Chun-Nam Lok

The University of Hong Kong, Hong Kong, Hong Kong

Are you Chun-Nam Lok?

Claim your profile

Publications (37)252.21 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Supramolecular interactions are of paramount importance in biology and chemistry, and can be used to develop new vehicles for drug delivery. Recently, there is a surge of interest on self-assembled functional supramolecular structures driven by intermolecular metal–metal interactions in cellular conditions. Herein we report a series of luminescent Pt(II) complexes [Pt(C^N^Npyr)(CNR)]+ [HC^N^Npyr = 2-phenyl-6-(1H-pyrazol-3-yl)-pyridine)] containing pincer type ligands having pyrazole moieties. These Pt(II) complexes exert potent cytotoxicity to a panel of cancer cell lines including primary bladder cancer cells and display strong phosphorescence that is highly sensitive to the local environment. The self-assembly of these complexes is significantly affected by pH of the solution medium. Based on TEM, SEM, ESI-MS, absorption and emission spectroscopy, and fluorescence microscopy together with cell based assays, [Pt(C^N^Npyr)(CNR)]+ complexes were observed to self-assemble into orange phosphorescent polymeric aggregates driven by intermolecular Pt(II)–Pt(II) and ligand–ligand interactions in a low-pH physiological medium. Importantly, the intracellular assembly and dis-assembly of [Pt(C^N^Npyr)(CNR)]+ are accompanied by change of emission color from orange to green. These [Pt(C^N^Npyr)(CNR)]+ complexes accumulated in the lysosomes of cancer cells, increased the lysosomal membrane permeability and induced cell death. One of these platinum(II) complexes formed hydrogels which displayed pH-responsive and sustained release properties, leading to low-pH-stimulated and time-dependent cytotoxicity towards cancer cells. These hydrogels can function as vehicles to deliver anti-cancer agent cargo, such as the bioactive natural products studied in this work.
    Chemical Science 04/2015; DOI:10.1039/C4SC03635B · 8.60 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Gold complexes have recently gained increasing attention in the design of new metal-based anticancer therapeutics. Gold(iii) complexes are generally reactive/unstable under physiological conditions via intracellular redox reactions, and the intracellular Au(III) to Au(I) reduction reaction has recently been "traced" by the introduction of appropriate fluorescent ligands. Similar to most Au(i) complexes, Au(iii) complexes can inhibit the activities of thiol-containing enzymes, including thioredoxin reductase, via ligand exchange reactions to form Au-S(Se) bonds. Nonetheless, there are examples of physiologically stable Au(iii) and Au(i) complexes, such as [Au(TPP)]Cl (H2TPP = 5,10,15,20-tetraphenylporphyrin) and [Au(dppe)2]Cl (dppe = 1,2-bis(diphenylphosphanyl)ethane), which are known to display highly potent in vitro and in vivo anticancer activities. In this review, we summarize our current understanding of anticancer gold complexes, including their mechanisms of action and the approaches adopted to improve their anticancer efficiency. Some recent examples of gold anticancer chemotherapeutics are highlighted.
    Chemical Society Reviews 04/2015; DOI:10.1039/c5cs00132c · 30.43 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background Our previous studies revealed that silver nanoparticles (AgNPs) promoted wound healing in part through their anti-inflammatory actions. As recent reports also suggested anti-inflammatory effects of dendrimers, we therefore undertook this study using dendrimer as the delivery system for AgNP to explore any potential synergistic anti-inflammatory efficacy. Methods Lipopolysaccharide (LPS) was added to cultured RAW264.7 and J774.1 cells to mimic in vitro inflammation condition, followed by the addition of either silver dendrimer nanocomposite (Ag-DNC), AgNPs, or dendrimer. The levels of inflammatory markers TNF-alpha and interleukin-6 were assessed using ELISA assay. Furthermore, in vivo effects such of Ag-DNC, AgNPs, or dendrimer were studied in a burn wound model in mice. Results Our results confirmed that both naked dendrimer and AgNPs had anti-inflammatory properties. In in vitro study, Ag-DNC was shown to have the best anti-inflammatory efficacy than AgNPs or dendrimer alone. In-vivo experiments also indicated that animals in the Ag-DNC group had the fastest healing time with the least inflammation. Conclusion Our study would suggest that dendrimer could provide additional anti-inflammatory benefits and might be an excellent delivery system for silver nanoparticles for future clinical application.
