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1.
The rise of supramolecular chemistry offers new tools to design therapeutics and delivery platforms for biomedical applications. This review aims to highlight the recent developments that harness host-guest interactions and self-assembly to design novel supramolecular Pt complexes as anticancer agents and drug delivery systems. These complexes range from small host-guest structures to large metallosupramolecules and nanoparticles. These supramolecular complexes integrate the biological properties of Pt compounds and novel supramolecular structures, which inspires new designs of anticancer approaches that overcome problems in conventional Pt drugs. Based on the differences in Pt cores and supramolecular structures, this review focuses on five different types of supramolecular Pt complexes, and they include host-guest complexes of the FDA-approved Pt(II) drugs, supramolecular complexes of nonclassical Pt(II) metallodrugs, supramolecular complexes of fatty acid-like Pt(IV) prodrugs, self-assembled nanotherapeutics of Pt(IV) prodrugs, and self-assembled Pt-based metallosupramolecules.  相似文献   

2.
Aptamers as therapeutic and diagnostic agents   总被引:29,自引:0,他引:29  
Aptamers are oligonucleotides derived from an in vitro evolution process called SELEX. Aptamers have been evolved to bind proteins which are associated with a number of disease states. Using this method, many powerful antagonists of such proteins have been found. In order for these antagonists to work in animal models of disease and in humans, it is necessary to modify the aptamers. First of all, sugar modifications of nucleoside triphosphates are necessary to render the resulting aptamers resistant to nucleases found in serum. Changing the 2'OH groups of ribose to 2'F or 2'NH2 groups yields aptamers which are long lived in blood. The relatively low molecular weight of aptamers (8000-12000) leads to rapid clearance from the blood. Aptamers can be kept in the circulation from hours to days by conjugating them to higher molecular weight vehicles. When modified, conjugated aptamers are injected into animals, they inhibit physiological functions known to be associated with their target proteins. A new approach to diagnostics is also described. Aptamer arrays on solid surfaces will become available rapidly because the SELEX protocol has been successfully automated. The use of photo-cross-linkable aptamers will allow the covalent attachment of aptamers to their cognate proteins, with very low backgrounds from other proteins in body fluids. Finally, protein staining with any reagent which distinguishes functional groups of amino acids from those of nucleic acids (and the solid support) will give a direct readout of proteins on the solid support.  相似文献   

3.
Although conventional cancer therapies such as chemotherapy and radiotherapy prevail in clinic, they tend to have narrow therapeutic windows. Many chemotherapies have unfavorable pharmacokinetics while radiotherapy incurs radiotoxicity to normal tissues surrounding tumors. The chemical tunability of supramolecular metal-based nanoparticles (SMNPs) enables the incorporation of various therapeutics, including hydrophilic and hydrophobic chemotherapeutic drugs, photosensitizers, radiosensitizers, and biological therapeutics for more effective delivery to tumors. In this mini-review, we highlight recent advances in SMNPs, namely nanoscale coordination polymers and nanoscale metal–organic frameworks, for drug delivery and cancer therapy. We particularly focus on innovative uses of metal clusters, ligands, pores, and surface modifications to load various therapeutics into SMNPs and critical evaluations of the anticancer efficacies of SMNPs.  相似文献   

4.
Fast and precise diagnosis of infectious and non-infectious animal diseases and their targeted treatments are of utmost importance for their clinical management. The existing biochemical, serological and molecular methods of disease diagnosis need improvement in their specificity, sensitivity and cost and, are generally not amenable for being used as points-of-care (POC) device. Further, with dramatic changes in environment and farm management practices, one should also arm ourselves and prepare for emerging and re-emerging animal diseases such as cancer, prion diseases, COVID-19, influenza etc. Aptamer – oligonucleotide or short peptides that can specifically bind to target molecules – have increasingly become popular in developing biosensors for sensitive detection of analytes, pathogens (bacteria, virus, fungus, prions), drug residues, toxins and, cancerous cells. They have also been proven successful in the cellular delivery of drugs and targeted therapy of infectious diseases and physiological disorders. However, the in vivo application of aptamer-mediated biosensing and therapy in animals has been limited. This paper reviews the existing reports on the application of aptamer-based biosensors and targeted therapy in animals. It also dissects the various modifications to aptamers that were found to be successful in in vivo application of the aptamers in diagnostics and therapeutics. Finally, it also highlights major challenges and future directions in the application of aptamers in the field of veterinary medicine.  相似文献   

