Poster session 38. Cells, materials and biochemistry V

Christin Bartlitz
2017 Biomedical Engineering  
FimH is an adhesin located on the surface of type-1 fimbriae and is known to have high mannose-binding properties. For example, it can bind to the zymogen granule membrane glycoprotein 2 (GP2), which is an autoantigen of pancreatic antibodies in inflammatory bowel diseases such as Crohn's disease and ulcerative colitis. This glycoprotein is expressed in the pancreas and on the apical surface of intestinal cells. However, the influence of different FimH structures on the binding behaviour to
more » ... ng behaviour to intestinal cell lines and proteins has not yet been determined. This attachment behaviour can be determined using adhesion assays that measure the amount of bacteria. For these experiments the new VideoScan-technology developed by the former HS Lausitz was used. Intestinal human and animal cell lines were incubated with bacterial suspension. Bound bacteria stained with a fluorescent dye were counted using VideoScan and were evaluated as bacteria per image. Non-pathogenic Escherichia coli, enteropathogenic E. coli (EPEC), and enterotoxigenic E. coli (ETEC) of human, porcine, and bovine excrement were used. The FimH sequences of the bacterial strains containing the adhesin were tested. Preliminary results have shown that approximately 93 % of tested E. coli strains contain the fimbrial adhesin. Furthermore, 30 different FimH variants have been identified. These FimH gene structures seem to be specific for the bacteria pathotypes. Such mutations in gene structures are the cause of different adhesion behaviour, which can cause different immune responses. Additive manufacturing (AM, also known as 3D printing) has been successfully introduced in the field of medical engineering over the last few years. In particular, patient individual implants, prothetics, orthoplastics or surgery models have been driving forces in establishing AM technologies. To raise AM in the field of medical engineering to the next level, new materials as well as innovative and for medical applications optimized 3D printers have to be developed. Especially the development of biocompatible printable high-perfomance (e.g. Polyetheretherketone, PEEK) and flexible (e.g. TPE, Silicone rubber) materials, as well as appropriate printing technologies that at the same time fulfill the strict purity requirements for the production of medical products, are of special interest. In addition two component 3D printers that can process rigid and flexible materials in one step will enable the manufacturing of biomechanically optimized medical products. At the Institute of Medical and Polymer Engineering at the Technical University of Munich, different 3D printing technologies (based on Fused Filament Fabrication), optimized for medical applications, have been developed and will be presented. These include a PEEK printer, a printer for flexible thermoplastic elastomers (down to hardness shore A 50), a printer for silicone rubber, as well as a two-component 3D printer. PEEK samples for tensil tests were produced by both, 3D printing and injection molding, to compare the mechanical properties. The influence of printing parameters on the appearance of internal defects of the printed parts was studied by microtomography. Promising approaches to print flexible (e.g. flexible small caliber tube systems) as well as hybrids out of rigid and flexible materials were evaluated, resulting into options to realize medical products with biomimetic properties in future.
doi:10.1515/bmt-2017-5083 fatcat:qqjoch2ex5bvzgmfy4slfae5ve