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In vivo comparison of the regenerative potential of two calcium phosphate-biopolymer osteoplastic composites: а) based on alginate (Alg) and hydroxyapatite (HA) – Alg/HA/CS/Zn/D2, b) based on chitosan (CS) and brushite (DCPD) – CS/DCPD/D2. 36 white male laboratory rats aged six months were used. A defect to the bone marrow canal in the middle of the femur diaphysis was made with a dental bur of 2 mm. The bone defect healed under the blood clot (control) in the different animal groups and was filled with Alg/HA/CS/Zn/D2 and CS/DCPD/D2. The regeneration of the bone defect was studied on the 30th, 90th, and 140th days by computer tomography (CT). On the 30th day, all groups' implantation site optical density (OD) was significantly lower than that of the adjacent maternal bone (MB). Intensity of bone formation for Alg/HA/CS/Zn/D2 exceeds CS/DCPD/D2. On the 90th day, the bone trauma site OD with Alg/HA/CS/Zn/D2 (1725.4 ± 86 HU) and CS/DCPD/D2 (1484.9 ± 69 HU) exceeded the OD of the control (942.5 ± 55 HU). On the 140th day, the OD of Alg/HA/CS/Zn/D2 and CS/DCPD/D2 implantation sites was higher than Control and MB OD. Visually, the area of the past injury with the Alg/HA/CS/Zn/D2 could be detected only by the presence of an endosteal bone callus and in the case of CS/DCPD/D2 - by the shadow of the remaining biomaterial in the bone marrow canal. According to CT data, Alg/HA/CS/Zn/D2 and CS/DCPD/D2 contribute to the complete healing of the femoral diaphysis defect in 140 days, but the regenerative potential of Alg/HA/CS/Zn/D2 from 30 days to 140 days is higher than CS/DCPD/D2 biomaterial. [ABSTRACT FROM AUTHOR]

Abstract A nanostructured composite material in the form of a hydrogel and beads based on hydroxyapatite (HA), sodium alginate (Alg) and ZnO microparticles was fabricated under the influence of microwave irradiation. An average crystallite size of the HA was 40 nm, while ZnO crystallites of the size 25 nm–11 µm were formed. The inorganic HA-ZnO phase of studied composite is distributed in the polysaccharide matrix of the alginate, which corresponds to the structures of natural bone nanocomposites. The introduction of ZnO into the composite increases its porosity up to 5 times and the degree of swelling in phosphate buffered saline up to 2 times, as well as provides weak antimicrobial activity. The effect of microwave and ultrasonic treatment on the structure of HA-ZnO and HA-Alg-ZnO composites' microcrystals was studied. The mechanism of antimicrobial activity of ZnO crystals in the HA-Alg-ZnO composite was proposed. The in vitro biocompatibility and cytotoxicity of the synthesized materials was studied and it was found that addition of ZnO make insignificant effect on biocompatibility. Thus, the main goal of our work was fabrication of the bioactive material using microwave and ultrasonic treatment for additional enhancement of antibacterial properties. [ABSTRACT FROM AUTHOR]

This work is devoted to the comparison of the physical and biological properties of synthesized osteoplastic composites with an experimentally determined content (375 μg/g) of the micro (ZnO MPs) and nano (ZnO NPs) particles, immobilized in Hydroxyapatite-Alginate-Chitosan matrix (HA-Alg-CS). ZnO NPs show pronounced antimicrobial activity against E.coli ATCC 25922 and S. aureus ATCC 25923, while ZnO MPs only in the CS presence. Composites containing ZnO NPs/MPs do not have a toxic effect on bone-forming cells - osteoblasts, preserving their ability to biomineralization. ZnO MPs and ZnO NPs to varying degrees, but significantly affect composites' swelling, porosity, shape stability, and prolong vitamin D3 release for 120h, compared to Control. Composites do not demonstrate unwanted "burst release." ZnO NPs/MPs increase Youngs' modulus of the HA-Alg matrix, namely 348 → 419 MPa (ZnO MPs), 348 → 646 MPa (ZnO NPs), and weaken the plastic (irreversible) deformations. The compressive strength of HA-Alg and HA-Alg/CS matrixes containing ZnO NPs (178 MPa and 251 MPa, respectively) is in the range of values for native cortical bone (170–193 MPa). Biocompatibility and lack of toxic effect give both composites a perspective for osteoplastic application, but composites doped with ZnO NPs are more attractive. [Display omitted] • ZnO MPs/NPs (micro- and nanoparticles)-Hydroxyapatite-Alginate composite synthesized. • ZnO MPs/NPs increase Youngs' modulus from 348 MPa (control) to 419/646 MPa. • Compressive strength of containing ZnO NPs composite is closed for native cortical bone. • ZnO MPs/NPs exhibit antimicrobial activity without a toxic effect on osteoblasts. • ZnO MPs/NPs prolong vitamin D3 release for 120h without "burst release.". [ABSTRACT FROM AUTHOR]

