Effective enantioseparation of Naftopidil and its derivatives by HPLC was accomplished using several different polysaccharide-based chiral stationary phases（CSPs）.In normal-phase mode,the compounds were eluted on fo...Effective enantioseparation of Naftopidil and its derivatives by HPLC was accomplished using several different polysaccharide-based chiral stationary phases（CSPs）.In normal-phase mode,the compounds were eluted on four coated-and two immobilized-columns with the mixture of n-hexane,isopropanol and diethylamine（DEA）.Polysaccharide tris（3,5- dimethylphenyl carbamate） was shown to be the best enantiomer selector.In addition,the immobilized column packed with Chiralpak IA or IB was applied under polar-organic and reversed-phase conditions,both of which exhibited excellent enantioselectivity for Naftopidil and its derivatives.Furthermore,the underlying possible chiral recognition mechanisms were discussed.展开更多
Six newly synthesized racemic 1-（substituted phenyl）-4-[3-（indole-4-yl-oxy）-2-hydroxypropyl]-piperazine 1-6 were successfully resolved by carbon dioxide supercritical fluid chromatography （SFC） on an analytical ...Six newly synthesized racemic 1-（substituted phenyl）-4-[3-（indole-4-yl-oxy）-2-hydroxypropyl]-piperazine 1-6 were successfully resolved by carbon dioxide supercritical fluid chromatography （SFC） on an analytical scale column packed with immobilized polysaccharide-based chiral stationary phases （CSPs）. We found that separation on the Chiralpak IA CSP was superior to the other two immobilized CSPs （Chiralpak IB and Chiralpak IC）, and isopropanol （IPA） was a superior modifier compared to the other five solvents including ethanol, methanol, tetrahydrofuran, acetonitrile and dichloromethane. The effects of organic modifier composition, back pressure, and column temperature for enantioseparation of all six compounds were studied. Of the physical parameters studied, modifier composition had the greatest impact on retention. Changing temperature generally had less impact on retention but produced the greatest selectivity changes. The optimum condition was found as follows： Chiralpak IA column, column temperature 35 ~C, back pressure 120 bar, 35% IPA containing 0.1% diethylamine （v/v） in mobile phase, flow rate of mobile phase 3.0 mL/min, UV detection 283 nm. Separation of all six racemic compounds was completed within 10 rain and excellent resolution was obtained. Thus, SFC was found to be the methodology of choice for resolving the enantiomers of this class of compounds.展开更多
Bacterial infections are one of the greatest threats to wound healing,and microbial resistance has increased the demand for new antimicrobial dressings.Artificial nanozymes possess myriad considerable advantages,inclu...Bacterial infections are one of the greatest threats to wound healing,and microbial resistance has increased the demand for new antimicrobial dressings.Artificial nanozymes possess myriad considerable advantages,including low cost and high activity,for targeted biological treatments.Despite significant efforts made in nanozyme engineering,significant challenge remains that their catalytic performance is far from satisfactory in wound treatment.Herein,based on biowaste valorisation,we propose a sustainable and efficient strategy to synthesize an ultrafine-Mn-loaded(3.0±1 nm)N,O-doped porous nanocarbons(Mn-PNCs)nanozyme via the Mott−Schottky effect.The nanozyme achieves mid-temperature(45.8℃)and superior photothermal conversion efficiency(77.62%),photothermally enhanced peroxidase-like activity that contributes to the effective treatment of methicillin-resistant Staphylococcus aureus-infected wounds.The photo-enzyme platform further reduced the inflammatory response,normalized epidermal tissue regeneration,and accelerated wound healing.Notably,the mechanism demonstrated that this Mott−Schottky catalyst can trigger the rapid transfer of electrons to release reactive oxygen species(ROS)species,as a heterojunction system is strongly capable of changing the electron density within the metal.Under photothermal induction,the Mott–Schottky contact can be used to fabricate other polysaccharide-derived nanozymes in tissue engineering,or on the high-value application of biomass resources.展开更多
Bio-adhesive polysaccharide-based hydrogels have attracted much attention in first-aid hemostasis and wound healing for excellent biocompatibility,antibacterial property and pro-healing bioactivity.Yet,the inadequate ...Bio-adhesive polysaccharide-based hydrogels have attracted much attention in first-aid hemostasis and wound healing for excellent biocompatibility,antibacterial property and pro-healing bioactivity.Yet,the inadequate mechanical properties and bio-adhesion limit their applications.Herein,based on dynamic covalent bonds,photo-triggered covalent bonds and hydrogen bonds,multifunctional bio-adhesive hydrogels comprising modified carboxymethyl chitosan,modified sodium alginate and tannic acid are developed.Multi-crosslinking strategy endows hydrogels with improved strength and flexibility simultaneously.Owing to cohesion enhancement strategy and self-healing ability,considerable bio-adhesion is presented by the hydrogel with a maximal adhesion strength of 162.6 kPa,12.3-fold that of commercial fibrin glue.Based on bio-adhesion and pro-coagulant activity(e.g.,the stimulative aggregation and adhesion of erythrocytes and platelets),the hydrogel reveals superior hemostatic performance in rabbit liver injury model with blood loss of 0.32 g,only 54.2%of that in fibrin glue.The healing efficiency of hydrogel for infected wounds is markedly better than commercial EGF Gel and Ag+Gel due to the enhanced antibacterial and antioxidant properties.Through the multi-crosslinking strategy,the hydrogels show enhanced mechanical properties,fabulous bio-adhesion,superior hemostatic performance and promoting healing ability,thereby have an appealing application value for the first-aid hemostasis and infected wound healing.展开更多
基金Guangzhou mega Projects of Science Research in 2009(Grant No.2009A1-E011-7)
文摘Effective enantioseparation of Naftopidil and its derivatives by HPLC was accomplished using several different polysaccharide-based chiral stationary phases（CSPs）.In normal-phase mode,the compounds were eluted on four coated-and two immobilized-columns with the mixture of n-hexane,isopropanol and diethylamine（DEA）.Polysaccharide tris（3,5- dimethylphenyl carbamate） was shown to be the best enantiomer selector.In addition,the immobilized column packed with Chiralpak IA or IB was applied under polar-organic and reversed-phase conditions,both of which exhibited excellent enantioselectivity for Naftopidil and its derivatives.Furthermore,the underlying possible chiral recognition mechanisms were discussed.
