Figure 4.

Examples of microphysiological systems that may be used to evaluate cell quality attributes. (a) A tumor-on-a chip with an engineered blood vessel and encapsulated tumor cells and NK cells can be used to evaluate NK cell exhaustion in a tumor microenvironment. Reprinted from [Ref. 59]. © The Authors, some rights reserved; exclusive licensee AAAS. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC) https://creativecommons.org/licenses/by-nc/4.0/. (b) A 3D microfluidic device consisting of agarose and DCs embedded in collagen and matrigel can create stable gradients of CCL19 and CCL21 to evaluate DC migration. ⁶⁰ (c) A bone marrow on a chip model consisting of a vascular channel lined with endothelial cells and a fibrin-collagen hydrogel containing bone marrow-derived MSCs and HSCs can recapitulate the bone marrow microenvironment. ⁶¹ Reprinted by permission from Nature Publishing Group. (d) Endothelialized microfluidic vessels in a collagen matrix with pericytes can recapitulate endothelial cell sprouting, an early stage of angiogenesis. ⁶² (e) A lung on a chip co-culturing lung epithelial cells, endothelial cells, circulating immune cells, and SARS-COV-2 can be used to recapitulate key immune responses of SARS-COV-2 infection in vitro. ⁶³ (A color version of this figure is available in the online journal.)