ABSTRACT
Alkaline phosphatase (ALP) is distributed widely in living organisms and is an important biomarker closely related to many physiological and pathological processes. However, in vivo real-time detection of ALP remains a significant challenge. Herein, we developed a turn-on molecular probe (denoted as LET-3) to visualize ALP activity in tumor tissues through near-infrared fluorescence (NIRF) and photoacoustic (PA) dual-modal imaging. LET-3, composed of NIR hemicyanine dye (LET-CyOH) and a phosphate moiety, showed a 23-fold NIRF enhancement at 730 nm and 27-fold PA enhancement at 710 nm upon activation by ALP. More importantly, both in vitro and in vivo diagnostic experiments indicated that LET-3 has a high sensitivity and good selectivity for ALP. These findings provide a promising strategy for in vivo ALP detection using NIRF and PA dual-channel turn-on probes.
Subject(s)
Alkaline Phosphatase/analysis , Molecular Imaging/methods , Molecular Probes/chemistry , Photoacoustic Techniques/methods , Alkaline Phosphatase/metabolism , Animals , Carbocyanines/chemistry , Female , Fluorescence , HeLa Cells , Humans , Limit of Detection , Mass Spectrometry/methods , Mice, Nude , Molecular Probes/chemical synthesis , Molecular Probes/toxicity , Neoplasms, Experimental/diagnostic imaging , Neoplasms, Experimental/metabolism , Phosphorylation , Sensitivity and Specificity , Xenograft Model Antitumor AssaysABSTRACT
Human cathepsin L is a ubiquitously expressed endopeptidase and is known to play critical roles in a wide variety of cellular signaling events. Its overexpression has been implicated in numerous human diseases, including highly invasive forms of cancer. Inhibition of cathepsin L is therefore considered a viable therapeutic strategy. Unfortunately, several redundant and even opposing roles of cathepsin L have recently emerged. Selective cathepsin L probes are therefore needed to dissect its function in context-specific manner before significant resources are directed into drug discovery efforts. Herein, the development of a clickable and tagless activity-based probe of cathepsin L is reported. The probe is highly efficient, active-site directed and activity-dependent, selective, cell penetrable, and non-toxic to human cells. Using zebrafish model, we demonstrate that the probe can inhibit cathepsin L function in vivo during the hatching process. It is anticipated that the probe will be a highly effective tool in dissecting cathepsin L biology at the proteome levels in both normal physiology and human diseases, thereby facilitating drug-discovery efforts targeting cathepsin L.
Subject(s)
Cathepsin L/antagonists & inhibitors , Molecular Probes/pharmacology , Animals , Catalytic Domain/drug effects , Cathepsin L/chemistry , Cell Line, Tumor , Cell Movement/drug effects , Click Chemistry , Humans , Molecular Probes/chemical synthesis , Molecular Probes/toxicity , ZebrafishABSTRACT
BACKGROUND: Clear tumor imaging is essential to the resection of hepatocellular carcinoma (HCC). This study aimed to create a novel biological probe to improve the HCC imaging. METHODS: Au nano-flower particles and CuInS2-ZnS core-shell quantum dots were synthesized by hydrothermal method. Au was coated with porous SiO2 and combined with anti-AFP antibody. HCC cell line HepG2 was used to evaluate the targeting efficacy of the probe, while flow cytometry and MTT assay were used to detect the cytotoxicity and bio-compatibility of the probe. Probes were subcutaneously injected to nude mice to explore light intensity and tissue penetration. RESULTS: The fluorescence stability of the probe was maintained 100% for 24â¯h, and the brightness value was 4 times stronger than that of the corresponding CuInS2-ZnS quantum dot. In the targeting experiment, the labeled HepG2 emitted yellow fluorescence. In the cytotoxicity experiments, MTT and flow cytometry results showed that the bio-compatibility of the probe was fine, the inhibition rate of HepG2 cell with 60% Cu-QDs/Anti-AFP probe and Au-QDs/Anti-AFP probe solution for 48â¯h were significantly different (86.3%±7.0% vs. 4.9%±1.3%, tâ¯=â¯19.745, P<0.05), and the apoptosis rates were 83.3%±5.1% vs. 4.4%±0.8% (P<0.001). In the animal experiment, the luminescence of the novel probe can penetrate the abdominal tissues of a mouse, stronger than that of CuInS2-ZnS quantum dot. CONCLUSIONS: The Au@SiO2@CuInS2-ZnS/Anti-AFP probe can targetedly recognize and label HepG2 cells with good bio-compatibility and no toxicity, and the strong tissue penetrability of luminescence may be helpful to surgeons.
