Metal (M = Cr, Mo, W, Re) carbonyl complexes with porphyrin and carborane isocyanide ligands: light-induced oxidation and carbon oxide release for antitumor efficacy.

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.

Evaluation of the antineoplastic properties of the photosensitizer biscyanine in 2D and 3D tumor cell models and artificial skin models.

Background: Photodynamic Therapy (PDT) is a therapeutic modality that combines the application of a photoactive compound (photosensitizer, PS) with low-power light to generate reactive oxygen species in the target tissue, resulting in cytotoxic damage and cell death, while sparing adjacent tissues. The objective of this study was to evaluate the phototoxicity of a cyanine dye with two chromophores (biscyanines, BCD) in systems with varying levels of cellular organization, and we used the Photogem® (a photosensitizer approved by the Brazilian ANVISA agency for clinical use in Photodynamic Therapy) as a positive control.

Materials And Methods: The cytotoxicity of the compounds was assessed in vitro in 2D monolayers, 3D spheroid cultures, and artificial skin models.

Response of Fluorescent Boron Difluoride β-Diketonates to X-Rays.

This paper reports the results of a detailed study of the optical response of boron difluoride curcuminoids to radiation exposure. Two lines of the dyes fundamentally different in structure (namely, symmetrical and asymmetrical) were tested. If the absorption responses of their solutions in chloroform to X-rays turns out to be quite close quantitatively (note that it has a very indicative visual manifestation - a gradual discoloration is observed in the dose range up to 300 Gy), the fluorescence ones differ notably: among other things, the former demonstrate much more sensitive reactions (the corresponding limit of detection values ​​differ by up to 2.

Fast Reaction of the Prussian Blue Based Nanozyme "Artificial Peroxidase" with the Substrates: Pre-Steady-State Kinetic Approach.

This letter introduces the pre-steady-state kinetic approach, which is traditional for evaluation of elementary constants in molecular (enzyme) catalysis, for nanozymes. Apparently, the most active peroxidase-mimicking nanozyme based on catalytically synthesized Prussian Blue nanoparticles has been chosen. The elementary constants () for the nanozymes' reduction by an electron-donor substrate (being the fastest stage according to steady-state kinetic data) have been determined by means of stopped-flow spectroscopy.

Shedding Light on Heavy Metal Contamination: Fluorescein-Based Chemosensor for Selective Detection of Hg in Water.

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.

Pharmaceutical Approach to Develop Novel Photosensitizer Nanoformulation: An Example of Design and Characterization Rationale of Chlorophyll α Derivative.

In this study, we described physico-chemical properties of novel nanoformulation of photosensitizer-pyropheophorbide α 17-diethylene glycol ester (XL) (chlorophyll α derivative), revealing insights into antitumor activity and maintaining quality, meeting the pharmaceutical approach of new nanoformulation design. Our formulation, based on poly(lactic-co-glycolic acid) (PLGA) nanoparticles, increased XL solubility and selective tumor-targeted accumulation. In our research, we revealed, for the first time, that XL binding to polyvinyl alcohol (PVA) enhances XL photophysical activity, providing the rationale for PVA application as a stabilizer for nanoformulations.

Oligohexamethylene Guanidine Derivative as a Means to Prevent Biological Fouling of a Polymer-Based Composite Optical Oxygen Sensor.

The use of biocidal agents is a common practice for protection against biofouling in biomass-rich environments. In this paper, oligohexamethyleneguanidine (OHMG) polymer, known for its biocidal properties, was further modified with para-aminosalicylic acid (PAS) to enhance its properties against microorganisms coated with a lipid membrane. The structure of the product was confirmed by H NMR, C NMR, and FTIR spectroscopy.

Optical Polymorphism of Liquid-Crystalline Dispersions of DNA at High Concentrations of Crowding Polymer.

Optically active liquid-crystalline dispersions (LCD) of nucleic acids, obtained by polymer- and salt-induced (-) condensation, e.g., by mixing of aqueous saline solutions of low molecular weight DNA (≤10 Da) and polyethylene glycol (PEG), possess an outstanding circular dichroism (CD) signal (so-called -CD) and are of interest for sensor applications.

Perfluorocarbon Nanoemulsions with Fluorous Chlorin-Type Photosensitizers for Antitumor Photodynamic Therapy in Hypoxia.

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.

