New substituted trimethyl ester chlorin e(6) derivatives possess pronounced fluorescent (Phi(fl) approximate to 0,3) and photosensitizing properties (Phi(Delta) > 0,6). The dyes are capable of binding with albumin (K-b similar to 10(5) M-1). The triplet state of the dye 3 in complex with BSA showed the ability to transfer electron from the electron donor molecule (ascorbic acid). The recombination rate constant for the dye 3 anion radicals was determined (1.8 x 10(8) M-1 s(-1)). These results show that the dye studied can act as a photosensitizer via both Type I and Type II reactions. The synthesized compounds exhibit low dark cytotoxicity at concentrations up to 50 mu M over 24 hours of incubation in HCT116 cells. When cells are photoexcited with a 660 nm laser, chlorins 3 and 4 cause rapid cell death at submicromolar concentrations, higher than that of the drug chlorin e(6) "Photolon". The phototoxicity of compound 2, 5 was lower than that of "Photolon". For the most photodynamically active compound 3, accumulation in the endoplasmic reticulum of cells and the mechanism of death are shown - rapid photo-induced necrosis.

The tetrapyrrolic macrocycle as a scaffold for various chemical modifications provides broad opportunities for the preparation of complex multifunctional conjugates suitable for binary antitumor therapies. Typically, illumination with monochromatic light triggers the photochemical generation of reactive oxygen species (ROS) (photodynamic effect). However, more therapeutically valuable effects can be achieved upon photoactivation of tetrapyrrole derivatives. Herein we report the novel porphyrin-based complexes of transition metals with isocyanide and carbonyl ligands. Synthesis of complexes presumed the use of 5-(p-isocyanophenyl)-10,15,20-triphenylporphyrin as a ligand in reactions with metal carbonyl complexes, M(CO)6 (M = Cr, Mo, W), Re2(CO)10 and Re(CO)5Cl. Based on these complexes and isocyanocarborane, the heteroleptic carbonyl complexes with porphyrin and carborane isocyanide ligands were prepared. In cell-free systems, the new compounds retained photochemical characteristics of the parental porphyrin derivative, such as triplet state formation and ROS generation, upon light-induced activation. In the cell culture, the carborane-containing derivatives demonstrated a more pronounced intracellular accumulation than their nonboronated counterparts. As expected, illumination at the Soret band (405 nm) of cells loaded with the new complexes caused photodynamic cell damage. In contrast, illumination at 530 nm instead initiated the release of carbon oxide (CO) followed by cell death independently of the photodynamic effect. Light-induced CO release was analyzed using second derivatives of UV-Vis spectra and our originally developed Spectrophotometric elimiNAtion of Photoinduced Side reactions (SNAPS) method. The yield of CO release decreased in the raw depending on metals in the carbonyl moiety: Mo ≥ Cr > W > Re ≥ Re2. Overall, our novel metal carbonyl complexes with porphyrin and carborane isocyanide ligands emerge as potent bi-functional conjugates for combined photodynamic and photoinducible CO-releasing antitumor agents.

Boron (3- diketonates are prospective fluorescent dyes for functional organic materials to new technologies in the fields of chemistry, NLO-optics, photonics and bio-imaging. The novel NIR-to-NIR luminophors - curcuminoids of boron difluoride with different substituents at the central carbon atom (at the gamma- position) of the chelate ring 1,7-bis(4 '-N,N '-dimethylaminophenyl)-4-organyl-gept-1,6-dien-3,5-dionate of boron difluoride (1-5) were synthesized. Luminescence in solutions, crystals and polymer matrices, photobiological properties and NLO properties in polystyrene (PS) and polymethylmethacrylate (PMMA) were studied. The crystal structure has been determined for 1 . For 1 - 5 , in PS film, upon excitation by laser (365 nm), two luminescence bands are observed in the blue (430 nm) and red (650-700 nm) regions of the spectrum. For 1 - 5 , two-photon luminescence is recorded in PS and PMMA films. PS 1 films demonstrate high photostability. The synthesized dyes turned out to be almost non-toxic for HCT116 tumor cells both in a long-term dark experiment (72 h) and after photoexcitation in accordance with absorption maxima in the submicromolar concentration range. The compounds were rapidly accumulated by cells within 3 h, demonstrating cytoplasmic distribution and the potential for use as cellular photoimaging agents. The accumulation of dyes with hydrocarbon gamma- substitutes (methyl, iso-propyl, phenyl) after 3 and 24 h is more effective compared to dye 2 (commercial product Cranad-2).

