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Relevance of the work is due to the need for new materials that are used in medicine as a substitute for natural bone tissue injuries, fractures, etc. The aim of the work is to obtain composites with improved biocompatible properties based on poly-L-lactide (PLA) and hydroxyapatite (HA) and to perform pilot analysis of interaction PLA, HA, composite PLA-HA with primary human monocytes-derived macrophages in vitro. The pilot experiments using human primary monocytes cultivated on the surface of the samples demonstrated that PLA-HA can stimulate release of anti-inflammatory cytokines that indicates the presence of potential anti-inflammatory properties of the composites

Low-grade chronic inflammation underlies the development of the most dangerous cardiometabolic disorders including type 2 diabetes and its vascular complications. In contrast to acute inflammation induced by bacteria and viruses, chronic inflammation can be driven by abnormal reaction to endogenous factors, including Th2 cytokines, metabolic factors like advanced glycation end products (AGEs), modified lipoproteins, or hyperglycemia. The key innate immune cells that recognize these factors in blood circulation are monocytes. Inflammatory programming of monocytes which migrate into tissues can, in turn, result into generation of tissue macrophages with pathological functions. Therefore, determination of the molecular and functional phenotype of circulating monocytes is a very promising diagnostic tool for the identification of hidden inflammation, which can precede the development of the pathology. Here we propose a new test system for the identification of inflammatory programming of monocytes: surface biomarkers and ex vivo functional system. We summarize the current knowledge about surface biomarkers for monocyte subsets, including CD16, CCR2, CX3CR1, CD64, stabilin-1 and CD36, and their association with inflammatory human disorders. Furthermore, we present the design of an ex vivo monocyte-based test system with minimal set of parameters as a potential diagnostic tool for the identification of personalized inflammatory responses.

Major problems with biomedical devices in particular implants located in nonsterile environments concern: (i) excessive immune response to the implant, (ii) development of bacterial biofilms, and (iii) yeast and fungi infections. An original multifunctional coating that addresses all these issues concomitantly is developed. A new exponentially growing polyelectrolyte multilayer film based on polyarginine (PAR) and hyaluronic acid (HA) is designed. The films have a strong inhibitory effect on the production of inflammatory cytokines released by human primary macrophage subpopulations. This could reduce potential chronic inflammatory reaction following implantation. Next, it is shown that PAR, due to its positive charges, has an antimicrobial activity in film format against Staphylococcus aureus for 24 h. In order to have a long-term antimicrobial activity, a precursor nanoscale silver coating is deposited on the surface before adding the PAR/HA films. Moreover, the PAR/HA films can be easily further functionalized by embedding antimicrobial peptides, like catestatin (CAT), a natural host defense peptide. This PAR/HA+CAT film proves to be effective as an antimicrobial coating against yeast and fungi and its cytocompatibility is also assessed. Finally, this all-in-one system constitutes an original strategy to limit inflammation and prevents bacteria, yeast, and fungi infections.

The preparation of novel 5-aryl-2-thio-1,3,4-oxadiazoles 4a-41 and the computer-aided study of their in vitro anti-tubercular activity against Mycobacterium tuberculosis H37Rv (ATCC 27294) are reported. The average accuracy of the electronic-topological method and neural network methods applied to the activity prediction in leave-one-out cross validation is 80%.

Orthopedic oncologic prostheses are essential in postoperative therapy and improvement of life quality of oncological patients. However, construction and composition of implants has to be improved for better biocompatibility and reduction of inflammatory responses. The materials based on polylactic acid (PLA) and hydroxyapatite (HA) have been suggested as promising solution for implant coating in order to improve reconstruction of bone defects, to reduce risk of inflammation and implant rejection. Objective To obtain the bioresorbable composites using biocompatible poly-L-lactide (PLA) with HA and to evaluate its effect on bone remodeling rate. Materials and methods After dissolution of PLA∗ in chloroform the powder-like HA (d = 20–40 nm) was added under vigorous stirring (PLA: HA = 75:25). The PLA/HA suspension was sonicated (40 kHz) and precipitated in ethanol. Fine fibers (d = 0.1– 0.5 μm, of more than 2 mm length) were formed. The PLA/HA composite fibers were air-dried; they consisted of HA nanoparticles homogeneously distributed in the PLA matrix. The composites ability to participate in bone remodeling was estimated by determination of the polymer matrix dissolution rate and by formation of the CPL on the surface of the composites. Results The degradation rate of the polymer matrix was calculated by measuring concentration of lactic acid (by HPLC method), being released from PLA macromolecules as the result of the hydrolysis in the physiologic solution (pH 7, ω(NaCl) = 0.9%). The PLA degradation rate during the first 4 days of soaking of the substrates (d = 10 mm, S = 190 mm2, m = 0.20 ± 0.01 g) in the solution is rather high (Clactic acid = 10 wt%), while on day 5 it decreases and stays constant during the rest of the time. The HA content increase in the composite results in the enhanced hydrolysis of PLA, caused both by the partial acid-base interaction between PLA and HA, and due to presence of the phase boundaries. Interesting to note that pure PLA (without HA) is hardly hydrolyzed in the physiologic solution even on the 30-th day of the experiment. Formation of calcium phosphate layer (CPL) was done in the SBF media, simulating the mineral constituents of the blood plasma at 37 °C, over 28 days period. The total concentration of Ca2+ and Mg2+ ions in the SBF-solution was determined by daily trilonometry in the ammonia buffer with eriochrome black T as indicator. This investigation clearly shows that the substrates both of HA and PLA/HA promote the CLP formation on their surfaces. On day 14 of the substrates soaking in the SBF solution the increment of Ca2+, Mg2+ ions adsorbed on the HA substrate rose to the value of m (Ca2+ + Mg2+)/VSBF = 0.11 mg/l, while the same value on the composite PLA/HA substrate was 0.06 mg/l. Thus the rate of adsorption of Ca2+ ions on the surface of HA is higher than that on the surface of the PLA/HA substrates. It is the result of the high HA content in the material. Pure PLA does not promote adsorption of Ca2+ and Mg2+ ions from the SBF media. Thus the HA particles incorporated in the PLA matrix may cause fast the CLP formation improving the ossification in the bone reconstruction processes. Biocompatibility and anti-inflammatory activity of PLA, HA and PLA/HA composite was studied in a pilot experiment in the cell-mediated immune response of individual donors in vitro using CD14+ human monocytes. Insignificant pro-inflammatory cytokine secretion of the M1 type (TNFα) is observed in the presence of PLA, while HA and PLA/HA composites don’t contribute to their release. The PLA promotes the release of M2 cytokine CCL18 on day 6 of macrophage culturing suggesting potential anti-inflammatory properties of the material. Conclusion The composite PLA/HA supports active bone-like layer formation on its surface improving ossification in the bone reconstruction process. The pilot experiment suggested that PLA/HA does not cause inflammatory reactions, while PLA can potentially regulate the balance between M1/M2 reaction to suppress unnecessary inflammation. ∗Mol. mass ca 60 kDa, prepared in the Laboratory of Catalytic Research of Tomsk State University. This Research is supported by Tomsk State University Competitiveness Improvement Program . The work was partially supported by the project Russian Foundation for Basic Research RFBR # 15-08-05496_a and EU IMMODGEL project, Grant No. (602694). Work was conducted with the application of the Tomsk regional common use center technical equipment acquired thanks to a grant of the Russian Ministry of the Agreement No. 14.594.21.0001 (RFMEFI59414X0001).

Carvone and cryptomerlone were synthesized selectively using electrochemical oxidation of α-pinene in the key step.