The immobilized technique of manganese peroxidase(MnP) in gelatin-containing microemulsion-based gels and the effects of storage time and reuse times on its catalytic activity were studied. The results show that the M...The immobilized technique of manganese peroxidase(MnP) in gelatin-containing microemulsion-based gels and the effects of storage time and reuse times on its catalytic activity were studied. The results show that the MnP immobilized together with Mn 2+ and H_2O_2 could effectively oxidize syringaldazine in n-heptane. The immobilized MnP still had a high catalytic activity after one-month storage under a freezing condition. The reuse times have a relation to the amount of the immobilized H_2O_2. When the amount of the immobilized H_2O_2 is sufficient, the microemulsion-based gels containing MnP could be used many times.展开更多
Introduction The formation of gelatin-containing mieroemulsionbased gels（MBGs） was first described in 1986 and the physical/structural characterization was carried out by a number of groups with a variety of techni...Introduction The formation of gelatin-containing mieroemulsionbased gels（MBGs） was first described in 1986 and the physical/structural characterization was carried out by a number of groups with a variety of techniques including tracer diffusion, electrical conductivity, NMR, X-ray and small angle neutron scattering. The MBGs were proposed to comprise an extensive, rigid, interconnected network of gelatin/water rods stabilized by a monolayer of surfactant, in coexistence with a po- pulation of conventional W/O microemulsion droplets.展开更多
Itraconazole (ITZ) is a broad spectrum triazole antifungal drug and commercially available as oral forms. However, effective topical forms are interesting to avoid systemic adverse effects,to directly deliver antifung...Itraconazole (ITZ) is a broad spectrum triazole antifungal drug and commercially available as oral forms. However, effective topical forms are interesting to avoid systemic adverse effects,to directly deliver antifungal drugs to the target sites and to enhance patient compliance (1)Microemulsion-based hydrogel (MBH), a semisolid form of microemulsion (ME), is one of novel formulations practically used as topical drug carriers [2].展开更多
Triptolide is a diterpenoid compound that inhibits the inflammation of rheumatoid arthritis(RA).However,the use of triptolide is limited due to its strong gastrointestinal toxicity.The purpose of this work was to deve...Triptolide is a diterpenoid compound that inhibits the inflammation of rheumatoid arthritis(RA).However,the use of triptolide is limited due to its strong gastrointestinal toxicity.The purpose of this work was to develop a transdermal delivery system for triptolide to reduce this toxicity.A microemulsion-based hydrogel(MBH)was prepared from the combination of Gemseal 40-oleic acid as oil phase,Tween 80-labrasol as surfactant,anhydrous ethanol as co-surfactant,water as aqueous phase and Poloxamer 407 as hydrogel matrix.Rheological measurements,environmental scanning electron microscopy(ESEM)and transdermal experiments in vitro were used to characterize triptolide-loaded and blank MBH preparations.The effects of Poloxamer 407 and triptolide on the rheological properties and microstructures of the MBH were determined.Transparent and homogeneous MBH could only be formed when the concentration of Poloxamer 407 in the selected O/W microemulsion was in the range of 14.0–16.0%(w/w).When the concentration of Poloxamer 407 increased,the rheological properties such as the yield stresses(sy),storage and loss moduli(G′,G″)of the formulations increased,and the network structures became more compact.The addition of triptolide did not change the interconnected network structures of the MBH preparations.MBH preparations afford a better sustained release profile when compared to microemulsions,a finding confirmed by an in vitro permeation test in mice.MBH appears to be a promising vehicle for transdermal delivery of triptolide.展开更多
Based on an unusual reversible sol-gel transition phenomenon. a novel method for the fabrication of a lipase electrode was developed. The response characteristics of the biosensor was studied by potentiometric techniq...Based on an unusual reversible sol-gel transition phenomenon. a novel method for the fabrication of a lipase electrode was developed. The response characteristics of the biosensor was studied by potentiometric technique using olive oil as substrate. After optimization, the lipase electrode demonstrated high activity and good stability.展开更多
CTAB/TX-100 microemtdsion-based gel（MBG）, which could be soaked in aqueous solution for a long time without mechanical strength and shape changes, was successfully prepared. Lipase immobilized in this gel had a high...CTAB/TX-100 microemtdsion-based gel（MBG）, which could be soaked in aqueous solution for a long time without mechanical strength and shape changes, was successfully prepared. Lipase immobilized in this gel had a higher activity than that in CTAB MBG when catalyzed the esterification reaction between n-hexanoic acid and n-octanol and its enantioselectivity was slightly higher when catalyzed the stereoselective esterification reaction between racemic ibuprofen and n-octanol. In aqueous solution, lipase in CTAB/TX-100 MBG could catalyze smoothly the hydrolysis reaction of olive oil and could be reused many times without the evident change of MBG mechanical strength although its activity decreased 41.8% after nine-time recycles.展开更多
文摘The immobilized technique of manganese peroxidase(MnP) in gelatin-containing microemulsion-based gels and the effects of storage time and reuse times on its catalytic activity were studied. The results show that the MnP immobilized together with Mn 2+ and H_2O_2 could effectively oxidize syringaldazine in n-heptane. The immobilized MnP still had a high catalytic activity after one-month storage under a freezing condition. The reuse times have a relation to the amount of the immobilized H_2O_2. When the amount of the immobilized H_2O_2 is sufficient, the microemulsion-based gels containing MnP could be used many times.
