Arsenic trioxide albumin microspheres (As_2O_3-BSA-NS) were prepared by using methods of chemical cross-linking. The desirability function (DF), calculated according to the size (<1 μm) distribution, drug loading ...Arsenic trioxide albumin microspheres (As_2O_3-BSA-NS) were prepared by using methods of chemical cross-linking. The desirability function (DF), calculated according to the size (<1 μm) distribution, drug loading and drug trapping efficiency, was introduced as a total index for the microspheres formulation. Four factors, inculding W/O ratio, decentralization speed, BSA concentration and stirring stabilization time, were selected and arranged in an orthogonal experimental table. The release characteristic was studied by the drug release experiment in vitro. The four factors affected DF differently. Decentralization speed behaved as the maximum (P<0.01), followed by BSA concentration (P<0.05) and the W/O ratio dose (P<0.05). Stirring stabilization time did not influence DF (P>0.05). The release experiment in vitro showed that As_2O_3 in As_2O_3-BSA-NS was released more slower than pure As_2O_3. It was concluded that regular As_2O_3-BSA-NS may be prepared by the methods of chemical cross-linking, which was optimized by orthogonal experimental analysis of different factors, and the microspheres can release As_2O_3 slowly.展开更多
Nano-silver loaded montmorillonite （Ag-MMT） was prepared by ion-exchange and then a UV-photoreduction two-step approach was applied. The silver content in Ag-MMT determined by Volhard method was about 6.4 wt%. The m...Nano-silver loaded montmorillonite （Ag-MMT） was prepared by ion-exchange and then a UV-photoreduction two-step approach was applied. The silver content in Ag-MMT determined by Volhard method was about 6.4 wt%. The morphology and structure of as-synthesized Ag-MMT were characterized by scanning electron microscopy （SEM） and X-ray diffraction （XRD）. The results showed that the Ag nanoparticles were spherical and their diameters were about 15-20 nm. Moreover, the structure of MMT did not change. The minimum inhibition concentration （MIC） of Ag-MMT was 100×10-6 and the sterilizing efficiency （SE） of Ag-MMT was approximately 100% against Escherichia coli ATCC 11229 （E. coli. In addition, the slow release property of silver in Ag-MMT was also demonstrated.展开更多
Functional porous microspheres used for the slow release carrier of actives in cosmetics or pharmaceuticals were prepared by modified suspension polymerization of styrene （ST） with divinylbenzene （DVB） in the pres...Functional porous microspheres used for the slow release carrier of actives in cosmetics or pharmaceuticals were prepared by modified suspension polymerization of styrene （ST） with divinylbenzene （DVB） in the presence of toluene, cyclohexanol and heptane as porogenic diluents. The use of ultrasonic dispersion decreases the beads＇ size and improves the uniformity. The effects of the porogen mixture, DVB content and solvent extraction on the surface performance of the synthesized beads were studied. The microspheres were characterized by scanning electron microscopy （SEM） and BET surface area determination. It was found that a great proportion of the non-solvating porogen increases the pore diameter and the specific surface area. High DVB concentration also results in the great specific surface area and porosity. When the ratio of toluene/cyclohexanol is 1：2, DVB content is at the range of 40%-60% and methylene chloride was used as extractant, the beads with good spherical shape and pore size were obtained. The prepared porous microspheres were applied as active carriers and showed satisfactory slow release effect. Over 10h constantly sustained release was observed in vitro releasing test for hydroquinone-loaded microspheres. Great surface area promoted high concentration of released hydroquinone.展开更多
Functional porous microspheres used for the slow release carrier of actives in cosmetics or pharmaceu- ticals were prepared by modified suspension polymerization of styrene (ST) with divinylbenzene (DVB) in the presen...Functional porous microspheres used for the slow release carrier of actives in cosmetics or pharmaceu- ticals were prepared by modified suspension polymerization of styrene (ST) with divinylbenzene (DVB) in the presence of toluene, cyclohexanol and heptane as porogenic diluents. The use of ultrasonic dispersion decreases the beads’ size and improves the uniformity. The effects of the porogen mixture, DVB content and solvent extraction on the surface performance of the synthesized beads were studied. The microspheres were characterized by scanning electron microscopy (SEM) and BET surface area determination. It was found that a great proportion of the non-solvating porogen increases the pore diameter and the specific surface area. High DVB concentration also re- sults in the great specific surface area and porosity. When the ratio of toluene/cyclohexanol is 1:2, DVB content is at the range of 40%—60% and methylene chloride was used as extractant, the beads with good spherical shape and pore size were obtained. The prepared porous microspheres were applied as active carriers and showed satisfactory slow release effect. Over 10h constantly sustained release was observed in vitro releasing test for hydro- quinone-loaded microspheres. Great surface area promoted high concentration of released hydroquinone.展开更多
We investigated the feasibility of using ammonium- and potassium-loaded zeolite (NK-Z) as carriers for fertilizer and for slow release of nitrogen (N) and potassium (K). Plant growth response and soil analysis were pe...We investigated the feasibility of using ammonium- and potassium-loaded zeolite (NK-Z) as carriers for fertilizer and for slow release of nitrogen (N) and potassium (K). Plant growth response and soil analysis were performed. The results indicated an increase in the total harvest weight of kale (Brassica alboglabra Bailey). Furthermore, higher levels of N and K were detected in soil applied with NK-Z than in soil applied with compound fertilizers. The leaf fresh weight of kale in the fertilizer treatments including NK-Z were 2118.4 and 2111.3 g·plant-1, while the leaf fresh weights of kale in the treatment without NK-Z was 2018.0 g·plant-1. The N and K contents in the soils were maintained in the high level in the NK-Z treatment compared that in control treatment. The results indicate that NK-Z has a great potential as the slow-release fertilizer reducing pollution by preventing leaching to the ground water.展开更多
基金This project was supported by State Youth Natural Sci-ences Foundation (No .30200284) .
