Near-infrared （NIR） photothermal therapy has developed very quickly in recent years. However, its clinical applications are hindered by many practical problems, such as low accumulation in tumors, high laser power d...Near-infrared （NIR） photothermal therapy has developed very quickly in recent years. However, its clinical applications are hindered by many practical problems, such as low accumulation in tumors, high laser power density and high biotoxicity in vivo. Herein, a versatile system combining chemotherapy with photothermal therapy for cancer therapy using ultrasmall Pd nanosheets （SPNS） has been developed. The SPNS can serve as pH-responsive drug carriers to efficiently deliver DOX into cancer cells and tumors. On the other hand, the coordinative loading of DOX on SPNS enhances its accumulation in tumor tissue. So we can efficiently ablate tumor using low-intensity laser radiation. Importantly, with ultrasmall size （-4.4 nm）, SPNS surface-functionalized with reduced glutathione （GSH） can be cleared from the body through the renal system into the urine. This cancer therapeutic nanosystem, which exhibits a significant synergistic effect and low systemic toxicity, has great potential for clinical applications.展开更多
Two-dimensional （2D） nanosheets have emerged as an important class of nanomaterial with great potential in the field of biomedicines, particularly in cancer theranostics. However, owing to the lack of effective meth...Two-dimensional （2D） nanosheets have emerged as an important class of nanomaterial with great potential in the field of biomedicines, particularly in cancer theranostics. However, owing to the lack of effective methods that synthesize uniform 2D nanomaterials with controlled size, systematic evaluation of size-dependent bio-behaviors of 2D nanomaterials is rarely reported. To the best of our knowledge, we are the first to report a systematic evaluation of the influence of size of 2D nanomaterials on their bio-behaviors. 2D Pd nanosheets with diameters ranging from 5 to 80 nm were synthesized and tested in cell and animal models to assess their size-dependent bioapplication, biodistribution, elimination, toxicity, and genomic gene expression profiles. Our results showed size significantly influences the biological behaviors of Pd nanosheets, including their photothermal and photoacoustic effects, pharmacokinetics, and toxicity. Compared to larger-sized Pd nanosheets, smaller-sized Pd nanosheets exhibited more advanced photoacoustic imaging and photothermal effects upon ultralow laser irradiation. Moreover, in vivo results indicated that 5-nm Pd nanosheets escape from the reticuloendothelial system with a longer blood half-life and can be cleared by renal excretion, while Pd nanosheets with larger sizes mainly accumulate in the liver and spleen. The 30-nm Pd nanosheets exhibited the highest tumor accumulation. Although Pd nanosheets did not cause any appreciable toxicity at the cellular level, we observed slight lipid accumulation in the liver and inflammation in the spleen. Genomic gene expression analysis showed that 80-nm Pd nanosheets interacted with more cellular components and affected more biological processes in the liver, as compared to 5-nm Pd nanosheets. We believe this work will provide valuable information and insights into the clinical application of 2D Pd nanosheets as nanomedicines.展开更多
Highly active and durable Pd-based electrocatalysts for ethanol oxidation reaction(EOR)play a crucial role in the commercialization of direct ethanol fuel cells(DEFCs).However,the poisonous intermediates(especially ad...Highly active and durable Pd-based electrocatalysts for ethanol oxidation reaction(EOR)play a crucial role in the commercialization of direct ethanol fuel cells(DEFCs).However,the poisonous intermediates(especially adsorbed CO species(COad))formed during the EOR process can easily adsorb and block the active sites on Pd electrodes,which in turn limits the catalytic efficiency.Hence,we present a series of Pd-based composites with a strong coupling interface consisting of Pd nanosheets and amorphous Bi(OH)_(3)species.The incorporation of Bi(OH)3 can induce an electron-rich state adjacent to the Pd sites and effectively separate the Pd ensemble,leading to excellent CO tolerance.The optimal Pd-Bi(OH)_(3)NSs catalyst manifests a mass activity of 2.2 A·mgPd^(-1),which is 5.7 and 2.0 times higher than that of Pd NSs and commercial Pd/C catalyst,respectively.Further CO-stripping experiments and CO-DRIFTS tests confirm the excellent CO tolerance on Pd-Bi(OH)3 NSs electrode,leading to the enhanced EOR durability.展开更多
