Untersuchung von strukturbildenden zellulären Prozessen im Kontext des tissue engineerings: alginat-basierte Gerüststrukturen

Die Kombination von Bio-(materialien) mit therapeutisch relevanten Zellen ist ein komplexes Feld im Bereich des Tissue Engineerings und der regenerativen Medizin. Neue zelluläre Umgebungen müssen derart gestaltet sein, dass sie auch bei empfindlichen Zelltypen, wie z.B. den humanen Stammzellen, eine optimale Mikroumgebung abbilden können. Diese Arbeit beschäftigt sich mit der Untersuchung der Modifikation von bioinerten Alginaten zur Gestaltung neuartiger Zell-Nischen. Die Entwicklung der Materialien erfolgt zunächst auf zweidimensionalen Substraten und wird auf dreidimensionale Konstrukte übertragen. Hierfür sind insbesondere bei der Analyse und Kultivie-rung der Zellen, aber auch bei einer finalen Rückgewinnung physiologische Bedingungen zwingend erforderlich. Mit einem neuartigen parallelisierten Mikroskopie-Ansatz konnten in dieser Arbeit systematische Untersuchungen bzgl. der Modifikation von Alginaten als Gerüststruktur durchge-führt werden. Die Modifikation z. B. durch kovalente Kopplung von Tyramin an Alginat, zeigte, dass diese exzellent für die direkte und indirekte Adhäsion von humanen Stammzellen geeignet ist. Schonende Mechanismen zur Degradierung der Gerüststruktur mittels einer Alginat-Lyase, sowie erste Ansätze für eine automatisierte Entwicklung von Gerüststrukturen konnten etabliert werden. Die Ergebnisse konnten final auf frei-schwimmende, dreidimensionale Gerüststrukturen übertragen werden.The combination of (Bio-)materials with therapeutically relevant cells is a challenging field in Tis-sue Engineering and Regenerative Medicine. Novel cellular environments require a sophisticated design in order to provide an optimal microenvironment for sensitive cell types like human stem cells. This thesis focuses on the study of alginate modifications designing novel cell niches. The initial developments are conducted using twodimensional substrates and are transferred in conse-quence to three-dimensional scaffolds. Physiological conditions are not only mandatory for the analysis and cultivation of cells, but also for the final recovery. Using a novel parallelized approach for living cell microscopy, systematic studies with respect to the modification of alginate hydrogels were performed. The results demonstrate that covalent coupling of tyramine molecules on alginate to be suitable for direct and indirect adhesion of human stem cells. In addition, gentle teatments for scaffold degradation using alginat lyases as well as first promising approaches for an automated engineering of scaffolds are established in this work. The knowledge gained from performed studies was finally transferred to free-floating, three-dimensional scaffolds

Success Factors of Plant Engineering Projects

AbstractProjects in plant manufacturing business are characterized by low margins and high risks. The knowledge and support of success factors, i.e. influencing factors that explain the success of a project, provide a suitable lever for plant manufacturing companies to improve their competitiveness. However, plant manufacturing business has not been a major field of success factor research yet. This contribution aims to close this research gap. In an extensive literature review existing success factors of other research fields are collected. 490 factors were examined on their applicability for engineering projects in expert interviews and an online survey. After consolidation, 41 success factors could be identified. If plant manufacturers consider these factors in project design and planning, project and business success can be influenced in a positive way. Since success factor research has been subject of criticism recently, this contribution includes a critical discussion of success factor research, too

System architectures for Industrie 4.0 applications

Industrie 4.0 principles demand increasing flexibility and modularity for automated production systems. Current system architectures provide an isolated view of specific applications and use cases, but lack a global, more generic approach. Based on the specific architectures of two EU projects and one German Industrie 4.0 project, a generic system architecture is proposed. This system architecture features the strengths of the three isolated proposals, such as cross-enterprise data sharing, service orchestration, and real-time capabilities, and can be applied to a wide field of applications. Future research should be directed towards considering the applicability of the architecture to other equal applications.info:eu-repo/semantics/publishedVersio

Vibrational spectroscopic imaging and live cell video microscopy for studying differentiation of primary human alveolar epithelial cells.

Vukosavljevic B, Hittinger M, Hachmeister H, et al. Vibrational spectroscopic imaging and live cell video microscopy for studying differentiation of primary human alveolar epithelial cells. Journal of Biophotonics. 2019;12(6): e201800052

National Planetary Health learning objectives for Germany: A steppingstone for medical education to promote transformative change

Physicians play an important role in adapting to and mitigating the adverse health effects of the unfolding climate and ecological crises. To fully harness this potential, future physicians need to acquire knowledge, values, skills, and leadership attributes to care for patients presenting with environmental change-related conditions and to initiate and propel transformative change in healthcare and other sectors of society including, but not limited to, the decarbonization of healthcare systems, the transition to renewable energies and the transformation of transport and food systems. Despite the potential of Planetary Health Education (PHE) to support medical students in becoming agents of change, best-practice examples of mainstreaming PHE in medical curricula remain scarce both in Germany and internationally. The process of revising and updating the Medical Licensing Regulations and the National Competency-based Catalog of Learning Objectives for Medical Education in Germany provided a window of opportunity to address this implementation challenge. In this article, we describe the development and content of national Planetary Health learning objectives for Germany. We anticipate that the learning objectives will stimulate the development and implementation of innovative Planetary Health teaching, learning and exam formats in medical schools and inform similar initiatives in other health professions. The availability of Planetary Health learning objectives in other countries will provide opportunities for cross-country and interdisciplinary exchange of experiences and validation of content, thus supporting the consolidation of Planetary Health learning objectives and the improvement of PHE for all health professionals globally.</p

