36 research outputs found

    Immunomodulation with self-crosslinked polyelectrolyte multilayer-based coatings

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    This study aims to design an optimal polyelectrolyte multilayer film of poly-L-lysine (PLL) and hyaluronic acid(HA) as an anti-inflammatory cytokine release system in order to decrease the implant failure due to any immune reactions. The chemical modification of the HA with aldehyde moieties allows self-cross-linking of the film and an improvement in the mechanical properties of the film. The cross-linking of the film and the release of immunomodulatory cytokine (IL-4) stimulate the differentiation of primary human monocytes seeded on the films into pro-healing macrophages phenotype. This induces the production of antiinflammatory cytokines (IL1-RA and CCL18) and the decrease of proinflammatory cytokines secreted (IL-12, TNF-α, and IL-1β). Moreover, we demonstrate that cross-linking PLL/HA film using HA-aldehyde is already effective by itself to limit inflammatory processes. Finally, this functionalized self-cross-linked PLL/HA-aldehyde films constitutes an innovative and efficient candidate for immunomodulation of any kind of implants of various architecture and properties

    Electrohydrodynamic printing as a method to micropattern large titanium implant surfaces with photocrosslinkable structures

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    Metallic implants are widely used in orthopaedic and orthodontic applications. However, generally surface treatment of the metallic surfaces is necessary to render them more biologically active. Herein, we describe a direct write printing method to modify metallic implant surfaces with biocompatible polymers with microscale precision. Application of polymeric micropatterns on metallic implant surfaces can (i) improve their interaction with the host tissue, (ii) enable the delivery of growth factors, antibiotics, anti-inflammatory cytokines etc from the implant surface and (iii) can control the immune responses to the implant via controlling the attachment of immune cells, such as macrophages. Surface patterns with a resolution of less than 50 μm can be created using an electro hydrodynamic (EHD) printing, a template-free and single-step process. We present a revised EHD printing method for the deposition of parallel strips of photocrosslinkable, cell adhesive polymeric composites with spacing of around 20 μm onto medical grade titanium substrates. Optimization of voltage, feeding rate and collection speed resulted in regular structures via very rapid movement of the grounded rotating collector driven to equivalent of the linear surface speed of above 100 cm s−1. In the experimental part a mixture of chemically modified PEG /gelatin was deposited onto a conductive titanium substrate with different surface pretreatments with an area of 400 mm2. Acid etched or UV treated titanium surfaces improved the stability of the printed structures. Polymeric lines induced temporary orientation of human monocytes (THP-1) and induced a thicker cell multilayer formation by 3T3 fibroblasts (p < 0.05). Staining of the monocytes for M1(CD80) and M2 (CD206) macrophage markers on the patterned surface showed mixed populations with higher anti-inflammatory cytokine secretion compared to tissue culture plastic control. The results demonstrate the suitability of this method for the preparation of biomaterials with structured surfaces on large areas and with desired chemical composition

    Consistent improvement with eculizumab across muscle groups in myasthenia gravis

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    Eculizumab improves fatigue in refractory generalized myasthenia gravis

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    FACTORS INFLUENCING THE GROSS VALUE ADDED IN THE SHEEP PRODUCTION CHAIN

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    The competitiveness of the sheep sector in East Europe has been decreasing from year to year. The value added in the sector is not generated in the countries as a high proportion of the lambs are exported. For example, in Hungary, 95% of the lambs, unnecessary for replacement, are sold at an average weight of 21 kg and are slaughtered abroad. A stochastic model was constructed to investigate the connections between the cycle phases of the mutton production. Three modules were distinguished, the lamb production, fattening and slaughtering-processing sub-modules. The aim of our study was to identify the gross value added generated in the three sub-modules and to analyse the main factors influencing its volume using the conditions in Hungary as an example. The major hypothesis of our research was that the profitability of the production chain is mainly determined by the breed. The results showed that, considering market prices, the gross value added in the processing module was mostly influenced by the number of lambs sold per ewe per year at the bottom level of the mutton product chain. The next most important factors were the weight gain in the lamb producing and fattening sub-modules and dressing percentage in slaughtering-processing sub-module. Contour plots were constructed which help to describe the relationship among analyzed factors. Using the contour plots, the gross value added for different combinations of these factors might be forecast

    Reclamation using waste rock impact on water quality in the Karvina region in Czech Republic

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    W referacie przedstawiono wpływ rekultywacji terenu za pomocą odpadów górniczych na obniżanie warstwy wodonośnej w regionie Karvina. Ocena została przeprowadzona dla 16 punktów, gdzie odpady zostały wykorzystane do poprawy systemu obwałowań. Dla oceny wpływu odpadów na właściwości chemiczne wody w warstwie wodonośnej określono wartości geochemiczne tła. Dla porównania wpływu opadów na jakość wody określono zmiany parametrów hydrochemicznych w punktach gdzie nie stosowano odpadów do nadbudowy obwałowań, gdzie odpady były stosowane częściowo (maksymalnie 1/2 obwodu osadnika) oraz gdy obwałowanie było zbudowane wyłącznie z odpadów.The evaluation of the impact of waste rock application in hydric reclamation of natural water-bearing subsidence troughs in the Karvina Region was carried out in sixteen localities where waste rock had been used in the past for the purposes of bank system improvement. Within the evaluation of waste rock impact on the chemical character of water in the subsidence troughs the values of geochemical background were identified. In order to compare the impact of waste rock on the quality of water, changes in the hydrochemical parameters were monitored in the localities without waste rock banking, with partial (maximum 1/2 circumference) and complete waste rock banking
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