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Objective To investigate the preventive and inhibitory effects of tumor cell lysate(TCL) combined with IL-2 on melanoma and the potential immune mechanism. Methods The B16F10 melanoma TCL cell were prepared using an ultrasonic disruptor. Twenty-four C57BL/6 mice were randomly divided into four groups which were immunized with PBS, IL-2, TCL and TCL+IL-2 for three weeks, and contra lateral tumors were implanted in the fourth week. We observed onset time of tumor and tumor size, collected peripheral blood continuously and monitored the expression of CD4+T and CD8+T cell subsets dynamically by flow cytometry. Spleen and tumor tissues of mice were also tested for CD4+T and CD8+T cell subsets by flow cytometry and immunohistochemistry, respectively. Results The preventive immunization of the TCL+IL-2 group significantly delayed the onset time of tumor (P=0.034); moreover, the tumor volume (P=0.023) and tumor weight (P=0.0015) were also significantly smaller than those in the control group. The expression of CD8+T cell subsets in the TCL+IL-2 group and the TCL-only group were significantly higher than that in the control group (P=0.0016, P=0.012). However, the CD4+T cell subsets of the TCL+IL-2 group decreased after tumor implantation, compared with the control group (P=0.0089). The expression of CD4+T and CD8+T cell subsets in spleen and tumor tissues were as same as those in peripheral blood. Conclusion The tumor vaccine of TCL combined with IL-2 could prevent the occurrence of melanoma in mouse and effectively inhibit tumor growth by activating CD8+T cells.
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As a treatment option for cancer, thermal ablation has satisfactory effects on many types of solid tumors (such as liver and renal cancers). However, its clinical applications for the treatment of thyroid nodules and metastatic cervical lymph nodes are still under debate both in China and abroad. In 2015, the “Zhejiang Expert consensus on thermal ablation for thyroid benign nodules, microcarcinoma, and metastatic cervical lymph nodes (2015 edition),” was released by the Thyroid Cancer Committee of Zhejiang Anti-Cancer Association, China. To further standardize the application of thermal ablation for thyroid tumors, the Thyroid Tumor Ablation Experts Group of Chinese Medical Doctor Association has organized many seminars and finally produced a consensus to formulate the “Expert consensus workshop report: Guidelines for thermal ablation of thyroid tumors (2019 edition).”
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To evaluate the feasibility of magnetic navigation ultrasonography system in guiding the puncture of percutaneous posterior endoscopic cervical discectomy ( PPECD ) . Methods T he cervical CT data of 6 patients with cervical spondylosis were used to made 3D printing model ,then the localized puncture of the model was guided by the magnetic navigation ultrasonography system ,1‐mm‐slice transection CT scans were obtained to confirm the placement of the needle tips after puncture . T he total puncture time and the distance between the pinpoint in the lateral and longitudinal directions from the ＂V point＂were recorded . Results All the 36 puncture operations accurately located the target segment without penetrating the spinal canal . T he average lateral distance of the needle tip from the ＂V point＂was 2 .88 mm ( 0－7 .12 mm ) ,meanw hile the average longitudinal distance was 1 .64 mm ( 0 －4 .45 mm ) ,and the the w hole process took 3 .72 min( 2 .42－5 .20 min) . T hirty‐three of 36 points were in the circle with ＂V point＂as the center and 5mm as the radius ,puncture success rate was 91% . Conclusions T he puncture model established in this study can be used as a teaching tool ,magnetic navigation ultrasonography system has successfully guided the posterior cervical intervertebral disc puncture on the model ,and there is no radiation exposure during the operation process ,which has a promising clinical application prospect .
