TY  - JOUR
A1  - Hochleitner, Gernot
A1  - Jüngst, Tomasz
A1  - Brown, Toby D
A1  - Hahn, Kathrin
A1  - Moseke, Claus
A1  - Jakob, Franz
A1  - Dalton, Paul D
A1  - Groll, Jürgen
T1  - Additive manufacturing of scaffolds with sub-micron filaments via melt electrospinning writing
JF  - Biofabrication
N2  - The aim of this study was to explore the lower resolution limits of an electrohydrodynamic process combined with direct writing technology of polymer melts. Termed melt electrospinning writing, filaments are deposited layer-by-layer to produce discrete three-dimensional scaffolds for in vitro research. Through optimization of the parameters (flow rate, spinneret diameter, voltage, collector distance) for poly-ϵ-caprolactone, we could direct-write coherent scaffolds with ultrafine filaments, the smallest being 817 ± 165 nm. These low diameter filaments were deposited to form box-structures with a periodicity of 100.6 ± 5.1 μm and a height of 80 μm (50 stacked filaments; 100 overlap at intersections). We also observed oriented crystalline regions within such ultrafine filaments after annealing at 55 °C. The scaffolds were printed upon NCO-sP(EO-stat-PO)-coated glass slide surfaces and withstood frequent liquid exchanges with negligible scaffold detachment for at least 10 days in vitro.
KW  - additive manufacturing
KW  - 3D printing
KW  - biodegradable polymers
KW  - microstructures
KW  - nanostructures
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-254053
VL  - 7
IS  - 3
ER  - 
TY  - JOUR
A1  - Schmitz, Tobias
A1  - Jannasch, Maren
A1  - Weigel, Tobias
A1  - Moseke, Claus
A1  - Gbureck, Uwe
A1  - Groll, Jürgen
A1  - Walles, Heike
A1  - Hansmann, Jan
T1  - Nanotopographical Coatings Induce an Early Phenotype-Specific Response of Primary Material-Resident M1 and M2 Macrophages
JF  - Materials
N2  - Implants elicit an immunological response after implantation that results in the worst case in a complete implant rejection. This biomaterial-induced inflammation is modulated by macrophages and can be influenced by nanotopographical surface structures such as titania nanotubes or fractal titanium nitride (TiN) surfaces. However, their specific impact on a distinct macrophage phenotype has not been identified. By using two different levels of nanostructures and smooth samples as controls, the influence of tubular TiO2 and fractal TiN nanostructures on primary human macrophages with M1 or M2-phenotype was investigated. Therefore, nanotopographical coatings were either, directly generated by physical vapor deposition (PVD) or by electrochemical anodization of titanium PVD coatings. The cellular response of macrophages was quantitatively assessed to demonstrate a difference in biocompatibility of nanotubes in respect to human M1 and M2-macrophages. Depending on the tube diameter of the nanotubular surfaces, low cell numbers and impaired cellular activity, was detected for M2-macrophages, whereas the impact of nanotubes on M1-polarized macrophages was negligible. Importantly, we could confirm this phenotypic response on the fractal TiN surfaces. The results indicate that the investigated topographies specifically impact the macrophage M2-subtype that modulates the formation of the fibrotic capsule and the long-term response to an implant.
KW  - nanotopographical surfaces
KW  - combination of physical vapor deposition and electrochemical etching
KW  - defined humanized test system
KW  - inflammatory response
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-203378
SN  - 1996-1944
VL  - 13
IS  - 5
ER  -