The undesirable enzymatic activity of nanozymes under near neutral p H condition and the traditional single signal output always restrict the analytical application of nanozyme-based biosensors.Herein,graphitic carbon...The undesirable enzymatic activity of nanozymes under near neutral p H condition and the traditional single signal output always restrict the analytical application of nanozyme-based biosensors.Herein,graphitic carbon nitride nanosheets supported palladium nanosheets composite (Pd/g-C_(3)N_(4)) with both oxidase-like activity and fluorescent property is synthesized.Notably,Pd/g-C_(3)N_(4)exhibits enhanced oxidase-like activity compared to Pd NSs under p H 7.4.By combining Pd/g-C_(3)N_(4)with o-phenylenediamine(OPD),a ratiometric fluorescence assay for acetylcholinesterase (ACh E) activity detection is developed.Pd/g-C_(3)N_(4)can catalyze oxidation of nonfluorescent OPD to fluorescent oxidized OPD (ox OPD,Em=565nm),which can quench fluorescence of g-C_(3)N_(4)supporter (Em=441 nm) through fluorescence resonance energy transfer (FRET).However,in presence of ACh E,acetylthiocholine can be hydrolyzed into thiocholine,which will block the oxidase-like activity of Pd/g-C_(3)N_(4)and then hamper the FRET process.This ratiometric fluorescence assay is also viable to screen ACh E inhibitor.This work will guide design of ratiometric fluorescence assay based on nanozymes with improved enzymatic activity.展开更多
文摘Near-infrared （NIR） photothermal therapy has developed very quickly in recent years. However, its clinical applications are hindered by many practical problems, such as low accumulation in tumors, high laser power density and high biotoxicity in vivo. Herein, a versatile system combining chemotherapy with photothermal therapy for cancer therapy using ultrasmall Pd nanosheets （SPNS） has been developed. The SPNS can serve as pH-responsive drug carriers to efficiently deliver DOX into cancer cells and tumors. On the other hand, the coordinative loading of DOX on SPNS enhances its accumulation in tumor tissue. So we can efficiently ablate tumor using low-intensity laser radiation. Importantly, with ultrasmall size （-4.4 nm）, SPNS surface-functionalized with reduced glutathione （GSH） can be cleared from the body through the renal system into the urine. This cancer therapeutic nanosystem, which exhibits a significant synergistic effect and low systemic toxicity, has great potential for clinical applications.
基金Acknowledgements This work was supported by the National Basic Research Program of China （Nos. 2014CB932004 and 2015CB932303） and the National Natural Science Foundation of China （Nos. 21420102001, 21131005 and 81422023）.
文摘Two-dimensional （2D） nanosheets have emerged as an important class of nanomaterial with great potential in the field of biomedicines, particularly in cancer theranostics. However, owing to the lack of effective methods that synthesize uniform 2D nanomaterials with controlled size, systematic evaluation of size-dependent bio-behaviors of 2D nanomaterials is rarely reported. To the best of our knowledge, we are the first to report a systematic evaluation of the influence of size of 2D nanomaterials on their bio-behaviors. 2D Pd nanosheets with diameters ranging from 5 to 80 nm were synthesized and tested in cell and animal models to assess their size-dependent bioapplication, biodistribution, elimination, toxicity, and genomic gene expression profiles. Our results showed size significantly influences the biological behaviors of Pd nanosheets, including their photothermal and photoacoustic effects, pharmacokinetics, and toxicity. Compared to larger-sized Pd nanosheets, smaller-sized Pd nanosheets exhibited more advanced photoacoustic imaging and photothermal effects upon ultralow laser irradiation. Moreover, in vivo results indicated that 5-nm Pd nanosheets escape from the reticuloendothelial system with a longer blood half-life and can be cleared by renal excretion, while Pd nanosheets with larger sizes mainly accumulate in the liver and spleen. The 30-nm Pd nanosheets exhibited the highest tumor accumulation. Although Pd nanosheets did not cause any appreciable toxicity at the cellular level, we observed slight lipid accumulation in the liver and inflammation in the spleen. Genomic gene expression analysis showed that 80-nm Pd nanosheets interacted with more cellular components and affected more biological processes in the liver, as compared to 5-nm Pd nanosheets. We believe this work will provide valuable information and insights into the clinical application of 2D Pd nanosheets as nanomedicines.