5.
Two divalent metal ions are required for primer‐extension catalyzed by DNA polymerases. One metal ion brings the 3′‐hydroxyl of the primer terminus and the α‐phosphorus atom of incoming dNTP together for bond formation so that the catalytically relevant conformation of the triphosphate tail of the dNTP is in an α,β,γ‐tridentate coordination complex with the second metal ion required for proper substrate alignment. A probable base selectivity mechanism derived from structural studies on Dpo4 suggests that the inability of mispaired dNTPs to form a substrate‐aligned, tridentate coordination complex could effectively cause the mispaired dNTPs to be rejected before catalysis. Nevertheless, we found that mispaired dNTPs can actually form a properly aligned tridentate coordination complex. However, complementary dNTPs occasionally form misaligned complexes with mutant RB69 DNA polymerases (RB69pols) that are not in a tridentate coordination state. Here, we report finding a β,γ‐bidentate coordination complex that contained the complementary dUpNpp opposite dA in the structure of a ternary complex formed by the wild type RB69pol at 1.88 Å resolution. Our observations suggest that several distinct metal‐ion coordination states can exist at the ground state in the polymerase active site and that base selectivity is unlikely to be based on metal‐ion coordination alone.  相似文献   

6.
Mixed supramolecular aggregates, obtained by assembling together two amphiphilic monomers (C18H37)2NCO(CH2)2CO(AdOO)5-G-CCK8 (AdOO is 8-amino-3,6-dioxaoctanoic acid, CCK8 is C-terminal octapeptide of cholecystokinin) and (C18H37)2NCO(CH2)2COLys(DTPAGlu)CONH2 (DTPAGlu is N,N-bis[2-[bis(carboxyethyl)amino]ethyl]-l-glutamic acid), are characterized for their structural parameters by dynamic light scattering and for their relaxometric properties, in the absence and in the presence of 0.9 wt% NaCl. Two different aggregates (micelles and bilayer structures) are present in the absence of NaCl, while only bilayer structures are observed at physiological ionic strength. The presence of NaCl increases the ionic strength, promoting a decrease in the repulsions between the polar heads and among the aggregates in solution, thus supporting the formation of large-curvature aggregates such as bilayer structures like vesicles. In these conditions the closed, vesicular shape and the large size (hydrodynamic radius of about 300 Å) of the aggregates allow a high number of paramagnetic gadolinium complexes and bioactive peptides to be accommodated on the inner and external surfaces . The presence of the salt causes a variation in the structural arrangement of the molecules and a partial rigidification of the assembled Gd(III) complexes on the surface vesicles, reducing their internal motions and giving an approximately 15% higher relaxivity value (r 1p = 21.0 and 18.6 Mm?1 s?1 in the presence and in the absence of NaCl, respectively). The vesicles obtained, for the high relaxivity of each gadolidium complex and for the presence of a surface-exposed bioactive peptide, are very promising candidates as target-selective MRI contrast agents.  相似文献   

