Innovative nanotechnology aims to develop particles that are small, monodisperse, smart, and do not cause unintentional side effects. Uniform magnetic Fe3O4 nanoparticles (12 nm in size) were prepared by thermal decomposition of iron(III) oleate. To make them colloidally stable and dispersible in water and cell culture medium, they were modified with phosphonic acid- (PA) and hydroxamic acid (HA)-terminated poly(ethylene glycol) yielding PA-PEG@Fe3O4 and HA-PEG@Fe3O4 nanoparticles; conventional γ-Fe2O3 particles were prepared as a control. Advanced techniques were used to evaluate the properties and safety of the particles. Completeness of the nanoparticle coating was tested by real-time polymerase chain reaction. Interaction of the particles with primary human peripheral blood cells, cellular uptake, cytotoxicity, and immunotoxicity were also investigated. Amount of internalized iron in peripheral blood mononuclear cells was 72, 38, and 25 pg Fe/cell for HA-PEG@Fe3O4, γ-Fe2O3, and PA-PEG@Fe3O4, respectively. Nanoparticles were localized within the cytoplasm and in the extracellular space. No cytotoxic effect of both PEGylated nanoparticles was observed (0.12-75 μg/cm2) after 24 and 72-h incubation. Moreover, no suppressive effect was found on the proliferative activity of T-lymphocytes and T-dependent B-cell response, phagocytic activity of monocytes and granulocytes, and respiratory burst of phagocytes. Similarly, no cytotoxic effect of γ-Fe2O3 particles was observed. However, they suppressed the proliferative activity of T-lymphocytes (75 μg/cm2, 72 h) and also decreased the phagocytic activity of monocytes (15 μg/cm2, 24 h; 3-75 μg/cm2, 72 h). We thus show that newly developed particles have great potential especially in cancer diagnostics and therapy.
- Klíčová slova
- Iron oxide nanoparticles, PCR inhibition, cell interaction and uptake, cytotoxicity and immunotoxicity, human peripheral blood leucocytes,
- MeSH
- cytokiny metabolismus MeSH
- fagocytóza účinky léků imunologie MeSH
- kultivované buňky MeSH
- kyseliny fosforité chemie MeSH
- kyseliny hydroxamové chemie MeSH
- leukocyty mononukleární účinky léků imunologie patologie MeSH
- lidé MeSH
- magnetické nanočástice chemie toxicita MeSH
- nanomedicína metody MeSH
- polyethylenglykoly chemie MeSH
- povrchové vlastnosti MeSH
- proliferace buněk účinky léků MeSH
- respirační vzplanutí účinky léků imunologie MeSH
- velikost částic MeSH
- viabilita buněk účinky léků imunologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- cytokiny MeSH
- kyseliny fosforité MeSH
- kyseliny hydroxamové MeSH
- magnetické nanočástice MeSH
- phosphonic acid MeSH Prohlížeč
- polyethylenglykoly MeSH
Influenza neuraminidase is responsible for the escape of new viral particles from the infected cell surface. Several neuraminidase inhibitors are used clinically to treat patients or stockpiled for emergencies. However, the increasing development of viral resistance against approved inhibitors has underscored the need for the development of new antivirals effective against resistant influenza strains. A facile, sensitive, and inexpensive screening method would help achieve this goal. Recently, we described a multiwell plate-based DNA-linked inhibitor antibody assay (DIANA). This highly sensitive method can quantify femtomolar concentrations of enzymes. DIANA also has been applied to high-throughput enzyme inhibitor screening, allowing the evaluation of inhibition constants from a single inhibitor concentration. Here, we report the design, synthesis, and structural characterization of a tamiphosphor derivative linked to a reporter DNA oligonucleotide for the development of a DIANA-type assay to screen potential influenza neuraminidase inhibitors. The neuraminidase is first captured by an immobilized antibody, and the test compound competes for binding to the enzyme with the oligo-linked detection probe, which is then quantified by qPCR. We validated this novel assay by comparing it with the standard fluorometric assay and demonstrated its usefulness for sensitive neuraminidase detection as well as high-throughput screening of potential new neuraminidase inhibitors.