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Objective To prepare a novel loaded NdFeB and Fe3O4 liquid-solid phase inversion poly (polylactic-co-glycolic acid,PLGA) in situ implant (PLGA 60％ NdFeB-20％ Fe3O4) for ultrasound-guided intratumoral injection,and to investigate its intensity of magnetism and therapeutic efficiency of nude mice bearing MDA-MB-231 breast cancer.Methods PLGA-60 ％ NdFeB-20 ％ Fe3O4 in situ implant was prepared.The microstructure of PLGA-60 ％ NdFeB-20 ％ Fe3O4 was tested with scanning electron microscope (SEM).Magnetometer was used to qualify the intensity of magnetism.For the in vitro assay,60 μl solid PLGA-60％ NdFeB-20％ Fe3O4 implant was put in the center of the electromagnetic induction heating coil.Infrared thermal video of the tubes was simultaneously recorded.The size of 2 cm × 2 cm× 2 cm fresh ex vivo bovine liver was prepared,and then 60 μl PLGA-60％ NdFeB-20％ Fe3O4 was injected into it.Similarly,ex vivo bovine liver was heated by the above intermittent time for 1,2,3,4 minutes,respectively,and the ablation volume was calculated.Finally,nude mice were equally divided into treatment group and control group.Mice in treatment group were discontinuously heated for 3 min after being injected with the above mentioned implant,while CEUS was performed before and after heating to observe the blood perfusion in the tumor.One nude mouse was executed on the next day in each group,then pathological sections and HE staining of tumor tissue were taken,whereas the growth of the remaining nude mice were observed daily.Results SEM showed the implant with rough and porous surface.The magnetism increased with the volume of material.The tube and bovine liver experiments showed that the PLGA-60 ％ NdFeB-20％ Fe3O4 generated heat efficiently.The bovine liver ablation experiment showed that the range of ablation of 60 μl PLGA-60 ％ NdFeB-20％ Fe3O4 implant reached (2.34±0.25)cm3 after 3 min heating.In vivo experiments showed that the tumor tissue began to form a scab on the 2nd day,and the scab began to desquamate on the 20th day.CEUS showed the original predominant enhancement disappeared significantly after the treatment.HE staining proved that cancer cells had coagulative necrosis,whereas tumors in control group became bigger.Conclusion PLGA-60％ NdFeB-20％ Fe3O4 in situ implant can produce obvious thermal effect under high frequency alternating magnetic field,therefore can be effectively ablated with nude mice MDA-MB-231 breast cancer during time interval heating.
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With the continuous development of musculoskeletal ultrasound,ultrasound diagnosis of inflammatory arthri tis,especially early diagnosis had an increasing important role.Psoriatic arthritis (PsA) was a kind of inflammatory arthritis,which was closely related with psoriasis.It could involve the whole body's large and small joints,especially peripheral joints (often asymmetric),sacroiliac joint and spine.The course of PsA was protracted and easy to recur.Clinical and ima ging manifestations of PsA are similar to rheumatoid arthritis (RA),and need to identify diagnosis.The diagnosis and antidiastole in musculoskeletal ultrasound of PsA were reviewed in this article.
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Caudal block has much advantages such as simple operation,less complications,obvious effect,flat and low anesthesia.For those reasons,caudal block is widely used in pain treatment and clinical anesthesia.The traditional way of sacral canal anesthesia is based on osseous marks.However,because of variable anatomical structure in sacral canal and the sacral horns,the traditional method has many defects.In recent years,as a new operation method,caudal block under the guidance of ultrasound has began to be applied gradually.The advantages,application progresses of this method were reviewed in this paper.
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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 .
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Objective To test using musculoskeletal ultrasound (MSUS) to observe uncovertebral joints (UJs) and to explain the ultrasound images of UJs and their adjacent tissues,especially the vertebral artery (VA).Methods MSUS was used first with human skeletons and cadavers to localize the UJs and VA on the MSUS images with the aid of implanted needles.MSUS was then used with a patient clinically diagnosed with cervical spondylosis of the vertebral artery type (CSA) to detail the image of a normal UJ and its relationship with the adjacent tissues,especially the VA.Whether there was a lateral spur from the uncinate process (UP) was assessed to try to establish a method for measuring osteophytes.Results During the examination the patient was in supine,the neck was elevated 15cm with a pillow and was at 45 degrees of rotation to the contralateral side.The probe was placed at the medial border of the sternocleidomastoid muscle.When the longitudinal section of the common carotid artery was shown,the probe was slowly moved laterally until the VA first appeared,and then was moved up along the VA.Once the VA entered the transverse foramen,moving the probe slightly allowed the UJ behind the VA to be seen between two transverse processes.The UJ thus lies between two transverse processes,that is,between the lateral margins of two vertebral bodies and outside the intervertebral disc.The echo of the lateral border of the UP is on a straight line with the echo of the lateral margin of the vertebral body,with the VA in front of the line.It was noticed that the image of a UP with lateral osteophyte formation crossed the line and reached closer to the VA.The transverse diameter of the UJ was measured as the distance from a line cutting the lateral cortical margin of the cervical vertebra to the outer cortical margin of the lateral UP.Conclusion MSUS can clearly show the UJ and its adjacent tissues,especially the VA.It can be used to assess and measure UJs with lateral osteophyte formation.
