ABSTRACT
Objective:To explore the mechanism of phase-transition fluorocarbon nanomaterials and evaluate its synergistic efficacy on microwave ablation (MWA).Methods:A novel phase transition nanodroplet (PTN) was designed with poly (lactic-co-glycolic acid) (PLGA) as the shell and perfluorocarbon (PFC) mixture as the core. Based on that, a phase-transition mechanism of microwave droplet vaporization (MWDV) was explored, which was based on the thermal phased transition. The basic physicochemical properties and biological characteristics of PTN were monitored by scanning electron microscope (SEM), dynamic laser light scattering (DLS), in vitro hemolysis and CCK-8 experiment.Based on the gel-hole model experiment in vitro, the phase transition of PTN were monitored; based on the live/dead cell double staining kit, flow cytometry and cytotoxicity test, the synergistic efficacy of phase-transition PTN on microwave ablation, which was mediated by MWDV was evaluated. Results:The phase-transition temperature of PTN was exactly the boundary temperature of microwave ablation (60 ℃) when the ratio between perfluoropentane (PFP) and perfluorohexane (PFH) in the core of PTN was 3∶2. Furthermore, the smart proportional PTN didn′t only have good stability and biocompatibility, but also could enhance the two-dimensional ultrasonic imaging and increase the efficacy of MWA under the mediation of MWDV.Conclusions:MWDV can be treated as a phase-transition mechanism of fluorocarbon nanomaterials, which provides a potential synergistic strategy for the thermal ablation of tumors.
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Objective To evaluate the inhibitory effect of phase change doxorubicin loaded carboxymethyl hexanoyl chitosan nanodroplet on ovarian cancer cells,and the effect of its ultrasound image in vitro.Methods The carboxymethyl hexanoyl chitosan synthesized through the acylationreaction with carboxymethyl chitosan and hexanoic anhydride.The drug loaded carboxymethyl hexanoyl chitosan nanodroplets were prepared by ultrasonic emulsification.The surface morphology,particle diameter and electric potential were characterized.Ultrasound imaging of the nanodroplet was evaluated in vitro.The encapsulation efficiency was determined by ultraviolet spectrophotometry.The survival rate of ovarian cancer cell was detected using CCK-8 reagent.The statistical analysis was performed.Results The drug loaded carboxymethyl hexanoyl chitosan nanodroplet was successfully prepared which showed regular morphology in microscope,the mean diameter of (458.33± 43.50)nm.The encapsulation efficiency was (52.06 ± 10.14)％.The nanodroplet could enhance ultrasonic imaging.The survival rate of ultrasound combined with drug loaded nanodroplet group ([62.54± 3.60]％) was lower than those of the free drug group ([75.55±7.21]％) and drug loaded nanodroplet group ([76.18±4.94]％),ultrasound group ([89.90±0.83]％;P＜0.05).Conclusion Ultrasound-mediated drug loaded nanodroplet can inhibit ovarian cancer cells,and has the potential for application in the clinical diagnosis and treatment.
ABSTRACT
Objective To explore the clinical value of a new tactic with novel dodecafluoropentane (C5F12,DDFP)acoustic vaporizable nano-droplets for the therapy of coronary micro-circulation thrombolysis.Methods Group A was poly butylene succinate buffer solution as blank control;group B was SonoVue microbubbles;group C was DDFP acoustic vaporizable nano-droplets,which were produced with emulsion process by ultrasonic oscillation instrument and rotary evaporator.The size of the nano-droplet was tested by Malvern laser particle size detector and observed with fluorescence microscope.The stability and efficiency of cavitation effect of group C for thrombolysis were tested in an in-vitro artificial vascular system with arterial thrombus model,comparing with group A and B.Weights and pathological sections of the inserted thrombus before and after the thrombolysis in these groups were compared for the thrombolytic efficiency.Results The average size of DDFP nano-droplets were(424.7±30.2)nm.More than 75% of the nano-droplets were ranged from 300-750 nm.The fluorescence microscope showed the DDFP nano-droplets were uniformed round-shaped and stable-structured with favorable dispersity;the nano-droplets had gradually turned into over 3 μm microbubbles under ultrasound irradiation.The thrombus weight loss after thrombolysis in group C[(199.0±35.8)mg,(32.1 ±4.4)%]was significantly larger than those in group A[(30.2 ± 17.8)mg,(5.0 ± 2.4)%]and B[(72.6 ± 20.7)mg,(12.7 ± 2.8)%](all P <0.01). Conclusions DDFP vaporizable nano-droplets with ultrasound irradiation is effective for thrombus elimination in coronary micro-circulation through lasting and stable cavitation effect.