7.
The aim of this study was to evaluate new ligands which can be applied for labeling biomolecules with scandium radionuclides. Two radionuclides of scandium, 47Sc and 44Sc, are perspective radioisotopes for radiotherapy and diagnostic imaging. 47Sc decays with a half-life of 3.35 days and a maximum β energy of 600 keV and could be an alternative to carrier added 177Lu radionuclide for targeted radionuclide therapy. Another scandium radionuclide 44Sc (t1/2 = 3.92 h) is an ideal β+ emitter for PET diagnosis. It can be obtained as a daughter of the long-lived 44Ti (t1/2 = 60.4 y) from 44Ti/44Sc generator. For complexation of scandium radionuclides macrocyclic ligands having a cavity size similar to Sc3+ ionic radius were selected: 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), 1,4,7-triazacyclononane-1,4,7 triacetic acid (NOTA), 1,4,7-triazacyclodecane-1,4,7 triacetic acid and 1,4,7-triazacycloundecane triacetic acid, and analogs of NOTA with 10, 11 and 12 atoms of the carbon in the ring. Our results have shown that from the studied macrocyclic ligands studied DOTA is most efficient for binding scandium radionuclides 44Sc and 47Sc to biomolecules. The determined stability constant of Sc-DOTA complex logK = 27.0 is comparable with stability constants for Y3+ and heaviest lanthanides but is higher than those for In3+ and Ga3+. Also 46Sc-DOTATATE conjugate exhibits high stability in-vitro studies. The 13C NMR studies have shown that Sc-DOTA like Lu-DOTA forms in solution complexes with eight-coordination geometry. The lipophilicity of Sc-DOTATATE is nearly identical to that of Lu-DOTATATE, which suggests similar receptor affinity of both radioconjugates.  相似文献   

8.
Herein we describe the design, efficient synthesis, and photophysical properties of two macrocycle dyes for cancer theranostics. This study compares a glycosylated chlorin with a glycosylated phthalocyanine designed to specifically target cancer, wherein the photophysical properties enable both fluorescence imaging and the sensitization of the formation of reactive oxygen species (ROS) for photodynamic therapy. Both the compounds show low darktoxicity (IC50 > 100 μM). The glycosylated phthalocyanine showed low phototoxicity (IC50 > 100 μM) while glycosylated chlorin showed high phototoxicity (IC50 = 1–2 μM). ZnPcGlc8 has low solubility and also form aggregates in aqueous media, thus resulting in minimal uptake in two different human breast cancer cell lines: MDA-MB-231 and MCF-7. The glycosylated chlorin however was efficiently taken up by these two cell lines, thus allows fluorescence imaging in cells and in xenograft tumor model in mice. In this study, we find that the chlorin conjugate is the more promising theranostic agent.  相似文献   

9.
Phenolics as potential antioxidant therapeutic agents: mechanism and actions   总被引:16,自引:0,他引:16  
Accumulating chemical, biochemical, clinical and epidemiological evidence supports the chemoprotective effects of phenolic antioxidants against oxidative stress-mediated disorders. The pharmacological actions of phenolic antioxidants stem mainly from their free radical scavenging and metal chelating properties as well as their effects on cell signaling pathways and on gene expression. The antioxidant capacities of phenolic compounds that are widely distributed in plant-based diets were assessed by the Trolox equivalent antioxidant capacity (TEAC), the ferric reducing antioxidant power (FRAP), the hypochlorite scavenging capacity, the deoxyribose method and the copper-phenanthroline-dependent DNA oxidation assays. Based on the TEAC, FRAP and hypochlorite scavenging data, the observed activity order was: procyanidin dimer > flavanol > flavonol > hydroxycinnamic acids > simple phenolic acids. Among the flavonol aglycones, the antioxidant propensities decrease in the order quercetin, myricetin and kaempferol. Gallic acid and rosmarinic acid were the most potent antioxidants among the simple phenolic and hydroxycinnamic acids, respectively. Ferulic acid displayed the highest inhibitory activity against deoxyribose degradation but no structure–activity relationship could be established for the activities of the phenolic compounds in the deoxyribose assay. The efficacies of the phenolic compounds differ depending on the mechanism of antioxidant action in the respective assay used, with procyanidin dimers and flavan-3-ols showing very potent activities in most of the systems tested. Compared to the physiologically active (glutathione, -tocopherol, ergothioneine) and synthetic (Trolox, BHA, BHT) antioxidants, these compounds exhibited much higher efficacy. Plant-derived phenolics represents good sources of natural antioxidants, however, further investigation on the molecular mechanism of action of these phytochemicals is crucial to the evaluation of their potential as prophylactic agents.  相似文献   