    Journal of Pediatric Surgery 12/2014; 49(12). DOI:10.1016/j.jpedsurg.2014.09.033 · 1.31 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In the design of anticancer gold(I) complexes with high in vivo efficacy, tuning the thiol reactivity to achieve stability towards blood thiols yet maintaining the thiol reactivity to target cellular thioredoxin reductase (TrxR) is of pivotal importance. Herein we describe a dinuclear gold(I) complex (1-PF6 ) utilizing a bridging bis(N-heterocyclic carbene) ligand to attain thiol stability and a diphosphine ligand to keep appropriate thiol reactivity. Complex 1-PF6 displays a favorable stability that allows it to inhibit TrxR activity without being attacked by blood thiols. In vivo studies reveal that 1-PF6 significantly inhibits tumor growth in mice bearing HeLa xenograft and mice bearing highly aggressive mouse B16-F10 melanoma. It inhibits angiogenesis in tumor models and inhibits sphere formation of cancer stem cells in vitro. Toxicology studies indicate that 1-PF6 does not show systemic anaphylaxis on guinea pigs and localized irritation on rabbits.
    Angewandte Chemie International Edition 06/2014; 126(23). DOI:10.1002/anie.201400142 · 11.34 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The synthesis of metal nanoparticles by using bacteria is of growing interest in nanobiotechnology as well as in the study of microbial metal metabolism. Some silver-resistant bacteria can produce considerable amounts of silver particles when exposed to silver salts at high concentration but the mechanism of biosynthesis is unknown. In this work, an Escherichia coli strain that carries chromosomally encoded silver resistance determinants has been shown to produce silver nanoparticles in the periplasmic space when it was exposed to Ag(I) salts, providing a prototypical model for studying the biosynthesis of silver nanoparticles. The synthesized silver nanoparticles are in the form of a zero-valent metallic silver lattice, and the production of which was observed to be favorable under anaerobic conditions, suggestive of the biological reduction of Ag+ ions. As the microbial c-type cytochromes are known to mediate respiratory reduction of metal ions, their role in the biosynthesis of silver nanoparticles was examined. A deletion mutant of the cytoplasmic membrane-anchored tetra-heme c-type cytochrome subunit of periplasmic nitrate reductase (NapC) showed markedly reduced production of silver nanoparticles. On the other hand, re-introduction of the NapC could recover the biosynthesis of the silver nanoparticles. This study has identified a molecular mechanism of biosynthesis of silver nanoparticles involving c-type cytochromes, having implications in the bioenvironmental process of mineralization and the synthetic biology of metal nano-materials.
    Chemical Science 01/2014; 5(8):3144. DOI:10.1039/c4sc00138a · 8.60 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Research in autophagy continues to accelerate,(1) and as a result many new scientists are entering the field. Accordingly, it is important to establish a standard set of criteria for monitoring macroautophagy in different organisms. Recent reviews have described the range of assays that have been used for this purpose.(2,3) There are many useful and convenient methods that can be used to monitor macroautophagy in yeast, but relatively few in other model systems, and there is much confusion regarding acceptable methods to measure macroautophagy in higher eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers of autophagosomes versus those that measure flux through the autophagy pathway; thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from fully functional autophagy that includes delivery to, and degradation within, lysosomes (in most higher eukaryotes) or the vacuole (in plants and fungi). Here, we present a set of guidelines for the selection and interpretation of the methods that can be used by investigators who are attempting to examine macroautophagy and related processes, as well as by reviewers who need to provide realistic and reasonable critiques of papers that investigate these processes. This set of guidelines is not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to verify an autophagic response.
  • [Show abstract] [Hide abstract]