基金Supported by the Natural Science Foundation of Shandong Province in China(No.Y2003B01).
文摘Introduction The formation of gelatin-containing mieroemulsionbased gels（MBGs） was first described in 1986 and the physical/structural characterization was carried out by a number of groups with a variety of techniques including tracer diffusion, electrical conductivity, NMR, X-ray and small angle neutron scattering. The MBGs were proposed to comprise an extensive, rigid, interconnected network of gelatin/water rods stabilized by a monolayer of surfactant, in coexistence with a po- pulation of conventional W/O microemulsion droplets.
文摘Itraconazole (ITZ) is a broad spectrum triazole antifungal drug and commercially available as oral forms. However, effective topical forms are interesting to avoid systemic adverse effects,to directly deliver antifungal drugs to the target sites and to enhance patient compliance (1)Microemulsion-based hydrogel (MBH), a semisolid form of microemulsion (ME), is one of novel formulations practically used as topical drug carriers [2].
基金by the Advanced Technology Platform of TCM Delivery System from State Center for Drug Research and Development(No.2009ZX09310-005)Jiangxi Young Scientist Training Program(No.20112BCB23011)Jiangxi Science and Technology Pillar Program(No.2010BSA18400).
文摘Triptolide is a diterpenoid compound that inhibits the inflammation of rheumatoid arthritis(RA).However,the use of triptolide is limited due to its strong gastrointestinal toxicity.The purpose of this work was to develop a transdermal delivery system for triptolide to reduce this toxicity.A microemulsion-based hydrogel(MBH)was prepared from the combination of Gemseal 40-oleic acid as oil phase,Tween 80-labrasol as surfactant,anhydrous ethanol as co-surfactant,water as aqueous phase and Poloxamer 407 as hydrogel matrix.Rheological measurements,environmental scanning electron microscopy(ESEM)and transdermal experiments in vitro were used to characterize triptolide-loaded and blank MBH preparations.The effects of Poloxamer 407 and triptolide on the rheological properties and microstructures of the MBH were determined.Transparent and homogeneous MBH could only be formed when the concentration of Poloxamer 407 in the selected O/W microemulsion was in the range of 14.0–16.0%(w/w).When the concentration of Poloxamer 407 increased,the rheological properties such as the yield stresses(sy),storage and loss moduli(G′,G″)of the formulations increased,and the network structures became more compact.The addition of triptolide did not change the interconnected network structures of the MBH preparations.MBH preparations afford a better sustained release profile when compared to microemulsions,a finding confirmed by an in vitro permeation test in mice.MBH appears to be a promising vehicle for transdermal delivery of triptolide.
文摘Based on an unusual reversible sol-gel transition phenomenon. a novel method for the fabrication of a lipase electrode was developed. The response characteristics of the biosensor was studied by potentiometric technique using olive oil as substrate. After optimization, the lipase electrode demonstrated high activity and good stability.
基金Supported by the National Natural Science Foundation of China(No. 20803044)the Foundation of Key Laboratory of Colloid and Interface Chemistry of Ministry of Education,Shandong University,China(No.200714)
文摘CTAB/TX-100 microemtdsion-based gel（MBG）, which could be soaked in aqueous solution for a long time without mechanical strength and shape changes, was successfully prepared. Lipase immobilized in this gel had a higher activity than that in CTAB MBG when catalyzed the esterification reaction between n-hexanoic acid and n-octanol and its enantioselectivity was slightly higher when catalyzed the stereoselective esterification reaction between racemic ibuprofen and n-octanol. In aqueous solution, lipase in CTAB/TX-100 MBG could catalyze smoothly the hydrolysis reaction of olive oil and could be reused many times without the evident change of MBG mechanical strength although its activity decreased 41.8% after nine-time recycles.
