Special Seminar: Tomasz Jüngst, Melt Electrowriting (MEW) for Biomedical Applications

Dept for Functional Materials in Medicine and Dentistry & Bavarian Polymer Institute (BPI), University of Würzburg

All dates for this event occur in the past.

477 Watts Hall
2041 College Rd
Columbus, OH 43210
United States

Abstract

Melt electrowriting (MEW) is a 3D printing approach that enables processing polymer melts into filaments. These filaments can be collected on a computer-controlled platform. If collection is done in a layer-by-layer approach, porous 3D constructs can be generated. In contrast to established techniques like fused deposition modelling (FDM) a high voltage is applied and used to stretch the molten material after it is extruded from the nozzle. This enables reducing the fiber diameters by around two orders of magnitude when compared to FDM. In contrast to solution electrospinning (SES), another method to generate scaffolds composed of thin fibers, jet instabilities that cause the jet to buckle and bend on the way to the collector can be suppressed in MEW and thus the fiber deposition is highly controlled. If biocompatible materials are processed using MEW, scaffolds can be generated that are composed of fibers with diameters of several micrometers. Collecting the filaments onto cylinders enables printing of tubular constructs that can be used in biomedical applications.

An example for a potential application of such tubular structures, that will be highlighted in the talk, are small diameter (<6 mm) blood vessels. Concerning their macroscopic shape, in a simplified view, one could see them as tubular constructs with a defined diameter. A closer look reveals that they have multiple layers (tunica intima, media, adventitia). Those layers are composed of different extracellular matrix components and cell types. In addition, the orientation of the cells and the extracellular matrix for example tailors their unique mechanical properties. If one wants to mimic the geometrical hierarchy of a blood vessel, multi-layered tubular scaffolds need to be produced. A possible approach combining SES and MEW to generate bi-layered constructs will be discussed. To achieve biomimetic architectures, first a nonwoven was electrospun onto a tubular collector and transferred to the MEW device to generate a second medial layer on top of the nonwoven. These bi-layered constructs were seeded with human endothelial colony (hECs) forming cells on the inner side and with human multipotent mesenchymal stromal cells (hMSCs) on the outer part of the scaffold. It could be shown that the SES layer was an appropriate substrate for the hECs, which formed a dense monolayer inside the bi-layered construct. The latest results of these experiments will be presented.

Bio

 

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Dr. Tomasz Jüngst

Tomasz Jüngst studied nanostructural engineering in the Department of Physics at the University of Würzburg (Germany). After receiving his Diploma, he did his PhD based on bioprinting under the supervision of Jürgen Groll. During this time, he also worked at the Queensland University of Technology in Brisbane (Australia) with Dietmar W. Hutmacher and Paul D. Dalton, where he gained experience in the field of melt electrowriting (MEW). He continued working on MEW and is currently setting up a work group focusing on three-dimensional structures for biofabrication, where he is developing fabrication systems and processing novel materials. His main interest is tubular structures for biomedical applications.

 

Note: this seminar is not part of the required colloquia in MSE or WE 7895.