PL
 |
EN
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 10

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available One step 3D printing of surface functionalized composite scaffolds for tissue engineering applications
Kotlarz M., Jordan R., Wegner E., Dobrzyński P., Neunzehn J., Lederer A., Wolf-Brandstetter C., Pamula E., Scharnweber D.
Acta of Bioengineering and Biomechanics
|
2018
|
Vol. 20, no. 2
35--45
EN
A successful approach widely used in materials science to adapt approved materials to specific applications is to design their surface properties. A main challenge in this area is the development of processing routes enabling for a simple but efficient surface design of complex shaped geometries. Against this background, this work aimed at the implementation of self-assembly principles for surface functionalization of 3D-printed poly(lactic-co-glycolic acid) (PLGA)-based constructs with macro- and microporous geometries via precision extruding deposition. Methods: Three-component melts from PLGA, CaCO3 and amphiphilic polymers (poly(2-oxazoline) block copolymer) were printed and their bulk and surface properties were studied. Results: Melts with up to 30 mass % of CaCO3 could be successfully printed with homogeneously distributed mineral particles. PLGA degradation during the printing process was temperature and time dependent: the molecular weight reached 10 to 15% of the initial values after ca. 120 min of heat exposure. Filament surfaces from melts containing CaCO3 show an increasing microroughness along with increasing CaCO3 content. Surface roughness and amphiphilic polymer content improve scaffold wettability with both factors showing synergistic effects. The CaCO3 content of the melts affected the inner filament structure during in vitro degradation in PBS, resulting in a homogeneous mineral particle-associated microporosity for mineral contents of 20 mass % and above. Conclusions: These results provide novel insights into the behavior of three-component melts from PLGA, CaCO3 and amphiphilic polymers during precision extruding deposition and show for the first time that self-assembly processes can be used to tailor scaffolds surface properties under such processing conditions.
2
Content available Integration of trace elements into calcium phosphate coatings on titanium and their characterization in vitro
Wolf-Brandstetter C., Urbanek S., Beutner R., Scharnweber D., Moseke C.
Engineering of Biomaterials
|
2017
|
Vol. 20, no. 143 spec. iss.
79
3
Content available Deposition of phosphate coatings on titanium within scaffold structure
Trybuś B., Zieliński A., Beutner R., Seramak T., Scharnweber D.
Acta of Bioengineering and Biomechanics
|
2017
|
Vol. 19, no. 2
65--72
EN
Purpose. Existing knowledge about the appearance, thickness, and chemical composition of 37 phosphate coatings on titanium inside porous structures is insufficient. Such knowledge is 38 important for the design and fabrication of porous implants. 39 Methods. Metallic scaffolds were fabricated by selective laser melting of 316L stainless steel 40 powder. Phosphate coatings were deposited on Ti sensors placed either outside the scaffolds 41 or in the holes in the scaffolds. The electrochemically-assisted cathodic deposition of 42 phosphate coatings was performed under galvanostatic conditions in an electrolyte containing 43 the calcium and phosphate ions. The phosphate deposits were microscopically investigated; 44 this included the performance of mass weight measurements and chemical analyses of the content of Ca2+ and PO4 2‒ 45 ions after the dissolution of deposits. 46 Results. The thicknesses of the calcium phosphate coatings were about 140 and 200 nm for 47 isolated titanium sensors and 170 and 300 nm for titanium sensors placed inside pores. 48 Deposition of calcium phosphate occurred inside the pores up to 150 mm below the scaffold 49 surface. The deposits were rich in Ca, with a Ca/P ratio ranging between 2 and 2.5. 50 Conclusions. Calcium phosphate coatings can be successfully deposited on a Ti surface 51 inside a model scaffold. An increase in cathodic current results in an increase in coating 52 thickness. Any decrease in the cathodic current inside the porous structure is slight. The 53 calcium phosphate inside the pores has a much higher Ca/P ratio than that of stoichiometric 54 HAp, likely due to a gradual increase in Ca fraction with distance from the surface.
4
Content available Studying glycosaminoglycan derivative/protein interaction - prerequisite for the design of functional biomaterials
Scharnweber D., Rother S., Kohler L., Hintze V.
Engineering of Biomaterials
|
2016
|
Vol. 19, no. 138 spec. iss.
25
5
Content available Resorbable scaffolds modified with collagen type I or hydroxyapatite : in vitro studies on human mesenchymal stem cells
Rumian Ł., Wojak I., Scharnweber D., Pamuła E.
