@article{SunStarlyDalyetal.2020, author = {Sun, Wei and Starly, Binil and Daly, Andrew C and Burdick, Jason A and Groll, J{\"u}rgen and Skeldon, Gregor and Shu, Wenmiao and Sakai, Yasuyuki and Shinohara, Marie and Nishikawa, Masaki and Jang, Jinah and Cho, Dong-Woo and Nie, Minghao and Takeuchi, Shoji and Ostrovidov, Serge and Khademhosseini, Ali and Kamm, Roger D and Mironov, Vladimir and Moroni, Lorenzo and Ozbolat, Ibrahim T}, title = {The bioprinting roadmap}, series = {Biofabrication}, volume = {12}, journal = {Biofabrication}, number = {2}, doi = {10.1088/1758-5090/ab5158}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-254027}, year = {2020}, abstract = {This bioprinting roadmap features salient advances in selected applications of the technique and highlights the status of current developments and challenges, as well as envisioned advances in science and technology, to address the challenges to the young and evolving technique. The topics covered in this roadmap encompass the broad spectrum of bioprinting; from cell expansion and novel bioink development to cell/stem cell printing, from organoid-based tissue organization to bioprinting of human-scale tissue structures, and from building cell/tissue/organ-on-a-chip to biomanufacturing of multicellular engineered living systems. The emerging application of printing-in-space and an overview of bioprinting technologies are also included in this roadmap. Due to the rapid pace of methodological advancements in bioprinting techniques and wide-ranging applications, the direction in which the field should advance is not immediately clear. This bioprinting roadmap addresses this unmet need by providing a comprehensive summary and recommendations useful to experienced researchers and newcomers to the field.}, language = {en} } @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{SchmidtAbinzanoMensingaetal.2020, author = {Schmidt, Stefanie and Abinzano, Florencia and Mensinga, Anneloes and Teßmar, J{\"o}rg and Groll, J{\"u}rgen and Malda, Jos and Levato, Riccardo and Blunk, Torsten}, title = {Differential production of cartilage ECM in 3D agarose constructs by equine articular cartilage progenitor cells and mesenchymal stromal cells}, series = {International Journal of Molecular Sciences}, volume = {21}, journal = {International Journal of Molecular Sciences}, number = {19}, issn = {1422-0067}, doi = {10.3390/ijms21197071}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-236180}, year = {2020}, abstract = {Identification of articular cartilage progenitor cells (ACPCs) has opened up new opportunities for cartilage repair. These cells may be used as alternatives for or in combination with mesenchymal stromal cells (MSCs) in cartilage engineering. However, their potential needs to be further investigated, since only a few studies have compared ACPCs and MSCs when cultured in hydrogels. Therefore, in this study, we compared chondrogenic differentiation of equine ACPCs and MSCs in agarose constructs as monocultures and as zonally layered co-cultures under both normoxic and hypoxic conditions. ACPCs and MSCs exhibited distinctly differential production of the cartilaginous extracellular matrix (ECM). For ACPC constructs, markedly higher glycosaminoglycan (GAG) contents were determined by histological and quantitative biochemical evaluation, both in normoxia and hypoxia. Differential GAG production was also reflected in layered co-culture constructs. For both cell types, similar staining for type II collagen was detected. However, distinctly weaker staining for undesired type I collagen was observed in the ACPC constructs. For ACPCs, only very low alkaline phosphatase (ALP) activity, a marker of terminal differentiation, was determined, in stark contrast to what was found for MSCs. This study underscores the potential of ACPCs as a promising cell source for cartilage engineering.}, language = {en} } @article{WeissenbergerWeissenbergerWagenbrenneretal.2020, author = {Weissenberger, Manuel and Weissenberger, Manuela H. and Wagenbrenner, Mike and Heinz, Tizian and Reboredo, Jenny and Holzapfel, Boris M. and Rudert, Maximilian and Groll, J{\"u}rgen and Evans, Christopher H. and Steinert, Andre F.}, title = {Different types of cartilage neotissue fabricated from collagen hydrogels and mesenchymal stromal cells via SOX9, TGFB1 or BMP2 gene transfer}, series = {PLoS One}, volume = {15}, journal = {PLoS One}, number = {8}, doi = {10.1371/journal.pone.0237479}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230494}, year = {2020}, abstract = {Objective As native cartilage consists of different phenotypical zones, this study aims to fabricate different types of neocartilage constructs from collagen hydrogels and human mesenchymal stromal cells (MSCs) genetically modified to express different chondrogenic factors. Design Human MSCs derived from bone-marrow of osteoarthritis (OA) hips were genetically modified using adenoviral vectors encoding sex-determining region Y-type high-mobility-group-box (SOX)9,transforming growth factor beta (TGFB) 1or bone morphogenetic protein (BMP) 2cDNA, placed in type I collagen hydrogels and maintained in serum-free chondrogenic media for three weeks. Control constructs contained unmodified MSCs or MSCs expressing GFP. The respective constructs were analyzed histologically, immunohistochemically, biochemically, and by qRT-PCR for chondrogenesis and hypertrophy. Results Chondrogenesis in MSCs was consistently and strongly induced in collagen I hydrogels by the transgenesSOX9,TGFB1andBMP2as evidenced by positive staining for proteoglycans, chondroitin-4-sulfate (CS4) and collagen (COL) type II, increased levels of glycosaminoglycan (GAG) synthesis, and expression of mRNAs associated with chondrogenesis. The control groups were entirely non-chondrogenic. The levels of hypertrophy, as judged by expression of alkaline phosphatase (ALP) and COL X on both the protein and mRNA levels revealed different stages of hypertrophy within the chondrogenic groups (BMP2>TGFB1>SOX9). Conclusions Different types of neocartilage with varying levels of hypertrophy could be generated from human MSCs in collagen hydrogels by transfer of genes encoding the chondrogenic factorsSOX9,TGFB1andBMP2. This technology may be harnessed for regeneration of specific zones of native cartilage upon damage.