707 Guiding skin organoid generation via extracellular matrix cues and spatially controlled morphogen gradients

Recent advances in generating human organoids from embryoid bodies (EBs) of induced pluripotent stem cells (iPSCs) provide a promising tool for modeling organ development and disease. A major limitation current developed petri-dishes is that the EBs are surrounded symmetrically on all sides by growth factors extracellular matrix (ECM), leading to uncontrolled spontaneous organization tissue. The goal this study was precisely guide self-organization differentiation iPSCs-derived into anatomically-relevant skin via ECM cues spatially-controlled morphogen gradients. Firstly, we evaluated performance chemically-defined hydrogels based dermis-relevant molecules, including collagen types I IV, laminin, fibronectin, vitronectin, hyaluronic acid, heparin. We found type supplemented with laminin fibronectin promoted generation significantly increased pigmentation hair follicle generation, compared culture medium suspension Matrigel. Next, 3D-bioprinted hydrogel-based microfluidic device can create asymmetrical cross-gradients factors, bone morphogenetic protein 4 fibroblast factor 2 single EB resolution. Under these steep gradients, showed spatial patterning polarized distinct cell lineages appendages. Interestingly, adopted an elongated shape device, as opposed their standard spherical shape, mature maximizing oxygen nutrients transport. Overall, ability tailor microenvironment gradients will generate physiologically-relevant which may have transformative impact our understanding morphogenesis developmental diseases.