HSA-Coated Magnetic Nanoparticles for MRI-Guided Photodynamic Cancer Therapy.

Background: Photodynamic therapy (PDT) is a promising technique for cancer treatment; however, low tissue permeability for irradiating light and insufficient photosensitizer (PS) accumulation in tumors limit its clinical potential. Nanoparticles are engineered to improve selective drug delivery to tumor sites, but its accumulation is highly variable between tumors and patients. Identifying PS accumulation peak in a personalized manner is crucial for therapeutic outcome.

The Mechanism of Low-Temperature Oxidation of Carbon Monoxide by Oxygen over the PdCl₂-CuCl₂/γ-Al₂O₃ Nanocatalyst.

The state of palladium and copper on the surface of the PdCl₂-CuCl₂/γ-Al₂O₃ nanocatalyst for the low-temperature oxidation of CO by molecular oxygen was studied by various spectroscopic techniques. Using X-ray absorption spectroscopy (XAS), powder X-ray diffraction (XRD), and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), freshly prepared samples of the catalyst were studied. The same samples were also evaluated after interaction with CO, O₂, and H₂O vapor in various combinations.

Pharmacokinetics of Chlorin e₆-Cobalt Bis(Dicarbollide) Conjugate in Balb/c Mice with Engrafted Carcinoma.

The necessary precondition for efficient boron neutron capture therapy (BNCT) is control over the content of isotope B in the tumor and normal tissues. In the case of boron-containing porphyrins, the fluorescent part of molecule can be used for quantitative assessment of the boron content. We performed a study of the biodistribution of the chlorin ₆-Cobalt bis(dicarbollide) conjugate in carcinoma-bearing Balb/c mice using ex vivo fluorescence imaging, and developed a mathematical model describing boron accumulation and release based on the obtained experimental data.

Planar and 3D fibrous polyaniline-based materials for memristive elements.

The memristive elements constructed using polymers - polyaniline (PANI) and polyethyleneoxide (PEO) - could be assembled on planar thin films or on 3D fibrous materials. Planar conductive PANI-based materials were made using the Langmuir-Schaefer (LS) method, and the 3D materials - using the electrospinning method which is a scalable technique. We have analyzed the influence of PANI molar mass, natures of solvent and subphase on the crystalline structure, thickness and conductivity of planar LS films, and the influence of PANI molar mass and the PANI-PEO ratio on the morphological and structural characteristics of 3D fibrous materials.

Cold Crystallization of Glassy Polylactide during Solvent Crazing.

Uniaxial tension accompanied by the orientation and crystallization of polymer chains is one of the powerful methods for the improvement of mechanical properties. Crystallization of amorphous isotropic polylactide (PLA) at room temperature is studied for the first time during the drawing of films in the presence of liquid adsorption-active media (ethanol, water-ethanol mixtures, and n-heptane) by the solvent crazing mechanism. The crystalline structure arises only under simultaneous actions of a liquid medium and a tensile stress and does not depend on the nature of the environment.

[Embryonic stem cells (from fundamental biology to medicine)].

The recent achievements in isolation, primary and long term culturing, cell Immunophenotyping, SAGE--mRNA--profiling, the clonogenic growth parameters of embryonic stem cells and mesenchymal stem cells have been outlined in connection with cell pluripotency and restricted differentiation, mediated by signals both in culture and in situ. Multidisciplinary data obtained by cell biologists, embryologists with recent functional genomic data give the new way for practical implementation of bioimplants derived from embryonic stem cell for cell-replacement therapy.

Liposomes containing dopamine entrapped in response to transmembrane ammonium sulfate gradient as carrier system for dopamine delivery into the brain of parkinsonian mice.

The active loading of liposomes with dopamine in response to an ammonium sulfate gradient was studied. This method can be regarded as a mean to more efficiently improve the liposomal dopamine/lipids ratio in comparison to conventional methods of liposome preparation. Trapping efficiency of dopamine into liposomes exhibiting a transmembrane ammonium sulfate gradient was shown to be dependent on liposome lipid composition, lipid concentration and temperature.

The synthesis of 1-O-(2-N-stearoyl-D-erythro-sphinganine-1-phosphoryl)-2-O- (alpha-D-mannopyranosyl-D-myo-inositol: a fragment of the naturally occurring inositol-containing glycophosphosphingolipids.

Chiral mannosylinositol containing sphingophospholipid was synthesized from D-erythro ceramide and optically active mannosyl-myo-inositol with the use of phosphite triester coupling procedure. The optical resolution of racemic 3,4,5,6-tetra-O-benzyl-myo-inositol to enantiomers was accomplished via diastereomeric menthoxyacetic esters. Iodonium ion-promoted glycosylation has been used for the preparation of chiral mannosyl-myo-inositol.

