10-Hydroxycamptothecin （HCPT） is a broad-spectrum anticancer drug, while its low solubility and instability severely limit its application. In this study, HCPT nanosuspension （HCPT-NSP）, also known as nanocrystal,...10-Hydroxycamptothecin （HCPT） is a broad-spectrum anticancer drug, while its low solubility and instability severely limit its application. In this study, HCPT nanosuspension （HCPT-NSP）, also known as nanocrystal, was prepared by micro-precipitation combined with high-pressure homogenization method. This nanosuspension was characterized by size, shape, zeta potential, drug loading efficiency and in vitro drug release behavior. Preferred formulation and process showed that particle size was （129.8±13.9） nm, PDI was 0.20±0.07, and drug loading efficiency was 36.5%±9.5%. Moreover, HCPT nanocrystal concentration reached （1.35±0.2） mg/mL in HCPT-NSP, which was more than 1000-fold higher than that of HCPT. Transmission electron microscopy （TEM） results showed that the nanosuspension was short rod in shape. X-ray powder diffraction （XRD）, thermogravimetric analysis （TGA）, derivative thermogravimetric analysis （DTA） and differential scanning calorimetry （DSC） further elaborated the crystal state of the HCPT. The drug concentration-time curve of HCPT-NSP in rats was in accordance with the three-compartment model, showing prolonged half-life. Taken together, our data suggested that HCPT-NSP was a promising drug delivery system.展开更多
Heterogeneous catalysis occurs through a process of interfacial reactions; therefore, both surface facet and size control can increase catalytic efficiency. Octahedral Pd nanocrystals, enclosed by {111} facets, should...Heterogeneous catalysis occurs through a process of interfacial reactions; therefore, both surface facet and size control can increase catalytic efficiency. Octahedral Pd nanocrystals, enclosed by {111} facets, should be the ideal geometrical shape for Heck coupling reactions; however, it is challenging to synthesize 5 nm Pd octahedrons with a relatively uniform size distribution using existing capping-agent techniques. Here, we used palladium as a model system to investigate how the kinetics of atomic addition could be precisely controlled using a syringe pump. As a result, our method produced Pd octahedrons as small as 5 nm, which increased the catalytic efficiency of Heck coupling reactions while reducing the weight of catalyst used.展开更多
Total paeony glycoside（TPG） is obtained from Radix Paeoniae Rubra with a variety of bioactivities. However, the low solubility and bioavailability limit its application. The present study aimed to develop TPG nanocr...Total paeony glycoside（TPG） is obtained from Radix Paeoniae Rubra with a variety of bioactivities. However, the low solubility and bioavailability limit its application. The present study aimed to develop TPG nanocrystals to increase the dissolution and then improve the oral bioavailability. TPG nanocrystals were prepared via precipitation and high-pressure homogenization method. The physical-chemical properties of the optimal TPG nanocrystals in terms of particle size, zeta potential, morphology and crystallinity were evaluated. The results showed that TPG nanocrystals had a mean particle size of（210.2±2.5） nm, a polydispersity index of 0.191±0.033 and a zeta potential of（–22.4±1.2） mV. The result of differential scanning calorimetry showed that the nanocrystals were still in crystalline state after the preparation procedure. Transmission electron microscopy（TEM） results showed that the nanosuspension was in spherical shape. The pharmacokinetics of TPG nanocrystals for rats was investigated by liquid chromatography-tandem mass spectroscopy（LC-MS/MS）. Compared with the TPG coarse suspension, TPG nanocrystals exhibited significant increase in AUC0–∞（approximately 1.85-fold）. Taken together, TPG nanocrystals could be used as a promising drug delivery system due to the enhanced oral bioavailability of TPG.展开更多
Nanoparticles in solution offer unique electrical, mechanical and thermal properties due to their physical presence and interac- tion with the state of dispersion. This work is aimed to study the effects of hydroxyapa...Nanoparticles in solution offer unique electrical, mechanical and thermal properties due to their physical presence and interac- tion with the state of dispersion. This work is aimed to study the effects of hydroxyapatite （HA） nanoparticles on the behavior of devitrification and recrystallization of glycerol （60% w/w） and PEG-600 （50% w/w） solutions during warming. HA nano- particles of different sizes （20, 40, 60 nm） and concentrations （0.1%, 0.5%, w/w） were incorporated into solutions, and were studied by calorimetric analysis coupled with cryomicroscopy. The presence of HA nanoparticles has little effect on the devit- rification end temperatures, but affects the devitrification onset temperatures of glycerol and PEG-600 solutions. The investi- gation with the cryomicroscope observed that the ice morphologies of glycerol and PEG-600 solutions are dendritic and spher- ic respectively. The ice fraction of glycerol solution containing 0.1% HA with the size of 60 nm decreased to 2/5 of that of the solution without nanoparticles at -45℃. The ice fractions of PEG-600 solutions increased signifcantly between -64℃ and -54℃, and the ice fraction of PEG-600 solution without nanoparticles increased by 92% within the temperature range. The findings have significant implications for biomaterial cryopreservation, cryosurgery, and food manufacturing. The complexity of ice crystal growth kinetics in nanoparticle-containing solutions awaits further study.展开更多
基金NSFC(Grant No.81473156,81673365)Fangzheng Foundation for funding of the work
文摘10-Hydroxycamptothecin （HCPT） is a broad-spectrum anticancer drug, while its low solubility and instability severely limit its application. In this study, HCPT nanosuspension （HCPT-NSP）, also known as nanocrystal, was prepared by micro-precipitation combined with high-pressure homogenization method. This nanosuspension was characterized by size, shape, zeta potential, drug loading efficiency and in vitro drug release behavior. Preferred formulation and process showed that particle size was （129.8±13.9） nm, PDI was 0.20±0.07, and drug loading efficiency was 36.5%±9.5%. Moreover, HCPT nanocrystal concentration reached （1.35±0.2） mg/mL in HCPT-NSP, which was more than 1000-fold higher than that of HCPT. Transmission electron microscopy （TEM） results showed that the nanosuspension was short rod in shape. X-ray powder diffraction （XRD）, thermogravimetric analysis （TGA）, derivative thermogravimetric analysis （DTA） and differential scanning calorimetry （DSC） further elaborated the crystal state of the HCPT. The drug concentration-time curve of HCPT-NSP in rats was in accordance with the three-compartment model, showing prolonged half-life. Taken together, our data suggested that HCPT-NSP was a promising drug delivery system.