基金This work was supported by the National Natural Science Foundation of China(Nos.51922073 and 21902109)the Natural Science Foundation of Jiangsu Province(Nos.BK20200960 and BK20180097)+1 种基金the Natural Science Foundation of Higher Education in Jiangsu Province(No.20KJB150041)the Natural Science Foundation of Nantong University for High-Level Talent(No.03083033).
文摘Highly active and durable Pd-based electrocatalysts for ethanol oxidation reaction(EOR)play a crucial role in the commercialization of direct ethanol fuel cells(DEFCs).However,the poisonous intermediates(especially adsorbed CO species(COad))formed during the EOR process can easily adsorb and block the active sites on Pd electrodes,which in turn limits the catalytic efficiency.Hence,we present a series of Pd-based composites with a strong coupling interface consisting of Pd nanosheets and amorphous Bi(OH)_(3)species.The incorporation of Bi(OH)3 can induce an electron-rich state adjacent to the Pd sites and effectively separate the Pd ensemble,leading to excellent CO tolerance.The optimal Pd-Bi(OH)_(3)NSs catalyst manifests a mass activity of 2.2 A·mgPd^(-1),which is 5.7 and 2.0 times higher than that of Pd NSs and commercial Pd/C catalyst,respectively.Further CO-stripping experiments and CO-DRIFTS tests confirm the excellent CO tolerance on Pd-Bi(OH)3 NSs electrode,leading to the enhanced EOR durability.
基金supported by the Natural Science Foundation of Shandong Province (Nos.ZR2020QB033 and ZR2019YQ10)the National Natural Science Foundation of China (Nos.21904048,21974132,21902061 and 21902062)the Young Taishan Scholars Program (No.tsqn201812080)。
文摘The undesirable enzymatic activity of nanozymes under near neutral p H condition and the traditional single signal output always restrict the analytical application of nanozyme-based biosensors.Herein,graphitic carbon nitride nanosheets supported palladium nanosheets composite (Pd/g-C_(3)N_(4)) with both oxidase-like activity and fluorescent property is synthesized.Notably,Pd/g-C_(3)N_(4)exhibits enhanced oxidase-like activity compared to Pd NSs under p H 7.4.By combining Pd/g-C_(3)N_(4)with o-phenylenediamine(OPD),a ratiometric fluorescence assay for acetylcholinesterase (ACh E) activity detection is developed.Pd/g-C_(3)N_(4)can catalyze oxidation of nonfluorescent OPD to fluorescent oxidized OPD (ox OPD,Em=565nm),which can quench fluorescence of g-C_(3)N_(4)supporter (Em=441 nm) through fluorescence resonance energy transfer (FRET).However,in presence of ACh E,acetylthiocholine can be hydrolyzed into thiocholine,which will block the oxidase-like activity of Pd/g-C_(3)N_(4)and then hamper the FRET process.This ratiometric fluorescence assay is also viable to screen ACh E inhibitor.This work will guide design of ratiometric fluorescence assay based on nanozymes with improved enzymatic activity.