Subject(s)
Carcinoma, Hepatocellular/diagnostic imaging , Liver Neoplasms/diagnostic imaging , Molecular Imaging/methods , Molecular Probes/administration & dosage , Optical Imaging/methods , alpha-Fetoproteins/metabolism , Animals , Carcinoma, Hepatocellular/metabolism , Hep G2 Cells , Humans , Injections, Subcutaneous , Liver Neoplasms/metabolism , Mice, Inbred BALB C , Mice, Nude , Molecular Probes/metabolism , Molecular Probes/toxicity , Nanoparticles , Quantum Dots , Tissue DistributionABSTRACT
The first biologically relevant clickable probe related to the antitumor marine lipid jaspineâ B is reported. The concise synthetic route to both enantiomers relied on the supercritical fluid chromatography (SFC) enantiomeric resolution of racemic materials. The eutomeric dextrogyre derivative represents the first jaspineâ B analogue with enhanced cytotoxicity with IC50 down to 30â nm. These enantiomeric probes revealed a chiralitydependent cytoplasmic imaging of U2OS cancer cells by in situ click labeling.
Subject(s)
Alkynes/chemistry , Antineoplastic Agents/chemistry , Fluorescent Dyes/chemistry , Molecular Probes/chemistry , Sphingosine/analogs & derivatives , Alkynes/chemical synthesis , Alkynes/toxicity , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/toxicity , Cell Line, Tumor , Click Chemistry , Fluorescent Dyes/chemical synthesis , Fluorescent Dyes/toxicity , Humans , Molecular Probes/chemical synthesis , Molecular Probes/toxicity , Sphingosine/chemical synthesis , Sphingosine/toxicity , StereoisomerismABSTRACT
Diacylglycerol lipases (DAGL) produce the endocannabinoid 2-arachidonoylglycerol, a key modulator of neurotransmitter release. Chemical tools that visualize endogenous DAGL activity are desired. Here, we report the design, synthesis and application of a triazole urea probe for DAGL equipped with a norbornene as a biorthogonal handle. The activity and selectivity of the probe was assessed with activity-based protein profiling. This probe was potent against endogenous DAGLα (IC50 = 5 nM) and it was successfully applied as a two-step activity-based probe for labeling of DAGLα using an inverse electron-demand Diels-Alder ligation in living cells.
Subject(s)
Lipoprotein Lipase/chemistry , Lipoprotein Lipase/metabolism , Animals , Brain/metabolism , Cell Line, Tumor , Cycloaddition Reaction , Density Functional Theory , Endocannabinoids/chemistry , Humans , Lipoprotein Lipase/antagonists & inhibitors , Mice , Molecular Probes/chemistry , Molecular Probes/toxicity , Norbornanes/chemistry , Proteome , Recombinant Proteins/chemistry , Recombinant Proteins/metabolism , Triazoles/chemistry , Urea/chemistryABSTRACT
BACKGROUND: Ag2S has the characteristics of conventional quantum dot such as broad excitation spectrum, narrow emission spectrum, long fluorescence lifetime, strong anti-bleaching ability, and other optical properties. Moreover, since its fluorescence emission is located in the NIR-II region, has stronger penetrating ability for tissue. Ag2S quantum dot has strong absorption during the visible and NIR regions, it has good photothermal and photoacoustic response under certain wavelength excitation. RESULTS: 200 nm aqueous probe Ag2S@DSPE-PEG2000-FA (Ag2S@DP-FA) with good dispersibility and stability was prepared by coating hydrophobic Ag2S with the mixture of folic acid (FA) modified DSPE-PEG2000 (DP) and other polymers, it was found the probe had good fluorescent, photoacoustic and photothermal responses, and a low cell cytotoxicity at 50 µg/mL Ag concentration. Blood biochemical analysis, liver enzyme and tissue histopathological test showed that no significant influence was observed on blood and organs within 15 days after injection of the probe. In vivo and in vitro fluorescence and photoacoustic imaging of the probe further demonstrated that the Ag2S@DP-FA probe had good active targeting ability for tumor. In vivo and in vitro photothermal therapy experiments confirmed that the probe also had good ability of killing tumor by photothermal. CONCLUSIONS: Ag2S@DP-FA was a safe, integrated diagnosis and treatment probe with multi-mode imaging, photothermal therapy and active targeting ability, which had a great application prospect in the early diagnosis and treatment of tumor.