The alginate (Alg) matrix with immobilized hydroxyapatite (HAp) and zinc oxide (ZnO), cross-linked by chitosan (CS) and metal ions (Men+) Ca2+, Zn2+, and Cu2+ was created as a wound dressing. The effect of Men+ and their concentrations on water vapor transition, fluid handling, dehydration, drug release, and healing are shown. Me-containing samples have a lower sorption capacity, than a commercial Kaltostat, however, a much lower degree of their dehydration provides a longer wound wet. The Men+ presence lowers the environmental pH to slightly acidic values promoting healing. Ca2+, Zn2+, and Cu2+ in complexes with CS increase antimicrobial effect against E. coli and S. aureus , slow down the Anaesthesine release, making it compatible with Fickian diffusion in the Zn2+ and Cu2+ presence, and non-Fickian transport under Ca2+ influence. The material promotes the proliferation of the fibroblasts, an increase of collagen fibres, and new arterial and venous capillaries, indicating the intensity of the healing process. [Display omitted] [ABSTRACT FROM AUTHOR]

Composite based on nano-sized hydroxyapatite (HA), zinc oxide (ZnO), chitosan (CS), alginate (Alg) with the function of sustained Ceftriaxone (CF) release was created as molecular sorption-aspiration drainage system (SADS), designed for the treatment of purulent cavities of various genesis, including peritonitis. ZnO stabilizes the composite structurally, reducing the swelling by 1.5 and porosity by 1.4 times. The absorption of tryptophan (Trp) by SADS for 72 h from aqueous solution is 80%, while from PBS - 50%. The content of ZnO (15,20%) slows the CF release by 1.6 times on the first day of SADS installation and reduces the likelihood of "burst" drug release. CF release exponent of ZnO-containing composites indicates the non-Fickian diffusion kinetics. 20%ZnO-containing composite is closest to zero-order kinetics. The reduction of the concentration of E. coli microbial cells for 43% in the presence of HA-nZnO-Alg/CS -based CADS and positive therapeutic pathomorphosis were observed in vivo. [Display omitted] • Hydroxyapatite-biopolymers-ZnO composite as a sorption-aspiration drainage system (SADS) created • ZnO stabilizes the composite structurally, reducing swelling and porosity by 1.5 and 1.4 times. • ZnO slows the Ceftriaxone release by 1.6 and reduces the likelihood of "burst" drug release. • SADS absorbs 80% of tryptophan amino acid from aqueous solution and 50% from PBS for 72 h. • SADS reduces the E. coli content in the intestinal cavity of animals with peritonitis by 43%. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: Mammalian cell culture is widely used for the cloning and expression of insoluble proteins. The established methods of sub-cellular fractionation of tissues are not always directly suitable for the sub-cellular fractionation of cultured cells. In this study we have optimized the conditions for the preparation of microsomal fractions from cultured cells with the aim of isolating intact vesicles that are suitable for the assay of transport proteins and lumenal enzymes. Methods: H4IIE cell cultures were used as a convenient model with high latency of internal endoplasmic reticulum enzyme glucose-6-phosphatase towards mannose-6-phosphate. Also 7-ethoxyresorufin O-deethylase (EROD) activity was determined as a reflection of the state of monooxygenase system. Results: The variations in a number of homogenization strokes and buffer composition revealed that one homogenization stroke in glass homogenizer with 0.25 M sucrose, 5 mM HEPES, pH 7.4 buffer provides the best latency/activity ratio for homogenates, but for the isolation of microsomes the higher number of strokes (10) as well as low-osmotic buffer (5 mM HEPES, pH 7.4) are needed. However EROD activity is largely reduced in the preparations using buffers containing sucrose, so 5 mM HEPES buffer is recommended as the most suitable to study the microsomal reactions in H4IIE cells. Discussion: The isolation of microsomes was followed by the significant proteolytic breakdown of the glucose-6-phosphatase enzyme. It is recommended to use cell culture homogenates for assays when possible. [Copyright &y& Elsevier]