    ABSTRACT: A panel of [Au(III)(C⁁N)(R2NCS2)](+) (HC⁁N = 2-phenylpyridine) complexes displayed significant deubiquitinases (DUBs) inhibitory activity; one of these complexes showed selective in vitro cytotoxicity towards breast cancer cells correlated to high cellular uptake of gold, and induced cell-cycle arrest, apoptosis, and anti-angiogenic property that could be related to DUB inhibitory activity.
    Chemical Communications 04/2013; 49(45). DOI:10.1039/c3cc41766b · 6.72 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A stable gold(III)–phosphine complex [(CNC)2Au2(μ-dppp)](CF3SO3)2 [Au3, HCNCH = 2,6-diphenylpyridine; dppp = bis(diphenylphosphino)propane] displays potent in vitro cytotoxicity towards various cancers with sub-micromolar range cytotoxic IC50 values, and is significantly more potent than its structural and iso-electronic platinum(II) analog [(CNN)2Pt2(μ-dppp)](CF3SO3)2 (HCNN = 6-phenyl-2,2′-bipyridine) and gold(III)–carbene complexes. Complex Au3 displays promising inhibition on tumor growth in animal models, and its acute and sub-chronic toxicities have been examined in mice and beagle dogs. Transcriptomic and connectivity map analyses have revealed that the transcriptional profile of Au3 is similar to those of inhibitors of thioredoxin reductase (TrxR) and inducers of endoplasmic reticulum (ER) stress. As we found that Au3 is also a nanomolar inhibitor of TrxR, a model of ER stress-induced cell death mediated by inhibition of TrxR is proposed. The transcriptomic analysis also leads to the identification of TRAIL, a ligand for death receptor 5 (DR5), as a synergistic agent of the anti-tumor activity of Au3. Collectively, our results demonstrate that the gold(III) complex Au3 effectively inhibits tumor growth in vivo, and displays promising cytotoxicity towards cancer cells in association with the inhibition of TrxR, induction of ER stress and also a death-receptor-dependent apoptotic pathway.
    Chemical Science 04/2013; 4(5):1979-1988. DOI:10.1039/C3SC21972K · 8.60 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A panel of luminescent platinum(ii) complexes containing bidentate N-heterocyclic carbene ligands selectively localize to the endoplasmic reticulum (ER) domain, induce ER stress and cell apoptosis. Some of them show potent photo-toxicity to cancer cells.
    Chemical Communications 03/2013; DOI:10.1039/c3cc40953h · 6.72 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A silver complex of N,N'-disubstituted cyclic thiourea inhibits inflammatory cytokine-stimulated NF-κB activity via IκB kinase inactivation.
    Chemical Communications 03/2013; DOI:10.1039/c3cc00063j · 6.72 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In the literature, very few ytterbium(III) complexes have been reported to display promising anti-cancer activities without photoactivation or conjugation to cytotoxic counterparts/radionuclides. By employing porphyrinato ligands, which provide a rigid molecular scaffold for the ytterbium(III) ion and enhance cellular-uptake efficacy, we have prepared and structurally characterized a series of ytterbium(III) porphyrin complexes showing potent anti-cancer activities with cytotoxic IC50 values down to the sub-micromolar range. The notable example is an ytterbium(III) octaethylporphyrin complex (1) which exists as a dimeric hydroxyl-bridged complex [Yb2(OEP)2(μ-OH)2] (where H2OEP = octaethylporphyrin) in CH2Cl2 solution and in solid state, and as monomeric [Yb(OEP)(DMSO)(OH)(OH2)] in DMSO/aqueous solution. Unlike various anti-cancer lanthanide complexes which are proposed to target cellular DNA, transcriptomics data, bioinformatics connectivity map analysis and biochemical experiments altogether indicate that 1 exerts its anti-cancer effect through apoptosis that is highly associated with the endoplasmic reticulum stress pathway.
    Chemical Science 01/2013; 4(2):747-754. DOI:10.1039/C2SC21541A · 8.60 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Ruthenium porphyrin catalyzes tandem nitrone formation/1,3-dipolar cycloaddition of diazo compounds, nitrosoarenes and alkenes to form isoxazolidines in good to high yields and with excellent regio-, chemo- and diastereo-selectivities. A broad substrate scope of alkenes is applicable to this protocol and various functional groups are compatible with the reaction conditions. In silico analysis and in vitro biological experiments revealed that some of the new isoxazolidines synthesized in this work could act as leukotriene A4 hydrolase inhibitors.