Subject(s)
Molecular Probes , Optical Imaging/methods , Photoacoustic Techniques/methods , Quantum Dots , Silver Compounds , A549 Cells , Animals , HeLa Cells , Humans , Hydrophobic and Hydrophilic Interactions , Male , Mice , Mice, Inbred BALB C , Molecular Probes/chemistry , Molecular Probes/toxicity , Phosphatidylethanolamines/chemistry , Phosphatidylethanolamines/toxicity , Phototherapy , Polyethylene Glycols/chemistry , Polyethylene Glycols/toxicity , Quantum Dots/chemistry , Quantum Dots/toxicity , Silver Compounds/chemistry , Silver Compounds/toxicityABSTRACT
Besides their superior photophysical properties, phosphorescent transition-metal complexes have some drawbacks for biological applications because of their poor solubility in aqueous solutions and toxicity. In order to avoid the biological environmental impacts on their optical function and solve the problems of water-solubility and toxicity in sensing and bioimaging, two biocompatible organic/inorganic hybrid phosphorescent nanoprobes (Ir-MSN) by using mesoporous silica nanoparticles (MSN) as carriers and an iridium(III) complex as signaling unit were prepared in the present study. In addition, folic acid (FA) was covalently attached to them to endow the particles with characteristic of tumor targeting. The photophysical properties, cell staining and tumor cell targeting functions of FA-ligated Ir-MSN were investigated. These results demonstrated that such a design strategy of phosphorescent nanoprobes is an effective way to develop excellent phosphorescent cellular probes for living cell applications.
Subject(s)
Folic Acid/chemistry , Iridium/chemistry , Luminescent Agents/chemistry , Molecular Probes/chemistry , Nanoparticles/chemistry , Silicon Dioxide/chemistry , Antineoplastic Agents , Cell Survival/drug effects , HeLa Cells , Humans , Microscopy, Confocal , Molecular Imaging , Molecular Probes/toxicity , Theranostic NanomedicineABSTRACT
Designing probes for real-time imaging of dynamic processes in living cells is a continuous challenge. Herein, a novel near-infrared (NIR) photoluminescence probe having a long lifetime was exploited for photoluminescence lifetime imaging (PLIM) using an iridium-alkyne complex. This probe offers the benefits of deep-red to NIR emission, a long Stokes shift, excellent cell penetration, low cytotoxicity, and good resistance to photobleaching. This example is the first PLIM probe applicable to the click reaction of copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) with remarkable lifetime shifts of 414â ns, before and after click reaction. The approach fully eliminates the background interference and distinguishes the reacted probes from the unreacted probes, thus enabling the wash-free imaging of the newly synthesized proteins within single living cells. Based on the unique properties of the iridium complexes, it is anticipated to have applications for imaging other processes within living cells.