文摘Arsenic trioxide albumin microspheres (As_2O_3-BSA-NS) were prepared by using methods of chemical cross-linking. The desirability function (DF), calculated according to the size (<1 μm) distribution, drug loading and drug trapping efficiency, was introduced as a total index for the microspheres formulation. Four factors, inculding W/O ratio, decentralization speed, BSA concentration and stirring stabilization time, were selected and arranged in an orthogonal experimental table. The release characteristic was studied by the drug release experiment in vitro. The four factors affected DF differently. Decentralization speed behaved as the maximum (P<0.01), followed by BSA concentration (P<0.05) and the W/O ratio dose (P<0.05). Stirring stabilization time did not influence DF (P>0.05). The release experiment in vitro showed that As_2O_3 in As_2O_3-BSA-NS was released more slower than pure As_2O_3. It was concluded that regular As_2O_3-BSA-NS may be prepared by the methods of chemical cross-linking, which was optimized by orthogonal experimental analysis of different factors, and the microspheres can release As_2O_3 slowly.
基金Huazhong University of Science and Technology,China, for the analytical support
文摘Nano-silver loaded montmorillonite （Ag-MMT） was prepared by ion-exchange and then a UV-photoreduction two-step approach was applied. The silver content in Ag-MMT determined by Volhard method was about 6.4 wt%. The morphology and structure of as-synthesized Ag-MMT were characterized by scanning electron microscopy （SEM） and X-ray diffraction （XRD）. The results showed that the Ag nanoparticles were spherical and their diameters were about 15-20 nm. Moreover, the structure of MMT did not change. The minimum inhibition concentration （MIC） of Ag-MMT was 100×10-6 and the sterilizing efficiency （SE） of Ag-MMT was approximately 100% against Escherichia coli ATCC 11229 （E. coli. In addition, the slow release property of silver in Ag-MMT was also demonstrated.
基金Natural Science Foundation of Guangdong Province （No.05006556）.
文摘Functional porous microspheres used for the slow release carrier of actives in cosmetics or pharmaceuticals were prepared by modified suspension polymerization of styrene （ST） with divinylbenzene （DVB） in the presence of toluene, cyclohexanol and heptane as porogenic diluents. The use of ultrasonic dispersion decreases the beads＇ size and improves the uniformity. The effects of the porogen mixture, DVB content and solvent extraction on the surface performance of the synthesized beads were studied. The microspheres were characterized by scanning electron microscopy （SEM） and BET surface area determination. It was found that a great proportion of the non-solvating porogen increases the pore diameter and the specific surface area. High DVB concentration also results in the great specific surface area and porosity. When the ratio of toluene/cyclohexanol is 1：2, DVB content is at the range of 40%-60% and methylene chloride was used as extractant, the beads with good spherical shape and pore size were obtained. The prepared porous microspheres were applied as active carriers and showed satisfactory slow release effect. Over 10h constantly sustained release was observed in vitro releasing test for hydroquinone-loaded microspheres. Great surface area promoted high concentration of released hydroquinone.
基金Supported by Natural Science Foundation of Guangdong Province (No.05006556).
文摘Functional porous microspheres used for the slow release carrier of actives in cosmetics or pharmaceu- ticals were prepared by modified suspension polymerization of styrene (ST) with divinylbenzene (DVB) in the presence of toluene, cyclohexanol and heptane as porogenic diluents. The use of ultrasonic dispersion decreases the beads’ size and improves the uniformity. The effects of the porogen mixture, DVB content and solvent extraction on the surface performance of the synthesized beads were studied. The microspheres were characterized by scanning electron microscopy (SEM) and BET surface area determination. It was found that a great proportion of the non-solvating porogen increases the pore diameter and the specific surface area. High DVB concentration also re- sults in the great specific surface area and porosity. When the ratio of toluene/cyclohexanol is 1:2, DVB content is at the range of 40%—60% and methylene chloride was used as extractant, the beads with good spherical shape and pore size were obtained. The prepared porous microspheres were applied as active carriers and showed satisfactory slow release effect. Over 10h constantly sustained release was observed in vitro releasing test for hydro- quinone-loaded microspheres. Great surface area promoted high concentration of released hydroquinone.
文摘We investigated the feasibility of using ammonium- and potassium-loaded zeolite (NK-Z) as carriers for fertilizer and for slow release of nitrogen (N) and potassium (K). Plant growth response and soil analysis were performed. The results indicated an increase in the total harvest weight of kale (Brassica alboglabra Bailey). Furthermore, higher levels of N and K were detected in soil applied with NK-Z than in soil applied with compound fertilizers. The leaf fresh weight of kale in the fertilizer treatments including NK-Z were 2118.4 and 2111.3 g·plant-1, while the leaf fresh weights of kale in the treatment without NK-Z was 2018.0 g·plant-1. The N and K contents in the soils were maintained in the high level in the NK-Z treatment compared that in control treatment. The results indicate that NK-Z has a great potential as the slow-release fertilizer reducing pollution by preventing leaching to the ground water.
