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A New Method for Assessing Haemolysis in a Rotary Blood Pump Using Large Eddy Simulations (LES)

Szwast M., Moskal A., Piątkiewicz W.

Chemical and Process Engineering

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2017

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Vol. 38, nr 2

231--239

EN

The opportunity to assess haemolysis in a designed artificial heart seems to be one of the most important stages in construction. We propose a new method for assessing haemolysis level in a rotary blood pump. This method is based on CFD calculations using large eddy simulations (LES). This paper presents an approach to haemolysis estimation and shows examples of numerical simulation. Our method does not determine the value of haemolysis but allows for comparison of haemolysis levels between different artificial heart constructions.

2

The evaluation of resorbable haemostatic wound dressings in contact with blood in vitro

Szymonowicz M., Kucharska M., Wiśniewska-Wrona M., Dobrzyński M., Kołodziejczyk K., Rybak Z.

Acta of Bioengineering and Biomechanics

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2017

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Vol. 19, no. 1

151--165

EN

Purpose: For many years research has been conducted on the development of resorbable, polymer, haemostatic materials designed to provide first aid and preliminary protection of injuries. The biological properties in vitro of a dressing in powder form called Hemoguard are expected to provide the ability to instantaneously stem bleeding with safe conditions of use. The aim of the study was to evaluate the haemostatic properties of a model of dressing based on micro- and nanofibrids of the chitosan, sodium/calcium alginate and/or carboxymethylcellulose complex. Dressings were prepared by spray-drying and freeze-drying. Methods: Human whole blood was subjected to timed contact with the haemostatic dressing model. Haemolytic action was determined by assaying the degree of haemolysis and evaluating blood cell morphology. Haemostatic action was determined on the basis of selected parameters of plasmatic clotting systems. Results: Dressings prepared by freeze-drying activated the coagulation system. The haemolytic index, plasma haemoglobin concentration values and blood cell morphological shapes were normal. Dressings prepared by spray-drying significantly activated coagulation. Activation of the coagulation process was evidenced by shorter clotting time of the plasma coagulation system and a longer process of clot formation. The dressing was associated with an increased haemolytic index and higher plasma haemoglobin concentration. The morphological shape of blood cells changed. Conclusions: The model of multi-resorbable wound dressings has haemostatic properties. The materials activate the clotting process more quickly than a single-dressing model. Increased activity was found for dressings prepared by spray-drying.

3

Haemocompatibility and cytotoxic studies of non-metallic composite materials modified with magnetic nano and microparticles

Szymonowicz M., Rybak Z., Fraczek-Szczypta A., Paluch D., Rusak A., Nowicka K., Blazewicz M.

Acta of Bioengineering and Biomechanics

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2015

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Vol. 17, no. 3

49--58

EN

Purpose: Preventing the formation of blood clots on the surface of biomaterials and investigation of the reasons of their formation are the leading topics of the research and development of biomaterials for implants placed into the bloodstream. Biocompatibility and stability of a material in body fluids and direct effect on blood cell counts components are related both to the structure and physico-chemical state of an implant surface. The aim of this study was to determine haemocompatibility and cytotoxicity of polysulfone-based samples containing nano and micro particles of magnetite (Fe3O4). Methods: The polysulfone-based samples modified with nanometric and micrometric magnetite particles were examined. Physicochemical properties of the composites were determined by testing their wettability and surface roughness. The action of haemolytic, activation of coagulation system and cytotoxicity of composites was evaluated. Results: Wettability and roughness of materials were correlated with nanoparticles and microparticles content. In the tests of plasma coagulation system shortening of activated partial thromboplastin time for polysulfone with nano magnetite and with micro magnetite particles was observed in comparison with pure polysulfone. Prothrombine time and thrombine time values as well as fibrinogen concentration were unchanged. Haemolysis values were normal. Morphology and viability of cells were normal. Conclusions: Composites made from polysulfone modified with nanoparticles and microparticles of magnetite cause neither haemolytic nor cytotoxic reaction. These composites evoke plasma endogenous system activation.