• Bioactive material includes Hydroxyapatite (HA), Chitosan (CS) and Fullerene C 60. • Cell viability test proves no toxicity of 0.3 and 0.15 mg/ml C 60 -containing composites. • C 60 concentration of 0.004 mg/ml provides an antimicrobial effect against S. aureus. • C 60 ensures a prolonged release of Anaesthesinum up to 18 days. • Anaesthesinum release is close to the zero-order kinetic release profile. Bioactive composite material in the form of beads, based on natural polysaccharide Chitosan (CS), hydroxyapatite (HA), and C 60 fullerene (C 60), was synthesized under influence of microwave irradiation (MW). The bead is a 3D matrix consisting of CS macromolecules cross-linked with sodium tripolyphosphate with HA and C 60 particles immobilized in its structure. XRD and FTIR data confirmed the formation of calcium deficient carbonate substituted HA with needle-shaped nanocrystallites of about 80 nm. MW does not influence CS structure. C 60 enhances the beads shape stability. HPLC studies suggest the (up to 18 days) prolonged release of hydrophobic Anaesthesinum from C 60 -containing composites. Changing the C 60 content allows adjusting the drug release time. The presence of CS and C 60 provides the Anaestesinum release profile, according to the calculated correlation coefficient (r = 0.99), close to the zero order kinetic release profile. The inhibition zone test (ZOI) shows the antimicrobial activity of the composites containing 0.004 mg/ml C 60 against S. aureus ATCC 25923 and E. coli ATCC 25922 (ZOI 16 ± 1 and 10 ± 2 mm, respectively). Cell viability test indicates no toxicity of 0.3 and 0.15 mg/ml C 60 -containing composites. [ABSTRACT FROM AUTHOR]

The main objective of the paper is to assess the impact of different factors which include building and human comfort parameters on indoor temperature conditions and energy need for heating for complex system “heat source – human comfort – building envelope”. The proposed method of mean radiant temperature calculation for human comfort models, which takes into account incoming solar radiation, will increase the accuracy of calculations by 1.3% – 4.7%. Regression models for comfort room air temperature determination, developed on the basis of energy and exergy human comfort approaches, significantly simplify further calculations and can be incorporated in complex system. As comfort temperature, determined in accordance with exergy approach is lower than based on energy one, the exergy concept use for providing comfort conditions accounts for less energy need for heating. Modelling results of various factors impact on energy need for heating are obtained based on energy and exergy approach to human comfort. [ABSTRACT FROM AUTHOR]

Abstract: Muscle form of lactate dehydrogenase (M-LDH) physically associate with KATP channel subunits, Kir6.2 and SUR2A, and is an integral part of the ATP-sensitive K+ (KATP) channel protein complex in the heart. Here, we have shown that concomitant introduction of viral constructs containing truncated and mutated forms of M-LDH (ΔM-LDH) and 193gly-M-LDH respectively, generate a phenotype of rat heart embryonic H9C2 cells that do not contain functional M-LDH as a part of the KATP channel protein complex. The K+ current was increased in wild type cells, but not in cells expressing ΔM-LDH/193gly-M-LDH, when they were exposed to chemical hypoxia induced by 2,4 dinitrophenol (DNP; 10mM). At the same time, the outcome of chemical hypoxia was much worse in ΔM-LDH/193gly-M-LDH phenotype than in the control one, and that was associated with increased loss of intracellular ATP in cells infected with ΔM-LDH/193gly-M-LDH. On the other hand, cells expressing Kir6.2AFA, a Kir6.2 mutant that abolishes KATP channel conductance without affecting intracellular ATP levels, survived chemical hypoxia much better than cells expressing ΔM-LDH/193gly-M-LDH. Based on the obtained results, we conclude that M-LDH physically associated with Kir6.2/SUR2A regulates the activity of sarcolemmal KATP channels as well as an intracellular ATP production during metabolic stress, both of which are important for cell survival. [Copyright &y& Elsevier]

Abstract: A kinetic model of atomization processes based on the solution of one-dimensional diffusion equation with two independent sources is proposed. One of the sources describes the atomization of atoms from the graphite furnace surface, while another one describes the atom formation inside the walls of the furnace and their subsequent outflow into the analytical zone. This mechanism is used to describe electrothermal atomization of Cu and Ag. The simulations show that the form of atomic absorption signal of Cu is determined to the great extent by the processes of desorption from the graphite surface and diffusion inside the graphite. The tailing of the back edge of absorption profile can be explained by the rather slow diffusion process of copper atoms in the graphite. At the same time, for the atomization of Ag, the process of separation of single atoms from clusters is the limiting process. A new interpretation for the shift of absorbance maximum as the initial mass of Ag increases is proposed. [Copyright &y& Elsevier]