TY  - JOUR
A1  - Pien, Nele
A1  - Bartolf–Kopp, Michael
A1  - Parmentier, Laurens
A1  - Delaey, Jasper
A1  - de Vos, Lobke
A1  - Mantovani, Diego
A1  - van Vlierberghe, Sandra
A1  - Dubruel, Peter
A1  - Jungst, Tomasz
T1  - Melt Electrowriting of a Photo–Crosslinkable Poly(ε–caprolactone)–Based Material into Tubular Constructs with Predefined Architecture and Tunable Mechanical Properties
JF  - Macromolecular Materials and Engineering
N2  - Melt electrowriting (MEW) is an additive manufacturing process that produces highly defined constructs with elements in the micrometer range. A specific configuration of MEW enables printing tubular constructs to create small-diameter tubular structures. The small pool of processable materials poses a bottleneck for wider application in biomedicine. To alleviate this obstacle, an acrylate-endcapped urethane-based polymer (AUP), using a poly(ε-caprolactone) (PCL) (molar mass: 20 000 g mol\(^{−1}\)) (AUP PCL20k) as backbone material, is synthesized and utilized for MEW. Spectroscopic analysis confirms the successful modification of the PCL backbone with photo-crosslinkable acrylate endgroups. Printing experiments of AUP PCL20k reveal limited printability but the photo-crosslinking ability is preserved post-printing. To improve printability and to tune the mechanical properties of printed constructs, the AUP-material is blended with commercially available PCL (AUP PCL20k:PCL in ratios 80:20, 60:40, 50:50). Print fidelity improves for 60:40 and 50:50 blends. Blending enables modification of the constructs' mechanical properties to approximate the range of blood vessels for transplantation surgeries. The crosslinking-ability of the material allows pure AUP to be manipulated post-printing and illustrates significant differences in mechanical properties of 80:20 blends after crosslinking. An in vitro cell compatibility assay using human umbilical vein endothelial cells also demonstrates the material's non-cytotoxicity.
KW  - acrylate-endcapped urethane-based polymer (AUP)
KW  - tubular constructs
KW  - physicochemical characterization
KW  - photo-crosslinking
KW  - melt electrowriting (MEW)
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-318524
SN  - 1438-7492
VL  - 307
IS  - 7
ER  - 
TY  - JOUR
A1  - Tylek, Tina
A1  - Blum, Carina
A1  - Hrynevich, Andrei
A1  - Schlegelmilch, Katrin
A1  - Schilling, Tatjana
A1  - Dalton, Paul D
A1  - Groll, Jürgen
T1  - Precisely defined fiber scaffolds with 40 μm porosity induce elongation driven M2-like polarization of human macrophages
JF  - Biofabrication
N2  - Macrophages are key players of the innate immune system that can roughly be divided into the pro-inflammatory M1 type and the anti-inflammatory, pro-healing M2 type. While a transient initial pro-inflammatory state is helpful, a prolonged inflammation deteriorates a proper healing and subsequent regeneration. One promising strategy to drive macrophage polarization by biomaterials is precise control over biomaterial geometry. For regenerative approaches, it is of particular interest to identify geometrical parameters that direct human macrophage polarization. For this purpose, we advanced melt electrowriting (MEW) towards the fabrication of fibrous scaffolds with box-shaped pores and precise inter-fiber spacing from 100 μm down to only 40 μm. These scaffolds facilitate primary human macrophage elongation accompanied by differentiation towards the M2 type, which was most pronounced for the smallest pore size of 40 μm. These new findings can be important in helping to design new biomaterials with an enhanced positive impact on tissue regeneration.
KW  - cell elongation
KW  - human macrophages
KW  - melt electrowriting (MEW)
KW  - macrophage polarization
KW  - 3D scaffolds
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-254012
VL  - 12
IS  - 2
ER  - 
TY  - JOUR
A1  - Jungst, Tomasz
A1  - Pennings, Iris
A1  - Schmitz, Michael
A1  - Rosenberg, Antoine J. W. P.
A1  - Groll, Jürgen
A1  - Gawlitta, Debby
T1  - Heterotypic Scaffold Design Orchestrates Primary Cell Organization and Phenotypes in Cocultured Small Diameter Vascular Grafts
JF  - Advanced Functional Materials
N2  - To facilitate true regeneration, a vascular graft should direct the evolution of a neovessel to obtain the function of a native vessel. For this, scaffolds have to permit the formation of an intraluminal endothelial cell monolayer, mimicking the tunica intima. In addition, when attempting to mimic a tunica media‐like outer layer, the stacking and orientation of vascular smooth muscle cells (vSMCs) should be recapitulated. An integral scaffold design that facilitates this has so far remained a challenge. A hybrid fabrication approach is introduced by combining solution electrospinning and melt electrowriting. This allows a tissue‐structure mimetic, hierarchically bilayered tubular scaffold, comprising an inner layer of randomly oriented dense fiber mesh and an outer layer of microfibers with controlled orientation. The scaffold supports the organization of a continuous luminal endothelial monolayer and oriented layers of vSM‐like cells in the media, thus facilitating control over specific and tissue‐mimetic cellular differentiation and support of the phenotypic morphology in the respective layers. Neither soluble factors nor a surface bioactivation of the scaffold is needed with this approach, demonstrating that heterotypic scaffold design can direct physiological tissue‐like cell organization and differentiation.
KW  - biofabricated vascular graft
KW  - heterotypic scaffold design
KW  - hybrid fabrication
KW  - primary vascular smooth muscle‐like cells (vSMCs)
KW  - melt electrowriting (MEW)
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-217039
VL  - 29
ER  -