4

Wpływ węgla pirolitycznego na parametry morfologiczne krwi

Szymonowicz M., Janus A., Pielka S., Obłąkowska D., Błażewicz S.

Engineering of Biomaterials

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2010

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Vol. 13, no. 96-98

83--87

PL

W pracy przedstawiono analizę ilościową wybranych parametrów morfologicznych krwi po jej czasowym kontakcie z materiałem węglowym LTI. Na podstawie uzyskanych wyników nie stwierdzono zmian w wartościach parametrów układu czerwonokrwinkowego, natomiast zaobserwowano zmiany w wartościach parametrów układu białokrwinkowego i płytkowego. Zaobserwowane zmiany w wartościach parametrów morfologicznych nie przekraczają zakresu wartości referencyjnych dla tych wskaźników.

EN

A quantitative analysis of selected morphological parameters of blood after its temporal contact with LTI carbon material was presented in the study. The obtained results indicate that the values of parameters of erythrocyte system did not change, while the values of parameters of leukocyte and platelet systems were altered. The changes in the values of parameters did not exceed the range of referential values for these indexes.

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Hamowanie procesu hemolizy w obecności proszku diamentowego w warunkach uszkodzenia przez wolne rodniki

Mitura K., Bartosz G., Mitura S.

Inżynieria Biomateriałów

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2005

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R. 8, nr 43-44

70--73

PL

Stres oksydacyjny jest zjawiskiem powodującym uszkodzenie błony komórkowej, w tym błony erytrocytu. Jest to łańcuchowa reakcja wolnorodnikowa, w wyniku której powstające wolne rodniki [1,2], uszkadzając strukturę tej błony, zmieniają jej właściwości półprzepuszczalne i powodują zmianę konformacji dwuwarstwy lipidowo-białkowej. Powstałe w wyniku procesu peroksydacji lipidów, toksyczne produkty -nadtlenki lipidów, wbudowując się w błonę komórkową, mogą być przyczyną uszkodzenia całej komórki, a przede wszystkim jej materiału genetycznego zawartego w jądrze komórkowym. Tak uszkodzona błona komórkowa erytrocytu, powoduje zaburzenie w funkcjonowaniu tej krwinki, które nazywa się zjawiskiem hemolizy. Klinicznie hemoliza to niedokrwistość hemolityczna, czyli zmniejszenie liczby krwinek czerwonych we krwi obwodowej, spowodowane rozpadem tej krwinki, z powodu uszkodzenia błony komórkowej, uwarunkowane czynnikami zewnątrz- lub wewnątrz-krwinkowymi. Istota samego zjawiska jest odzwierciedleniem procesu chorobowego, jaki dotyka krwinkę czerwoną, a co za tym idzie, wymaga właściwego postępowania terapeutycznego. Leki, które hamują proces hemolizy, nie zawsze spełniają oczekiwania lekarzy i niejednokrotnie nie powodują całkowitego wyleczenia, a działają wyłącznie objawowo. Wydaje się, że zastosowanie proszku diamentowego może być alternatywnym sposobem leczenia tego rodzaju zaburzeń [6].

EN

Oxidative stress is the phenomenon which takes partin the damage of cell membrane, for ex.: the erythrocyte membrane. This mechanism is based on the free radical chain reactions [1,2]. The result of this process are the products: free radicals - the cause of the damage of cell membrane structure and change properties of cell membrane fluidity and conformations of phospholipid bilayer. Lipid peroxidation is the cause of the form the toxic products -superoxides lipids in cell membrane and the damage of nucleus which contains a genetic material (DNA) of this cell. Erythrocyte membrane can be destroyed in mechanism of oxidative stress and it is the base of developing the phenomenon of haemolysis. The clinical name of this process is "anemia haemolytica" - the decreasing of amount of erythrocytes in peripheral blood from the egzogenic or endogenic factors. Haemolysis is the pathological process in human organism and in aspect of disease can be treated successfully. Medicines, which doctors use to treat this disorder are not completely good because always mechanism of its activity contains only the symptomatic treatment. It seems that Diamond Powder Particles can be used as the alternative therapy of anemia haemolytica [6].