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1

Integrin αv signaling influences phenotype and maturation of primary human osteoblasts on alumina surface

Wróbel E., Witkowska-Zimny M., Mrówka P., Głodkowska-Mrówka E.

Engineering of Biomaterials

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2014

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Vol. 17, no. 127

33--39

EN

Due to the growing interest in stem cells application in tissue engineering the better understanding of primary human osteoblasts behavior in vitro, on biomaterial surface, is required. Among other molecules integrins may be taken into account as being involved in these phenomena. Integrins are a family of cell adhesion receptors, which may regulate many cellular functions e.g., adhesion, motility, phenotype and cell maturation. The aim of this study was to determine the effect of the biomaterial surfaces and αv integrin signaling pathway on the behavior, phenotype and maturation of human osteoblasts in vitro. Human bone derived cells (HBDCs) obtained from adult femoral bone fragments were cultured on both alumina disks and tissue culture polystyrene (TCPS) dishes. After 7, 14, and 21 days of culture, localization and mRNA expression level of αv integrin subunits and BGLAP (osteocalcin) on polystyrene were analyzed in addition, we treated the cell cultures with monoclonal antibodies against human αv integrin to block its ligand-binding activity, on both alumina and TCPS substrates. We found that the αv integrin was present in focal contacts and cell cytoplasm at subsequent stages of cell maturation and the level of αv integrin mRNA was the highest in mature osteoblasts. Blocking αv integrin transduction pathway caused changes in cell activity and morphology, decreased cells proliferation on TCPS and reduced expression of alkaline phosphatase (ALP) on both materials. The results suggest that αv integrin is involved as an important receptor facilitating osteogenic differentiation.

2

Black Orlon as promising material for bone tissue engineering

Parizek M., Vetrik M., Hruby M., Lisa V., Bacakova L.

Engineering of Biomaterials

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2014

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Vol. 17, no. 128-129

4--6

3

Improved adhesion and growth of osteoblast-like MG-63 cells in cultures on titanium modified by gold particles

Parizek M., Base T., Hruby M., Lisa V., Bacakova L.

Engineering of Biomaterials

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2013

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Vol. 16, no. 122-123 spec. iss.

77

EN

Metallic materials are important for load-bearing bone implants. The osteointegration of these implants can be improved by appropriate surface modifications. Therefore, we present here a study of the cell growth on titanium surfaces modified with films created from gold microparticles. These particles in the form of microplates or polyhedral microcrystals were deposited on titanium plates from ethanol solutions, dried and annealed with a hydrogen flame. Some samples were additionally modified by polyethylene imine. The materials engendered from these modifications were used to investigate the adhesion and growth of human osteoblast-like MG-63 cells on these surfaces in the DMEM medium with 10% of fetal bovine serum. One day after seeding, the highest number of initially adhered cells was found on the surfaces modified by both types of gold microparticles. This trend was the same three and seven days after seeding. The numbers of cells on pure Ti and Ti modified only with gold particles were significantly higher than on samples which were modified with polyethylene imine. The cell spreading areas projected on the materials were significantly larger in cells on the samples with polyethylene imine modification. However, the shape of these cells was mostly rounded or star-like with thin and long protrusions, while on the materials without polyethylene imine, it was mostly polygonal. The cell proliferation activity was estimated from XTT test, based on the activity of mitochondrial enzymes. This test showed that the proliferation activities of osteoblast-like MG-63 cells of the 3rd and 7th days of the experiment were more pronounced on the samples modified only by gold microparticles. Immunofluorescence showed that the focal adhesion plaques containing vinculin and the fibers containing β-actin were most apparent, more numerous and more brightly stained in cells on Ti modified by gold microplates and gold polyhedral microcrystals, especially in comparison with the corresponding samples modified with polyethylene imine (Fig. 1). Thus, it can be concluded that the modification of titanium samples by both types of gold microparticles enhanced the adhesion and growth of MG 63 cells.

4

Influence of surface topography and morphology of PU/PLA films on fibroblasts performance

Bednarz P., Krok M., Laska J.

Engineering of Biomaterials

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2012

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Vol. 15, no. 116-117 spec. iss.