10.
Pheophorbide-a, a chlorine based photosensitizer known to be selectively accumulated in cancer cells, was conjugated with anticancer drugs, doxorubicin and paclitaxel in the purpose of selective cancer diagnosis and therapy. Pheophorbide-a was conjugated with anticancer drugs via directly and by the use of selective cleavage linkers in cancer cell. The fluorescence of pheophorbide-a and doxorubicin conjugate by excitation at 420 or 440 nm was greatly diminished possibly by the energy transfer mechanism between two fluorescent groups. However, upon treatment in cancer cells, the conjugate showed to be cleaved to restore each fluorescence of pheophorbide-a and doxorubicin after 48 h of incubation. Also, pheophorbide-a conjugates either with doxorubicin and paclitaxel inhibited the growth of various cancer cells more potently than pheophorbide-a, which displayed very weak inhibitory activity. The results indicated that the pheophorbide-a conjugates with anticancer drugs could be utilized for selective cancer therapy as well as for the fluorescence detection of cancer.  相似文献   

11.
Triple-negative breast cancer (TNBC) has been reported to be correlated with high expression of proliferation markers as well as constitutive activation of metastasis-relevant signaling pathways. For many years, breast cancer researchers have been investigating specific and effective methods to treat or to control the development of TNBC, but promising therapeutic options remain elusive. In this study, we have demonstrated that alkylamide derivatives of bexarotene DK-1–150 and DK-1–166 induce apoptotic cell death in TNBC cell lines without causing cytotoxicity in the normal mammary epithelial cell line. Furthermore, the bexarotene derivatives also showed significant effects in inhibiting TNBC cell proliferation and migration, modulating cancer stem cell markers expressions, as well as limiting the epithelial-mesenchymal transition (EMT) activities of TNBC cell lines in terms of downregulating EMT marker and blocking nuclear translocation of β-catenin. Therefore, we propose the alkylamide derivatives of bexarotene as potential candidates for novel anticancer therapeutics against TNBC.  相似文献   

12.
A series of four new supramolecular complexes of cadmium(II), {[CdBr(H2biim)(PyCO2)(H2O)](H2O)} (1) (H2biim = 2,2′-biimidazole, PyCO2 = isonicotinate), [Cd(H2biim)2(HBDC)2] (2) (H2BDC = terephthalic acid), [Cd(H2biim)2(H2O)2](BDC) (3) and [Cd(H2biim)2(H2O)2](PyCO2)2 · 4H2O (4) have been prepared and characterized by X-ray crystallography, IR, fluorescence spectra and thermogravimetric analysis. Compound 1 exhibits an infinite chain-like structure through bridging isonicotinate. Strong interchain hydrogen bonds between isonicotinate and H2biim result in the robust 2-D sheet structure, responsible for the insolubility. The similar hydrogen bonds between H2biim and the coordinated 1,4-bdc and complementary hydrogen bonds between monoprotonated bdc are responsible for the robust 2-D layered structure of 2 that is insoluble in aqueous solution. 1,4-Bdc becomes uncoordinated in the soluble complex 3, although it has hydrogen bonded 2-D structure as well.  相似文献   

13.
Two new chiral thiosemicarbazide ligands and their Cu (II), Ni (II), Pd (II), and Zn (II) complexes were synthesized and characterized by nuclear magnetic resonance (NMR) (only for ligand), Fourier transform infrared (FT‐IR), ultraviolet visible (UV‐Vis), mass, and elemental analysis. The antioxidant activity of ligands and their metal complexes was examined. It was found that the antioxidant activity of metal complexes was better than their ligands. In addition, the antioxidant activity, as reflected by free radical scavenging, was evaluated. Besides, Pd (II) complexes exhibited better antioxidant activity than Ni (II), Cu (II), and Zn (II) complexes. Therefore, complexes (3a‐Pd and 3b‐Pd) can be used as an antioxidant agent or antioxidant test standard.  相似文献   

14.
The new complexes with 2-salicyloylhydrazono-1,3-dithiolane ligand (H2L) have been obtained with good yields (≈85%) by reacting manganese (II) acetate tetrahydrate or manganese (II) acetylacetonate with 2-salicyloylhydrazono-1,3-dithiolane ligand in DMF, THF or Py (L′). These compounds have been fully characterized by spectroscopic methods and single crystal X-ray diffraction. In the solid state, supramolecular networks are described and discussed in terms of weak H-bonds and short contacts. The new monomeric complexes will be considered as candidates to obtain polynuclear complexes.  相似文献   

