Biodistribution of photosensitizer (PS) in photodynamic therapy (PDT) can be assessed by fluorescence imaging that visualizes the accumulation of PS in malignant tissue prior to PDT. At the same ...time, excitation of the PS during an assessment of its biodistribution results in premature photobleaching and can cause toxicity to healthy tissues. Combination of PS with a separate fluorescent moiety, which can be excited apart from PS activation, provides a possibility for fluorescence imaging (FI) guided delivery of PS to cancer site, followed by PDT.
In this work, we report nanoformulations (NFs) of core-shell polymeric nanoparticles (NPs) co-loaded with PS 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a, HPPH and near infrared fluorescent organic dyes (NIRFDs) that can be excited in the first or second near-infrared windows of tissue optical transparency (NIR-I, ~ 700-950 nm and NIR-II, ~ 1000-1350 nm), where HPPH does not absorb and emit. After addition to nanoparticle suspensions, PS and NIRFDs are entrapped by the nanoparticle shell of co-polymer of N-isopropylacrylamide and acrylamide poly(NIPAM-co-AA), while do not bind with the polystyrene (polySt) core alone. Loading of the NIRFD and PS to the NPs shell precludes aggregation of these hydrophobic molecules in water, preventing fluorescence quenching and reduction of singlet oxygen generation. Moreover, shift of the absorption of NIRFD to longer wavelengths was found to strongly reduce an efficiency of the electronic excitation energy transfer between PS and NIRFD, increasing the efficacy of PDT with PS-NIRFD combination. As a result, use of the NFs of PS and NIR-II NIRFD enables fluorescence imaging guided PDT, as it was shown by confocal microscopy and PDT of the cancer cells in vitro. In vivo studies with subcutaneously tumored mice demonstrated a possibility to image biodistribution of tumor targeted NFs both using HPPH fluorescence with conventional imaging camera sensitive in visible and NIR-I ranges (~ 400-750 nm) and imaging camera for short-wave infrared (SWIR) region (~ 1000-1700 nm), which was recently shown to be beneficial for in vivo optical imaging.
A combination of PS with fluorescence in visible and NIR-I spectral ranges and, NIR-II fluorescent dye allowed us to obtain PS nanoformulation promising for see-and-treat PDT guided with visible-NIR-SWIR fluorescence imaging.
•High-speed multicapillary column.•Multicapillary column for gas-solid chromatography.•Multicapillary column with inorganic and organic sorbents.
Multicapillary columns (MCCs) for gas chromatography ...make it possible to perform high-speed analysis of the mixtures of gaseous and volatile substances at a relatively large amount of the loaded sample. The study was performed using PLOT MCCs for gas-solid chromatography (GSC) with different stationary phases (SP) based on alumina, silica and poly-(1-trimethylsilyl-1-propyne) (PTMSP) polymer as well as porous polymers divinylbenzene-styrene (DVB-St), divinylbenzene-vinylimidazole (DVB-VIm) and divinylbenzene-ethylene glycol dimethacrylate (DVB-EGD). These MCCs have the efficiency of 4000–10000 theoretical plates per meter (TP/m) and at a column length of 25–30cm can separate within 10–20s multicomponent mixtures of substances belonging to different classes of chemical compounds. The sample amount not overloading the column is 0.03–1μg and depends on the features of a porous layer. Examples of separations on some of the studied columns are considered.
—We report the first results of the application of UltraWAVE reactor-type microwave system for geological sample preparation (
T
= 250°C and P up to 80 bar) with a mixture of concentrated nitric and ...hydrochloric acids (3 : 1). Determination of the platinum group elements – Ru, Pd, Ir, Pt (PGE) and Re after acid digestion was carried out by isotope dilution using the high-resolution mass-spectrometer ELEMENT after chromatographic separation of analytes on an AG50Wx8 cation exchange resin. The monoisotopic rhodium was determined with
195
Pt as an internal standard. The achieved detection limits were from 0.003 ng/g (Ir) to 0.09 ng/g (Pt). The correctness of the new procedure was confirmed by the analysis of geological reference samples—GP-13, UB-N, BHVO-2. The proposed procedure significantly accelerates and simplifies the preparation of geological samples for PGE and Re determination compared to the Carius tube technique.
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•The synthesis of new terpene ligands and palladium complexes is presented.•The study of the toxic effect was carried out on various cell lines of tumor.•Some possible mechanisms of ...potential antitumor action were analyzed.