Subject(s)
Alkynes/chemistry , Iridium/chemistry , Molecular Probes/chemistry , Photochemical Processes , Proteins/metabolism , Biocompatible Materials , Catalysis , Cell Survival , Click Chemistry , Copper/chemistry , Cycloaddition Reaction , Fluorescence , HeLa Cells , Humans , Luminescence , Molecular Probes/chemical synthesis , Molecular Probes/toxicity , PhotobleachingABSTRACT
A common method of evaluating cellular proliferation is to label DNA with chemical probes. 5-Ethynyl-2'-deoxyuridine (EdU) is a widely utilized chemical probe for labeling DNA, and upon incorporation, EdU treatment of cells is followed by a reaction with a small molecule fluorescent azide to allow detection. The limitations when using EdU include cytotoxicity and a reliance on nucleoside active transport mechanisms for entry into cells. Here we have developed six novel EdU pro-labels that consist of EdU modified with variable lipophilic acyl ester moieties. This pro-label:chemical probe relationship parallels the prodrug:drug relationship that is employed widely in medicinal chemistry. EdU and EdU pro-labels were evaluated for their labeling efficacy and cytotoxicity. Several EdU pro-label analogues incorporate into DNA at a similar level to EdU, suggesting that nucleoside transporters can be bypassed by the pro-labels. These EdU pro-labels also had reduced toxicity compared to EdU.
Subject(s)
Deoxyuridine/analogs & derivatives , Deoxyuridine/pharmacology , Fluorescent Dyes/pharmacology , Molecular Probes/pharmacology , Cell Line, Tumor , Cell Proliferation , DNA/genetics , Deoxyuridine/chemical synthesis , Deoxyuridine/toxicity , Esters/chemical synthesis , Esters/pharmacology , Esters/toxicity , Fluorescence , Fluorescent Dyes/chemical synthesis , Fluorescent Dyes/toxicity , HEK293 Cells , Humans , Molecular Probes/chemical synthesis , Molecular Probes/genetics , Molecular Probes/toxicity , Structure-Activity RelationshipABSTRACT
There is considerable interest in using nanoparticles as labels or to deliver drugs and other bioactive compounds to cells in vitro and in vivo. Fluorescent imaging, commonly used to study internalization and subcellular localization of nanoparticles, does not allow unequivocal distinction between cell surface-bound and internalized particles, as there is no methodology to turn particles 'off'. We have developed a simple technique to rapidly remove silver nanoparticles outside living cells, leaving only the internalized pool for imaging or quantification. The silver nanoparticle (AgNP) etching is based on the sensitivity of Ag to a hexacyanoferrate-thiosulphate redox-based destain solution. In demonstration of the technique we present a class of multicoloured plasmonic nanoprobes comprising dye-labelled AgNPs that are exceptionally bright and photostable, carry peptides as model targeting ligands, can be etched rapidly and with minimal toxicity in mice, and that show tumour uptake in vivo.
Subject(s)
Cells/metabolism , Metal Nanoparticles , Molecular Imaging/methods , Molecular Probes/chemistry , Molecular Probes/metabolism , Silver/chemistry , Silver/metabolism , Animals , Avidin/chemistry , Biological Transport , Cell Line, Tumor , Female , Humans , Mice , Molecular Probes/analysis , Molecular Probes/toxicity , Polyethylene Glycols/chemistry , Silver/toxicityABSTRACT
Folate-conjugated cryptophane was developed for targeting cryptophane to membrane-bound folate receptors that are overexpressed in many human cancers. The cryptophane biosensor was synthesized in 20 nonlinear steps, which included functionalization with folate recognition moiety, solubilizing peptide, and Cy3 fluorophore. Hyperpolarized (129)Xe NMR studies confirmed xenon binding to the folate-conjugated cryptophane. Cellular internalization of biosensor was monitored by confocal laser scanning microscopy and quantified by flow cytometry. Competitive blocking studies confirmed cryptophane endocytosis through a folate receptor-mediated pathway. Flow cytometry revealed 10-fold higher cellular internalization in KB cancer cells overexpressing folate receptors compared to HT-1080 cells with normal folate receptor expression. The biosensor was determined to be nontoxic in HT-1080 and KB cells by MTT assay at low micromolar concentrations typically used for hyperpolarized (129)Xe NMR experiments.
