Study On Preparation Of A Novel Adriamycin-loaded Microbubble And Targeted Therapy On Vx2Tumor

PART I STUDY ON PREPARATION OF A NOVELADRIAMYCIN-LOADED MICROBUBBLE AND RELEASECHARACTERISTICS IN VITROObjective To combine the active poly lactic co-glycolic acid （PLGA）microsphere with Adriamycin in side （ADM-PLGA） on the surface ofultrasound lipid micrbubbles in covalent bonding and to prepare a novelAdriamycin-loading micrbubble， and to observe the physicochemicalproperty. To quantify drug-loading amounts, drug encapsulation efficiencyand drug-release properties in vitro and to observe the effect of tumorimaging.Methods The preparation for ADM-PLGA were using doubleemulsification method. The carboxyl activation of ADM-PLGA were usingcarbodiimide method. The preparation for Amino ultrasound lipidmicrobubbles （MB-NH₂） were using mechanical shaking method. Thecarboxyl of ADM-NP and the MB-NH₂could take place condensationreaction after hours. Light microscope was used to observe the distribution and shape of the novel micrbubble. High Performance LiquidChromatography （HPLC） was used to quantify drug loading amounts anddrug encapsulation efficiency. This novel microbubbles were put into2dialysis bag to observe the releasing properties of ADM in vitro,and one ofthe bag was using low frequency ultrasound irradiation for120s,to observethe effect of VX2tumor imaging of the novel microbubble.Results After48hours，a number of ADM-PLGA adhered to theMB-NH₂like a wreath. Determination of entrapment efficiency and drugloading of it by HPLC were （86.11±6.76）%and （8.71±0.46）%respectively.The sustained release of ADM in vitro could last for more than48hours.And the release characteristics of the2groups in vitro was in accord withHiguchi equation，and no difference was observed in the2groups（P＞0.05）.The VX2tumor imaging showed typical enhancement pattems of"quick wash—in and quick wash—out"with the novel microbubble.Conclusions To combine the ADM-PLGA to the surface of microbubbleswith covalent bonding, it could prepare a novel efficient drug-loadingmicrobubbles for a original technique of ultrasound-targeted microbubbledestruction（UTMD）. PART II STUDY ON TREATMENT OF RABBIT LIVERVX2TUMOR WITH A NOVEL ADRUANAYCIN-LOADEDMICROBUBBLE WITH ULTRASOUND TARGETEDMICROBUBBLE DESTRUCTIONObjective To study the treatment effect of the novel Adruanaycin-loaded microbubble with ultrasound Targeted microbubble destruction（UTMD）on Rabbit liver VX2tumor.Methods The novel Adruanaycin-loaded microbubble was preparedwith carbodiimide method. Set up30rabbit liver VX2tumor models.The30rabbits were divided into3groups，Each10.A,ADM-PLGA withUTMD group（ADM-PLGA+UTMD）: Inject ADM-PLGA5ml to theRabbit ear vein; B,mixing with UTMD group（ADM-PLGA+MB-NH₂+UTMD）: Inject mixing liquor5ml to the Rabbit ear vein. C,the novelmicrobubble with UTMD group（ADM-PLGA-MB-NH₂+UTMD）: Injectthe novel microbubble liquor5ml to the Rabbit ear vein. To irradiate thetumor with low frequency ultrasound after injection.Tumor in each groupwere harvested to measure size with2D ultrasound. TUNEL was used toobserve apoptosis of the VX2tumor. PCNA exrpression was detected byImmunohisto chemistry of the VX2tumor. To calculate Growth rate （GR），Proliferation index（PI） and Apoptotic Index （AI）of the VX2tumor.Results The GR of the3groups were （74.82±7.25）%、 （60.77±8.48）%and（55.94±6.97）%respectively，the PI were（74.82±7.25）%、（60.77±8.48）%and（55.94±6.97）%respectively, andthe AI were（31.7±6.42）%，（50.35±3.82）%and（72.47±5.93）%respectively. The GR of the C group was lower than the other2groups（P＜0.05）.And the PI was the lowest but AI was the hightest.Conclusions The effect on treatment of rabbit liver VX2tumor wassignificantly improved by using the novel microbubble with UTMD.And toprovide a new way for targeted therapy on malignant tumor.