Objective To prepare the folate receptor-targeted and paclitaxel-loaded ultrasound contrast agent (folate-poly(lactide-co-glycolide)-paclitaxel,FOL-PLGA-PTX) and to investigate its targeting and imaging performance in vitro.Methods Paclitaxel-loaded PLGA-COOH micmcapsules with a core of liquid perfluorocarbon (PLGA-PTX) were prepared using single emulsion technique and then conjugated with folate by carbodiimide method.The size,surface potential,entrapment efficiency and drug loading efficiency were measured by Malvern laser detector and HPLC.The connectivity condition of PLGA-PTX with folate and the binding rate of fluorescent antibody were detected by immunofluorescence staining and flow cytometry.The targeting performance of FOL-PLGA-PTX was checked after co-incubated with human SKOV3cell lines in vitro and compared with that of non-targeted group and free folic acid intervention group.In vitro experiments were performed to explore the effects of FOL-PLGA-PTX on the enhancement of ultrasound imaging after irradiation by high intensity focused ultrasound (HIFU).Two-sample t test and one-way analysis of variance were used to analyze data.Results The average diameter of FOL-PLGA-PTX was (244.43 ±13.32) nm,with the drug entrapment efficiency of (86.23 ± 1.23)％ and loading amount of (8.62±0.12)％.The binding rate of folate was as high as (98.49± 1.28)％.The connection rate of FOL-PLGAPTX on SKOV3 cells was higher than that of non-targeted group ((84.32±4.25) ％ vs (16.45±2.89) ％; F289.45,t=10.654,P＜0.01) and the free folic acid intervention group ((36.33±3.23)％; t=8.923,P＜0.01).During in vitro ultrasound imaging,the average grey scale of FOL-PLGA-PTX before HIFU irradiation was significantly lower than that after HIFU irradiation (39.32±3.64 vs 126.44±7.15 ; t =4.829,P＜0.01).Conclusion FOL-PLGA-PTX has been prepared successfully,with high entrapment efficiency and much drug loading,which can target to SKOV3 cells specifically and effectively in vitro,and enhance the ultrasound imaging greatly after HIFU irradiation.

Objective To prepare a novel extravascular human epithelial growth factor receptor 2 (HER2)-targeted polylactic-co-glycolic acid (PLGA)-COOH ultrasound contrast agent with liquid perfluorocarbons(PFH-PLGA-tra),and to observe it's general properties and it's effects on ultrasound imaging in vitro.Methods Polymeric nanocapsules of liquid perfluorocarbons were prepared by the single emulsion technique and conjugated with trastuzumab monoclonal antibody by EDC/NHS.The general characteristics were observed.The conjugation was demonstrated by immunofluorescence and the targeting performance of the agent was checked in human MCF-7 cells line in vitro.The encapsulation of liquid fluorocarbons was detected by heating in vitro.The effects on ultrasound imaging were observed in vitro.Results The mean diameter of agents was (261 ± 28)nm.The targeted nanocapsules were positive in immunofluorescence.In the targeted study,it was shown that a number of targeted nanocapsules conjugated with MCF-7 cells in vitro.Droplet-to-bubble transition experiment in vitro showed that there were no nano/microbubbles formed by heating in control groups at 80℃,while there were a lot of nano/microbubbles appeared in nanocapsules formulations at 80 ℃.The agents presented a good ultrasound imaging in vitro.Conclusions The HER2-targeted polymeric nanocapsules of liquid perfluorocarbons are successfully prepared,which may become a novel extravascular targeted ultrasound contrast agents.

Objective To explore the application value of CEUS in diagnosis of renal occupying lesions.Methods Totally 67 patients with renal occupying lesions underwent conventional ultrasound and CEUS before surgical operation.CEUS enhancement characteristics were observed and compared between 40 patients with clear cell renal cell carcinoma (CCRCC)and 14 patients with angiomyolipoma (AML).Meanwhile the time-intensity curves were analyzed,including peak intensity (IMAX),rise time (RT),time-to-peak time (TTP) and mean transit time (mTT).Results There were significant differences in enhancement patterns,degrees,homogeneity of enhancement and pseudocapsule sign between CCRCC and AML (all P＜0.01).Compared with AML,IMAX of CCRCC was higher,RT and mTT were both earlier (P＜0.05).The sensitivity,specificity and accuracy of CEUS in diagnosis of malignant renal occupying lesions was 91.49 ％ (43/47),75.00 ％(15/20) and 86.57％ (58/67),respectively.Conclusion CEUS combined with quantitative analysis software is helpful to diagnosis and identification of CCRCC and AML.