Subject(s)
Folic Acid/chemistry , Molecular Probes/chemistry , Molecular Probes/metabolism , Polycyclic Compounds/chemistry , Polycyclic Compounds/metabolism , Biological Transport , Cell Line, Tumor , Fluorescent Dyes/chemistry , Folic Acid Transporters/metabolism , Humans , Magnetic Resonance Spectroscopy , Molecular Probes/chemical synthesis , Molecular Probes/toxicity , Polycyclic Compounds/chemical synthesis , Polycyclic Compounds/toxicityABSTRACT
We demonstrate that the incorporation of one or two amino acids of phenylalanine (F) or 4-fluoro phenylalanine ((f)F) will greatly lower the background fluorescence intensities of conventional quenched probes with quenchers. This enhanced quenching effect was due to the synergetic effect of the aggregation caused quenching and the presence of a quencher. Such strategy will not greatly affect the enzyme recognition properties to the probes. We also demonstrated that our self-assembled nanoprobe with the enhanced quenching effect showed a better performance in cells for the detection of cell apoptosis than the unassembled probes. Our study demonstrates that using molecular self-assembly can optimize and improve the performance of molecular probes and it provides a simple but very useful strategy to boost the signal-to-noise ratios of fluorescence probes.
Subject(s)
Molecular Probes/chemistry , Amino Acid Sequence , Apoptosis/drug effects , Fluorescein-5-isothiocyanate/chemistry , Fluorescein-5-isothiocyanate/metabolism , Fluorescein-5-isothiocyanate/toxicity , Fluorescence Resonance Energy Transfer , Fluorescent Dyes/chemistry , Fluorescent Dyes/metabolism , Fluorescent Dyes/toxicity , HeLa Cells , Humans , Microscopy, Confocal , Molecular Probes/metabolism , Molecular Probes/toxicity , Peptides/chemical synthesis , Peptides/chemistry , Peptides/metabolism , Rhodamines/chemistry , Rhodamines/metabolism , Rhodamines/toxicity , Signal-To-Noise RatioABSTRACT
A nicked molecular beacon (MB)-functionalized probe has been designed for in situ imaging and detection of intracellular telomerase activity. The nick separates the MB into two segments: a shorter telomerase primer (TSP) sequence as a part of the 5'-end stem and a longer sequence to form a loop with one thiol-labeled 3'-end stem. The MB can be opened by substitutional hybridization of the telomerase-triggered stem elongation product, which leads to separation of the Cy5 at the 5'-end nick from the gold nanoparticle (AuNP) as the nanocarrier and thus inhibits the energy transfer from Cy5 to AuNP. Upon endocytosis of the probe, the TSP can be extended by intracellular telomerase at its 3' end to produce the telomeric repeated sequence, which leads to the inner chain substitution and thus turns on the fluorescence of Cy5. The probe provides a one-step incubation technique for quantification and monitoring of the telomerase activity in living cells. The practicality of the proposed approach for distinguishing tumor cells from normal cells and monitoring the decrease of telomerase activity during treatment with antitumor drugs demonstrates its potential in clinical diagnostic and therapeutic monitoring.
Subject(s)
Fluorescent Dyes/chemistry , Molecular Probe Techniques , Molecular Probes/chemistry , Telomerase/metabolism , Cell Line, Tumor , Cell Survival/drug effects , Enzyme-Linked Immunosorbent Assay , Fluorescent Dyes/toxicity , Gold/chemistry , Humans , Metal Nanoparticles/chemistry , Microscopy, Confocal , Molecular Probes/toxicity , Sensitivity and Specificity , Telomerase/chemistryABSTRACT
Developing multifunctional and easily prepared nanoplatforms with integrated different modalities is highly challenging for molecular imaging. Here, we report the successful transfer of an important molecular target, melanin, into a novel multimodality imaging nanoplatform. Melanin is abundantly expressed in melanotic melanomas and thus has been actively studied as a target for melanoma imaging. In our work, the multifunctional biopolymer nanoplatform based on ultrasmall (<10 nm) water-soluble melanin nanoparticle (MNP) was developed and showed unique photoacoustic property and natural binding ability with metal ions (for example, (64)Cu(2+), Fe(3+)). Therefore, MNP can serve not only as a photoacoustic contrast agent, but also as a nanoplatform for positron emission tomography (PET) and magnetic resonance imaging (MRI). Traditional passive nanoplatforms require complicated and time-consuming processes for prebuilding reporting moieties or chemical modifications using active groups to integrate different contrast properties into one entity. In comparison, utilizing functional biomarker melanin can greatly simplify the building process. We further conjugated αvß3 integrins, cyclic c(RGDfC) peptide, to MNPs to allow for U87MG tumor accumulation due to its targeting property combined with the enhanced permeability and retention (EPR) effect. The multimodal properties of MNPs demonstrate the high potential of endogenous materials with multifunctions as nanoplatforms for molecular theranostics and clinical translation.