120--122

5

Surface functionalization for tissue analog of blood contacting materials

Major R., Lackner J. M., Wilczek P., Sanak M., Sobota M., Kowalczuk M., Marczak J., Maksymow K., Major B.

Inżynieria Materiałowa

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2011

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Vol. 32, nr 4

545-548

EN

Selection of materials designed for surface modification of blood contacting polymer devices has been made. The materials like: TiN, Ti(C, N) and a-C:H (DLC doted with Si or Ti) were selected. Fabrication of functional coatings on polymer surfaces modified using surface engineering methods was realized. It determines an essential progress in problems development leading to fabrication of a final organic coating contacting with blood. This has been postulated by medical doctors. Biomimetic surface modification in direction of extracellular matrix (ECM) formation onto implant surfaces of cardiovascular devices seems to be a perspective method for hemocompatibility improvement. Re-creation of internal structure of vessel wall could be a good solution which allows a long term implantation. For optimization of cell growth it is an essential creation of a suitable spatial scaffold architecture on which cells are deposited. In reality, cells do not go into a direct contact with the material of scaffold, but always joint with a layer of adsorbed respective proteins which nature state and type have an essential influence on cell adhesion. Research work has been performed in area of four problems i.e. (i) cell migration inside migration channels, laser ablation was used for channel fabrication; (ii) analysis of protein adsorption with application of Foetal Buffer Serum, adsorption of albumin was studied, (iii) surface functionalization with application of electrospinning and polyelectrolites which in subsequent stages should lead to design of tissue analog; (iv) analysis of survival and endothelium cell proliferation, human endothelium cells HUVEC line were used in the study. Structure diagnostic was carried out with application of confocal microscopy dedicated to biomedical studies. Reaction of cell-material was studied in static and dynamic conditions.

PL

Na podstawie zrealizowanych badań strukturalnych i diagnostyki biomedycznej dokonano selekcji materiałów przeznaczonych do modyfikacji powierzchni elementów polimerowych przewidzianych do kontaktu z krwią. Wytypowano następujące materiały: stechiometryczny TiN, Ti(C, N) oraz a-C:H (DLC dotowane Si lub Ti). Wykonano funkcjonalne powłoki na materiałach poliuretanowych zmodyfikowanych metodami inżynierii powierzchni. Stanowi to bardzo istotny postęp w rozwoju problematyki i prowadzi do uzyskania organicznej finalnej powłoki kontaktowej z krwią, co postulowane jest przez lekarzy. Biomimetyczna modyfikacja powierzchniowa w kierunku struktury macierzy zewnątrzkomórkowej implantów układu sercowo-naczyniowego jest obiecującą metodą poprawy hemozgodności. Odtworzenie struktury wewnętrznej ściany naczynia może być właściwym rozwiązaniem pozwalającym na długoterminową implantację. W celu optymalizacji wzrostu komórek istotne jest odtworzenie właściwej przestrzennej architektury rusztowania, na którym są osadzane komórki. W rzeczywistości komórki nie wchodzą w bezpośredni kontakt z materiałem rusztowania, ale zawsze łączą się z warstwą zaadsorbowanych odpowiednich białek, których natura i typ ma istotny wpływ na adhezję komórkową. Badania prowadzono w obszarze czterech zagadnień: (i) migracji komórkowej na materiałach z kanalikami migracyjnymi uzyskanymi metodą ablacji laserowej; (ii) analizy adsorpcji białek z zastosowaniem surowicy cielęcej (Foetal Buffer Serum), analizowano adsorpcję albuminy; (iii) funkcjonalizacji powierzchni z zastosowaniem polielektrolitów, które w dalszych etapach powinno doprowadzić do konstrukcji analogu tkankowego; (iv) analizy przeżywalności i proliferacji komórek śródbłonka, do badań zastosowano ludzkie komórki śródbłonka linii HUVEC. Diagnostykę strukturalną realizowano z zastosowaniem mikroskopu konfokalnego dedykowanego do badań biomedycznych. Oddziaływanie materiał-komórka rozważane było w warunkach statycznych i dynamicznych.

6

Chemical modification of poly ε-caprolactone with wollastonite and its influence on biological properties of osteoblast like-cells MG-63

Ścisłowska-Czarnecka A., Menaszek E., Kołaczkowska E., Błażewicz M., Podporska J.