A method for the synthesis of a nanostructured turpentine oil lyosol by bubbling an emulsion of turpentine oil in water with air in a mass ratio of 1:200 to 1:2200 by the separation of nanoparticles using nanofiltration has been proposed. Changing the mass ratio of turpentine oil to the aqueous phase during the synthesis was shown to influence the size of the resulting nanoparticles. An increase in the Z-average size of nanoparticles from 50 to 320 nm along with a gradual decreasing turpentine content from 1:200 to 1:1000 was observed. A further decrease in the turpentine load from 1:1000 to 1:2200 led to decreasing the Z-average particle size up to 160 nm. The fact of the formation of stable non-covalent complexes of the lyosol particles with fluorescein has been established. The fluorescein-stained lyosol particles were used to study the efficiency of their phagocytosis by chicken blood monocytes using confocal microscopy. The maximum efficiency of the lyosol phagocytosis by the chicken monocytes was observed when the Z-average lyosol particle size was 50 nm, which was achieved with a turpentine dry matter ratio of 1:200 during the synthesis.

A cobalt polyacrylate tight complex was synthesized from polyacrylic acid (PAA) with average molecular masses of 9356 and 184,631 kDa. The source PAA with programmed molecular weight was synthesized under controlled conditions using isopropanol as a chain growth controlling agent. Tight complexes with Co2+ yielded 1:32 PAA units in the case of 10 kDa (Hestatin 10) and 1:19 in the case of 200 kDa (Hestatin 200). Purification of the tight complexes from the Co2+ in the weakly bound salt form was carried out by using sequential dialysis against deionized water. Testing of the haemostatic activity of the manufactured tight complexes on an animal model of capillary and venous bleeding was carried out; free PAA 10 and PAA 200 were used as the control samples. The experiment demonstrated high haemostatic efficacy of Hestatin 200, Hestatin 10, and PAA 10, whereas PAA 200 acted as an antithrombotic agent.

This paper describes the development and characterization of a hydrazone-type chemosensor for the detection of Al3+ ions. Hydrazone is based on pyridoxal 5 '-phosphate and pyrazine-2-carbohydrazide and exhibits a blue emissive turn-on response upon binding to Al3+. The aggregation-induced emission enhancement phenomenon of the sensor and its Al3+ complex was investigated in mixed DMSO/H2O solvents. The sensor is capable of detecting extremely low levels of Al3+ ions (8 nM) in almost pure water, making it suitable for analyzing water with good ion recovery. Quantum chemical calculations were used to optimize the structure and electron absorption spectra of the sensor and its Al complex. The chemosensor has low toxicity levels (up to 50 mu M) on tumor and non-tumor cell lines, which makes it a potential candidate for bioimaging use. This study provides valuable insights into the development of fluorescence sensors for precise recognition of metal ions.

This article discusses the design and analysis of a new chemical chemosensor for detecting mercury(II) ions. The chemosensor is a hydrazone made from 4-methylthiazole-5-carbaldehyde and fluorescein hydrazide. The structure of the chemosensor was confirmed using various methods, including nuclear magnetic resonance spectroscopy, infrared spectroscopy with Fourier transformation, mass spectroscopy, and quantum chemical calculations. The sensor’s ability in the highly selective and sensitive discovery of Hg2+ ions in water was demonstrated. The detection limit for mercury(II) ions was determined to be 0.23 µM. The new chemosensor was also used to detect Hg2+ ions in real samples and living cells using fluorescence spectroscopy. Chemosensor 1 and its complex with Hg2+ demonstrate a significant tendency to enter and accumulate in cells even at very low concentrations.

Curcuminoids of boron difluoride, 1-aryl(hetaryl)-5-phenylpenta-2,4-dien-1-onates of boron difluoride, have been synthesized. A comparative study of the electronic structure, luminescent properties and their potential for applications in bio-imaging has been carried out. The influence of the electronic structure of a-substituents on the luminescence of compounds was studied by the methods of stationary and time-resolved luminescence spectroscopy and DFT modeling. The introduction of rc-donor substituents leads to a noticeable bathochromic shift and an increase in the Stokes shift in the luminescence spectra. On going from a-donor substituents in the phenyl ring to rc-donor substituents, the luminescence quantum yield increases from 0.03 to 0.22. The maximum Stokes shift and high quantum yield of luminescence is exhibited by the complex with a stilbene substituent, which has the longest rc-system and the maximum efficiency of charge transfer. Dyes are able to penetrate into the cells of the model cell line and accumulate, moreover, accumulation occurs mainly in the cytoplasm of cells. The compounds penetrate into the cells by 12 h of incubation without damaging it's structure and without causing rapid cell death. The submicromolar range of non-toxic concentrations during long-term incubation for a model cell line was determined, which is a characteristic of fluorescent imaging. Due to uniform distribution in the cytoplasm of cells dye with naphtyl substituent is promising for visualization of the cell cytoplasm. This leader compound has the lowest cytotoxicity for cells from the synthesized series of dyes, which makes it promising for further studies as a fluorescent imaging agent.