    Organic & Biomolecular Chemistry 09/2012; 10(46). DOI:10.1039/c2ob26518d · 3.49 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Dirhodium(II,II) carboxylates are documented to exhibit both in vitro and in vivo anticancer properties. In literatures, DNA is a proposed molecular target of anticancer active dirhodium(II,II) compounds. Herein, we provide compelling evidences that for the dirhodium(II,II) carboxylates examined in this work (Rh2L4, where L = μ2-OOCMe RhA, μ2-OOCnPr RhB, μ2-OOCiBu RhIsoVal, μ2-OOCiPr RhIsoButyl, μ2-OOCC2H4COPh RhPCOPh or μ2-OOCC3H6COPh RhBCOPh), a prominent mechanism of action is the inhibition of ubiquitin–proteasome system (UPS). Using an unbiased connectivity map analysis, the changes in global gene expression upon treatment of cells with dirhodium(II,II) acetate and butyrate are similar to that of proteasome inhibitors. Cellular studies revealed that dirhodium(II,II) butyrate at submicromolar concentrations exerts a strong inhibition of UPS, attributable to impairment of proteasomal proteolysis and deubiquitinating enzyme activities. The UPS inhibitory potencies of the dirhodium(II,II) carboxylates also exhibit strong correlation with the cytotoxicities. Of note, the dirhodium(II,II) carboxylates inhibit UPS at concentrations that were at least 10-fold lower than that required for eliciting DNA damage as determined by comet assay. While cisplatin, oxaliplatin and carboplatin readily induce significant double strand break as indicated by γ-H2AX induction, the dirhodium(II,II) carboxylates do not. Our findings revealed that the dirhodium(II,II) carboxylates exhibit potent UPS inhibitory property which is linked to their cytotoxic actions.
    Chemical Science 05/2012; 3(6):1785-1793. DOI:10.1039/C2SC00620K · 8.60 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
    Autophagy 04/2012; 8(4):445. · 11.42 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
    Autophagy 04/2012; 8(4):1-100. DOI:10.4161/auto.19496 · 11.42 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure flux through the autophagy pathway (i.e., the complete process);5,6 thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
    Autophagy 04/2012; 8(4). · 11.42 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
    Autophagy 04/2012; 8(4):445-544. · 11.42 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Cyclometalated platinum(II) complexes [Pt(II)(C^N^N)(C≡NR)](+) (HC^N^N = 6-phenyl-2,2'-bipyridyl) display significant inhibition towards TNF-α stimulated NF-κB-dependent gene transcription at concentrations down to the micromolar range.
    Chemical Communications 11/2011; 48(2):230-2. DOI:10.1039/c1cc15317j · 6.72 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We have recently reported a kinetic and mechanistic study on oxidative dissolution of silver nanoparticles (AgNPs) by H(2)O(2). In the present study, the parameters that govern the dissolution of AgNPs by O(2) were revealed by using UV/Vis spectrophotometry. Under the same reaction conditions (Tris-HOAc, pH 8.5, I=0.1 M at 25 °C) the apparent dissolution rate (k(app)) of AgNPs (10±2.8 nm) by O(2) is about 100-fold slower than that of H(2)O(2). The reaction rate is first-order with respect to [Ag(0)], [O(2)], and [Tris](T), and inverse first-order with respect to [Ag(+)] (where [Ag(0)]=total concentration of Ag metal and [Tris](T)=total concentration of Tris). The rate constant is dependent on the size of AgNPs. No free superoxide (O(2)(-)) and hydroxyl radical (·OH) were detected by trapping experiments. On the basis of kinetic and trapping experiments, an amine-activated pathway for the oxidation of AgNPs by O(2) is proposed.
    Chemistry - An Asian Journal 09/2011; 6(9):2506-11. DOI:10.1002/asia.201100034 · 3.94 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Nitric oxide-releasing ruthenium nanoparticles were synthesized by the reaction of alkanethiolate-protected ruthenium nanoparticles with tert-butyl nitrite ((t)BuONO), and their water-soluble derivatives are able to deliver NO to proteins such as reduced myoglobin upon light irradiation in aqueous media.
    Chemical Communications 09/2011; 47(38):10776-8. DOI:10.1039/c1cc13830h · 6.72 Impact Factor

Publication Stats

2k Citations
252.21 Total Impact Points

Institutions

  • 2006–2015
    • The University of Hong Kong
      • • Department of Chemistry
      • • Department of Anatomy
      Hong Kong, Hong Kong
  • 2012
    • University of Michigan
      • Life Sciences Institute
      Ann Arbor, MI, United States
  • 2010
    • Hong Kong SAR Government
      Hong Kong, Hong Kong