- Klíčová slova
- DIANA, assay, crystallography, influenza neuraminidase,
- MeSH
- antivirové látky chemie farmakologie MeSH
- chřipka lidská farmakoterapie enzymologie virologie MeSH
- DNA chemie MeSH
- inhibitory enzymů chemie farmakologie MeSH
- kyseliny fosforité chemie MeSH
- lidé MeSH
- neuraminidasa antagonisté a inhibitory metabolismus MeSH
- oseltamivir analogy a deriváty chemie MeSH
- preklinické hodnocení léčiv metody MeSH
- reprodukovatelnost výsledků MeSH
- virové proteiny antagonisté a inhibitory metabolismus MeSH
- virus chřipky A účinky léků enzymologie fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- antivirové látky MeSH
- DNA MeSH
- inhibitory enzymů MeSH
- kyseliny fosforité MeSH
- neuraminidasa MeSH
- oseltamivir MeSH
- tamiphosphor MeSH Prohlížeč
- virové proteiny MeSH
The complexation ability of DOTA analogs bearing one methylenephosphonic (DO3AP) or methylenephosphinic (DO3AP(PrA) and DO3AP(ABn)) acid pendant arm toward scandium was evaluated. Stability constants of their scandium(iii) complexes were determined by potentiometry combined with (45)Sc NMR spectroscopy. The stability constants of the monophosphinate analogues are somewhat lower than that of the Sc-DOTA complex. The phosphorus acid moiety interacts with trivalent scandium even in very acidic solutions forming out-of-cage complexes; the strong affinity of the phosphonate group to Sc(iii) precludes stability constant determination of the Sc-DO3AP complex. These results were compared with those obtained by the free-ion selective radiotracer extraction (FISRE) method which is suitable for trace concentrations. FISRE underestimated the stability constants but their relative order was preserved. Nonetheless, as this method is experimentally simple, it is suitable for a quick relative comparison of stability constant values under trace concentrations. Radiolabelling of the ligands with (44)Sc was performed using the radioisotope from two sources, a (44)Ti/(44)Sc generator and (44m)Sc/(44)Sc from a cyclotron. The best radiolabelling conditions for the ligands were pH = 4, 70 °C and 20 min which were, however, not superior to those of the parent DOTA. Nonetheless, in vitro behaviour of the Sc(iii) complexes in the presence of hydroxyapatite and rat serum showed sufficient stability of (44)Sc complexes of these ligands for in vivo applications. PET images and ex vivo biodistribution of the (44)Sc-DO3AP complex performed on healthy Wistar male rats showed no specific bone uptake and rapid clearance through urine.
- MeSH
- heterocyklické sloučeniny monocyklické chemie MeSH
- krysa rodu Rattus MeSH
- kyseliny fosforité chemie MeSH
- ligandy MeSH
- magnetická rezonanční spektroskopie MeSH
- molekulární struktura MeSH
- organokovové sloučeniny chemická syntéza chemie MeSH
- potenciometrie MeSH
- potkani Wistar MeSH
- radionuklidy chemie MeSH
- skandium chemie MeSH
- termodynamika * MeSH
- titan chemie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- 1,4,7,10-tetraazacyclododecane- 1,4,7,10-tetraacetic acid MeSH Prohlížeč
- heterocyklické sloučeniny monocyklické MeSH
- kyseliny fosforité MeSH
- ligandy MeSH
- organokovové sloučeniny MeSH
- radionuklidy MeSH
- skandium MeSH
- titan MeSH
Two macrocyclic ligands based on cyclam with trans-disposed N-methyl and N-(4-aminobenzyl) substituents as well as two methylphosphinic (H2L1) or methylphosphonic (H4L2) acid pendant arms were synthesised and investigated in solution. The ligands form stable complexes with transition metal ions. Both ligands show high thermodynamic selectivity for divalent copper over nickel(II) and zinc(II)-K(CuL) is larger than K(Ni/ZnL) by about seven orders of magnitude. Complexation is significantly faster for the phosphonate ligand H4L2, probably due to the stronger coordination ability of the more basic phosphonate groups, which efficiently bind the metal ion in an "out-of-cage" complex and thus accelerate its "in-cage" binding. The rate of Cu(II) complexation by the phosphinate ligand H2L1 is comparable to that of cyclam itself and its derivatives with non-coordinating substituents. Acid-assisted decomplexation of the copper(II) complexes is relatively fast (τ1/2 = 44 and 42 s in 1 M aq. HClO4 at 25 °C for H2L1 and H4L2, respectively). This combination of properties is convenient for selective copper removal/purification. Thus, the title ligands were employed in the preparation of ion-selective resins for radiocopper(II) separation. Glycidyl methacrylate copolymer beads were modified with the ligands through a diazotisation reaction. The separation ability of the modified polymers was tested with cold copper(II) and non-carrier-added (64)Cu in the presence of a large excess of both nickel(II) and zinc(II). The experiments exhibited high overall separation efficiency leading to 60-70% recovery of radiocopper with high selectivity over the other metal ions, which were originally present in 900-fold molar excess. The results showed that chelating resins with properly tuned selectivity of their complexing moieties can be employed for radiocopper separation.