Engineering of Biomaterials

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2011

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Vol. 14, no. 102

11--14

EN

PCL (poly-ε-caprolactone) is a biocompatible and biodegradable polymer of aliphatic polyester group. However, PCL does not effectively bind to the bone in contrast to bioactive inorganic compounds such as wollastonite. For this wollastonite (WS) is regarded as a potential bioactive material for bone tissue engeenering although its main drawback is brittlennes. Therefore we synthesized polymer nanocomposite materials composed of poly-ε-caprolactone and wollastonite (PCL/wollastonite) containing either 0.5% or 5% of the latter modifying filler. And we aimed to verify biological properties of the nanocomposite PCL/WS materials, in comparison to the pure PCL, on cultures of osteoblast-like cells MG-63. The study revealed that the adherence of the osteoblast-like cells to the tested materials was enhanced by the PCL modification (PCL/5WS > PCL/0.5WS > PCL) while cell viability/proliferation was not altered. Furthermore, the activity of alkaline phosphatase indicative of osteoblast differentiation (maturation) was enhanced when the cells were cultured with either PCL/5WS or PCL/0.5WS. Overall, our results indicate that PCL-modified wollastonite improves biological properties of the basic biomaterial suggesting its potential usefulness/application for the bone tissue regeneration.

7

Functional cardio-biomaterials

Major R., Lackner J., Wilczek P., Sanak M., Jakieła B., Stolarzewicz B., Kowalczuk M., Sobota M., Maksymow K., Spisak M., Major B.

Advances in Materials Science

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2011

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Vol. 11, nr 2(28)

5-25

EN

Titanium as well as carbon based biomaterials, seem to be good candidates for future blood-contact applications. Bio-materials such as: Ti, Ti+DLC, TiN; Ti(C,N) with higher carbon concentration and DLC (diamond like carbon) were under examinations. Trials on surface modification of PU (polyurethane) substrate using ion mill were performed. Materials were deposited as thin films by the hybrid pulsed laser deposition (PLD) technique to examine the influence of the fabricated surfaces on cell behavior. The metallic titanium as a target was used for titanium based-film and graphite one for DLC. Phase content of deposited films was controlled by the flowing gas mixture of Ar+N2 and Ar+N2+C2H2 type in the reactive chamber. Sputtering of graphite was carried out in Ar atmosphere. The kinetic energy of the evaporated particles was controlled by application of variation of different reactive and non reactive atmospheres during deposition. Transmission electron microscopy (TEM) was used to reveal structure dependence on specific atmosphere in the reactive chamber. The measurement of the strength of bonds between biomaterials and cells is a major challenge in cellular biology since it allows for the identification of different species in adhesion phenomena. The biomaterial examinations were performed in static conditions with Dictyostelium discoideum cells and then subjected to a dynamical test to observe the cell detachment kinetics. For a given cell, detachment occurs for critical stress values caused by the applied hydrodynamic pressure above a threshold which depends on cell size and physicochemical properties of the substrate, but it is not affected by depolymerization of the actin and tubulin cytoskeleton. Tests revealed differences in behavior in respect to the applied coating material. The strongest cell-biomaterial interaction was observed for the carbon-based materials compared to the titanium and titanium nitride. A surface fuctionalization was realized by: (i) fabrication of migration channels by laser ablation, (ii) electrospinning and (iii) deposition of multilayer film from polyelectrolites. A goal of the performed research was formation of scaffolds for bio-mimetic coatings. Surface morphology examinations and biomedical studies on porous and semi-porous materials with application of human endothelial cells HUVEC line were performed by application of confocal laser scanning microscopy (CLSM).

8

Wpływ struktury powłok na bazie tytanu i węgla na właściwości biofizyczne biomateriałów do kontaktu z krwią

Major Ł., Lackner J. M., Wilczek P., Maksymow K., Major B.

