02859nas a2200421   4500000000100000000000100001008004100002260001500043653001100058653002600069653002000095653002500115653001700140100001500157700002200172700001400194700002100208700002000229700001800249700002300267700001700290700002500307700002400332700002000356700001700376700001900393700001900412700002100431700002200452700002300474700001700497700002200514245009600536300001200632490000800644520177100652022001402423       2022                            d  c2022-07-2810aHumans10aLab-On-A-Chip Devices10ain vitro models10anew approach methods10atissue chips1 aIvan Rusyn1 aCourtney Sakolish1 aYuki Kato1 aClifford Stephan1 aLeoncio Vergara1 aPhilip Hewitt1 aVasanthi Bhaskaran1 aMyrtle Davis1 aRhiannon N. Hardwick1 aStephen S. Ferguson1 aJason P. Stanko1 aPiyush Bajaj1 aKarissa Adkins1 aNisha S. Sipes1 aE. Sidney Hunter1 aMaria T. Baltazar1 aPaul L. Carmichael1 aKritika Sadh1 aRichard A. Becker00aMicrophysiological Systems Evaluation: Experience of TEX-VAL Tissue Chip Testing Consortium  a143-1520 v1883 aMuch has been written and said about the promise and excitement of microphysiological systems, miniature devices that aim to recreate aspects of human physiology on a chip. The rapid explosion of the offerings and persistent publicity placed high expectations on both product manufacturers and regulatory agencies to adopt the data. Inevitably, discussions of where this technology fits in chemical testing paradigms are ongoing. Some end-users became early adopters, whereas others have taken a more cautious approach because of the high cost and uncertainties of their utility. Here, we detail the experience of a public-private collaboration established for testing of diverse microphysiological systems. Collectively, we present a number of considerations on practical aspects of using microphysiological systems in the context of their applications in decision-making. Specifically, future end-users need to be prepared for extensive on-site optimization and have access to a wide range of imaging and other equipment. We reason that cells, related reagents, and the technical skills of the research staff, not the devices themselves, are the most critical determinants of success. Extrapolation from concentration-response effects in microphysiological systems to human blood or oral exposures, difficulties with replicating the whole organ, and long-term functionality remain as critical challenges. Overall, we conclude that it is unlikely that a rodent- or human-equivalent model is achievable through a finite number of microphysiological systems in the near future; therefore, building consensus and promoting the gradual incorporation of these models into tiered approaches for safety assessment and decision-making is the sensible path to wide adoption.  a1096-0929