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Objective To investigate the size and diversification of peripheral nerve measured by high frequency ultrasound in di-abetic peripheral neuropathy patient .Methods The endings of the medial branch of deep peripheral nerves(DPN) were interrogated by high frequency ultrasound and nerve electrophysiology ,and the nerve conduction characters were studied in a cohort of 150 clini-cally diagnosed diabetic peripheral neuropathy patients and a control group of 100 healthy volunteers .At the sametime these cases underwent electrophysiological examination .Results Distinct echoic appearances were consistently detected between the DPN nerves of diabetic peripheral neuropathy patients and healthy volunteers .The sensitivity rate of high frequency ultrasound and nerve electrophysiological examination in diagnosis of diabetic peripheral neuropathy were 91 .33% and 74 .67% ,and the specificity rate were 91% and 82% .Conclusion High frequency ultrasound may play a role in the diagnosis of diabetic peripheral neuropathy .
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Objective To prepare a kind of superparamagnetic iron oxide (SPIO) and doxorubicin loaded multifunctional polymer microbubbles (MPMBs),and to explore its potential application as an ultrasound(US)/magnetic resonance (MR) imaging contrast agent in vitro.Methods The MPMBs and normal polymer microbubbles (PMBs) were made by double emulsion and freeze-drying methods.The physical property,drug encapsulation efficiency and the drug-loading efficiency of MPMBs were determined,and the release property and US/MR imaging enhancement of MPMBs were observed.Results The MPMBs had a regular shape and narrow size distribution.The drug encapsulation efficiency was (60.20±2.69) ％,and the drug-loading efficiency was (6.02 ± 0.27) ％.The in vitro release experiment showed that ultrasound can promote the release of doxorubicin in MPMBs.US imaging in vitro showed that the enhancement of MPMBs was better than PMBs,and MR imaging in vitro conformed that MPMBs could well enhance MR imaging.Conclusions The MPMBs is a multifunctional contrast agent with the treatment function as well as US/MR dual-mode imaging enhancement effect.
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Objective To prepare the multi-functional ultrasound contrast agents,which were investigated for ultrasound(US)/MR dual-mode imaging and high-intensity focused ultrasound(HIFU)synergism in vitro.Methods Double emulsion method was used to prepare the superparamagnetic iron oxide(SPIO)-loaded PLGA microcapsules(s-PLGA),and its morphology,size,Fe3O4 loading capacity were assessed.Then,the prepared s-PLGA microcapsules with different concentrations were applied to perform ultrasound and MR imaging in vitro.In addition,the degassed bovine liver in vitro was directly injected into 200 μl s-PLGA in saline(0.5 mg Fe/ml)just before HIFU ablation,the saline(200 μl)and pure PLGA (200 μl)were employed for control.After HIFU ablation,the volume of coagulated tissue irradiated by HIFU was calculated.Results The s-PLGA microcapsules were observed with regular spherical morphology and its average size was(885.6 ± 133.2)nm.In vitro,the s-PLGA showed hyperechogenicity in US imaging and MR negatively enhanced effeet in T2WI,the volume of coagulated tissue irradiated by HIFU after local injection of s-PLGA was larger than that of saline and pure PLGA(P＜0.05).Conclusions The prepared s-PLGA microcapsules are successfully acted as dual-mode biological imaging contrast agents for ultrasound and MR imaging and HIFU synergism in vitro.
