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Fibrous scaffolds based on (bio)polymers are observed as mimicking the microstructure of the extracellular matrix. Thus, they are considered as an example of a utilitarian scaffold, useful for the regeneration of various types of tissues. The techniques described in the literature are well known to obtain submicrometric and nanometric fibers that, when randomly arranged, mimic the ECM. The biomimetic scaffold criterion might be even better reflected if the cell adhesion sites are present on the surface of such fibers. They promote the formation of the focal adhesion contact or facilitate the formation of a protein film on the fiber surface. Such a process is enhanced by an appropriate physical or chemical modification that activates the protein adsorption and the subsequent cell adhesion. The aim of this paper is to present different methods of physical and/or chemical modifications of fibrous materials: which can serve as scaffolds to support the regeneration processes of various tissues. In terms of physical methods, only weak interactions between the surface and the modifier were observed. This technique is simple but not durable. Chemisorption used as a second method of fiber modification is possible if a covalent or ionic bond is formed between the fiber and the modifier. Therefore, the chemical adsorption may not be fully reversible and requires a sequence of chemical actions to form a chemical bond. The most commonly used methods are the combined methods where the first step is the physical activation of the fiber surface, which facilitates the chemical modification step.
Content available remote Cell attachment on ion implanted titanium surface
Purpose: Of outmost importance for the successful use of an implant is a good adhesion of the surrounding tissue to the biomaterial. In addition to the surface composition of the implant, the surface topography also influences the properties of the adherent cells. In the present investigation, ion implanted and untreated surfaces were compared for cell adhesion and spreading. Design/methodology/approach: The surface topography of the surfaces were analyzed using AFM and the cell studies with SEM. Findings: The results of our present investigation is indicative of the fact that ion implanted titanium surface offer better cell binding affinity compared to untreated/polished surface. Practical implications: Success of non-biodegradable implants will first and foremost depend on biocompatibility, followed by the capacity of the surface topography of the implants to evince desired cell matrix, surface cell matrix interactions. In the present study, the cell growth on ion implanted Ti material is analyzed and discussed. Originality/value: In this paper, we have utilized ion implantation technique, which will produce nano-texturing of the surface without producing any detrimental effects to both the dimensions and properties of the implants.
Lactoferrin, a glycoprotein found in milk, has stimulated osteoblast proliferation and differentiation, but has remained relatively unexplored as a biomaterial component. In this study, artificial extracellular matrices consisting of fibrils of collagen type I containing lactoferrin were used as coatings for the biocompatible polymer poly(lactic-co-glycolic acid) (PLGA). The numbers of cells, their viability and proliferation rate were evaluated in various time intervals. Additionally, cell initial spreading area on day 1 was measured. The results show that lactoferrin accelerates fibril-logenesis, leads to increased osteoblast cell numbers 1 and 3 days post-seeding, and encourages their proliferation in each of the tested time intervals.
The common pathway leading to liver fibrosis and cirrhosis is growing deposition of extracellular matrix (ECM). It results from molecular and histological rearrangement of collagens, glycoproteins and hyaluronans. Hyaluronic acid is a chief component of the extracellular matrix of connective tissues and plays the main structural role in the formation of ECM. The most important organ involved in the synthesis of hyaluronic acid is the liver. In this paper the meaning of hyaluronic acid in the diagnostics of liver diseases is discussed. Here, we focus on the described changes of hyaluronic acid concentration in the pathological processes of the liver, including alcoholic and non-alcoholic liver diseases. The results of published clinical studies have shown its high diagnostic sensitivity, which probably enables its application in laboratory diagnosis.
Breast cancer is a leading cause of mortality and morbidity in women, mostly due to high metastatic capacity of mammary carcinoma cells. It has been revealed recently that metastases of breast cancer comprise a fraction of specific stem-like cells, denoted as cancer stem cells (CSCs). Breast CSCs, expressing specific surface markers CD44+CD24-/lowESA+ usually disseminate in the bone marrow, being able to spread further and cause late metastases. The fundamental factor influencing the growth of CSCs is the microenvironment, especially the interaction of CSCs with extracellular matrix (ECM). The structure and function of ECM proteins, such as the dominating ECM protein collagen, is influenced not only by cancer cells but also by various cancer treatments. Since surgery, radio and chemotherapy are associated with oxidative stress we analyzed the growth of breast cancer CD44+CD24-/lowESA+ cell line SUM159 cultured on collagen matrix in vitro, using either native collagen or the one modified by hydroxyl radical. While native collagen supported the growth of CSCs, oxidatively modified one was not supportive. The SUM159 cell cultures were further exposed to a supraphysiological (35 µM) dose of the major bioactive lipid peroxidation product 4-hydroxynonenal (HNE), a well known as 'second messenger of free radicals', which has a strong affinity to bind to proteins and acts as a cytotoxic or as growth regulating signaling molecule. Native collagen, but not oxidised, abolished cytotoxicity of HNE, while oxidized collagen did not reduce cytotoxicity of HNE at all. These preliminary findings indicate that beside direct cytotoxic effects of anticancer therapies consequential oxidative stress and lipid peroxidation modify the microenvironment of CSCs influencing oxidative homeostasis that could additionally act against cancer.
In this paper we investigate a mathematical model of cancer invasion of tissue, which incorporates haptotaxis, chemotaxis, proliferation and degradation rates for cancer cells and the extracellular matrix, kinetics of urokinase receptor, and urokinase plasminogen activator cycle. We solve the model using spectrally accurate approximations and compare its numerical solutions with laboratory data. The spectral accuracy allows to use low-dimensional matrices and vectors, which speeds up the computations of the numerical solutions and thus to estimate the parameter values for the model equations. Our numerical results demonstrate correlations between numerical data computed from the mathematical model and in vivo tumour growth rates from prostate cell lines.
Celem pracy była ocena stabilności struktury macierzy zewnątrzkomórkowej osierdzia świni po usunięciu z nich komórek. Badano wpływ substancji powodujących usuwanie komórek na właściwości biochemiczne i morfologiczne tkanek. Tkanki traktowano roztworami zawierającymi trypsynę i wersenian sodu (EDTA) lub dodecylosiarczan sodu (SDS) i chlorek sodu (NaCl). W badaniach wykorzystano elektroforezę SDS-PAGE i mikroskopię optyczną. Wykazano, że oddziaływanie na tkanki roztworu zawierającego 0,05% trypsyny i 0,02% EDTA pozwala na uzyskanie materiału bezkomórkowego.
The aim of the present study was to evaluate the stability of the extracellular matrix structure in porcine pericardium after their decellularization. The influence of decellularizing substances on the tissues biochemical and morphological properties has been investigated. Tissues have been treated with solutions containing trypsin and sodium versenate (EDTA) or sodium dodecyl-sulfate (SDS) and sodium chloride. The SDS-PAGE electrophoresis and the optical microscopy have been used in researches. It has been shown that the tissues treatment with the solution containing 0.05% trypsin and 0.02% EDTA allows to obtain the acellular material.
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