基金This work was financially supported by the NSFC （No. 21101145）, Recruitment Program of Global Experts, CAS Hundred Talent Program, Fundamental Research Funds for the Central Universities （Nos. WK2060190025, WK2060190037, WK2310000035）, and China Postdoctoral Science Foundation （No. 2014M560514）.
文摘Heterogeneous catalysis occurs through a process of interfacial reactions; therefore, both surface facet and size control can increase catalytic efficiency. Octahedral Pd nanocrystals, enclosed by {111} facets, should be the ideal geometrical shape for Heck coupling reactions; however, it is challenging to synthesize 5 nm Pd octahedrons with a relatively uniform size distribution using existing capping-agent techniques. Here, we used palladium as a model system to investigate how the kinetics of atomic addition could be precisely controlled using a syringe pump. As a result, our method produced Pd octahedrons as small as 5 nm, which increased the catalytic efficiency of Heck coupling reactions while reducing the weight of catalyst used.
基金Innovation Team Project(Grant No.LT2015011)from the Education Department of Liaoning ProvinceImportant Sci entific and Technical Achievements Transformation Project(Gr ant No.Z17-5-078)+1 种基金Applied Basic Research Project(Grant No.F16205144)of Science and Technology Bureau of Shenyangthe Liaoning Provincial Education Department Project of China(Grant No.L2015192)
文摘Total paeony glycoside（TPG） is obtained from Radix Paeoniae Rubra with a variety of bioactivities. However, the low solubility and bioavailability limit its application. The present study aimed to develop TPG nanocrystals to increase the dissolution and then improve the oral bioavailability. TPG nanocrystals were prepared via precipitation and high-pressure homogenization method. The physical-chemical properties of the optimal TPG nanocrystals in terms of particle size, zeta potential, morphology and crystallinity were evaluated. The results showed that TPG nanocrystals had a mean particle size of（210.2±2.5） nm, a polydispersity index of 0.191±0.033 and a zeta potential of（–22.4±1.2） mV. The result of differential scanning calorimetry showed that the nanocrystals were still in crystalline state after the preparation procedure. Transmission electron microscopy（TEM） results showed that the nanosuspension was in spherical shape. The pharmacokinetics of TPG nanocrystals for rats was investigated by liquid chromatography-tandem mass spectroscopy（LC-MS/MS）. Compared with the TPG coarse suspension, TPG nanocrystals exhibited significant increase in AUC0–∞（approximately 1.85-fold）. Taken together, TPG nanocrystals could be used as a promising drug delivery system due to the enhanced oral bioavailability of TPG.
基金supported by the National Natural Science Foundation of China(Grant No.51076108)the Doctoral Program(Grant No.20103120110005)the Shanghai Dongfang Scholars Program
文摘Nanoparticles in solution offer unique electrical, mechanical and thermal properties due to their physical presence and interac- tion with the state of dispersion. This work is aimed to study the effects of hydroxyapatite （HA） nanoparticles on the behavior of devitrification and recrystallization of glycerol （60% w/w） and PEG-600 （50% w/w） solutions during warming. HA nano- particles of different sizes （20, 40, 60 nm） and concentrations （0.1%, 0.5%, w/w） were incorporated into solutions, and were studied by calorimetric analysis coupled with cryomicroscopy. The presence of HA nanoparticles has little effect on the devit- rification end temperatures, but affects the devitrification onset temperatures of glycerol and PEG-600 solutions. The investi- gation with the cryomicroscope observed that the ice morphologies of glycerol and PEG-600 solutions are dendritic and spher- ic respectively. The ice fraction of glycerol solution containing 0.1% HA with the size of 60 nm decreased to 2/5 of that of the solution without nanoparticles at -45℃. The ice fractions of PEG-600 solutions increased signifcantly between -64℃ and -54℃, and the ice fraction of PEG-600 solution without nanoparticles increased by 92% within the temperature range. The findings have significant implications for biomaterial cryopreservation, cryosurgery, and food manufacturing. The complexity of ice crystal growth kinetics in nanoparticle-containing solutions awaits further study.