15.
Five new silver(I) triple salts: (Ag2C2)(AgNO3)4(AgL1)2(L1H)2 (1), (Ag2C2)(AgCF3CO2)2(AgL1)2(L1H)1/2 (2), [(Ag2C2)(AgCF3CO2)4(L2)(H2O)] · (L2H2) (3), (Ag2C2)(AgNO3)3(AgL3)2 (4), and [(Ag2C2)(AgCF3CO2)4(AgL3)2(H2O)2] · H2O (5) (L1H = nicotinic acid, L2H = isonicotinic acid, L3H = 2-pyrazinecarboxylic acid) have been synthesized by the hydrothermal method. All five compounds contain polyhedral silver(I) cages each encapsulating an acetylenediide dianion, . In 1, C2@Ag8 cages in the shape of bicapped trigonal prisms are interlinked by nitrate, L1, and L1H ligands into a three-dimensional architecture. In 2, silver(I) columns generated from fusion of triangulated dodecahedra are linked by L1 into a layer structure. Compound 3 provides a rare example of a (L2H2)+-pillared three-dimensional structure via hydrogen bonding. In 4, nitrate ligands together with L3 link the C2@Ag7 cages into a three-dimensional architecture. Compound 5 also exhibits a three-dimensional architecture generated from trifluoroacetate and L3-linked C2@Ag8 cages.  相似文献   

16.
Tuning the substituents of triazoles, we obtained di- and tri-nuclearic triazole-nickel complexes [Ni2(deatrz)4(H2O)5](SO4)2 · 7H2O (1) and [Ni3(dmtrz)6(H2O)6](SO4)3 · 21H2O (2) (deatrz = 3,5-diethanyl-4-amino-1,2,4-triazole; dmtrz = 3,5-dimethanyl-1,2,4-triazole). The X-ray single-crystal diffraction results reveal that sulfate anions and water clusters form supramolecular networks in both complexes. In 1, a supramolecular two-dimensional structure was fabricated by nano-sized grid with novel tetramer water rings templated via binuclear-nickel(II) cations, while in 2, water molecules and sulfate anions construct the first sulfate-water three-dimensional supramolecular network as host to encapsulate trinuclear-nickel guests.  相似文献   

17.
The use of Photodynamic Therapy (PDT) for the treatment of several kinds of cancer as well as bacterial, fungal or viral infections has received increasing attention during the last decade. However, the currently clinically approved photosensitizers (PSs) have several drawbacks, including photobleaching, slow clearance from the organism and poor water solubility. To overcome these shortcomings, many efforts have been made in the development of new types of PSs, such as Ru(II) polypyridyl complexes. Nevertheless, most studied Ru(II) polypyridyl complexes have a low absorbance in the spectral therapeutic window. In this work, we show that, by carefully selecting substituents on the polypyridyl complex, it is possible to prepare a complex absorbing at a much higher wavelength. Specifically, we report on the synthesis as well as in-depth experimental and theoretical characterisation of a Ru(II) polypyridyl complex (complex 3) combining a shift in absorbance towards the spectral therapeutic window with a high 1O2 production. To overcome the absence or poor selectivity of most approved PSs into targeted cells/bacteria, they can be linked to targeting moieties. In this line, compound 3 was designed with reactive aldehyde groups, which can be used as a highly versatile synthetic precursor for further conjugation. As a proof of concept, 3 was reacted with benzylamine and the stability of the resulting conjugate 4 was investigated in DMSO, PBS and cell media. 4 showed an impressive ability to act as a PDT PS with no measurable dark cytotoxicity and photocytotoxicity in the low micromolar range against cancerous HeLa cells from 450 nm up to 540 nm.  相似文献   