Inżynieria Materiałowa

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2010

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Vol. 31, nr 4

1085-1090

PL

Określenie oddziaływania komórka-materiał odgrywa podstawową rolę w projektowaniu biomateriałów. W pracy podjęto analizę wpływu struktury i składu powłok na właściwości biofizyczne. Oddziaływanie materiał-komórka rozważane było w warunkach statycznych i dynamicznych. Przedmiotem badań był: metaliczny Ti, azotek tytanu (TiN), węgloazotek tytanu Ti(N, C) z wysoką i niską zawartością węgla oraz powłoki węglowe, jako planowane materiały do kontaktu z krwią. Najlepsze właściwości obserwowano dla TiN, jakkolwiek stwierdzono silny wpływ na biozgodność stechiometrii TiN (stosunku atomowego Ti/N). Obserwowane oddziaływanie komórka-materiał analizowane było w aspekcie wpływu orientacji krystalograficznej, składu i mikrostruktury.

EN

Determination of reaction cell-material is a major challenge in biomaterial design. Contribution of structure and chemical content on biophysical properties has been studied in the work. As planned perspective coating materials for blood contacting purposes, Ti, TiN, Ti(C, N) with high and low carbon content and DLC have been studied. Good properties in respect to blood contact were observed for TiN, however, strong contribution of TiN stoichiometry (atomic proportion Ti/N) on biocompatibility were stated. Reaction of cell-material has been analyzed in relation to crystallographic orientation, chemical content and microstructure.

9

Polish Artificial Heart - new coatings, technology, diagnostics

Sarna J., Kustosz R., Major R., Lackner J., Major B.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2010

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Vol. 58, nr 2

329-335

EN

Since 1991, the Foundation for Cardiac Surgery Development in Zabrze has been implementing research on the artificial heart. In 1995, an artificial ventricle, POLVAD, was implanted to a patient, and in 1998, the prototype of a clinical controller, POLPDU-401, was created. A further development of the studies on an implantable artificial heart requires an integrated approach and an application of advanced methods of materials sciences in order to develop new materials suitable for the contact with blood, as well as to apply a multilateral biomedical diagnostics in hydrodynamic conditions. The estimation of the cell–material interaction plays an important role in the biomaterial design. An analysis of the influence of the carbon content in titanium nitride on the biological and biophysical properties of biomaterial coatings was studied. The cell-material reactions were considered in dynamic and static conditions. Three groups of materials were under examinations – titanium nitride (TiN), as well as titanium carbonitride with a low and high carbon content – of which the best properties were observed for TiN. We found a strong influence of the stoichiometry of TiN (atomic ratio of Ti/N) on the biocompatibility. A non-stoichiometric TiN could have a negative influence on the surrounding tissue.

10

Vascular smooth muscle cells in cultures on low density polyethylene modified with plasma discharge and biofunctionalization

Parizek M., Kasalkova N., Bacakova L., Kolarova K., Lisa V., Svorcik V.

Engineering of Biomaterials

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2009

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Vol. 12, no. 89-91

25--28

EN

Low density polyethylene (LDPE) was modified by an Ar plasma discharge and then grafted with glycine (Gly), bovine serum albumin (BSA) or polyethylene glykol (PEG). Some plasma-treated samples and samples grafted with BSA were exposed to a suspension of colloidal carbon particles (C, BSA+C). Pristine LDPE and tissue culture polystyrene dishes (PSC) were used as control samples. The materials were seeded with rat aortic smooth muscle cells and incubated in a medium DMEM with 10% of fetal bovine serum. On day 1 after seeding, the cells on LDPE modified with plasma only, Gly, BSA and BSA+C adhered in similar numbers as on PSC, while the values on non-modified and PEG-modified samples were significantly lower. On day 5, the highest cell numbers were found again on LDPE with Gly, BSA and BSA+C. On day 7, the highest number of cells was found on LDPE modified only with plasma. The latter cells also dis-played the largest cell spreading area. The increased cell colonization was probably due to the formation of oxygen-containing chemical functional groups after plasma irradiation, and also due to positive effects of grafted Gly, BSA and BSA in combination with colloidal C particles.

11

Interaction of parylene C with biological objects

Kamińska M., Okrój W., Szymański W., Jakubowski W., Komorowski P., Nosal A., Szymanowski H., Gazicki-Lipman M., Jerczyńska H., Pawłowska Z., Walkowiak B.