Coating stability and insertion forces of an alginate-cell-based drug delivery implant system for the inner ear

Long-term drug delivery to the inner ear for neuroprotection might improve the outcome for hearing disabled patients treated with a cochlear implant (CI). Neurotrophic factor (NTF) producing cells encapsulated in an alginate-matrix, to shield them from the host immune system and to avoid migration, and applied as viscose solution or electrode coating could address this requirement. Both application methods were tested for their feasibility in an artificial human cochlea model. Since both strategies potentially influence the electrode implantability, insertion forces and coating stability were analyzed on custom-made electrode arrays. Both, injection of the alginate-cell solution into the model and a manual dip coating of electrode arrays with subsequent insertion into the model were possible. The insertion forces of coated arrays were reduced by 75% of an uncoated reference. In contrast, filling of the model with non-crosslinked alginate-cell solution slightly increased the insertion forces. A good stability of the coating was observed after first insertion (85%) but abrasion increased after multiple insertions (50%). Both application strategies are possible options for cell-induced drug-delivery to the inner ear, but an alginate-cell coating of CI-electrodes has a great potential to combine an endogenous NTF-source with a strong reduction of insertion forces

Stem Cell Based Drug Delivery for Protection of Auditory Neurons in a Guinea Pig Model of Cochlear Implantation

Background: The success of a cochlear implant (CI), which is the standard therapy for patients suffering from severe to profound sensorineural hearing loss, depends on the number and excitability of spiral ganglion neurons (SGNs). Brain-derived neurotrophic factor (BDNF) has a protective effect on SGNs but should be applied chronically to guarantee their lifelong survival. Long-term administration of BDNF could be achieved using genetically modified mesenchymal stem cells (MSCs), but these cells should be protected – by ultra-high viscous (UHV-) alginate (‘alginate-MSCs’) – from the recipient immune system and from uncontrolled migration.Methods: Brain-derived neurotrophic factor-producing MSCs were encapsulated in UHV-alginate. Four experimental groups were investigated using guinea pigs as an animal model. Three of them were systemically deafened and (unilaterally) received one of the following: (I) a CI; (II) an alginate-MSC-coated CI; (III) an injection of alginate-embedded MSCs into the scala tympani followed by CI insertion and alginate polymerization. Group IV was normal hearing, with CI insertion in both ears and a unilateral injection of alginate-MSCs. Using acoustically evoked auditory brainstem response measurements, hearing thresholds were determined before implantation and before sacrificing the animals. Electrode impedance was measured weekly. Four weeks after implantation, the animals were sacrificed and the SGN density and degree of fibrosis were evaluated.Results: The MSCs survived being implanted for 4 weeks in vivo. Neither the alginate-MSC injection nor the coating affected electrode impedance or fibrosis. CI insertion with and without previous alginate injection in normal-hearing animals resulted in increased hearing thresholds within the high-frequency range. Low-frequency hearing loss was additionally observed in the alginate-injected and implanted cochleae, but not in those treated only with a CI. In deafened animals, the alginate-MSC coating of the CI significantly prevented SGN from degeneration, but the injection of alginate-MSCs did not.Conclusion: Brain-derived neurotrophic factor-producing MSCs encapsulated in UHV-alginate prevent SGNs from degeneration in the form of coating on the CI surface, but not in the form of an injection. No increase in fibrosis or impedance was detected. Further research and development aimed at verifying long-term mechanical and biological properties of coated electrodes in vitro and in vivo, in combination with chronic electrical stimulation, is needed before the current concept can be tested in clinical trials

Distributed automated manufacturing of pluripotent stem cell products

Establishing how to effectively manufacture cell therapies is an industry-level problem. Decentralised manufacturing is of increasing importance, and its challenges are recognised by healthcare regulators with deviations and comparability issues receiving specific attention from them. This paper is the first to report the deviations and other risks encountered when implementing the expansion of human pluripotent stem cells (hPSCs) in an automated three international site–decentralised manufacturing setting. An experimental demonstrator project expanded a human embryonal carcinoma cell line (2102Ep) at three development sites in France, Germany and the UK using the CompacT SelecT (Sartorius Stedim, Royston, UK) automated cell culture platform. Anticipated variations between sites spanned material input, features of the process itself and production system details including different quality management systems and personnel. Where possible, these were pre-addressed by implementing strategies including standardisation, cell bank mycoplasma testing and specific engineering and process improvements. However, despite such measures, unexpected deviations occurred between sites including software incompatibility and machine/process errors together with uncharacteristic contaminations. Many only became apparent during process proving or during the process run. Further, parameters including growth rate and viability discrepancies could only be determined post-run, preventing ‘live’ corrective measures. The work confirms the critical nature of approaches usually taken in Good Manufacturing Practice (GMP) manufacturing settings and especially emphasises the requirement for monitoring steps to be included within the production system. Real-time process monitoring coupled with carefully structured quality systems is essential for multiple site working including clarity of decision-making roles. Additionally, an over-reliance upon post-process visual microscopic comparisons has major limitations; it is difficult for non-experts to detect deleterious culture changes and such detection is slow