Interaction of N-(2-hydroxybenzyl)-omega-amino carbonic acids, novel amphipathic fatty acid derivatives, with membrane: partition coefficients.

The methods for partition coefficient (Kp) determination were developed for different concentrations of N-(2-hydroxybenzyl)-omega-amino carbonic acids, a new class of amphipathic fatty acid derivatives (An), their deutero (AnD) and bromine (AnBr) derivatives. To do this the following methods were used: 2H-NMR, equilibrium dialysis, centrifugation and fluorescence spectroscopy. Kp dependence on the An concentration is discussed.

Effect of novel aromatic derivative of GABA on lipid peroxidation in chronically morphinized rats.

Effect of novel aromatic GABA derivative (AFA) on lipid peroxidation (LP) was studied in the male rats of the Wistar strain. The morphine-received animals had the higher level of LP in blood plasma, decreased level of total antioxidant activity, the increased rate of LP in the ascorbate-induced system in liver homogenate. In the case of AFA administration with morphine, all the above mentioned effects were almost withdrawn.

(2)H- and(13)C-labeled amino acids generated by obligate methylotrophs Biosynthesis and MS monitoring.

Biosynthetic preparation of(2)H- and(13)C- labeled amino acids was studied using a leucine-producing mutant of the obligate methylotroph,Methylobacillus flagellatum. The strain was cultivated in various media containing(13)C- or(2)H-analogs of methanol. The total protein from each experiment was subjected to acid hydrolysis and converted into a mixture of dansyl amino acid methyl esters.

N-(2-hydroxybenzyl)-omega-amino carbonic acids and their derivatives as tools for biochemical and biophysical investigations.

We propose N-(2-hydroxybenzyl)-omega-amino carbonic acids (An) as multifunctional probes for fatty acid metabolism studies. Multifunctionality could be achieved by introduction of different isotopes into An molecule. Deuteration of An results in probes for 2H-NMR membrane studies.

Haematoporphyrin derivatives: distribution in a living organism.

Pharmacokinetics of accumulation in organs and tissues was studied for two haematoporphyrin-based photosensitizers. These sensitizers, haematoporphyrin derivative (HpD) and an oligomeric haematoporphyrin (OHp), contained different amounts of monomeric fraction (25% and 5% respectively) and in OHp the macrocycles were bonded together with ether bonds. OHp was shown to accumulate in tumours in higher amounts than HpD.

Proteolytic fragment of protein kinase C (kinase M) phosphorylates in vitro phosphatidylinositol-4-phosphate.

Limited tryptic proteolysis of homogeneous protein kinase C induces the formation of a catalytically active fragment of 50 kDa (kinase M) which, unlike native PK C acquires the ability to phosphorylate PIP. Both ATP and GTP were found to be capable of serving as phosphate donors in this process. Incubation of purified kinase M with a preparation of rat brain membrane fraction enhanced the level of phosphorylation of PIP in the presence and in the absence of exogenous PIP.

Acyclic analogs of dideoxydidehydronucleosides.

A new type of acyclic nucleoside analogs is proposed, containing C5 hydroxyalkyl fragments, where the distance between 5'-hydroxyl group and the heterocyclic moiety corresponds to that in dideoxydidehydronucleosides (as confirmed by computer modelling). Condensation between 5-0-acetyl-1-bromo-2-pentene and persilylated heterocyclic bases (pyrimidines and guanine) or adenine sodium salt gives rise to the acyclic nucleosides (5a-d, 6a-d) with the yields ranging from 40% up to 85%. Deprotection by NH3/MeOH results in the desired nucleosides (1a-d, 2a-d) formation.

Hematoporphyrin derivatives: an oligomeric composition study.

The oligomeric composition of HpD, Photofrin II and other hematoporphyrin derivatives useful for the diagnosis and therapy of tumors has been studied. Gel chromatographic procedures were used that excluded porphyrin aggregation. Photofrin and hematoporphyrin derivatives were shown to contain different quantities of monomer, dimer and other oligomeric porphyrins.

Synapsin I from human brain. Phosphorylation by Ca2+, phospholipid-dependent protein kinase.

Synapsin I has been isolated from human brain by a rapid and efficient purification technique, and its phosphorylation by human brain Ca2+, phospholipid-dependent protein kinase (protein kinase C) has been studied. The inhibitory effect of calmodulin on this process has been demonstrated. It is also found that non-esterified fatty acids and acidic phospholipids are inhibitory for synapsin I phosphorylation by Ca2+, calmodulin-dependent protein kinase II.

Diol lipids are activators of protein kinase C.

Diol lipids (dioleoyl- and dioctanoylethylene glycol) at relatively low concentrations (approximately 10 microM) were found to activate significantly protein kinase C in the presence of phosphatidylserine or phosphatidylinositol. Since diol lipids are widespread minor lipid constituents of many cells [(1974) Chem. Ind.