Formulation of perspective hepatoprotector polymeric forms based on silybin and ursodeoxycholic acid

Russian Chemical Bulletin - Silybin (Slb) and ursodeoxycholic acid (UDCA) are hepatoprotectors used in the pathogenetic therapy of liver and biliary tract. However, low bioavailability of these...     

Analysis of the Effect of Physico-Mechanical Characteristics of Cumulative Liner Material on Parameters of a High-Speed Element

Technical Physics - In this paper, we present the results of numerical simulation of explosive formation of a high-speed compact element from copper, steel, and aluminum cumulative liners combining...     

Polymer particles containing Fe-based metalloporphyrin as a highly efficient stimulator of reactive oxygen species formation in vitro and in vivo

Russian Chemical Bulletin - Reactive oxygen species are generated by the redox reaction involving metalloporphyrin and ascorbic acid (AA) and lead to oxidative stress followed by cancer cell death....     

Calcium phosphate particles containing superoxide dismutase are a promising agent for the treatment of eye diseases accompanied by oxidative stress

A method for the preparation of calcium phosphate particles is optimized. Particles with entrapped superoxide dismutase are obtained. The size, surface charge, and stability of the calcium phosphate particles are determined under different conditions. The kinetics of the enzyme release from the particles and the influence of the drug release on the size and surface charge of the particles are investigated. On the rabbit model of immunogenic uveitis (the model of an inflammatory process in the eye accompanied by oxidative stress), it is shown that superoxide dismutase enclosed in calcium phosphate particles has a higher antiinflammatory effect than superoxide dismutase in an aqueous solution.     

Role of the Solid–Aqueous Medium Interface in Transferring Light-Induced Excitation of Silicon

Technical Physics - An effect has been discovered that irradiation of a silicon sample by light changes the properties of another silicon sample several centimeters away from the former. This...     

Energy spectrum of primary cosmic rays at energies of 2 × 10<Superscript>13</Superscript> to 5 × 10<Superscript>17</Superscript> eV,according to Tien Shan data

The primary cosmic ray energy spectrum at energies of 10¹⁵ to 5 × 10¹⁷ eV is presented using the results from observations by the Tien Shan HADRON array. The spectrum was obtained from the spectrum of showers according to the number of electrons using a new way of determining the parameter of spatial distribution function S of electrons. The energy spectrum can be extended to low energies up to 2 × 10¹³ eV using data from separate experiments at the former Tien Shan array. Conclusions are drawn regarding changes in the form of the spectrum and its chemical composition at energies over 10¹⁶ eV. The spectrum is compared to the results from the TUNKA installation.     

An anomaly in the properties of primary cosmic rays from the Vela cluster

Based on experimental data obtained by the GAMMA array for the knee energy region, an anomaly is found in the mass composition of primary cosmic rays arriving from the region of the Vela cluster. An original difference method is used that offers high sensitivity, protection against accidental experimental errors, and the ability to separate anomalies associated with the laboratory coordinate system from those in celestial coordinates. Allowing for the multiple scattering of charged particles in the galactic magnetic fields allows parts of the sky not directly visible from the array to be studied.     

Polymer nanoparticles loaded with FeCl-tetraphenylporphyrin for binary catalytic therapy of neoplasms

Russian Chemical Bulletin - In order to study the possibility of using a metal complex of the porphyrin series, FeIIICl-tetraphenylporphyrin (FeClTPP), and its polymeric form as antitumor agents...     

Development of a polymer system for the delivery of daunorubicin to tumor cells to overcome drug resistance

Method for the synthesis of polymeric nanoparticles (NP) with encapsulated daunorubicin (DNR) was developed on the basis of double emulsion solvent evaporation technique using biodegradable poly(lactide-co-glycolide) (PLGA), which is aimed at customization of pharmacokinetic properties of the preparation, enhanced accumulation of DNR in tumor cells and prolongation of its action. The obtained polymer nanoparticles (DNR-PLGA) had average size ranging around 138±36 nm, with zeta-potential of –25.3 mV and the polydispersity index (PDI) of 0.072. The release kinetics of DNR from polymer nanoparticles at pH 7.4 and 5.0 has been studied. In vitro studies showed similar specific activity of DNR- PLGA in K562 and MCF-7 cancer cell lines together with an increase in activity in K562 Adr and MCF-7 Adr cell lines, which are anthracycline resistant, by 1.6 and 3.4 times. The study demonstrated the efficacy of the developed PLGA-based DNR delivery system in the improvement of antitumor effect of DNR, overcoming multidrug resistance in cancer cells, and also in the decrease in nonspecific toxicity of the preparation.     

Sensitivity and selectivity of electrochemical enzyme sensors for inhibitor determination

The performance of electrochemical biosensors developed for the determination of inhibiting species is considered. The role of various factors affecting the analytical characteristics of biosensors, their selectivity toward inhibitors to be tested as well as operational characteristics is discussed. The choice of enzyme-inhibitor system, the influence of enzyme immobilization on the behaviour of a biosensor, the modes of the optimization of working conditions are discussed. Most conclusions are illustrated with the models of the application of biosensors for monitoring environmental pollutants.