Photoinduced Reduction of Novel Dual-Action Riboplatin Pt(IV) Prodrug.

Controlled photoreduction of Pt(IV) prodrugs is a challenging task due to the possibility of targeted light-controlled activation of anticancer agents without affecting healthy tissues. Also, a conjugation of photosensitizers and clinically used platinum drugs into one Pt(IV) prodrug allows combining photodynamic therapy and chemotherapy approaches into one molecule. Herein, we designed the cisplatin-based Pt(IV) prodrug Riboplatin with tetraacetylriboflavin in the axial position.

Benzylidene Cyclopentanone Derivative Photoinitiator for Two-Photon Photopolymerization-Photochemistry and 3D Structures Fabrication for X-ray Application.

Micron- and submicron-scale 3D structure realization nowadays is possible due to the two-photon photopolymerization (TPP) direct laser writing photolithography (DLW photolithography) method. However, the achievement of lithographic features with dimensions less than 100 nm is in demand for the fabrication of micro-optical elements with high curvature values, including X-ray microlenses. Spectroscopic and photochemical study of a photoinitiator (PI) based on a methyl methacrylate derivative of 2,5-bis(4-(dimethylamino)benzylidene) cyclopentanone was performed.

Characterization of a Novel Amphiphilic Cationic Chlorin Photosensitizer for Photodynamic Applications.

A novel amphiphilic cationic chlorin derivative was investigated as a promising photosensitizer for photodynamic therapy. Two cationic -N(CH) groups on the periphery of the macrocycle provide additional hydrophilization of the molecule and ensure its electrostatic binding to the mitochondrial membranes and bacterial cell walls. The presence of a hydrophobic phytol residue in the same molecule results in its increased affinity towards the phospholipid membranes while decreasing its stability towards aggregation in aqueous media.

Mechanistic aspects of the transamination reactions catalyzed by D-amino acid transaminase from Haliscomenobacter hydrossis.

Pyridoxal-5'-phosphate-(PLP-) dependent D-amino acid transaminases (DAATs) catalyze stereoselective reversible transfer of the amino group between D-amino acids and keto acids. In vivo DAATs are commonly known to synthesize D-glutamate for cell wall peptidoglycans. Today DAATs meet increasing attention for application in the synthesis of D-amino acids, whereas little is known about the mechanism of substrate recognition and catalytic steps of the D-amino acids conversion by DAATs.

Multicomponent Molecular Systems Based on Porphyrins, 1,3,5-Triazine and Carboranes: Synthesis and Characterization.

2,4,6-Trichloro-1,3,5-triazine (cyanuric chloride) is an excellent coupling reagent for the preparation of highly structured multifunctional molecules. Three component systems based on porphyrin, cyanuric chloride and carborane clusters were prepared by a one-pot stepwise amination of cyanuric chloride with 5-(4-aminophenyl)-10,15,20-triphenylporphyrin, followed by replacement of the remaining chlorine atoms with carborane - or -nucleophiles. Some variants of 1,3,5-triazine derivatives containing porphyrin, carborane and residues of biologically active compounds such as maleimide, glycine methyl ester as well as thioglycolic acid, mercaptoethanol and hexafluoroisopropanol were also prepared.

Intramolecular photo-driven charge transfer in a series of pyridyl substituted phenyloxazoles. Structural relaxation in meta-substituted ethylpyridinium derivative of phenyloxazole.

A series of pyridyl (pyridinium) substituted benzoxazoles were studied by steady state absorption, fluorescence spectroscopy, time-resolved fluorescence spectroscopy, fs pulse absorption and polarization spectroscopy, and quantum-chemical calculations. The spectral and kinetic parameters of the fluorophores in MeCN and EtOAc were obtained experimentally and were calculated by means of DFT and TDDFT methods. A scheme including four transient excited states was proposed for the interpretation of differential absorption kinetics of the charged fluorophores.

Odderon Exchange from Elastic Scattering Differences between pp and pp[over ¯] Data at 1.96 TeV and from pp Forward Scattering Measurements.

We describe an analysis comparing the pp[over ¯] elastic cross section as measured by the D0 Collaboration at a center-of-mass energy of 1.96 TeV to that in pp collisions as measured by the TOTEM Collaboration at 2.76, 7, 8, and 13 TeV using a model-independent approach.