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Objective To prepare polyclactic-co-glycolic acid(PLGA) polymer ultrasound contrast agent loading sudan black dye (SB-PLGA) and study the enhancement effect of it on rabbit lymph nodes imaging and as a sentinel lymph node (SLN) biopsy in the feasibility and value of the indicator.Methods SB-PLGA ultrasound contrast agent was made by double emulsion and freeze-drying methods.Thigh subcutaneous rabbit VX2 tumor model of eight lymph nodes were set up with the foot pad subcutaneous injection of contrast agents to get contrast-enhanced ultrasound imaging of the popliteal lymph node and the second inguinal lymph node stations.Then the blue stained lymph nodes were resected by popliteal lymph node dissection and the second station lymph nodes were also observed after 30 mins respectively,lymph nodes were examined by frozen sections HE staining in parallel.Results SB-PLGA microbubbles had a tight size distribution.Ultrasound imaging can be significantly enhanced lymph node imaging,the second station lymph node imaging was not obvious.Popliteal lymph node dissection for lymph node staining,30minutes later,frozen sections HE staining were seen within the lymph node contrast agent present in the lymphatic sinus and a large entry of macrophages.Inguinal lymph node dissection showed the second station of lymph nodes no blue staining.Conclusions SB-PLGA ultrasound contrast agent is good for sentinel lymph node imaging and biopsy indicator.Contrast agent retention and accumulation in the lymph nodes by the uptake of macrophages may be associated with the mechanisms of lymph node enhanced imaging.
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Objective To evaluate the performance of virtual touch tissue quantification (VTQ)technique in noninvasive assessment of esophageal varices (EV) in patients with hepatitis B cirrhosis.Methods One hundred and thirty-five patients were enrolled in this study.Liver shear wave velocity (LSWV) and spleen shear wave velocity (SSWV) were obtained by VTQ technique,and the detection of EV was performed by upper endoscopy per patient.The severity of EV was staged on a G1-G3 scale.Liver function was also tested.ResultsThe mean value of LSWV in patients with cirrhosis was (2.48±0.50)m/s,LSWV was not correlated with the stage of EV.The mean value of SSWV was (3.25 ± 0.44) m/s,a significant,direct,linear correlation ( r =0.66,P＜0.001 ) was found between SSWV and the stage of EV.The cut-off value of SSWV for predicting the presence of EV was 3.16 m/s and the area under ROC curve was 0.83,with the sensitivity and specificity of 0.83 and 0.80,respectively.The cut-off value of SSWV for predicting severe EV was 3.39m/s and the area under ROC curve was 0.84,with the sensitivity and specificity of 0.83 and 0.77,respectively.ConclusionsIn cirrhotic patients infected with hepatitis B virus,SSWV measured by VTQ technique can be used as a noninvasive method for determining the presence and the severity of EV,however evidence to support a similar role for LSWV is lacking.
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ObjectiveTo study the optimal power of self-made polymeric microcapsules with liquid perfluorocarbon enhancing high intensity focused ultrasound (HIFU) ablation of normal bovine in vitro and the treatment efficacy of HIFU ablation of normal rabbit liver in vivo.Methods The experiment was divided into two parts:the first part was HIFU ablation of bovine in vitro:The bovine was injected different drugs before HIFU ablation to find the optimal power and treatment time.It was divided into four groups:①HIFU + 0.9％ NaCl(NACL) group; (② HIFU + poly( lactic-co-glycolic acid) (PLGA) group; ③ HIFU + perfluorohexane(PFH) group; ④ HIFU + PLGA + PFH group; The second part was HIFU ablation of normal rabbit liver.Similarly,It was also divided into four groups as above.Each group was undergone HIFU ablation with same parameters after ear vein injection of drug.Then the ultrasonographic changes and its value,and the actual situation of liver damage in target areas of each group were observed and compared before and after the ablation area.ResultsIn experiments of vitro bovine,gray scale changes and coagulation necrosis could be seen in the liver in group 2,3,4 with HIFU power of 150 W and treatment time of 2 s.In experiment of normal rabbit liver,the average gray-scale of group 3 and 4 were larger than that in group 1 and 2,the difference was statistically significant (P ＜0.001),and its gray change area gradually reduced with time elapsed.While there was no statistically significant difference between group 3 and 4 ( P ＞0.05).In pathological specimens,there was no significant liver damage in group 1 and 2.There was hemorrhagic necrosis and white coagulation necrosis in group 3 and 4.Conclusions The polymeric microcapsules with liquid perfluorocarbon can effectively enhance the efficacy of HIFU ablation and be used as a good synergist for HIFU.