Optically active liquid–crystalline dispersions (LCD) of nucleic acids, obtained by polymer- and salt-induced (psi-) condensation, e.g., by mixing of aqueous saline solutions of low molecular weight DNA (≤106 Da) and polyethylene glycol (PEG), possess an outstanding circular dichroism (CD) signal (so-called psi-CD) and are of interest for sensor applications. Typically, such CD signals are observed in PEG content from ≈12.5% to ≈22%. However, in the literature, there are very conflicting data on the existence of psi-CD in DNA LCDs at a higher content of crowding polymer up to 30–40%. In the present work, we demonstrate that, in the range of PEG content in the system above ≈24%, optically polymorphic LCDs can be formed, characterized by both negative and positive psi-CD signals, as well as by ones rather slightly differing from the spectrum of isotropic DNA solution. Such a change in the CD signal is determined by the concentration of the stock solution of PEG used for the preparation of LCDs. We assume that various saturation of polymer chains with water molecules may affect the amount of active water, which in turn leads to a change in the hydration of DNA molecules and their transition from B-form to Z-form.

The efficacy of photodynamic therapy (PDT) strictly depends on the availability of molecular oxygen to trigger the light-induced generation of reactive species. Fluorocarbons have an increased ability to dissolve oxygen and are attractive tools for gas delivery. We synthesized three fluorous derivatives of chlorin with peripheral polyfluoroalkyl substituents. These compounds were used as precursors for preparing nanoemulsions with perfluorodecalin as an oxygen depot. Therefore, our formulations contained hydrophobic photosensitizers capable of absorbing monochromatic light in the long wavelength region and the oxygen carrier. These modifications did not alter the photosensitizing characteristics of chlorin such as the generation of singlet oxygen, the major cytocidal species in PDT. Emulsions readily entered HCT116 colon carcinoma cells and accumulated largely in mitochondria. Illumination of cells loaded with emulsions rapidly caused peroxidation of lipids and the loss of the plasma membrane integrity (photonecrosis). Most importantly, in PDT settings, emulsions potently sensitized cells cultured under prolonged (8 weeks) hypoxia as well as cells after oxygen depletion with sodium sulfite (acute hypoxia). The photodamaging potency of emulsions in hypoxia was significantly more pronounced compared to emulsion-free counterparts. Considering a negligible dark cytotoxicity, our materials emerge as efficient and biocompatible instruments for PDT-assisted eradication of hypoxic cells.

The photophysical characteristics of a new bis-carbocyanine dye (BCD) with 4-methylpyridine fragment in the polymethine chain as well as its interaction with human serum albumin (HSA) and DNA were studied by means of steady-state and time-resolved optical absorption and fluorescence spectroscopies. We also obtained the rate of penetration and localization of BCD in the human colon adenocarcinoma cells (HTC116) and the data on its dark and photoinduced cytotoxicity toward these cells. The molecular dynamics method was employed to detect the localization of the BCD molecule within the HSA and DNA structures and to assess the BCD conformational behavior in different environments. The BCD binding constants to HSA and DNA were (8.2 +/- 2.3) x 104 M-1 and (2.6 +/- 1.3) x 105 M-1, respectively. The BCD fluorescence quantum yield increases 10-fold after binding to HSA. The molecular docking and molecular dynamics analysis showed that BCD bound to HSA is located in a wide moderately polar pocket between the IIA and IIIA albumin subdomains. BCD demonstrated rapid infiltration into the HCT116 cell interior and exceptionally low phototoxicity toward these cells which is explained by the absence of the BCD triplet state upon direct photoexcitation. This makes BCD a promising fluorescence agent for in vivo imaging in angiography. In the field of medical diagnostics, there is a request for the creation of fluorescent labels with fluorescence in the 650-700 nm range for existing equipment that does not require IR lasers and cameras.

This paper reports on the synthesis and characterization of a new selective fluorescence probe for gallium ions in water and living cells. Hydrazone of pyridoxal 5 & PRIME;-phosphate and thiophene-3-carbohydrazide was demonstrated to be a "turn-on" fluorescence sensor that can selectively detect Ga3+ with a noticeable appearance of cyan fluorescence in aqueous DMSO. The complex stoichiometry of the probe for Ga3+ was determined through various methods and its structure and electronic spectra were optimized by quantum chemical calculations. The probe showed a low detection limit of 34 nM, and is suitable for river water analysis with high ion recovery and exhibits low toxicity on different cell lines. This study provides valuable insights into the design and optimization of fluorescence probes for selective detection of metal ions.