基金Science and Technology Program of Guangzhou City(Grant No.2010U1-E0531-2)
文摘Six newly synthesized racemic 1-（substituted phenyl）-4-[3-（indole-4-yl-oxy）-2-hydroxypropyl]-piperazine 1-6 were successfully resolved by carbon dioxide supercritical fluid chromatography （SFC） on an analytical scale column packed with immobilized polysaccharide-based chiral stationary phases （CSPs）. We found that separation on the Chiralpak IA CSP was superior to the other two immobilized CSPs （Chiralpak IB and Chiralpak IC）, and isopropanol （IPA） was a superior modifier compared to the other five solvents including ethanol, methanol, tetrahydrofuran, acetonitrile and dichloromethane. The effects of organic modifier composition, back pressure, and column temperature for enantioseparation of all six compounds were studied. Of the physical parameters studied, modifier composition had the greatest impact on retention. Changing temperature generally had less impact on retention but produced the greatest selectivity changes. The optimum condition was found as follows： Chiralpak IA column, column temperature 35 ~C, back pressure 120 bar, 35% IPA containing 0.1% diethylamine （v/v） in mobile phase, flow rate of mobile phase 3.0 mL/min, UV detection 283 nm. Separation of all six racemic compounds was completed within 10 rain and excellent resolution was obtained. Thus, SFC was found to be the methodology of choice for resolving the enantiomers of this class of compounds.
基金supported by Research Funding of Wuhan Polytechnic University(2023RZ019)the Young Top-Notch Talent Cultivation Program of Hubei Province,the Wuhan Science and Technology Bureau(2022020801010389)+2 种基金the National Natural Science Foundation of China(51973166)the Key Research and Development Program of Hubei Province(2020BCA079)the Beijing Natural Science Foundation(L248026).
文摘Bacterial infections are one of the greatest threats to wound healing,and microbial resistance has increased the demand for new antimicrobial dressings.Artificial nanozymes possess myriad considerable advantages,including low cost and high activity,for targeted biological treatments.Despite significant efforts made in nanozyme engineering,significant challenge remains that their catalytic performance is far from satisfactory in wound treatment.Herein,based on biowaste valorisation,we propose a sustainable and efficient strategy to synthesize an ultrafine-Mn-loaded(3.0±1 nm)N,O-doped porous nanocarbons(Mn-PNCs)nanozyme via the Mott−Schottky effect.The nanozyme achieves mid-temperature(45.8℃)and superior photothermal conversion efficiency(77.62%),photothermally enhanced peroxidase-like activity that contributes to the effective treatment of methicillin-resistant Staphylococcus aureus-infected wounds.The photo-enzyme platform further reduced the inflammatory response,normalized epidermal tissue regeneration,and accelerated wound healing.Notably,the mechanism demonstrated that this Mott−Schottky catalyst can trigger the rapid transfer of electrons to release reactive oxygen species(ROS)species,as a heterojunction system is strongly capable of changing the electron density within the metal.Under photothermal induction,the Mott–Schottky contact can be used to fabricate other polysaccharide-derived nanozymes in tissue engineering,or on the high-value application of biomass resources.
基金sponsored by the National Natural Science Foundation of China(Grant No.32171351)the“1.3.5”Project for Disciplines of Excellence,West China Hospital,Sichuan University(Grant No.ZYJC18002)Med-X Innovation Programme of Med-X Center for Materials,Sichuan University(Grant No.MCM202104).
文摘Bio-adhesive polysaccharide-based hydrogels have attracted much attention in first-aid hemostasis and wound healing for excellent biocompatibility,antibacterial property and pro-healing bioactivity.Yet,the inadequate mechanical properties and bio-adhesion limit their applications.Herein,based on dynamic covalent bonds,photo-triggered covalent bonds and hydrogen bonds,multifunctional bio-adhesive hydrogels comprising modified carboxymethyl chitosan,modified sodium alginate and tannic acid are developed.Multi-crosslinking strategy endows hydrogels with improved strength and flexibility simultaneously.Owing to cohesion enhancement strategy and self-healing ability,considerable bio-adhesion is presented by the hydrogel with a maximal adhesion strength of 162.6 kPa,12.3-fold that of commercial fibrin glue.Based on bio-adhesion and pro-coagulant activity(e.g.,the stimulative aggregation and adhesion of erythrocytes and platelets),the hydrogel reveals superior hemostatic performance in rabbit liver injury model with blood loss of 0.32 g,only 54.2%of that in fibrin glue.The healing efficiency of hydrogel for infected wounds is markedly better than commercial EGF Gel and Ag+Gel due to the enhanced antibacterial and antioxidant properties.Through the multi-crosslinking strategy,the hydrogels show enhanced mechanical properties,fabulous bio-adhesion,superior hemostatic performance and promoting healing ability,thereby have an appealing application value for the first-aid hemostasis and infected wound healing.