- Klíčová slova
- copper, ion-selective resins, kinetics, macrocyclic ligands, radiochemistry,
- MeSH
- chelátory chemie MeSH
- elektrochemické techniky MeSH
- heterocyklické sloučeniny chemie MeSH
- kinetika MeSH
- komplexní sloučeniny chemická syntéza chemie MeSH
- koncentrace vodíkových iontů MeSH
- kyseliny fosfinové chemická syntéza chemie MeSH
- kyseliny fosforité chemická syntéza chemie MeSH
- kyseliny fosforu chemie MeSH
- ligandy MeSH
- měď chemie MeSH
- nikl chemie MeSH
- radioizotopy mědi chemie izolace a purifikace MeSH
- termodynamika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- chelátory MeSH
- cyclam MeSH Prohlížeč
- heterocyklické sloučeniny MeSH
- komplexní sloučeniny MeSH
- kyseliny fosfinové MeSH
- kyseliny fosforité MeSH
- kyseliny fosforu MeSH
- ligandy MeSH
- měď MeSH
- nikl MeSH
- phosphonic acid MeSH Prohlížeč
- radioizotopy mědi MeSH
A series of conformationally constrained uridine-based nucleoside phosphonic acids containing annealed 1,3-dioxolane and 1,4-dioxane rings and their "open-structure" isosteres were synthesized and evaluated as potential multisubstrate-like inhibitors of the human recombinant thymidine phosphorylase (TP, EC 2.4.2.4) and TP obtained from peripheral blood mononuclear cells (PBMC). From a large set of tested nucleoside phosphonic acids, several potent compounds were identified that exhibited Ki values in the range of 0.048-1 μM. The inhibition potency of the studied compounds strongly depended on the degree of conformational flexibility of the phosphonate moiety, the stereochemical arrangement of the sugar-phosphonate component, and the substituent at position 5 of the pyrimidine nucleobase.
- Klíčová slova
- Bi-substrate-like inhibitor, Conformationally constrained nucleotide analog, Human thymidine phosphorylase, Michael addition, PBMC, Phosphonate,
- MeSH
- inhibitory enzymů farmakologie MeSH
- kyseliny fosforité chemie farmakologie MeSH
- lidé MeSH
- molekulární konformace MeSH
- pyrimidinové nukleosidy farmakologie MeSH
- thymidinfosforylasa antagonisté a inhibitory MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- inhibitory enzymů MeSH
- kyseliny fosforité MeSH
- pyrimidinové nukleosidy MeSH
- thymidinfosforylasa MeSH
Hexadecyloxypropyl esters of acyclic nucleoside phosphonates containing guanine (G) or hypoxanthine (Hx) and a (S)-[3-hydroxy-2-(phosphonomethoxy)propyl] [(S)-HPMP] or 2-(2-phosphonoethoxy)ethyl (PEE) acyclic moiety have been prepared. The activity of the prodrugs was evaluated in vitro against different virus families. Whereas ester derivatives of PEEHx and (S)-HPMPHx were antivirally inactive, monoesters of PEEG, and mono- and diesters of (S)-HPMPG showed pronounced antiviral activity against vaccinia virus and/or herpesviruses. Monoesters of (S)-HPMPG emerged as the most potent and selective derivatives against these DNA viruses. None of the compounds were inhibitory against RNA viruses and retroviruses.
- MeSH
- antivirové látky chemická syntéza chemie metabolismus farmakologie MeSH
- buněčné linie MeSH
- DNA viry účinky léků MeSH
- guanin analogy a deriváty chemie MeSH
- hypoxanthin chemie MeSH
- hypoxanthiny chemie MeSH
- kyseliny fosforité chemie MeSH
- lidé MeSH
- nukleosidy chemie MeSH
- organofosfonáty chemická syntéza chemie metabolismus farmakologie MeSH
- prekurzory léčiv metabolismus MeSH
- techniky syntetické chemie MeSH
- vztahy mezi strukturou a aktivitou MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- antivirové látky MeSH
- guanin MeSH
- hypoxanthin MeSH
- hypoxanthiny MeSH
- kyseliny fosforité MeSH
- nukleosidy MeSH
- organofosfonáty MeSH
- prekurzory léčiv MeSH
