Study Of 10-HCPT Loaded Phase-Change Nanoparticles About Its Ultrasonic Molecular Imaging And Therapy In Vitro

PART Ⅰ PREPARATION OF 10-HCPT LOADED PERFLUOROPENTANE NANOPARTICLES AND ITS STUDY OF ULTRASONIC MOLECULAR IMAGING AND THERAPYObjective To prepare a novel drug-loaded nano-scale ultrasound contrast agent and observe its enhancement effect for ultrasound imaging in vitro.Methods The 10-HCPT loaded perfluoropentane (PFP) nanoparticles were prepared with rotary evaporator and probe-type sonication methods. The morphology and structure of nanoparticles were observed by optical microscope and transmission electron microscope (TEM). The mean diameter and charge of the nanoparticles were measured by Malvern instrument. The entrapment efficiency was determined by ultraviolet spectrophotometer. The emulsion of drug-loaded nanoparticles were heated by the heating plate and sonicated by low intensity focused ultrasound (LIFU),the phase-shift result and enhancement effect for ultrasound imaging were then observed.Results The drug-loaded nanoparticles appeared as milk white suspension, showed uniform size and regular shape under the microscope and TEM. The mean diameter and charge were (500.82±25.97) nm and (-47.77±3.09) mV, respectively. When the nanoparticles were heated to a temperature of 50℃ and after sonicating by LIFU, nanoparticles changed phase and transformed into microbubbles as found under the microscope, the ultrasound imaging of nanoparticle suspension was significantly enhanced both under the fundamental mode and harmonic mode.Conclusion The 10-HCPT loaded perfluoropentane nanoparticles are successfully prepared and would become a novel kind of multifunctional ultrasound contrast agent.PART II STUDY ON ACOUSTIC PHASE TRANSITION CONDITIONS OF 10-HCPT LOADED PERFLUOROPENTANE NANOPARTICLES AND ITS DRUG RELEASE PROPERTIESObjective Study on acoustic phase transition conditions of 10-HCPT loaded perfluoropentane nanoparticles and their enhancement effect for ultrasonic imaging.And observe their drug release properties and their cell toxicity studies on human hepatoma SMMC-7721 in vitro.Methods The emulsions of drug-loaded nanoparticles were sonicated by low intensity focused ultrasound (LIFU).The power of LIFU and the concentration of nanoparticles for imaging were studied in order to acquire the best visualization.The entrapment efficiency with different mass ratio of drug and phospholipid was determined with ultraviolet spectrophotometer. The release of 10-HCPT was observed with dialysis method. The cytotoxic effect of drug-loaded nanoparticles on human hepatoma SMMC-7721 was measured by cell counting kit-8(CCK-8).Results After being sonicated by LIFU, it showed the best ultrasound enhancement imaging when the irradiation power is 5 w, the irradiation time is 2 min and the concentration of nanoparticles is 8.53×109/ml. The highest entrapment efficiency was obtained when the mass ratio of drug and phospholipid was 1:10.The drug was released slowly from the drug-loaded nanoparticles and significantly inhibited the proliferation of human hepatoma SMMC-7721 after 48 hours.Conclusion As phase-shift and 10-HCPT loaded perfluoropentane nanoparticles,it can enhance ultrasound imaging greatly with appropriate conditions and it released drug slowly to inhibit the proliferation of human hepatoma SMMC-7721...