The ability of gold polyacrylate (aurumacryl) to increase the sensitivity of murine tumor (В-16/F10 melanoma) to radiation treatment has been explored. Radiation therapy employed in combination with aurumacryl leads to a moderate but significant inhibition of tumor growth by 81–90

Water-dispersible complexes of 4-methyl-N-[5-methyl-3-(3,4,5-trimethoxyphenyl)isoxazol-4-yl]benzamide possessing anticancer activity were prepared by its immobilization with biocompatible polymer nanocontainers based on sodium alginate cross-linked with Ca2+ and Mg2+ ions. It was found that this isoxazole derivative retains its structure during immobilization. Colloidal stable nanocontainers filled with this compound exhibit toxicity toward the colon carcinoma (HCT116) tumor cell line.

Liquid crystals (LCs) can be promising for detection of ionising radiation (IR). However, there is little information about their interaction with IR and there are no systemic studies of the dosimetric application of LCs. In this communication, we show for the first time the capabilities of a new type of radiation detector - cholesteric liquid-crystalline dispersion (CLCD) of DNA obtained using polyethylene glycol (PEG) and salt indued condensation. Irradiation of the DNA CLCD samples with 0-100 kGy of 7.6 MeV bremsstrahlung led to significant change in their circular dichroism (CD): approximate to 5% and approximate to 12% increase in the signal was observed at 10 and 20 kGy, while in the range of 20-90 kGy the CD signal decreased linearly. Thus, detectors based on DNA CLCD could be of interest for such application of IR as material modification or radiation sterilisation. At the same time irradiation can help to stabilise dispersion particles and can be used to prevent their sedimentation. Unirradiated samples degraded within 24 h after preparation, while the irradiated ones were able to maintain the intensity of CD signal for more than 168 h.Schematic representation of the dual effect of radiation exposure the DNA CLCD.

Boron subphthalocyanines bearing a wide range of functional groups were tested as prospective photosensitizers and fluorophores. Synthetic protocols to novel 4-ethoxycarbonylphenoxy-substituted subphthalocyanine and phenoxy-substituted subphthalocyanine boron phenolate were presented. Differential triplet-triplet absorption spectra of subphthalocyanines were registered and triplet state lifetimes (rT = 0.6 - 3.1 ms) were obtained. The results of flash photolysis measurements predicted the good ability of target subphthalocyanines to produce singlet oxygen and it was supported by the measurements of 1O2 quantum yields (phi Delta = 0.47 - 0.85). At the same time, satisfactory yields of fluorescence (phi f = 0.13 - 0.50) were observed for most of the subphthalocyanines. The fluorescence decay kinetics were studied to determine the fluorescence lifetimes (rf = 0.30 - 3.05 ns) and confirm the regularities obtained for fluorescence yields. Pronounced fluorescent properties allowed investigating the distribution of subphthalocyanines in the endoplasmic reticulum. In addition, the binding constants with human serum albumin were determined. tert-Butyl- and iodo-substituted subphthalocyanines demonstrated remarkable photocytotoxicity in human epidermoid carcinoma cells at micromolar concentrations. At the same time, target boron subphthalocyanines exhibited low dark cytotoxicity. All mentioned above make boron subphthalocyanines promising candidates as highly effective photosensitizers for photodynamic therapy and fluorescent labels for diagnostic.

Neutral and water soluble anionic carborane derivatives of 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) were efficiently synthesized via nucleophilic aromatic substitution of p-fluorine atom in meso-8-pentafluorophenyl-substituted BODIPYs with carborane S-nucleophiles. Using this synthetic approach a series of thiocarboranyl-BODIPYs was generated in good yields under mild reaction conditions such as room temperature and a short reaction time. Individual carborane-BODIPY conjugates formed stable complexes with serum albumin and generated singlet oxygen. In cell based experiments compounds 6 (8-[4-((m-carboran-9-yl)thio)-2,3,5,6-tetrafluorophenyl]-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) and 11 ({8-[4-((1-carba-closo-dodecaboran-1-yl)thio)-2,3,5,6-tetrafluorophenyl]-1,3,5,7-tetramethyl-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene} caesium) were negligibly cytotoxic in the dark whereas the plasma membrane photodamage and cell death were registered rapidly after illumination. Thus, the new chemotype of boronated BODIPYs emerges as a biocompatible and efficient tool for binary therapeutic modalities.

Spectral, luminescent and photochemical properties of a series of hetarylazo dyes with dihydroquinoline and tetrazole moieties, which differ by the position of methyl substituent at the tetrazole fragment, were investigated in aqueous solutions at various pH by stationary spectrophotometry, fluorimetry and time-resolved methods. The results were supported by quantum chemical calculations. From the pH-dependence of the absorption spectra, it has been shown that azonium cations and dications additionally protonated at the tetrazole fragment are formed upon protonation of the E isomers. Opposite to the azonium cations studied earlier, the long-wavelength absorption band of the azonium cations is hypsochromically shifted relative to that of the neutral form. Weak fluorescence in aqueous solutions growing in acidic media is the specific feature of the dyes. Time-resolved experiments have shown that proton transfer reactions play important role in the transformations of the dyes after excitation in aqueous solutions.