Acta of Bioengineering and Biomechanics

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2009

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Vol. 11, nr 3

19-25

EN

The aim of the present work was to examine the interactions of parylene C with such selected biological objects as: blood plasma proteins, platelets, endothelial cells, and bacterial biofilm produced by E. coli cells. The results obtained strongly support the thesis that parylene C is a material worth considering for biomedical use. Parylene C coating on polished medical steel significantly reduces platelet adhesion to this surface. On the other hand, in the case of the surface of machined medical steel coated with parylene C, the number of adhered platelets is significantly higher. This also means that surface texture of substrate material is very well reproduced by parylene C coating and is an important factor facilitating the platelet adhesion. Adsorption of plasma proteins at parylene C surface is very effective, and this finding confirms a notion that cell interaction with surfaces is mediated by the adsorbed proteins. In the light of the above, a high susceptibility of parylene C surface to bacterial colonization is easy to explain. The results showing reduced proliferation and changes in endothelial cell gene expression should also be seriously analysed when parylene C is considered for the use in contact with blood vessels.

12

The effect of titanium alloy modified with a-C:N:H and a-SiCxNY(H) coatings on adhesion and immune response of human osteoblast-like MG-63 cells

Ścisłowska-Czarnecka A., Menaszek E., Kołaczkowska E., Januś M., Stypuła B.

Engineering of Biomaterials

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2008

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Vol. 11, no. 81-84

126--128

EN

The study was conducted in order to determine the effects of modified titanium alloy (Ti-6Al-4V) surfaces on the biological response of a human osteoblast-like cell line. MG-63 cells were cultured on disk-shaped Ti-alloys: unmodified, and covered with a-C:N:H or a-SiCxNy(H) layers. Interactions between materials and cells were examined through determination of cells adhesion and secretion of cytokines involved in the development of immune response.

13

The adhesion and growth of vascular smooth muscle cells in cultures on carboranethiol-modified gold films

Parizek M., Base T., Londesborough M. G. S., Lisa V., Bacakova L.

Engineering of Biomaterials

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2008

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Vol. 11, no. 81-84

117--119

EN

Metal surfaces have become important over the last decade for potential surgical implants, and within this context we present here a study of the cell growth on modified gold surfaces. Gold films, deposited on glass plates and annealed with a hydrogen flame, were modified with four different carboranethiol derivatives: 1-(HS)-1,2-C2B10H11 (A), 1,2-(HS)2-1,2-C2B10H10 (B), 9,12-(HS)2-1,2-C2B10H10 (C) and 1,12-(HS)2-1,12- C2B10H10 (D). The materials engendered from these modifications were used to investigate the adhesion and growth of rat aortic smooth muscle cells cultured on these surfaces in a DMEM medium with 10% of fetal bovine serum. One day after seeding, the highest number of initially adhered cells was found on the surface of a bare gold film. However, three days after seeding, the number of cells on carboranethiol-modified gold samples B, C and D was significantly higher than the number on a bare gold film. After seven days, the number of cells on a bare gold film and on gold films modified with derivatives A, B and D was very similar, but the surface of a gold film modified with derivative C exhibited a significantly smaller number of cells. This may be explained by the exposure of the CH vertices of the carborane cluster, which are more acidic than the BH vertices exposed toward the cells in either A or B.

14

The adhesion and growth of vascular smooth muscle cells in cultures on carboranethiol-modified gold films

Parizek M., Base T., Londesborough M. G. S., Lisa V., Bacakova L.

Engineering of Biomaterials

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2008

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Vol. 11, no. 75

6--8

EN

Metal surfaces have become important over the last decade for potential surgical implants, and within this context we present here a study of the cell growth on modified gold surfaces. Gold films, deposited on glass plates and annealed with a hydrogen flame, were modified with four different carboranethiol derivatives: 1-(HS)-1,2-C2 B10H11(A), 1,2-(HS)2-1,2-C2B10H10(B), 9,12-(HS)2-1,2-C2B10H10(C) and 1,12-(HS)2-1,12- C2B10H10(D). The materials engendered from these modifications were used to investigate the adhesion and growth of rat aortic smooth muscle cells cultured on these surfaces in a DMEM medium with 10% of fetal bovine serum. One day after seeding, the highest number of initially adhered cells was found on the surface of a bare gold film. However, three days after seeding, the number of cells on carboranethiol-modified gold samples B, C and D was significantly higher than the number on a bare gold film. After seven days, the number of cells on a bare gold film and on gold films modified with derivatives A, B and D was very similar, but the surface of a gold film modified with derivative C exhibited a significantly smaller number of cells. This may be explained by the exposure of the CH vertices of the carborane cluster, which are more acidic than the BH vertices exposed toward the cells in either A or B.