}, language = {en} } @article{HorvatVogelKampfetal.2020, author = {Horvat, Sonja and Vogel, Patrick and Kampf, Thomas and Brandl, Andreas and Alshamsan, Aws and Alhadlaq, Hisham A. and Ahamed, Maqusood and Albrecht, Krystyna and Behr, Volker C. and Beilhack, Andreas and Groll, J{\"u}rgen}, title = {Crosslinked Coating Improves the Signal-to-Noise Ratio of Iron Oxide Nanoparticles in Magnetic Particle Imaging (MPI)}, series = {ChemNanoMat}, volume = {6}, journal = {ChemNanoMat}, number = {5}, doi = {10.1002/cnma.202000009}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-214718}, pages = {755 -- 758}, year = {2020}, abstract = {Magnetic particle imaging is an emerging tomographic method used for evaluation of the spatial distribution of iron-oxide nanoparticles. In this work, the effect of the polymer coating on the response of particles was studied. Particles with covalently crosslinked coating showed improved signal and image resolution.}, language = {en} } @article{SchmitzJannaschWeigeletal.2020, author = {Schmitz, Tobias and Jannasch, Maren and Weigel, Tobias and Moseke, Claus and Gbureck, Uwe and Groll, J{\"u}rgen and Walles, Heike and Hansmann, Jan}, title = {Nanotopographical Coatings Induce an Early Phenotype-Specific Response of Primary Material-Resident M1 and M2 Macrophages}, series = {Materials}, volume = {13}, journal = {Materials}, number = {5}, issn = {1996-1944}, doi = {10.3390/ma13051142}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-203378}, year = {2020}, abstract = {Implants elicit an immunological response after implantation that results in the worst case in a complete implant rejection. This biomaterial-induced inflammation is modulated by macrophages and can be influenced by nanotopographical surface structures such as titania nanotubes or fractal titanium nitride (TiN) surfaces. However, their specific impact on a distinct macrophage phenotype has not been identified. By using two different levels of nanostructures and smooth samples as controls, the influence of tubular TiO2 and fractal TiN nanostructures on primary human macrophages with M1 or M2-phenotype was investigated. Therefore, nanotopographical coatings were either, directly generated by physical vapor deposition (PVD) or by electrochemical anodization of titanium PVD coatings. The cellular response of macrophages was quantitatively assessed to demonstrate a difference in biocompatibility of nanotubes in respect to human M1 and M2-macrophages. Depending on the tube diameter of the nanotubular surfaces, low cell numbers and impaired cellular activity, was detected for M2-macrophages, whereas the impact of nanotubes on M1-polarized macrophages was negligible. Importantly, we could confirm this phenotypic response on the fractal TiN surfaces. The results indicate that the investigated topographies specifically impact the macrophage M2-subtype that modulates the formation of the fibrotic capsule and the long-term response to an implant.}, language = {en} } @article{LiebscherTessmarGroll2020, author = {Liebscher, Julia and Teßmar, Joerg Karl and Groll, J{\"u}rgen}, title = {In Situ Polymer Analogue Generation of Azlactone Functions at Poly(oxazoline)s for Peptide Conjugation}, series = {Macromolecular Chemistry and Physics}, volume = {221}, journal = {Macromolecular Chemistry and Physics}, number = {1}, doi = {10.1002/macp.201900500}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-208147}, pages = {1900500}, year = {2020}, abstract = {The physical and chemical stability of peptides for biomedical applications can be greatly enhanced through the conjugation of polymers. A well-known but rather underemployed selective coupling functionality is the azlactone group, which readily reacts with a number of different nucleophiles without the need for activation and the formation of any by-products. For example, azlactone functional polymers are used to react with peptides and proteins, rich in amino and thiol groups, to form polymeric beads for affinity-based column chromatography. So far, side chain functional azlactone polymers have been mainly synthesized by radical polymerization using 2-vinyl-4,4-dimethyl azlactone together with different acrylate monomers. Here, a new azlactone precursor equipped with a functional thiol is presented, which can be attached to any vinyl functional polymer by thiol-ene chemistry. Subsequently, the formation of the reactive azlactone ring can be performed in situ at high conversion rate without the need for illumination. This approach is tested on an azlactone side functional poly(2-oxazoline) by coupling amine containing molecules including a model peptide and is proven via \(^1\)H NMR spectroscopy, IR spectroscopy, as well as HPLC measurements.}, language = {en} }