@article{TylekBlumHrynevichetal.2020, author = {Tylek, Tina and Blum, Carina and Hrynevich, Andrei and Schlegelmilch, Katrin and Schilling, Tatjana and Dalton, Paul D and Groll, J{\"u}rgen}, title = {Precisely defined fiber scaffolds with 40 μm porosity induce elongation driven M2-like polarization of human macrophages}, series = {Biofabrication}, volume = {12}, journal = {Biofabrication}, number = {2}, doi = {10.1088/1758-5090/ab5f4e}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-254012}, year = {2020}, abstract = {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.}, language = {en} } @article{TylekSchillingSchlegelmilchetal.2019, author = {Tylek, Tina and Schilling, Tatjana and Schlegelmilch, Katrin and Ries, Maximilian and Rudert, Maximilian and Jakob, Franz and Groll, J{\"u}rgen}, title = {Platelet lysate outperforms FCS and human serum for co-culture of primary human macrophages and hMSCs}, series = {Scientific Reports}, volume = {9}, journal = {Scientific Reports}, doi = {10.1038/s41598-019-40190-9}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-229174}, year = {2019}, abstract = {In vitro co-cultures of different primary human cell types are pivotal for the testing and evaluation of biomaterials under conditions that are closer to the human in vivo situation. Especially co-cultures of macrophages and mesenchymal stem cells (MSCs) are of interest, as they are both present and involved in tissue regeneration and inflammatory reactions and play crucial roles in the immediate inflammatory reactions and the onset of regenerative processes, thus reflecting the decisive early phase of biomaterial contact with the host. A co-culture system of these cell types might thus allow for the assessment of the biocompatibility of biomaterials. The establishment of such a co-culture is challenging due to the different in vitro cell culture conditions. For human macrophages, medium is usually supplemented with human serum (hS), whereas hMSC culture is mostly performed using fetal calf serum (FCS), and these conditions are disadvantageous for the respective other cell type. We demonstrate that human platelet lysate (hPL) can replace hS in macrophage cultivation and appears to be the best option for co-cultivation of human macrophages with hMSCs. In contrast to FCS and hS, hPL maintained the phenotype of both cell types, comparable to that of their respective standard culture serum, as well as the percentage of each cell population. Moreover, the expression profile and phagocytosis activity of macrophages was similar to hS.}, language = {en} } @article{BlumTaskinShanetal.2021, author = {Blum, Carina and Taskin, Mehmet Berat and Shan, Junwen and Schilling, Tatjana and Schlegelmilch, Katrin and Teßmar, J{\"o}rg and Groll, J{\"u}rgen}, title = {Appreciating the First Line of the Human Innate Immune Defense: A Strategy to Model and Alleviate the Neutrophil Elastase-Mediated Attack toward Bioactivated Biomaterials}, series = {Small}, volume = {17}, journal = {Small}, number = {13}, doi = {10.1002/smll.202007551}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-257691}, year = {2021}, abstract = {Biointerface engineering is a wide-spread strategy to improve the healing process and subsequent tissue integration of biomaterials. Especially the integration of specific peptides is one promising strategy to promote the regenerative capacity of implants and 3D scaffolds. In vivo, these tailored interfaces are, however, first confronted with the innate immune response. Neutrophils are cells with pronounced proteolytic potential and the first recruited immune cells at the implant site; nonetheless, they have so far been underappreciated in the design of biomaterial interfaces. Herein, an in vitro approach is introduced to model and analyze the neutrophil interaction with bioactivated materials at the example of nano-bioinspired electrospun surfaces that reveals the vulnerability of a given biointerface design to the contact with neutrophils. A sacrificial, transient hydrogel coating that demonstrates optimal protection for peptide-modified surfaces and thus alleviates the immediate cleavage by neutrophil elastase is further introduced.}, language = {en} }