15

Kinetics of eukaryote cells adhesion under shear flow detachment on the PLD deposited surfaces

Major R., Bruckert F., Lackner J.M., Waldhauser W., Pietrzyk M.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2008

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Vol. 56, nr 3

223-228

EN

Hybryd PLD method was used for deposition high quality thin Ti, TiN, Ti(C,N) and DLC coatings. The kinetic energy of the evaporated particles was controlled by application of variation of different reactive and non reactive atmospheres during deposition. The purpose was to improve adhesion by building a bridge between the real ceramic coating and the substrate. A new layer composition layout was proposed by application of a buffer, starting layer. Advanced HRTEM investigation based on high resolution transmission electron microscopy was used to reveal structure dependence on specific atmosphere in the reactive chamber. New experimental technique to examine the crystallographic orientation based on X-ray texture tomography was applied to estimate contribution of the atmosphere to crystal orientation. Using Dictyostelium discoideum cells as a model organism for specific and nonspecific adhesion, kinetics of shear flow-induced cell detachment was studied. For a given cell, detachment occurs for critical stress values caused by the applied hydrodynamic pressure above a threshold. Cells are then removed from the substrate with an apparent first-order rate reaction that strongly depends on the stress. The threshold stress depends on cell size and physicochemical properties of the substrate, but it is not affected by depolymerization of the actin and tubulin cytoskeleton.

16

Coatings on TiN and Ti(C,N) basis for biomedical application to blood contact and TiN/CrN multilayered tribological systems produced by pulsed laser deposition

Major B., Bruckert F., Lackner J. M., Ebner R., Kustosz R., Lacki P.

Archives of Metallurgy and Materials

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2008

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Vol. 53, iss. 1

39-48

EN

Research activity on surface en g ineering performed at the IMIM PAS in last years has been presented. Experiments were focused on TiN and Ti(C,N) thin coatings produced on titanium and biologically applied polyurethane substrates by application of pulsed laser deposition (PLD), magnetron sputtering (MS), and hybrid PLD/MS, at room temperature. Bio-physical tests of the kinetics of shear flow-induced cell detachment have been carried out. Model eucariotic cells easy to manipulate using technics of molecular biology have been used in experiments. Fluorescence patterns obtained after the performed test at kinetics condition tests have been used to establish kinetics curves. A microstructure examination by application of XRD and transmission electron microscopy have been performed. On the basis of the real cell detachment experiment, a finite element simulation was done. The highest shear stress was estimated for the region of the radius of the whole pierced in the center of the upper disc. There are an increasing number of applications in tribology where the properties of a sin gle material are not sufficient. One way to surmount this problem is to use a multilayer coating. Application of metallic interlayers improves adhesion of nitride hard layer in multilayer systems. Tribological coatings consisted of 4, 8 and 32 layers of Cr/CrN and Ti/TiN types were fabricated with the PLD technique. It is found in transmission electron examinations on thin foils prepared from cross-section that both nitride-based multilayer structures studied are characterized by small columnar crystallite sizes and high defect density, what might raise their hardness but compromise coating adhesion. The intermediate metallic layers contained larger sized and less defective columnar structure compared to the nitride layers located at close to the substrate which should improve the coatings toughness. Switching from single layer to multi-layer metal/nitride composition improved resistance to delamination.

