting ability to MCF-7 cells,Morever,ultrasound/photoacoustic signal emitted the by nanoparticle increased significantly.These properties make the targeted nanoparticle a great potential to become a distinguished uhrasound/photoacoustic dual modality contrast agent,which lays good foundation for further targeted imaging application in vivo.
ABSTRACT
Objective To assess the applicative value of near infrared fluorescence compound PZ -1009 in tumor imaging .Methods Near infrared fluorescence imaging properties of the compound was evaluated in a mouse model of ovarian cancer .The athymic nude mice were inoculated with SKOV -3 ovarian cancer cells and imaged in vivo and ex vivo after injecting PZ -1009 and were performed periodically .Results The tumor loca-tion was clearly imaged after 1 h of injection.The maximum fluorescence intensity was at 6 h time point and there was still a few fluorescent signal in tumors after 48hrs.A professional software was used to measure the intensity including all tumors and normal regions .The results showed that the intensity of tumors was higher than all normal regions in any time points .Conclusion The compound of PZ -1009 can efficiently target tumor sites and has great potential in noninvasive real time early tumor diagnosis .
ABSTRACT
Objective To synthesize a photoacoustic contrast agent loaded with gold nanorod and liquid perflurocarbon which was used to observe its photoacoustic imaging in vitro,and then investigate the variation of the photoacoustic signal during and after the vaporization.Methods The PLGA nanoparticle (GNP)loaded with gold nanorod(GNR) and liquid perflurocarbon was synthesized via double emulsion technology.The experiments were divided into three groups:1)GNP group:PLGA nanoparticle loaded with gold nanorod and liquid perflurocarbon; 2) GNR group:gold nanorod ; 3) control group:PLGA nanoparticle unloaded with gold nanorod.A pulsed laser system was used to trigger the three samples.The photoacoustic image and time-signal intensity kinetics were acquired by the photoacoustic microscope.The optical microscope was used to observe the image after the vaporization.Results The gold nanoparticle was successfully prepared,the average size of the gold nanoparticle was 504.9 nm.after triggered by the pulsed laser system,the vaporized image of the GNP group could be observed by the optical microscope.The photoacoustic signal was detected in both GNP and GNR groups,and the signal intensity increased along with the concentration of the GNR.However,the photoacoustic signal of PLGA group was not detected.The photoacoustic signal kinetics of GNP group showed a descending trend from high signal amplitude to steadystate.The GNR group photoacoustic signal kinetics only showed a steady-state signal amplitude.Conclusions The PLGA nanoparticle loaded with gold nanorod and liquid perflurocarbon emerged a phase transient which produces a strong photoacoustic signal after triggered by pulsed laser system.This kind of phenomenon leads the nanoparticle to be a better photoacoustic contrast agent and lays a foundation for in vivo research and photothermal therapy in vivo.
ABSTRACT
Purpose To explore the apoptosis mechanism of human ovarian cancer cells SKOV3 processed with ultrasound (US) combined with photodynamic therapy (PDT), with self-contained lactic acid/glycolic acid (PLGA) microbubbles (MBQDs/PLGA) containing quantum dots (QDs) as a photosensitizer. Materials and Methods MBQDs/PLGA was prepared with double emulsion method, and MTT was used to compare the cytotoxic activity difference between QDs and MBQDs/PLGA, to determine the proper treatment condition. SKOV3 cells were treated under selective conditions, cell damage manifestation was observed with HE staining, and double staining flow cytometry was used to detect cell apoptosis. Results When cells were treated with PDT with energy density of 180.0 J/cm2 and US with sound intensity of 0.5 W/cm2 (1.0 MHz, 10 s), cell deformation could be observed under a microscope in both US-PDT-MBQDs/PLGA group and PDT-MBQDs/PLGA group, and cell connections were absent between cells;transmission electron microscope showed dense chromatin gathered along the nuclear membrane, with the formation of apoptotic bodies also be displayed. Maximum apoptosis rate was (22.17±0.38)% Conclusion MBQDs/PLGA-mediated PDT contains proliferation inhibition effect for SKOV3 cells, which can be synergied with low-power ultrasonic irradiation due to sonoporation effect.