Acta of Bioengineering and Biomechanics
|
2013
|
Vol. 15, no. 1
61--67
EN
Poly(L-lactide-co-glycolide) (PLGA) scaffolds of pore size within the range of 250–320 μm were produced by solvent casting/ porogen leaching method. Afterwards, they were modified through adsorption of collagen type I and incubation in simulated body fluid (SBF) to allow deposition of hydroxyapatite (HAp). The wettability of the scaffolds was measured by sessile drop test. Scanning electron microscopy (SEM) evaluation and energy dispersive X-ray analysis (EDX) were also performed. SEM evaluation and EDX analysis depicted the presence of HAp deposits and a collagen layer on the pore walls on the surface and in the bulk of the scaffolds. Wettability and water droplets penetration time within the scaffolds decreased considerably after applying modifications. Human mesenchymal stem cells (hMSC) were cultured on the scaffolds for 28 days and cell morphology, proliferation and differentiation as well as calcium deposition were evaluated. Lactate dehydrogenase (LDH) activity results revealed that cells cultured on tissue culture polystyrene (TCPS) exhibited high proliferation capacity. Cell growth on the scaffolds was slower in comparison to TCPS and did not depend on modification applied. On the other hand, osteogenic differentiation of hMSC as confirmed by alkaline phosphatase (ALP) activity and mineralization results was enhanced on the scaffolds modified with hydroxyapatite and collagen.
6
Content available In vitro evaluation of poly(L-lactide-co-glycolide) membrane
Krok M., Hess R., Wojak I., Kościelniak D., Scharnweber D., Pamuła E.
Engineering of Biomaterials
|
2010
|
Vol. 13, no. 94
7--10
EN
The aim of this study was to prepare and evaluate the properties of a new membrane dedicated for the treatment of bone defects in periodontology according to guided tissue regeneration (GTR) technique. The first part of this study was to prepare the membrane from resorbable poly(L-lactide-co-glycolide) (PLGA) and verify its microstructure. Biological evaluation was lead using the cells interesting from the point of view of GTR, e.g. human fibroblasts and mesenchymal stem cells (hMSC). It was found that the obtained membrane has asymmetric microstructure and defined pore size. Cell culture experiments show that the membrane is biocompatible with fibroblasts and hMSC. Both types of cell proliferated well on the membrane. HMSC cultured on the membrane exhibited better osteogenic differentiation and higher mineralization as compared to control tissue culture polystyrene.
7
Content available Coating of poly(l-lactide-co-glycolide) scaffolds with collagen/glycosaminoglycan matrices and their effects on osteoblast behaviour
Wojak I., Pamuła E., Dobrzyński P., Zimmermann H., Worch H., Scharnweber D., Hintze V.
Engineering of Biomaterials
|
2009
|
Vol. 12, no. 86
9-13
EN
Collagen type I and glycosaminoglycans (GAGs) were immobilized on the surfaces of two types of porous biodegradable poly(L-lactide-co-glycolide) (PLGA) scaffolds with pore size in the range of 250-320 µm and 400-600 µm. Two methods of coating were evaluated differing in the way of how the fibrillogenesis solution was introduced into the pores. The distribution of the immunostained collagen in the volume of the scaffolds was analysed with a laser confocal microscope (LSM). The total amount of collagen and GAGs was measured by Sirius Red and Toluidine Blue assays, respectively. The potential of the scaffolds for cell colonization and differentiation was tested in a dynamic cell culture system using human osteosarcoma cells (SAOS-2). The proliferation of SAOS-2 cells was measured by determining the DNA content on days 2 and 7, while differentiation was analyzed by Calcium- and Phosphate-Assays on days 7 and 14. Differentiation of cells was improved by increasing the pore diameter of the scaffolds, and artificial extracellular matrix (aECM) coatings had an additional positive effect for the scaffolds of both pore sizes.
8
Content available Impact of modified hyaluronan on binding of biological mediators
Hintze V., Hempel U., Schnabelrauch M., Rosler M., Worch H., Scharnweber D.
Engineering of Biomaterials
|
2008
|
Vol. 11, no. 77-80
18--19
9
Content available Sztuczne macierze pozakomórkowe na podstawie włókien kolagena i proteoglikanów (PGS)
Douglas T., Hempel U., Mietrach C., Heinemann S., Knieb C., Bierbaum S., Scharnweber D., Worch H.
Inżynieria Biomateriałów
|
2006
|
R. 9, nr 58-60
36-38
10
Content available Extra-cellular matrices for titanium implants
Douglas T., Hempel U., Bierbaum S., Scharnweber D., Worch H.
Inżynieria Biomateriałów
|
2005
|
R. 8, nr 47-53
12--13
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.