In Vivo Study of Entero- and Hepatotoxicity of Silver Nanoparticles Stabilized with Benzyldimethyl-[3-myristoylamine)-propyl]ammonium Chloride (Miramistin) to CBF1 Mice upon Enteral Administration.

Silver nanoparticles (AgNPs) are the most widely studied antimicrobial nanomaterials. However, their use in biomedicine is currently limited due to the availability of data that prove the nanosilver toxicity associated primarily with oxidative stress development in mammalian cells. The surface modification of AgNPs is a potent technique of improvement of their biocompatibility.

Fluorescence characteristics of lipofuscin fluorophores from human retinal pigment epithelium.

Lipofuscin granules accumulate in the retinal pigment epithelium (RPE) with age, especially in patients with visual diseases, including progressive age-related macular degeneration (AMD). Bisretinoids and their photooxidation and photodegradation products are major sources of lipofuscin granule fluorescence. The present study focused on examining the fluorescence decay characteristics of bisretinoid photooxidation and photodegradation products to evaluate the connection between fluorescence lifetime and spectral characteristics of target fluorophore groups.

Photoactivated biscarbocyanine dye with two conjugated chromophores: complexes with albumin, photochemical and phototoxic properties.

Complexes of photosensitizers with blood proteins play an essential role in their delivery to the cell, as well as in the efficacy of photodynamic therapy. Biscarbocyanine dye non-covalently binds human serum albumin (HSA), the dissociation constant of the dye with albumin being Kd = (1.7 ± 0.

Measurement of the Effective Weak Mixing Angle in pp[over ¯]→Z/γ^{*}→ℓ^{+}ℓ^{-} Events.

We present a measurement of the effective weak mixing angle parameter sin^{2}θ_{eff}^{ℓ} in pp[over ¯]→Z/γ^{*}→μ^{+}μ^{-} events at a center-of-mass energy of 1.96 TeV, collected by the D0 detector at the Fermilab Tevatron Collider and corresponding to 8.6  fb^{-1} of integrated luminosity.

Spectral analysis of fundus autofluorescence pattern as a tool to detect early stages of degeneration in the retina and retinal pigment epithelium.

Purpose: The aim of this work is the determination of quantitative diagnostic criteria based on the spectral characteristics of fundus autofluorescence to detect early stages of degeneration in the retina and retinal pigment epithelium (RPE).

Methods: RPE cell suspension samples were obtained from the cadaver eyes with and without signs of age-related macular degeneration (AMD). Fluorescence analysis at an excitation wavelength of 488 nm was performed.

Combined Forward-Backward Asymmetry Measurements in Top-Antitop Quark Production at the Tevatron.

The CDF and D0 experiments at the Fermilab Tevatron have measured the asymmetry between yields of forward- and backward-produced top and antitop quarks based on their rapidity difference and the asymmetry between their decay leptons. These measurements use the full data sets collected in proton-antiproton collisions at a center-of-mass energy of sqrt[s]=1.96  TeV.

Stimulation of Cysteine-Coated CdSe/ZnS Quantum Dot Luminescence by meso-Tetrakis (p-sulfonato-phenyl) Porphyrin.

Interaction between porphyrins and quantum dots (QD) via energy and/or charge transfer is usually accompanied by reduction of the QD luminescence intensity and lifetime. However, for CdSe/ZnS-Cys QD water solutions, kept at 276 K during 3 months (aged QD), the significant increase in the luminescence intensity at the addition of meso-tetrakis (p-sulfonato-phenyl) porphyrin (TPPS) has been observed in this study. Aggregation of QD during the storage provokes reduction in the quantum yield and lifetime of their luminescence.

The fluorescence lifetime of lipofuscin granule fluorophores contained in the retinal pigment epithelium cells from human cadaver eyes in normal state and in the case of visualized pathology.

A comparative analysis of fluorescence lifetime of lipofuscin granule fluorophores contained in the retinal pigment epithelium cells from human cadaver eyes in normal state and in the case of visualized pathology was carried out. Measurements of fluorescence lifetimes of bis-retinoids and their photooxidation and photodegradation products were carried out using the method of counting time-correlated photons. Comparative analysis showed that, in the case of visualized pathology, the contribution of photooxidation and photodegradation products of bis-retinoids to the total fluorescence of the retinal pigment epithelium cell suspension increases in comparison with the norm.