PL

Przedstawiono działalność IMIM PAN prowadzoną w ostatnich latach w zakresie inżynierii powierzchni. Badania koncentrowaly się na cienkich warstwach typu TiN i Ti(C,N) wytwarzanych z wykorzystaniem metody osadzania laserem impulsowym (PLD), magnetronowej (MS) oraz hybrydowej PLD/MS w temperaturze pokojowej na podłożu metalicznego tytanu oraz stosowanego biologicznie poliuretanu. Przeprowadzono testy biofizyczne kinetyki wymywania komórek w warunkach naprężenia ścinania generowanego przepływem. W badaniach zastosowano modelowe komórki eukariota, które są dogodne do wykorzystania w eksperymentalnych technikach biologii molekularnej. Obrazy fluorescencyjne uzyskane po przeprowadzonych testach w warunkach kinetycznych wykorzystane zostaly do wyznaczenia krzywych kinetycznych. Przeprowadzono badania mikrostruktury metodą dyfrakcji rentgenowskiej i transmisyjnej mikroskopii elektronowej. Wykorzystując wyniki rzeczywistego eksperymentu wymywania komórek, przeprowadzono modelowanie metodą elementów skończonych. Najwyższe naprężenia ścinające uzyskano dla obszaru leżącego na brzegu otworu centralnego górnego dysku. Wzrasta ilość zastosowań w tribologii gdy właściwości tworzywa jednowarstwowego są niewystarczające. Jednym z rozwiązań jest wytwarzanie powłok wielowarstwowych. Zastosowanie wielowarstwy metalicznej w układzie Ti/TiN, zawierającym twardą warstwę azotkową, poprawia adhezje. Wytworzone zostały metodą PLD układy tribologiczne składające się z 4, 8 oraz 32 warstw typu Cr/CrN i Ti/TiN. Stwierdzono w badaniach metodą transmisyjnej mikroskopii elektronowej na cienkich foliach uzyskanych z przekroju poprzecznego, że obydwa wielowarstwowe systemy charakteryzują się drobnokrystaliczną strukturą o małej wielkości ziaren kolumnowych z dużą gęstością defektów. Może to wpływać na wzrost twardości, obniżając jednak adhezję powłoki. Międzywarstwy metaliczne zawierają nieco większych rozmiarów i mniej zdefektowaną strukturę kolumnową niż warstwy azotkowe. Warstwa metaliczna jest pierwsząwarstwąprzy podłożu i podnosi ona plastyczność powłoki. Przechodząc od warstwy pojedynczej do wielowarstwy typu metal/azotek uzyskuje siępoprawę odporności na delaminację.

17

Improved adhesion and growth of vascular smooth muscle cells in cultures on polyethylene modified by plasma discharge

Parizek M., Kasalkova N., Bacakova L., Kolarova K., Lisa V., Svorcik V.

Engineering of Biomaterials

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2007

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Vol. 10, no. 67-68

1-4

EN

The attractiveness of synthetic polymers for cell colonization can be affected by physical and chemical modification of the polymer surface. In this study, high density polyethylene (HDPE, m.w. 0.952g/cm3) and low density polyethylene (LDPE, m.w. 0.922g/cm3) were modified by an Ar plasma discharge using Balzers SCD 050 device (exposure time 10, 50, 150 and 400 seconds, discharge power 1.7W). The material was then seeded with rat aortic smooth muscle cells (RASMC; passages 8 to 9, 17 000 cells/cm3) and incubated in a DMEM medium with 10% of fetal calf serum. On day 1 after seeding, the number of initially adhered cells was significantly higher on all modified HDPE and LDPE samples. On day 2, this difference persisted in HDPE, whereas in LDPE only the values on the samples modified by 150 and 400 seconds were significantly higher. On the 5th and 7th day, there were no significant differences in cell number among all LDPE samples. However, on the HDPE foils, significant differences were still apparent on the samples modified for 400 seconds. The cell spreading areas measured on day 1 after seeding were significantly larger on all modified LDPE samples, and, on day 2, on the HDPE samples exposed for 150s. The increased cell colonization was probably due to the formation of oxygen-containing chemical functional groups in the polymer. These results suggest that the responsiveness of the cell to the changes in physiochemical surface properties was more pronounced in HDPE than in LDPE. On both types of polyethylene, the most appropriate exposure time for the enhancement of cell adhesion and growth seemed to be 150 and 400 seconds.

18

New gradient coatings on TiN and TiCN basis for biomedical application to blood contact

Major B., Major R., Bruckert F., Lackner J.M., Ebner R., Kustosz R., Lacki P.

