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EN
The natural wound healing process consists of four basic phases: homeostasis, inflammation, proliferation, and remodelling. Macrophages play an important role in the body’s response to biomaterials, as they are modulators of the wound healing process and can polarize into different phenotypes capable of inducing both deleterious and beneficial effects on tissue repair. Curcumin (CU) is known for its anti-inflammatory properties and has the potential to treat diabetic foot ulcers, but it should be delivered to wounds in a controlled manner. In this study, the encapsulation of curcumin in polymeric microparticles based on poly(sebacic anhydride) (PSA) was developed using an emulsification method. PSA-based microparticles containing different concentrations of CU were obtained: 0% weight (wt). CU (unloaded microparticles), 5, 10, and 20 wt% CU. CU encapsulation efficiency and loading were determined using a fluorescence-based calibration curve method and semi-quantitative Fourier-transform infrared spectroscopy (FTIR) analysis. The potential cytotoxicity of the obtained biomaterials in contact with primary human macrophages and their susceptibility to polarization from the M1 (pro-inflammatory) phenotype to the M2 (antiinflammatory) phenotype were evaluated. The morphology of cells cultured in contact with polymeric microparticles was evaluated using phalloidin red and 4′,6-diamidino2-phenylindole (DAPI) staining. Macrophage phenotype was assessed using flow cytometry. The obtained biomaterials showed no cytotoxic effect on primary human macrophages. Flow cytometry studies showed enhanced polarization of macrophages into anti-inflammatory M2 phenotype when exposed to microparticles loaded with CU and CU powder as compared to unloaded microparticles
EN
Accurate image segmentation of cells and tissues is a challenging research area due to its vast applications in medical diagnosis. Seed detection is the basic and most essential step for the automated segmentation of microscopic images. This paper presents a robust, accurate and novel method for detecting cell nuclei which can be efficiently used for cell segmentation. We propose a template matching method using a feature similarity index measure (FSIM) for detecting nuclei positions in the image which can be further used as seeds for segmentation tasks. Initially, a Fuzzy C-Means clustering algorithm is applied on the image for separating the foreground region containing the individual and clustered nuclei regions. FSIM based template matching approach is then used for nuclei detection. FSIM makes use of low level texture features for comparisons and hence gives good results. The performance of the proposed method is evaluated on the gold standard dataset containing 36 images (_8000 nuclei) of tissue samples and also in vitro cultured cell images of Stromal Fibroblasts (5 images) and Human Macrophage cell line (4 images) using the statistical measures of Precision and Recall. The results are analyzed and compared with other state-of-the-art methods in the literature and software tools to prove its efficiency. Precision is found to be comparable and the Recall rate is found to exceed 92% for the gold standard dataset which shows considerable performance improvement over existing methods.
EN
Macrophages remove foreign material from the body and are recruited to sites were there are particles present. Multinucleate giant cells from by the fusion of macrophages. In the presence of particles, macrophages produce various chemical mediators, known as cytokines, as well as enzymes. Some of the cytokines are pro-inflammatory (for example, IL1Beta, IL6 and TNFalpha) while others promote giant cell formation (GM-CSF, M-CSF, TGF). The presence of these cellular products can be shown by examining tissue sections with immunohistochemistry and by western blotting. The message (mRNA) for the synthesis of these molecules can be demonstrated by in situ hybridization and the polymerase chain reaction. Macrophages process ingested material and present it as antigen to lymphocytes. Antigen-presenting macrophages play an important part in the initiation of metal sensitization. Surface receptors and their counterligands are expressed on macrophages and lymphocytes during antigen presentation. The particles present in tissues around joint prostheses have been isolated and characterized. Over 95% of these are less than 1 micron (ECD) in size. Transmission electron microscopy has revealed nanoparticles of metal in the range 15-20 nm. Such particles are too small to be phagocytosed. Hydroxyapatite, diamond-like carbon (nano-diamond) and metal particles are being studied and results compared with those of particles in the micrometer range. There is a different response to different nanoparticles.
PL
Badano proces degradacji kwasu poli(L-mlekowego) w obecności makrofagów (Mf) oraz biozgodność układu PLLA+Mf. Postęp degradacji oceniano na podstawie pomiarów lepkości polimeru, analizy widm w zakresie podczerwieni oraz oznaczenia ilości uwalnianego kwasu mlekowego. Porównano żywotność makrofagów oraz sekrecję cytokin w hodowlach makrofagów w nieobecności biomateriału oraz w układach zawierających filmy PLLA i makrofagi. Stwierdzono wzrost szybkości degradacji PLLA w obecności makrofagów oraz zadowalającą biozgodność poli(kwasu L-mlekowego) i komórek linii makrofagowej.
EN
The process of degradation of poly(L-lactic acid) (PLLA) in the presence of macrophages (Mf) and the biocompatibility of the system PLLA+Mf was studies. The progress of the degradation was monitored by the measurements of polymer viscosity and IR spectra of the films as well as the concentration of the released lactic acid. The viability of macrophages and the secretion of cytokines were compared for the systems containing PLLA films immersed in macrophage suspension and macrophages cultured without the polymer. The results confirm the increase in the rate of PLLA degradation in the presence of macrophages as well as the satisfactory biocompatibility of poly(L-lactic acid) and macrophage cells.
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