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Objective To prepare the Fe3O4 loaded polymer microspheres(Fe3O4/PLGA),and to investigate the influence of Fe3O4/PLGA combined with high-intensity focused ultrasound (HIFU) on rabbits bearing breast tumor.Methods Double emulsion method were utilized to prepare the Fe3O4/PLGA.14 days after implantation of VX2 tumor in breast,32 rabbits were randomly divided into four equal groups.In group Ⅱ,Ⅲ,and Ⅳ,the rabbits received a percutaneous injection of 0.5 ml saline,PLGA,and Fe3O4/PLGA microcapsules solution into breast tumor at 3,6,9,12 dots,about 3 mm around the tumor respectively,and massaged for 1 min before receiving HIFU ablation,while HIFU group received HIFU ablation only.HIFU ablation parameters were the same:ablated-dot mode,acoustic power 150 W,exposure duration 5 s.After HIFU ablation,the volume of coagulative necrosis was calculated,HE staining,TEM and immunohistochemical examination of PCNA were performed to detect the structure changes of the targeted tissue caused by HIFU ablation.Results The volume of coagulative necrosis caused by HIFU ablation was substantially larger and the positive index of PCNA was lower in the necrotic region after the injection of Fe3O4/PLGA microcapsules compared to the group without injection agents,the group of saline and the group of pure PLGA microspheres under the same irritation(P ＜0.05).Pathological examination demonstrated the targeted tissue was destroyed severely,Fe3O4 nanoparticles were seen depositing in residual tumor cells under TEM.Conclusions The self-made Fe3O4/PLGA microspheres can effectively enhanced the biomedical effect of HIFU surgery on rabbits bearing VX2 breast tumor.
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Objective To prepare the liver targeting nano-liquid perfluorocarbon ultrasound contrast agent and observe its general characteristics;to observe the targeting combined effects of the human liver cells L02 and the targeted ultrasound contrast agent ;to evaluate the gathering imaging effects of the targeted ultrasound contrast agent. Methods Amine method was used to prepared asialoglycoprotein Gal specific ligand polylysine (Gal-PLL), rotary evaporator and sonicated liquid fluorocarbon were used to prepare nano lipid ultrasound contrast agent. Human liver cell L02 were cultured, the combined effects were observed according to the reacting time of the cells and the targeted nano-lipid ultrasound contrast agent. The nanolipid ultrasound contrast agent and the degassed_ water_ were loaded into cysts and their ultrasound imaging effects were observed by ultrasound diagnostic apparatus Philips iU22. Results The particle size of the liquid fluorocarbon nano-targeted lipid ultrasound contrast agent was extremely small, uniform, cylindrical and spherical. The cysts in vitro showed that the side of the targeted liquid perfluorocarbon nano-lipid ultrasound contrast agent showed high echo. Conclusions The targeted liquid perfluorocarbon nano-lipid ultrasound contrast agent can be effectively targeted to the human liver cells L02 due to carrying home-made Gal-PLL. The targeted ultrasound contrast agents can be imaging by ultrasound and be confirmed in vitro.The size of the contrast agent was small, therefore, it can be considered an ideal ultrasonic molecular probe and achieve the ultrasound molecular imaging in cell level.
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Objective To study the feasibility of the Fe3O4-loaded lipid perfluorooctylbromide nanoparticles (Fe3O4-PFOB) for enhanced ultrasound imaging.Methods The Fe3O4-PFOB nanoparticles,incubated with RAW264.7 macrophage cells,were monitored by microscope and ultrasound.Twelve SD rats were randomized into two groups,Fe3O4-PFOB group and PFOB group.Ultrasound imaging of rats' liver was performed before and after intravenous injection of the contrast agents.The liver echogenic intensity was quantified by DFY ultrasound quantified system analysis.Results Incubation of the Fe3O4-PFOB nanoparticles with macrophages resulted in the uptake of Fe3O4-PFOB by macrophages.Macrophages loaded with Fe3O4-PFOB exhibited enhanced echogenicity in vitro.In in vivo imaging,Fe3O4-PFOB produced better and prolonged ultrasound enhancement of rats' liver compared to PFOB nanoparticles.Conclusions Fe3O4-PFOB nanoparticles could enhance ultrasound imaging and may potentially serve as a multimodal probe for ultrasound,CT and MR imaging.