Subject(s)
Melanins , Molecular Probes , Multimodal Imaging/methods , Nanoparticles , Animals , Biomarkers/chemistry , Cell Line, Tumor , Cell Survival/drug effects , Copper/chemistry , Drug Stability , Female , Humans , Iron/chemistry , Materials Testing , Melanins/chemistry , Melanins/toxicity , Mice , Molecular Probes/chemistry , Molecular Probes/toxicity , Oligopeptides/chemistry , Polyethylene Glycols/chemistry , Water/chemistryABSTRACT
A novel mitochondrial localizing ruthenium(II) peptide conjugate capable of monitoring dynamic changes in local O2 concentrations within living cells is presented. The complex is comprised of luminescent dinuclear ruthenium(II) polypyridyl complex bridged across a single mitochondrial penetrating peptide, FrFKFrFK-CONH2 (r = D-arginine). The membrane permeability and selective uptake of the peptide conjugate at the mitochondria of mammalian cells was demonstrated using confocal microscopy. Dye co-localization studies confirmed very precise localization and preconcentration of the probe at the mitochondria. This precision permitted collection of luminescent lifetime images of the probe, without the need for co-localizing dye and permitted semiquantitative determination of oxygen concentration at the mitochondria using calibration curves collected at 37 °C for the peptide conjugate in PBS buffer. Using Antimycin A the ability of the probe to respond dynamically to changing O2 concentrations within live HeLa cells was demonstrated. Furthermore, based on lifetime data it was evident that the probe also responds to elevated reactive oxygen species (ROS) levels within the mitochondria, where the greater quenching capacity of these species led to luminescent lifetimes of the probe at longer Antimycin A incubation times which lay outside of the O2 concentration range. Although both the dinuclear complex and a mononuclear analogue conjugated to an octaarginine peptide sequence exhibited some cytotoxicity over 24 h, cells were tolerant of the probes over periods of 4 to 6 h which facilitated imaging. These metal-peptide conjugated probes offer a valuable opportunity for following dynamic changes to mitochondrial function which should be of use across domains in which the metabolic activity of live cells are of interest from molecular biology and drug discovery.
Subject(s)
Mitochondria/metabolism , Molecular Probes/chemistry , Oligopeptides/chemistry , Organometallic Compounds/chemistry , Oxygen/metabolism , Reactive Oxygen Species/metabolism , Ruthenium/chemistry , Amino Acid Sequence , Antimycin A/pharmacology , Biological Transport , Cell Membrane Permeability , Cell Survival/drug effects , HeLa Cells , Humans , Mitochondria/drug effects , Molecular Probes/metabolism , Molecular Probes/toxicity , Molecular Sequence Data , Optical Imaging , Organometallic Compounds/metabolism , Organometallic Compounds/toxicity , TemperatureABSTRACT
A smart vesicle kit was designed for in situ imaging and detection of cytoplasmic telomerase activity. The vesicle kit contained a telomerase primer (TSP) and a Cy5-tagged molecular beacon (MB) functionalized gold nanoparticle probe, which were encapsulated in liposome for intracellular delivery. After the vesicle kit was transfected into cytoplasm, the released TSP could be extended in the presence of telomerase to produce a telomeric repeated sequence at the 3' end, which was just complementary with the loop of MB assembled on probe surface. Thus, the MB was opened upon hybridization to switch the fluorescent state from "off" to "on". The fluorescence signal depended on telomerase activity, leading to a novel strategy for in situ imaging and quantitative detection of the cytoplasmic telomerase activity. The cytoplasmic telomerase activity was estimated to be 3.2 × 10(-11), 2.4 × 10(-11), and 8.6 × 10(-13) IU in each HeLa, BEL tumor and QSG normal cell, respectively, demonstrating the capability of this approach to distinguish tumor from normal cells. The proposed method could be employed for dynamic monitoring of the cytoplasmic telomerase activity in response to a telomerase-based drug, suggesting the potential application in discovery and screening of telomerase-targeted anticancer drugs.