The synthesis of new terpene ligands and palladium complexes based on them has been described. The stereoselective synthesis of new derivatives (−)-(1R,4S)-camphorquinone and N,N-dimethylethylenediamine (1 and 2) and palladium chelate complexes (3 and 4) based on them is presented. It was found that the direct cyclometallation of (1R,2R,3R,5R)-3-(benzylamino)-2,6,6-trimethylbicyclo3.1.1heptane-2-ol (5) with palladium acetate leads to the formation of palladacycle 6. The cytotoxic activity of new (3,4,6) and previously described (7–14) palladium complexes of various types has been studied. The study of the toxic effect was carried out on various cell lines of tumor origin (pulmonary adenocarcinoma A549, neuroblastoma SH-SY5Y, laryngeal epidermoid Hep-2 and cervical carcinoma HeLa cells). It was found that palladium complexes 6–10 with terpene derivatives of benzylamine and a complex 11 with N,N,O-donor terpene ligand have the most pronounced antitumor properties. For 11 the lowest values of the cytotoxic effect IC50 were found in all cell lines, especially in relation to SH-SY5Y (IC50 < 0.1 µM). In the course of studying the possible mechanisms of their antineoplastic action, it was found that these substances are able to modulate the processes associated with oxidative stress and have a damaging effect on mitochondria, as well as inhibit the process of HeLa cancer cell glycolysis.
Optical bioimaging with exogenous luminophores emitting in short-wave infrared spectral region (SWIR, ~ 1000–1700 nm) is a rapidly developing field, and the development of multiple ...SWIR-photoluminescent nanoprobes has recently been reported. In this regard, hyperspectral imaging (HSI), combined with unmixing algorithms, is a promising tool that can allow for efficient multiplexing of the SWIR-emitting nanoagents by their photoluminescence (PL) spectral profiles. The SWIR HSI technique reported here is developed to multiplex two types of nanoprobes: polymeric nanoparticles doped with organic dye (PNPs) and rare-earth doped fluoride nanoparticles (RENPs). Both types of nanoprobes exhibit PL in the same spectral range (~ 900–1200 nm), which hinders spectral separation of PL with optical filters and limits possibilities for their multiplexed imaging in biological tissues. By applying SWIR HSI, we exploited differences in the PL spectral profiles and achieved the spectrally selective and sensitive imaging of the PL signal from every type of nanoparticles. Unmixing of acquired data allowed for multiplexing of the spectrally overlapping nanoprobes by their PL profile. Both quantitative and spatial distribution for every type of nanoparticles were obtained from their mixed suspensions. Finally, the SWIR HSI technique with unmixing protocol was applied to in vivo imaging of mice subcutaneously injected with PNPs and RENPs. The applicability of hyperspectral techniques to multiplex nanoprobes in the in vivo imaging was successfully demonstrated.
Nickel and cobalt ferrite nanoparticles have been synthesized using the chemical precipitation method; the nanoparticle sizes were found to be 63 ± 22 and 26 ± 4 nm, respectively. The static ...hysteresis loops and Mössbauer spectra have been measured. It is shown that cobalt ferrite powders are magnetically harder than nickel ferrite powders. Ferromagnetic resonance (FMR) curves have been studied. It is found that the FMR absorption for cobalt ferrite is observed at room temperature and above. The time dependences of the nanoparticle warm-up under FMR conditions have been measured. The maximum temperature changes for nickel ferrite and cobalt ferrite particles are 8 and 11 K, respectively. Using the example of cobalt ferrite powder, the possibility of effectively heating of particles in the FMR mode in their own field without using a DC magnetic field source is shown. The observed effect can be used in magnetic hyperthermia.