18.
A series of m-terphenylphosphines TerphPCl2, TerphPH2 and TerphPMe2 (Terph = 2,6-Mes2C6H3-, 2,6-(4-t-BuC6H4)2C6H3-, 2,6-(3,5-Me2C6H3)2C6H3-, 2,6-(2,6-Et2C6H3)2C6H3-, and 2,6-(2,6-i-Pr2C6H3)2C6H3-; Mes = 2,4,6-Me3C6H2-) was prepared and fully characterized. The structural investigation by X-ray crystallography and density functional theory revealed significant distortions in the environment of the ipso carbon and phosphorus centers. These can be traced back to steric interactions and repulsions of the chlorine and methyl substituents on phosphorus with one of the flanking arenes of the m-terphenyl substituents. The primary phosphine 2,6-Mes2C6H3PH2, 6, and the dimethylphosphine 2,6-(3,5-Me2C6H3)2C6H3PMe2, 9, readily form complexes with the Cl2Ru(p-cymene) complex fragment, whereas the larger phosphine 2,6-Mes2C6H3PMe2, 8, does not. Heating of the complexes TerphPR2Ru(Cl2)(p-cymene) 11 and 12 and the mixture of 8 and {(p-cymene)RuCl2}2 lead to expulsion of the p-cymene ligand and intramolecular η6 coordination of one of the flanking arene rings to the ruthenium center to afford the complexes Cl2RuP(H2)C6H3-2-η6-Mes-6-Mes, 13, Cl2RuP(Me2)C6H3-2-η6-Mes-6-Mes, 14, and Cl2RuP(H2)C6H3-2-η6-(3,5-Me2C6H3)-6-(3,5-Me2C6H3), 15. All complexes were characterized by NMR spectroscopy and complexes 14 and 15 also by X-ray crystallography.  相似文献   

19.
Two novel hybrid host-guest architectures based on metal-organic fragments and Keggin polyoxometalates, namely [α-Cu12(trz)8][PMo12O40] · H2O (1) and [β-Cu12(trz)8][PMo12O40] · 2H2O (2) (trz = 1,2,4-triazole), have been prepared under hydrothermal conditions and characterized by single-crystal X-ray diffraction (XRD), elemental analysis, powder XRD, ESR, FT-IR, UV-Vis, and thermogravimetric analysis (TGA). The [Cu12(trz)8]4+ hosts in compounds 1 and 2 are two-dimensional (2D) supramolecular isomers, which present 44 topology based on Cu4(trz)4 cyclic units and 63 topology based on Cu3(trz)3 cyclic units, respectively. The metalmacrocyclic Cu8(trz)8 and Cu9(trz)9 rings represent the largest examples in the coordination chemistry of 1,2,4-triazole. 2D metal-organic fragments and Keggin anions both are connected via hydrogen bonds and Cu?O short contacts to form interesting 3D host-guest architectures of 1 and 2.  相似文献   

20.
In the present work, the synthesis, characterization (FT-IR, multinuclear (1H and 13C) NMR, AAS, Raman, and elemental analysis), DNA binding (cyclic voltammetry, UV–Vis spectroscopy and viscometry), and in vitro biological assessment of nine new ferrocene-based ureas are reported. The desulphurization of ferrocenyl thioureas to the corresponding oxo analogues using aqueous sodium hydroxide and mercuric chloride led to the ferrocenyl ureas (F1–F9) in high yields. The DNA binding studies performed by cyclic voltammetry and UV–Vis spectroscopy produced results that are in close agreement with one another for the binding constants (K) and an electrostatic mode of interaction was observed. The nature and the extent of interaction with DNA was further investigated by viscometry. The DFT/B3LYP method was used to determine the charge distribution and HOMO/LUMO energies of the optimized structure. The DFT calculated HOMO and LUMO energies correlate well with the experimentally determined redox potential values. The synthesized ferrocenyl derivatives exhibited good scavenging activity against 1,1-diphenyl-2-picrylhydrazyl radical (DPPH). These complexes were also scanned for their in vitro cytotoxicity against human carcinoma cell line THP-1 (leukemia cells). The results showed a moderate level of cytotoxicity against the subjected cancer cell line as compared with the standard chemotherapeutic drug (cisplatin).  相似文献   

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