Subject(s)
Enzyme Assays/instrumentation , Microscopy, Fluorescence , Molecular Probes/chemistry , Telomerase/analysis , Carbocyanines/chemistry , Cell Line, Tumor , Cell Survival/drug effects , Gold/chemistry , HeLa Cells , Humans , Liposomes/chemistry , Liposomes/metabolism , Metal Nanoparticles/chemistry , Molecular Probes/metabolism , Molecular Probes/toxicity , Telomerase/metabolism , TransfectionABSTRACT
A cross-linking methodology for the study of DNA-protein interactions is described. The method is inspired by the metabolic activation of furans causing toxic DNA damage, including DNA-protein cross-links (DPC). The furan moiety, representing a latent functionality, is easily incorporated into oligonucleotides, and can be activated on demand to release a reactive aldehyde. Reaction with nucleophilic lysine side chains is shown to be distance-sensitive and allows for site-selective DPC formation.
Subject(s)
Cross-Linking Reagents/chemistry , DNA/chemistry , DNA/metabolism , Furans/chemistry , Molecular Probes/chemistry , Peptides/chemistry , Peptides/metabolism , Amino Acid Sequence , Base Sequence , DNA/genetics , DNA Damage , Furans/toxicity , Models, Molecular , Molecular Probes/toxicity , Molecular Sequence Data , Nucleic Acid Conformation , Protein Binding , Protein ConformationABSTRACT
In the last few decades, coordination complexes based on d(6) metal centres and polypyridyl ligand architectures been developed as structure- and site-specific reversible DNA binding agents. Due to their attractive photophysical properties, much of this research has focused on complexes based on ruthenium(II) centres and, more recently, attention has turned to the use of these complexes in biological contexts. As the rules that govern the cellular uptake and cellular localisation of such systems are determined they are finding numerous applications ranging from imaging to therapeutics. This review illustrates how the interdisciplinary nature of this research-which takes in synthetic chemistry, biophysical and in cellulo studies-makes this an exciting area in which an array of further applications are likely to emerge.
Subject(s)
DNA/metabolism , Molecular Imaging/methods , Organometallic Compounds/metabolism , Organometallic Compounds/therapeutic use , Pyridines/chemistry , Ruthenium/chemistry , Cell Line, Tumor , DNA/chemistry , Humans , Molecular Probes/chemistry , Molecular Probes/metabolism , Molecular Probes/therapeutic use , Molecular Probes/toxicity , Organometallic Compounds/chemistry , Organometallic Compounds/toxicityABSTRACT
Cadmium selenide (CdSe) quantum dots have gained increased attention for their potential use in biomedical applications. This has raised interest in assessing their toxicity. In this study, water-soluble, cysteine-capped CdSe nanocrystals with an average size of 15 nm were prepared through a one-pot solution-based method. The CdSe nanoparticles were synthesized in batches in which the concentration of the capping agent was varied with the aim of stabilizing the quantum dot core. The effects of the CdSe quantum dots on DNA stability, aggregation of blood platelets, and reducing activity of iron were evaluated in vitro . DNA damage was observed at a concentration of 200 µg/mL of CdSe quantum dots. Furthermore, the CdSe nanocrystals exhibited high reducing power and chelating activity, suggesting that they may impair the function of haemoglobin by interacting with iron. In addition, the CdSe quantum dots promoted aggregation of blood platelets in a dose dependent manner.