Throughout history, humans have been attempting to develop the ornamental features of domestic animals in addition to their productive qualities. Many chicken breeds have developed tufts of elongated ...feathers that jut out from the sides and bottom of the beak, leading to the phenotype known as muffs and beard. It is an incomplete autosomal dominant phenotype determined by the Mb locus localised on chromosome GGA27. This project aimed to analyse the genetic diversity of chicken breeds using full genomic genotyping with the Chicken 60K BeadChip. A total of 53,313 Single Nucleotide Polymorphisms were analysed. DNA was obtained from breeds with the muffs and beard as a marker phenotype: Faverolles (n = 20), Ukrainian Muffed (n = 18), Orloff (n = 20), Novopavlov White (n = 20), and Novopavlov Coloured (n = 15). The Russian White (n = 20) was selected as an alternative breed without the muffs and beard phenotype. The chickens are owned by the Centre of Collective Use "Genetic Collection of Rare and Endangered Breeds of Chickens" (St. Petersburg region, Pushkin), and are also included in the Core Shared Research Facility (CSRF) and/or Large-Scale Research Facility (LSRF). Multidimensional scaling revealed that the Novopavlov White and the Novopavlov Coloured populations formed a separate group. The Ukrainian Muffed and the Orloff have also been combined into a separate group. Based on cluster analysis, with the cross-validation error and the most probable number of clusters K = 4 taken into account, the Orloff was singled out as a separate group. The Ukrainian Muffed exhibited a notable similarity with the Orloff under the same conditions. At K = 5, the populations of the Novopavlov White and the Novopavlov Coloured diverged. Only at K = 6, a distinct and separate cluster was formed by the Ukrainian Muffed. The Russian White had the greatest number of short (1-2 Mb) homozygous regions. If the HOXB8 gene is located between 3.402 and 3.404 Mb on chromosome GGA27, homozygous regions are rarely found in the chickens with the muffs and beard phenotype. Scanning the chicken genome with the Chicken 60K BeadChip provided enough information about the genetic diversity of the chicken breeds for the peculiarities of the development of the ornamental muffs and beard phenotypes in them to be understood. For example, Phoenix bantams, whose tail feathers grow throughout their lives, require greater consideration of husbandry conditions.
New organo-mineral composites SiO
2
/poly(styrene-b-4-vinylpyridine) were obtained by adsorption of block- copolymers poly(styrene-b-4-vinylpyridine) with molar ratios of styrene (St) and ...4-vinylpyridie (4-VP) St:4-VP = 1:4 and St:4-VP = 1:5 from THF solution onto silica gel surface. Block-copolymers were synthesized by controlled radical polymerization of styrene with RAFT agent and further copolymerization with 4-vinylpyridine. Also blok-copolymer with thiol end-group was obtained and has been employed for preparation of the composite. Composition of the block-copolymers and surface morphology of composites obtained were determined using
1
H NMR and FT-IR spectroscopy, differential scanning calorimetry, thermogravimetric analysis and scanning electron microscopy. It was established that sorption capacity of the organo-mineral composites toward Pb(ІІ), Fe(ІІІ) and Cu(ІІ) ions is in 2-4 times higher in comparison with parent silica gel.
The literature shows that practically no attention has been paid to the size and shape of the particles of bulk ammonia borane (NH3BH3). The published results about the influence of the dispersity of ...this hydride on its dehydrogenation are not numerous and contradictory. This work presents new results on the low-temperature solid-state dehydrogenation of bulk NH3BH3. The samples under study were recrystallized using different procedures and had, therefore, different particle characteristics. The reactivity of these samples of NH3BH3 was compared on the basis of thermal analysis data obtained under non-isothermal conditions, including the Kissinger kinetics, and H2 evolution under isothermal conditions (84–96°С) using Avrami-Erofeev kinetics. The finely dispersed sample with a particle size of <40 μm was found to be the most active one. A correlation between the NH3BH3 melting temperature and the temperature of its dehydrogenation has been established. A filamentous NH3BH3 with a length-to-thickness ratio of the filaments of >100 was synthesized and described for the first time. It was suggested that its relatively high reactivity was determined by its ordered structure. These results show the importance of further investigations of bulk ammonia borane with different types of particles.
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•Effect of dispersity of bulk NH3BH3 (AB) on its dehydrogenation is still contradictory.•AB of different characteristics were prepared by different recrystallization methods.•Мelting temperature of AB correlates with the temperature of its dehydrogenation.•Finely dispersed AB with a particle size of <40 μm is the most active one.•Relatively high activity of non-dispersed but ordered filamentous AB is discussed.
We study the Lyapunov asymptotic stability of the stationary solution of the spatially one-dimensional initial–boundary value problem for a nonlinear singularly perturbed differential equation of the ...reaction–diffusion–advection (RDA) type in the case where the advection and reaction terms undergo a discontinuity of the first kind at some interior point of an interval. Sufficient conditions are derived for the existence of a stable stationary solution with a large gradient near the point of discontinuity. An asymptotic method of differential inequalities is used to prove the existence and stability theorems. The resulting stability conditions can be employed to create mathematical models and develop numerical methods for solving “stiff” problems arising in various applications, for example, when simulating combustion processes and in nonlinear wave theory.
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