We describe novel composite nanoparticles consisting of a gold-silver nanocage core and a mesoporous silica shell functionalized with the photodynamic sensitizer Yb-2,4-dimethoxyhematoporphyrin (Yb-HP). In addition to the long-wavelength plasmon resonance near 750-800 nm, the composite particles exhibited a 400-nm absorbance peak and two fluorescence peaks, near 580 and 630 nm, corresponding to bound Yb-HP. The fabricated nanocomposites generated singlet oxygen under 630-nm excitation and produced heat under laser irradiation at the plasmon resonance wavelength (750-800 nm). In particular, we observed enhanced killing of HeLa cells incubated with nanocomposites and irradiated by 630-nm light. Furthermore, an additional advantage of fabricated conjugates was an IR-luminescence band (900-1060 nm), originating from Yb(3+) ions of bound Yb-HP and located in the long-wavelength part of the tissue transparency window. This modality was used to control the accumulation and biodistribution of composite particles in mice bearing Ehrlich carcinoma tumors in a comparative study with intravenously injected free Yb-HP molecules. Thus, these multifunctional nanocomposites seem an attractive theranostic platform for simultaneous IR-luminescence diagnostic and photodynamic therapy owing to Yb-HP and for plasmonic photothermal therapy owing to Au-Ag nanocages.

Genetically encoded photosensitizers, proteins that produce reactive oxygen species when illuminated with visible light, are increasingly used as optogenetic tools. Their applications range from ablation of specific cell populations to precise optical inactivation of cellular proteins. Here, we report an orange mutant of red fluorescent protein KillerRed that becomes toxic when illuminated with blue or green light. This new protein, KillerOrange, carries a tryptophan-based chromophore that is novel for photosensitizers. We show that KillerOrange can be used simultaneously and independently from KillerRed in both bacterial and mammalian cells offering chromatic orthogonality for light-activated toxicity.

We report here a combined anti-cancer therapy directed toward HER2 and EpCAM, common tumor-associated antigens of breast cancer cells. The combined therapeutic effect is achieved owing to two highly toxic proteins – a low immunogenic variant of Pseudomonas aeruginosa exotoxin A and ribonuclease Barnase from Bacillus amyloliquefaciens. The delivery of toxins to cancer cells was carried out by targeting designed ankyrin repeat proteins (DARPins). We have shown that both target agents efficiently accumulate in the tumor. Simultaneous treatment of breast carcinoma-bearing mice with anti-EpCAM fusion toxin based on LoPE and HER2-specific liposomes loaded with Barnase leads to concurrent elimination of primary tumor and metastases. Monotherapy with anti-HER2- or anti-EpCAM-toxins did not produce a comparable effect on metastases. The proposed approach can be considered as a promising strategy for significant improvement of cancer therapy.

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Protoporphyrin IX (PpIX) is widely used in photodynamic diagnosis. To date, the details of molecular mechanisms underlying PpIX accumulation in malignant cells after 5-ALA administration remain unclear. The fluorescence of PpIX was studied in human glioma cells. Several cell cultures were established from glioma tumor tissue to study the differences between fluorescence-positive and fluorescence-negative human glioma tumors. The cell cultures demonstrated fluorescence profiles similar to those of source tumor tissues, which allows us to use these cultures in experimental research. Dynamics of the rates of synthesis and degradation of fluorescent protoporphyrin IX was studied in the cultures obtained. In addition, the expression of CPOX, an enzyme involved in PpIX synthesis, was evaluated. mRNA levels of heme biosynthesis enzymes were analyzed, and PpIX fluorescence proved to correlate with the CPOX protein level, whereas no such correlation was observed at the mRNA level. Fluorescence intensity decreased at low levels of the enzyme, which indicates its critical role in PpIX fluorescence. Finally, the fluorescence intensity proved to correlate with the proliferative activity.

IntroductionDifficulties in non-vitamin K anticoagulant (NOAC) administration in acute stroke can be associated with changes in pharmacokinetic parameters of NOAC such as biotransformation, distribution, and excretion. Therefore, obtaining data on pharmacokinetics of NOAC and factors that affect it may help develop algorithms for personalized use of this drug class in patients with acute cardioembolic stroke.Patients and methodsPharmacokinetics of apixaban in patients with acute stroke was studied earlier by Kryukov et al. The present study enrolled 17 patients with cardioembolic stroke, who received 5 mg of apixaban. In order to evaluate the pharmacokinetic parameters of apixaban, venous blood samples were collected before taking 5 mg of apixaban (point 0) and 1, 2, 3, 4, 10, and 12 hours after drug intake. Blood samples were centrifuged at 3000 rpm for 15 minutes. Separate plasma was aliquoted in Eppendorf tubes and frozen at −70°C until analysis. High-performance liquid chromatography mass spectrometry analysis was used to determine apixaban plasma concentration. Genotyping was performed by real-time polymerase chain reaction. CYP3A isoenzyme group activity was evaluated by determining urinary concentration of endogenous substrate of the enzyme and its metabolite (6-β-hydroxycortisol to cortisol ratio). Statistical analysis was performed using SPSS Statistics version 20.0. The protocol of this study was reviewed and approved by the ethics committee; patients or their representatives signed an informed consent.ResultsABCB1 (rs1045642 and rs4148738) gene polymorphisms do not affect the pharmacokinetics of apixaban as well as CYP3A5 (rs776746) gene polymorphisms. Apixaban pharmacokinetics in groups with different genotypes did not differ statistically significantly. Correlation analysis showed no statistically significant relationship between pharmacokinetic parameters of apixaban and the metabolic activity of CYP3A.ConclusionQuestions such as depending on genotyping results for apixaban dosing and implementation of express genotyping in clinical practice remain open for NOACs. Large population studies are required to clarify the clinical significance of genotyping for this drug class.

The composition and macroscopic structure of the floating oxygenic phototrophic communities from Kulunda steppe soda lakes (Cock Soda Lake, Tanatar VI, and Bitter Lake 3) was described based on the data of the 2011 and 2012 expeditions (Winogradsky Institute of Microbiology). The algo-bacterial commu nity with a green alga Ctenocladus circinnatus as an edificator was the typical one. Filamentous Geitlerinema sp. and Nodosilinea sp. were the dominant cyanobacteria. Apart from C. circinnatus, the algological compo nent of the community contained unicellular green algae Dunaliella viridis and cf. Chlorella minutissima, as well as diatoms (Anomoeoneis sphaerophora, Brachysira brebissonii, Brachysira zellensis, Mastogloia pusilla var. subcapitata, Nitzschia amphibia, Nitzschia communis, and Nitzschia sp.1). The latter have not been previ ously identified in the lakes under study. In all lakes, a considerable increase in salinity was found to result in changes in the composition and macroscopic structure of algo-bacterial communities.