Study On Treatment Of Tumor Or Ultrasound Imaging Using Phase-change Nanocapsules And Low Intensity Focused Ultrasound In Vitro

PARTI PHASE CHANGE OF POLYMERICNANOCAPSULES WITH LIQUID PERFLUOROCARBONAND ULTRASOUND IMAGING IN VITRO EXPERIMENTObjective To prepare a new ultrasound contrast agents polymericnanocapsules of liquid perfluorocarbons, and to observe its physicalcharacteristics, phase change by heating or ultrasound and effects onultrasound imaging in vitro.Methods Polymeric nanocapsules of liquid perfluorocarbons(P-NP)were prepared by using emulsion solvent-evaporation process. Themorphology and distribution were observed with optical microscope. Thesize and electric potential were obtained. The phase change ofnanocapsules of liquid Perfluorocarbons on heatingplate was observed byoptical microscope instantaneously. After using low intensity focusedultrasound(LIFU), the effects on ultrasound imaging were observed invitro. Results The prepared polymeric nanocapsules of PFP was opacifiedsuspension in appearance, the distribution and size were uniformed withcore-shell structure, with the average size and potential of (393.2±40.7) nmand (-5.23±8.69) mV respectively. When heatingplate show the temperatureis about42.6℃, the phase change of nanocapsules had just begun, and thehigher temperature, the more bubbles formed. After LIFU ablation, theP-NP has a obvious enhancement of ultrasound imaging was observedunder the model of fundamental and harmonic wave in vitro.Conclusion The polymeric nanocapsules of liquid perfluorocarbons（P-NP）are successfully prepared, and can enhance ultrasound imagingafter LIFU ablation in vitro, which may become a new type of ultrasoundcontrast agents. PART II STUDY ON TREATMENT OF BREASTCANCER USING DRUG-LOADED PHASE-CHANGENANOCAPSULES AND LIFU IN VITROObjective To investigate the auxiliary application of cancer chemotherapy using PT-NP and LIFU.Methods PT-NP were prepared by using emulsion solvent-evaporation process. Morphology were observed with scanning andtransmission electron microscope. To observe phase change by heatingwith optical microscope and ultrasound imaging after LIFU ablation invitro. HPLC was used to quantify drug loading amounts or drugencapsulation efficiency and to observe the releasing properties of TAX invitro. Trypan blue was used to evaluate MCF-7cell survival after LIFUablation.CCK-8experiment was used to evaluate cell proliferation.Results PT-NP was spherical. Porous structure and brush structureon surface of PT-NP. When heatingplate show the temperature is about43℃, the phase change ofPT-NP had just begun. After LIFU ablation(0.78w/cm2,2min), the PT-NP has a obvious enhancement of ultrasoundimaging. The group of PT-NP with LIFU has the highest drug release in48h. LIFU ablation(0.78w/cm2,2min) was not obviously harmful to cells.The group of PT-NP with LIFU restrain the cell proliferation which is thebest remarkable.Conclusion PT-NP are successfully prepared, and can enhanceultrasound imaging after LIFU ablation at the same time will help thecancer chemotherapy.