This study examines the adhesive properties and cytotoxicity of polyelectrolyte nanofilms from polyethyleneimine (PEI), polyallylamine hydrochloride (PAH) and sodium polystyrene sulfonate (PSS) on human bone marrow mesenchymal stromal cells (h-MSCs) and mouse adipose tissue (m-MSC) in vitro. Films are formed on 24- and 96-well culture plates in the combinations: PEI, PAH, PEI-PSS, PEI-PSS-PAH, PEI-PSS-PEI. An analysis of the culture results show that direct contact of h-MSCs with the PEI surface promotes adhesion (93–95% of adhesive cells versus 40% in the control). On the PEI surface, h-MSCs are evenly distributed, form colonies and 80% monolayer after 72 h of culture, as in the control on culture plastic. On nanofilms from PAH and PEI-PSS-PAH, cells grow in the form of rosette-like colonies with long and thin processes similar to neurites. The cytotoxic properties of PSS were revealed in direct contact with h-MSCs (more than 40% of nonviable cells with damaged plasma membranes). On the PSS surface, cells lost their adhesiveness. To culture and stably grow the cell mass of h-MSCs, it is better to use monolayer nanofilms made of highly adhesive and non-toxic PEI polyelectrolyte, which can bind the growth factors of blood serum and platelet lysate, ensuring the growth of h-MSCs under in vitro deprivation conditions.

This paper describes an online realtime data acquisition system.The design utilizes ARM singleboard computers that bring very low power requirements, portability and lightweightness.We have implemented a unified approach to acquire, transfer and store the measurements.The approach takes advantages of SeedLink protocol to establish online realtime data flows between the components of the system.Communication over IPv4 rely on secure virtual private networks.The system features remote management of data logger and all connected devices.For purposes of testing and technology showcase we've implemented support for a range of variometer-type magnetometers.

Hemolysin II (HlyII), one of several cytolytic proteins encoded by the opportunistic human pathogen Bacillus cereus, is a member of the family of oligomeric beta-barrel pore-forming toxins. This work has studied the pore-forming properties of HlyII using a number of biochemical and biophysical approaches. According to electron microscopy, HlyII protein interacts with liposomes to form ordered heptamer-like macromolecular assemblies with an inner pore diameter of 1.5-2 nm and an outer diameter of 6-8 nm. This is consistent with inner pore diameter obtained from osmotic protection assay. According to the 3D model obtained, seven HlyII monomers might form a pore, the outer size of which has been estimated to be slightly larger than by the other method, with an inner diameter changing from 1 to 4 nm along the channel length. The hemolysis rate has been found to be temperature-dependent, with an explicit lag at lower temperatures. Temperature jump experiments have indicated the pore structures formed at 37 degrees C and 4 degrees C to be different. The channels formed by HlyII are anion-selective in lipid bilayers and show a rising conductance as the salt concentration increases. The results presented show for the first time that at high salt concentration HlyII pores demonstrate voltage-induced gating observed at low negative potentials. Taken together we have found that the membrane-binding properties of hemolysin II as well as the properties of its pores strongly depend on environmental conditions. The study of the properties together with structural modeling allows a better understanding of channel functioning.

A potentiometric biosensor has been designed on the basis of glass pH-electrode with a sensing device of the microcellular polyelectrolytic coating containing urease. The polymeric walls of the coating are readily permeable for low-molecular weight compounds, including urea, but are impermeable for macromolecules. The main characteristics of the biosensor in various experimental solutions containing urea, low-molecular-weight salt, and buffer have been obtained. The sensor has been shown to be stable for at least three weeks. The standard curves of the sensor are linear in the range of urea concentrations from 0.2 to 20 mM.

Fluorescent probes were used to study structural changes in different membranes affected by gamma-radiation, protonophores and radioprotective agents, tegalide and bithionol. The preparations of the defined concentrations decreased the microviscosity of membranes, lowered the peaks and changed the temperature of phase transitions in liposomes from dipalmitoyl lecithin, and induced the output of Ca2+ from mitochondria. The effects depended on the radiation dose, the structure, concentration and lipophilicity of the preparation; protonophores produced a specific effect.