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Objective To investigate how many probably benign lesions on ultrasound(US) fulfilled the published criteria and to evaluate how clinical and personal factors influenced the categorization of breast lesions.Methods A total of 487 lesions in 487 women with more than 12 months follow-up after the initial category 3 assessment on US were included.The initial US images were retrospectively reviewed according to previously published criteria,and evaluated several factors that could influence the characterization of breast lesions in clinical practice such as age,multiplicity,palpability,radiologist 's experience,and lesion size.Results Of 487 lesions,479 (98.36%) were benign and 8 (1.64%) were malignant.Of 487 lesions,203(41.68%) including 8 malignancies were reassessed as category 4.If strict criteria had been applied at initial US examination,the positive biopsy rate would have been only 3.94% (8/203) and 96.06% (195 of 203) biopsies would have been unnecessary.Lesions in women 40 years or older and multiple lesions were more frequently reassessed as category 4 (P = 0.008 and P = 0.006,respectively).The presence of palpability,lesion size,and the radiologist 's experience did not significantly influence the categorization of breast lesions on US.Of 487 probably benign lesions,41.68 % could be classified as category 4 lesions when strict criteria were applied in initial practice.Conclusions The multiplicity of the lesion and the patient 's age were found to have a significant influence on the classifcation of probably benign solid masses.
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Objective To preparation a kind of Herceptin loaded and breast cancer targeted high molecular polymer ultrasound contrast agent and investigate their affinity for breast cancer in vitro. Methods The high molecular polymer PLGA-COOH ultrasound contrast agents were produced by the double emulsion technique. Herceptin was covalently linked to the PLGA-COOH nanoparticle surface using a carbodiimide technique. Its physical property was determined. The combination of Herceptin with the PLGA-COOH nanoparticle was proved by immunofluorescent assay,and the PLGA-COOH nanoparticle targeting specifity to breast cancer cells was observed with light microscope and confocal microscope,normal PLGA-COOH nanoparticle was served as control group. Results The diameter range of targeted high molecular polymer ultrasound contrast agents was 466.8～857.6 nm, the average diameter was (662.2 ± 69. 7) nm,85.9% of the diameter was in the range. Green punctiform fluorescence was observed by fluorescence microscope,and the conjugation of the targeted high molecular polymer ultrasound contrast agents with MCF-7 cells was tight while the conjugation in control group was negative. Conclusions The Herceptin loaded PLGA-COOH targeted ultrasound contrast agents was prepared successfully. The targeted ultrasound contrast agents can bind to breast cancer effectively in vitro.
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Objective To prepare a kind of new lipid perfluorooctylbromide(PFOB) nanoparticles and to explore its potential application as an ultrasound contrast agent. Methods Lipid PFOB nanoparticles were prepared by microfluidization techniques. The morphology and distribution were observed with optical microscope and transmission electron microscope. Particle size and electric potential were determined with Malvern laser light scattering analyzer. Twelve normal Wistar rats were performed directly contrast imaging after injection of PFOB nanoparticles via caudal vein. Vital signs of the rats were monitored during the whole study. And eehogenie intensity of the liver was dynamically quantified through DFY ultrasound quantified analysis system. The mechanism of enhancement was studied by the frozen sections of rat's liver and spleen. Results The nanoparticles size and distribution were highly uniformed. The grey scale ultrasound imaging of the rat's liver and spleen were enhanced by PFOB nanoparticles. Ten seconds after PFOB nanoparticles injected,enhancement of liver began, the peak time was approximately 3 - 4 min, the duration of contrast enhancement was nearly up to 1 h, The enhancement of spleen was more significant and the duration was much longer. No abnormal changes of the rat's vital signs appeared during the study. Frozen sections suggested that PFOB nanoparticles accumulated in the liver and spleen was the potential mechanism of enhancement. Conclusions This novel and safe lipid PFOB nanoparticles could make prolonged enhancement of rat's liver and spleen,which has a good potency for ultrasound application.