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Objective@#To prepare a novel magnetic heating phasetransition nanoparticle contrast agent (PFH-HIONS), and to study its performance on enhancing photoacoustic imaging, magnetic resonance imaging and ultrasound imaging after phasetransition by magnetic-thermo in vitro.@*Methods@#Firstly, the superparamagnetic nano hollow iron spheres (HIONS) were prepared by a one-pot solvothermal method, and then the phasetransition liquid perfluorocarbon (PFH) was loaded on the HIONS by vacuum adsorption to obtain PFH-HIONS. After characterization of the nanoparticles, photoacoustic imaging, magnetic resonance imaging and ultrasound imaging after phasetransition with magnetic-thermo were performed in vitro, and the results were analyzed by a software.@*Results@#PFH-HIONS was successfully prepared with uniform particle size of (537.3±24.8)nm. PFH-HIONS could apparently enhance photoacoustic imaging and magnetic resonance imaging in vitro. In an alternating magnetic field, it could significantly increase the temperature, which promotes phasetransion of the PFH to produce microbubbles, thereby enhancing ultrasound imaging. Furthermore, as the concentration increased, the imaging intensity was enhanced, and the differences in imaging intensity between different concentration groups were statistically significant (P<0.05).@*Conclusions@#The PFH-HIONS can enhance the multimodal imaging including ultrasound, photoacoustic and magnetic resonance, and it also has obvious magnetic heating performance. It provides a new and efficient research platform for theranostics based on molecular imaging, therefore it has promising application prospects.
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Objective To prepare ultrasound(US)responsive nanodroplets(NDs)simultaneously loaded with anticancer drug Sorafenib(SF)and Doxorubicin(DOX),and to characterize its ultrasound responsibility in vitro and in vivo.Methods The SF/DOX NDs were prepared using the thin-film hydration method.The particle diameter,Zeta potential and drug-encapsulation efficiency were characterized.The acoustic droplets vaporization activity was monitored by in vitro ultrasound imaging and light microscope. The cavitation effect was monitored by in vitro ultrasound imaging and transmission electron microscopy. Results SF/DOX NDs were round in shape,the mean diameter and Zeta potential of SF/DOX NDs was (498 ± 67.34)nm,-(38.87 ± 3.78)mV,respectively.The entrapment efficiency of SF and DOX was (58.14±2.93)%,(51.23±4.11)%,respectively.SF/DOX NDs underwent a phase transition into bubbles and could be continuously imaged for more than 25 min in vitro,and afterward therapeutic ultrasound pulse induced inertial cavitation and substantially enhanced treatment.Conclusions US-responsible SF/DOX NDs are prepared using thin-film hydration mehtod,it can enhance ultrasonic echo in vitro and release anticancer drug by the aid of US exposure,which possesses greater researching and applicating value.
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Objective:To determine the phase-transition temperature of white vaseline produced by different processes by differen-tial scanning calorimetry ( DSC) in order to analyze the relevance between the melting point and the phase-transition temperature and the relevance between different production processes and the phase-transition temperature. Methods: Hermertic aluminum pans were used to encapsulate the samples, and the testing conditions were optimized. The sample weight was about 10 mg, and the range of measuring temperature was -20-100℃. The heating rate was 5℃·min-1 and the flow rate of nitrogen was 30 ml·min-1 . Results:The phase-transition temperature and the melting point were significantly different. The phase-transition temperature of white vaseline samples produced by different processes was quite different. Conclusion:Melting point determination in the current standard method of white vaseline exists defects, and the composition of white vaseline produced by various processes is quite different.
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Objective To prepare a novel ultrasound contrast agent , targeted phase-shift lipid nanoparticles mediated by tumor homing and penetrating peptide tLyP-1 ,and to evaluate its characteristics . Methods The nanoparticles were prepared by filming-rehydration and acoustic-vibration methods .The morphology ,distribution ,particle size and zeta potential were detected . After heating and irradiating of low intensity focused ultrasound ( LIFU) ,the phase-shift characteristic and the enhancement effect in vitro were observed . The tumor homing and cell-penetrating properties of the nanoparticles were examined by confocal laser scanning microscopy and flow cytometry . The cytotoxicity of the nanoparticles was evaluated by CCK 8 assay . Results The size and distribution of nanoparticles were uniformed . The size and zeta potential of nanoparticles were ( 399 .50 ± 29 .98) nm and ( 3 .28 ± 1 .72) mV ,respectively . When the nanoparticles were heated to a temperature of 45 ℃ or after irradiated by LIFU ,nanoparticles generated phase-shift and enhanced ultrasound imaging in vitro ( P 0 .05 ) . Conclusions A novel ultrasound contrast agent , targeted phase-shift lipid nanoparticles mediated by tumor homing and penetrating peptide tLyP-1 ,is prepared successfully . It can target to MDA-MB-231 cell and penetrate into the cell in vitro ,and enhance ultrasound imaging in vitro after LIFU irradiation ,which expected to become a novel tumor targeted ultrasound contrast agent and achieve ultrasound molecular imaging at the level of tumor cell .