@article{SchmidtAltDeoghareetal.2022,
  author    = {Schmidt, Sven and Alt, Yvonne and Deoghare, Nikita and Kr{\"u}ger, Sarah and Kern, Anna and Rockel, Anna Frederike and Wagner, Nicole and Erg{\"u}n, S{\"u}leyman and W{\"o}rsd{\"o}rfer, Philipp},
  title     = {A blood vessel organoid model recapitulating aspects of vasculogenesis, angiogenesis and vessel wall maturation},
  series = {Organoids},
  volume    = {1},
  journal   = {Organoids},
  number    = {1},
  issn      = {2674-1172},
  doi       = {10.3390/organoids1010005},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-284043},
  pages     = {41 -- 53},
  year      = {2022},
  abstract  = {Blood vessel organoids are an important in vitro model to understand the underlying mechanisms of human blood vessel development and for toxicity testing or high throughput drug screening. Here we present a novel, cost-effective, and easy to manufacture vascular organoid model. To engineer the organoids, a defined number of human induced pluripotent stem cells are seeded in non-adhesive agarose coated wells of a 96-well plate and directed towards a lateral plate mesoderm fate by activation of Wnt and BMP4 signaling. We observe the formation of a circular layer of angioblasts around days 5-6. Induced by VEGF application, CD31\(^+\) vascular endothelial cells appear within this vasculogenic zone at approximately day 7 of organoid culture. These cells arrange to form a primitive vascular plexus from which angiogenic sprouting is observed after 10 days of culture. The differentiation outcome is highly reproducible, and the size of organoids is scalable depending on the number of starting cells. We observe that the initial vascular ring forms at the interface between two cell populations. The inner cellular compartment can be distinguished from the outer by the expression of GATA6, a marker of lateral plate mesoderm. Finally, 14-days-old organoids were transplanted on the chorioallantois membrane of chicken embryos resulting in a functional connection of the human vascular network to the chicken circulation. Perfusion of the vessels leads to vessel wall maturation and remodeling as indicated by the formation of a continuous layer of smooth muscle actin expressing cells enwrapping the endothelium. In summary, our organoid model recapitulates human vasculogenesis, angiogenesis as well as vessel wall maturation and therefore represents an easy and cost-effective tool to study all steps of blood vessel development and maturation directly in the human setting without animal experimentation.},
  language  = {en}
}
@article{WoersdoerferIAsahinaetal.2020,
  author    = {W{\"o}rsd{\"o}rfer, Philipp and I, Takashi and Asahina, Izumi and Sumita, Yoshinori and Erg{\"u}n, S{\"u}leyman},
  title     = {Do not keep it simple: recent advances in the generation of complex organoids},
  series = {Journal of Neural Transmission},
  volume    = {127},
  journal   = {Journal of Neural Transmission},
  issn      = {0300-9564},
  doi       = {10.1007/s00702-020-02198-8},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-235628},
  pages     = {1569-1577},
  year      = {2020},
  abstract  = {3D cell culture models which closely resemble real human tissues are of high interest for disease modelling, drug screening as well as a deeper understanding of human developmental biology. Such structures are termed organoids. Within the last years, several human organoid models were described. These are usually stem cell derived, arise by self-organization, mimic mechanisms of normal tissue development, show typical organ morphogenesis and recapitulate at least some organ specific functions. Many tissues have been reproduced in vitro such as gut, liver, lung, kidney and brain. The resulting entities can be either derived from an adult stem cell population, or generated from pluripotent stem cells using a specific differentiation protocol. However, many organoid models only recapitulate the organs parenchyma but are devoid of stromal components such as blood vessels, connective tissue and inflammatory cells. Recent studies show that the incorporation of endothelial and mesenchymal cells into organoids improved their maturation and might be required to create fully functional micro-tissues, which will allow deeper insights into human embryogenesis as well as disease development and progression. In this review article, we will summarize and discuss recent works trying to incorporate stromal components into organoids, with a special focus on neural organoid models.},
  language  = {en}
}