ABSTRACT
Objective To explore the feasibility of virtual touch tissue quantification(VTQ) technique in noninvasive assessment of transjugular intrahepatic portosystemic stent shunt (TIPSS).Methods Twenty-four patients were enrolled in this study.Shear wave velocity(SWV) of the liver and spleen were obtained by VTQ technique on one day before TIPSS insertion and one week after TIPSS placement,and the portal vein pressure was measured while placing the TIPSS.The correlation between SWV of the liver and spleen and portal venous pressure were analysed.In addition,fourteen patients were followed up for one month after TIPSS placement.Results There was significant difference in portal vein pressure pre [(27.82 ± 4.07) mm Hg] and post [(16.26-± 3.10) mm Hg] TIPSS insertion.The SWV of the liver in patients pre and post TIPSS measured (2.43 ± 0.37)m/s and (2.40 ± 0.34)m/s,respectively.The SWV of the spleen in patients pre and post TIPSS were (3.49 ± 0.40)m/s and (3.08 ± 0.39)m/s,respectively,there was significant difference (P =0.000).However,SWV of the liver pre and post TIPSS placement was no significant difference(P =0.130).And as well as the patients which were followed up for one month after TIPSS placement.A significant,direct,linear correlation(r =0.602,P =0.000) was found between SWV of the spleen and portal vein pressure,but liver SWV was not correlated with the portal venous pressure.Conclusions SWV of the spleen measured by VTQ technique has a significant correlation with portal vein pressure.Hence,the spleen SWV based on VTQ technique can be used as a non-invasive method for quantitatively in monitoring the portal vein pressure as the function of the TIPSS.However,evidence to support a similar role for liver stiffness is lacking.
ABSTRACT
Objective To prepare the quantum dots(QDs) (CdTe-MPA)-loaded polymer(lactic-coglycolic acid,PLGA) microbubbles(MBQDs@PLGA) as dual-modality imaging agent for both fluorescent and ultrasonic imaging ability.Methods The MBQDs@PLGA were generated by the double emulsion technique,then filling in C3F8 after freeze-drying.Confocal laser scanning microscope(CLSM) and transmission electron microscope(TEM) were used to confirm the load of quantum dots in the MBs.Fluorospectro photometer spectra of the MBQDs@PLGA were analyzed to demonstrate the fluorescent imaging ability and determine the encapsulation efficiency by using the regression equation.Imaging experiments was applied to validate the fluorescent and ultrasonic imaging ability of the MBQDs@PLGA both by imaging of the model in vitro and by imaging of ovarian tumor blood vessels of tumor-bearing nude mouse in vivo.Results At excitation 272 nm the MBQDs@PLGA peak of the emission spectrum was 549 nm,and the encapsulation efficiency was 54％.The average diameter of MBQDs@PLGA was (1.7 ±0.2)μm,CLSM and TEM results confirmed the QDs-loaded in MBQDs-PLGA.The imaging results of MBQDs@PLGA showed a dual-modality imaging ability both fluorescent and ultrasonic imaging.Conclusions MBQDs@PLGA present fluorescence-ultrasound dual mode imaging performance by the QDs embedding in polymer microbubbles,and explore a new development train of thought of multi-mode imaging agent.
ABSTRACT
Objective To combine the active poly lactic co-glycolic acid (PLGA) nanosperes with adriamycin in side (ADM-NP) on the surface of ultrasound micrbubbles in covalent bonding and to prepare a novel drug-loading ultrasound micrbubble,and observe the physicochemical property.To quantify drug encapsulation efficiency and drug-loading amounts and drug-release properties in vitro and the effect of tumor imaging.Methods ADM-NP were prepared with double emulsification method,The surface carboxyl of ADM-NP was activated with carbodiimide method.Amino ultrasound microbubbles (MB-NH2) were prepared with mechanical shaking.The carboxyl of ADM-NP and the MB-NH2 could take place condensation reaction under a certain condition.Light microscope was used to observe the shape and distribution of the novel micrbubble.High performance liquid chromatography (HPLC) was used to quantify drug encapsulation efficiency and drug loading amounts.This novel microbubbles were put in 2 dialysis bag to observe the releasing properties of ADM in vitro,and one of the bag was using low frequency ultrasound irradiation for 120 s.The effect of tumor imaging using this novel microbubble was observed.Results After 48 hours,a number of ADM-NP attacted to the MB-NH2 like a gar land.Determination of entrapment efficiency and drug loading of it by HPLC weare (86.11 ± 6.76)％ and (8.71 ± 0.46)％.The sustained release in vitro can last for more than 48 hours.More than 90％ of ADM encapsulated in the 2 groups was sustained released for 48 hours.And the release characteristics of the 2 groups in vitro was in accord with Higuchi equation,and no difference was observed in the 2 groups (P ＞0.05).The tumor showed typical enhancement pattems of quick wash-in and quick wash-out.Conclusions To combine the nanospheres to the surface of microbubbles with covalent bonding,it could prepare a novel efficient drug-loading microbubbles for a original technique of ultrasound-targeted microbubble destruction(UTMD).