In this work, the nickel-aluminum layered double hydroxide （Ni-Al LDH） with nitrate interlayer anion was synthesized and used as a solid phase extraction sorbent for the selective separation and pre-concentration of...In this work, the nickel-aluminum layered double hydroxide （Ni-Al LDH） with nitrate interlayer anion was synthesized and used as a solid phase extraction sorbent for the selective separation and pre-concentration of mefenamic acid prior to quantification by UV detection at λmax ？ 286 nm. Extraction procedure is based on the adsorption of mefenamate anions on the Ni-Al（NO3？ ） LDH and/or their exchange with LDH interlayer NO3？ anions. The effects of several parameters such as cations and interlayer anions type in LDH structure, pH, sample flow rate, elution conditions, amount of nano-sorbent and co-existing ions on the extraction were investigated and optimized. Under the optimum conditions, the calibration graph was linear within the range of 2-1000 mg/L with a correlation coefficient of 0.9995. The limit of detection and relative standard deviation were 0.6 mg/L and 0.84% （30 mg/L, n ？ 6）, respectively. The presented method was successfully applied to determine of mefenamic acid in human serum and pharmaceutical wastewater samples.展开更多
Combining photodynamic therapy(PDT)with chemodynamic therapy(CDT)has been proven to be a promising strategy to improve the treatment efficiency of cancer,because of the synergistic therapeutic effect arising between t...Combining photodynamic therapy(PDT)with chemodynamic therapy(CDT)has been proven to be a promising strategy to improve the treatment efficiency of cancer,because of the synergistic therapeutic effect arising between the two modalities.Herein,we report an inorganic nanoagent based on ternary NiCoTi-layered double hydroxide(NiCoTi-LDH)nanosheets to realize highly efficient photodynamic/chemodynamic synergistic therapy.The NiCoTi-LDH nanosheets exhibit oxygen vacancy-promoted electron-hole separation and photogenerated holeinduced O_(2)-independent reactive oxygen species(ROS)generation under acidic circumstances,realizing in situ pH-responsive PDT.Moreover,due to the effective conversion between Co^(3+)and Co^(2+)caused by photogenerated electrons,the NiCoTi-LDH nanosheets catalyze the release of hydroxyl radicals(-OH)from H_(2)O_(2)through Fenton reactions,resulting in CDT.Laser irradiation enhances the catalyzed ability of the NiCoTi-LDH nanosheets to promote the ROS generation,resulting in a better performance than TiO_(2)nanoparticles at pH 6.5.In vitro and in vivo experimental results show conclusively that NiCoTi-LDH nanosheets plus irradiation lead to efficient cell apoptosis and significant inhibition of tumor growth.This study reports a new pH-responsive inorganic nanoagent with oxygen vacancy-promoted photodynamic/chemodynamic synergistic performance,offering a potentially appealing clinical strategy for selective tumor elimination.展开更多
基金support from the Research Council of Azarbaijan Shahid Madani University (ASMU,Iran)
文摘In this work, the nickel-aluminum layered double hydroxide （Ni-Al LDH） with nitrate interlayer anion was synthesized and used as a solid phase extraction sorbent for the selective separation and pre-concentration of mefenamic acid prior to quantification by UV detection at λmax ？ 286 nm. Extraction procedure is based on the adsorption of mefenamate anions on the Ni-Al（NO3？ ） LDH and/or their exchange with LDH interlayer NO3？ anions. The effects of several parameters such as cations and interlayer anions type in LDH structure, pH, sample flow rate, elution conditions, amount of nano-sorbent and co-existing ions on the extraction were investigated and optimized. Under the optimum conditions, the calibration graph was linear within the range of 2-1000 mg/L with a correlation coefficient of 0.9995. The limit of detection and relative standard deviation were 0.6 mg/L and 0.84% （30 mg/L, n ？ 6）, respectively. The presented method was successfully applied to determine of mefenamic acid in human serum and pharmaceutical wastewater samples.
基金National Natural Science Foundation of China(21971007)the Beijing Natural Science Foundation(2212044).C.T+1 种基金thanks the funding support from the National Natural Science Foundation of China(52122002 and 22005259)the Start-Up Grant(9610495)from City University of Hong Kong.
文摘Combining photodynamic therapy(PDT)with chemodynamic therapy(CDT)has been proven to be a promising strategy to improve the treatment efficiency of cancer,because of the synergistic therapeutic effect arising between the two modalities.Herein,we report an inorganic nanoagent based on ternary NiCoTi-layered double hydroxide(NiCoTi-LDH)nanosheets to realize highly efficient photodynamic/chemodynamic synergistic therapy.The NiCoTi-LDH nanosheets exhibit oxygen vacancy-promoted electron-hole separation and photogenerated holeinduced O_(2)-independent reactive oxygen species(ROS)generation under acidic circumstances,realizing in situ pH-responsive PDT.Moreover,due to the effective conversion between Co^(3+)and Co^(2+)caused by photogenerated electrons,the NiCoTi-LDH nanosheets catalyze the release of hydroxyl radicals(-OH)from H_(2)O_(2)through Fenton reactions,resulting in CDT.Laser irradiation enhances the catalyzed ability of the NiCoTi-LDH nanosheets to promote the ROS generation,resulting in a better performance than TiO_(2)nanoparticles at pH 6.5.In vitro and in vivo experimental results show conclusively that NiCoTi-LDH nanosheets plus irradiation lead to efficient cell apoptosis and significant inhibition of tumor growth.This study reports a new pH-responsive inorganic nanoagent with oxygen vacancy-promoted photodynamic/chemodynamic synergistic performance,offering a potentially appealing clinical strategy for selective tumor elimination.