Advances in Materials Science

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2007

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Vol. 7, nr 3(13)

63-70

EN

Adhesion of blood cells and its activation to material surface used as implants is a problem of crucial importance. Structure parameters influence essentially the interaction of biomedical materials with a human connective tissue. The work is focused on TiN and TiCN thin coatings produced on titanium substrate by application of different methods i.e. pulsed laser deposition (PLD), magnetron sputtering, and hybrid PLD, at room temperature. Biophysical tests of the kinetics of shear flow-induced cell detachment have been carried out. Model eucariotic cells easy to manipulate using technics of molecular biology have been used in experiments. Fluorescence patterns obtained after the performed test at kinetics condition tests have been used to establish kinetics curves. A microstructure examination by application of XRD and transmission electron microscopy have been performed. The work is realized in cooperation with the Foundation of Cardiac Surgery Development in the frame-work of partially implanted prosthesis of the artificial heart project.

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Adhesion and growth of human osteoblast-like cells on aliphatic polyesters with different chemical composition, surface roughness and modification with hydroxyapatite

Vagaska B., Bacakova L., Pamuła E., Lisa V., Dobrzyński P.

Inżynieria Biomateriałów

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2006

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R. 9, nr 58-60

4-7

EN

In this study we have investigated the effect of three groups of polymeric foils on the behavior of MG 63 osteoblast-like cells. These included (1) poly(L-lactide) (PLLA) compared with newly synthesized copolymer of L-lactide and trimethylene carbonate (PLTMC 50:50), (2) three samples made of glycolide and epsylon-caprolactone copolymer (PGCap) with different surface roughness and topography, and finally (3) copolymer of glycolide with L-lactide (PGLA) compared with its modification with hyroxyapatite deposits. On the 1st and 4th day of cultivation the cell number on all of the samples was lower than on control polystyrene culture dish. However, on day 8 after seeding, the values on the tested samples caught up with the control polystyrene. In the first group the cell number of PLTMC was higher than on polystyrene or PLLA. In the second group, the number of cells on PGCap samples of the lower surface roughness (RRMS 130 and 180 nm) was significantly higher than that on the control polystyrene, whereas on the PGCap samples with the rounghness in micrometers, it was comparable to the value on the polystyrene. Moreover, the surface roughness influenced the cell adhesion area. The cells on the sample with the highest roughness index were roundly shaped and their adhesion area was significantly lower, because the cells were restricted in their spreading by the surface structure of the material. In the last group, the number of cells on day 8 on the polymer with hydroxyapatite deposits was significantly higher than on standard tissue culture polystyrene dish, as well as on unmodified PGLA foil, which suggested that hydroxyapatite supports cell proliferation.

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Pro-angiogenic effects of X-rays on murine endothelial cells

Lisiak E., Dziekiewicz M., Meineke V., Bilski M., Janiak M.

Nukleonika

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2005

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Vol. 50,suppl.2

17-20

EN

Recently, significant attention has been paid to the possibility of thwarting cancer progression by inhibition of neoangiogenesis (formation of new blood vessels) in growing tumors. Although general mechanisms of angiogenesis have been elucidated, virtually nothing is known about the effects of low doses of ionizing radiation on pro-angiogenic properties of endothelial cells. In the present study, we evaluated the effects of a low (0.2 Gy), intermediate (1 Gy), and high (4 Gy) doses of X-rays on a few angiogenesis-related parameters of isolated murine endothelial cells. We show here that 24 to 48 hours after irradiation with 0.2 Gy the cell proliferation was inhibited to a similar extent as after the exposure to 1 Gy. Also, adhesion of the 0.2 Gy-irradiated cells to both gelatin and MatrigelŽ was inhibited 24 hours post-exposure, whereas irradiation with 1 or 4 Gy resulted in the increased adhesion of the cells to these substrata. Similar effects were observed during the "wound" migration assay. Finally, 24 hours after exposure of the cells to 0.2 Gy of X-rays, the surface expression of the â3 integrin subunit was down-regulated, whereas irradiations with 1 and 4 Gy of X-rays resulted in the significantly elevated expression of this subunit. These results indicate that proliferating endothelial cells are sensitive in vitro to relatively low doses of ionizing radiation