ABSTRACT
Oxidative stress caused by an overproduction of reactive oxygen species (ROS) is the key factor in developing a variety of pathological conditions. Recently various nanomaterials have attracted growing interest as nanoantioxidants with ROS-regulating ability. Here, for the first time, we report on high antioxidant behavior (enzyme-like activity) of GdYVO4:Eu3+nanoparticles (GdYVO NPs) revealed by spectroscopic methods both in cell-free and biological milieu using various ROS sensors. It was revealed that GdYVO NPs (d= 2 nm) effectively scavenge hydroxyl radicals·OH,superoxide anionsO2·-,hydrogen peroxideH2O2,peroxyl radicalsROO·,and remarkably reduce the lipopolysaccharide-induced ROS generation in rat leukocytes. The antioxidant activity of GdYVO NPs is ascribed to high amount of V4+and V3+ions in the structure of the NPs and the reversible switchingV3+âV4+andV4+âV5+vanadium oxidation states.
Subject(s)
Antioxidants/chemistry , Gadolinium/chemistry , Metal Nanoparticles/chemistry , Vanadates/chemistry , Yttrium/chemistry , Animals , Hydroxyl Radical/analysis , Hydroxyl Radical/chemistry , Leukocytes/drug effects , Leukocytes/metabolism , Lipid Peroxidation/drug effects , MiceABSTRACT
Light-triggered redox activity of small (d = 2 nm) GdYVO4:Eu3+ nanoparticles (NPs) in aqueous solutions and lipid suspensions is reported. It has been revealed that depending on pre-treatment conditions (exposure to UV light or storage in the dark) the same NPs exhibit pro- or anti-oxidant properties. Pro-/anti-oxidant activity in aqueous solutions was evaluated by UV-vis spectroscopy using probe molecules for hydroxyl radicals (·OH) and superoxide anions (O2â¢-). Lipid oxidation under the effect of NPs has been also analyzed. Multi-functional GdYVO4:Eu3+ NPs are assumed to be a new theranostic agent in cancer therapy, which exhibit fluorescent properties, triggered redox activity and drug-carrier ability.
ABSTRACT
Studying the complexes of inorganic nanoparticles - organic dye molecules is of great importance for their theranostics application. In this paper, we report gadolinium-yttrium orthovanadate nanoparticles (VNPs) - Acridine Orange (AO) complex formation in water solutions. To study the interactions between VNPs and AO, the methods of steady-state and time-resolved spectroscopy were used. It was shown that in aqueous solutions containing VNPs, AO aggregation takes place with a sandwich-like stacking of AO molecules in the near-surface layer of VNPs. The VNPs-AO complex formation causes significant changes in the AO fluorescence spectrum, namely, the appearance of a new broad, structureless band in the long-wavelength spectral edge, which was not observed in AO spectrum in a pure water solution. By analyzing of the absorption, fluorescence excitation spectra and fluorescence decay, the static excimer origin of the long-wavelength fluorescence band has been established.
ABSTRACT
UNLABELLED: The aim of this research is to study the dynamics and efficiency of liposome accumulation in sensitive and resistant human breast cancer cells. METHODS: Methods of fluorescence microscopy, fluorescence microspectroscopy and MTT-test have been used. RESULTS: The liposome-to-cell interaction and dye cellular uptake in sensitive, cisplatin-resistant and doxorubicin-resistant MCF-7 human breast cancer cells have been analyzed using time changes in both fluorescence resonance energy transfer signal from the donor probe DiO to the acceptor one DiI preloaded in liposomes and cell image brightness. CONCLUSION: Obtained results show that resistant cells accumulate dye-loaded liposomes more effectively and reveal more effective dye molecule cellular uptake.
Subject(s)
Antineoplastic Agents/administration & dosage , Antineoplastic Agents/pharmacology , Breast Neoplasms/metabolism , Drug Carriers/pharmacokinetics , Drug Resistance, Neoplasm , Fluorescent Dyes/pharmacokinetics , Carbocyanines/chemistry , Carbocyanines/pharmacokinetics , Cisplatin/administration & dosage , Cisplatin/pharmacology , Doxorubicin/administration & dosage , Doxorubicin/pharmacology , Drug Carriers/chemistry , Fluorescence Resonance Energy Transfer , Fluorescent Dyes/chemistry , Humans , Lipid Bilayers/chemistry , Liposomes , MCF-7 Cells , Microscopy, Fluorescence , Molecular Structure , Phosphatidylcholines/chemistry , Spectrometry, Fluorescence , Tissue DistributionABSTRACT
Optical spectroscopy experiments were used to study the features of cyanine dye 3,3'-dimethyl-9-(2-thienyl)-thiacarbocyanine iodide (L-21) aggregation in binary solutions DMF:Tris-HCl buffer (pH = 8) containing nucleic acids (DNA or RNA). The appearance of absorption and luminescence bands associated with J-aggregates and dimers that are formed within the minor groove of DNA has been observed. The model of L-21 J-aggregate structure is proposed. It has been found that dimers are the building blocks of L-21 J-aggregates. Disorientation in dimers caused by the minor groove curvature is reason of observation of Davydov splitting in absorption spectrum of L-21 J-aggregates. In the solution containing DNA the absorption and luminescence bands of L-21 J-aggregates exhibit the specific properties that allows the dye L-21 to be used as a fluorescent probe for DNA detection.
