02586nas a2200301   4500000000100000000000100001008004100002260000900043653001600052653002400068653001900092653002000111653002100131100002000152700002200172700001600194700001600210700002100226700001600247700002100263700001600284700001900300245012000319300001200439490000700451520181200458022001402270       2023                            d  c202310abone marrow10aexperimental design10aflow cytometry10aorgan on a chip10atoxicity testing1 aJonathan Cairns1 aEmilyanne Leonard1 aKainat Khan1 aConor Parks1 aGareth Maglennon1 aBairu Zhang1 aStanley E. Lazic1 aLorna Ewart1 aRhiannon David00aOptimal experimental design for efficient toxicity testing in microphysiological systems: A bone marrow application  a11425810 v143 aIntroduction: Microphysiological systems (MPS; organ-on-a-chip) aim to recapitulate the 3D organ microenvironment and improve clinical predictivity relative to previous approaches. Though MPS studies provide great promise to explore treatment options in a multifactorial manner, they are often very complex. It is therefore important to assess and manage technical confounding factors, to maximise power, efficiency and scalability. Methods: As an illustration of how MPS studies can benefit from a systematic evaluation of confounders, we developed an experimental design approach for a bone marrow (BM) MPS and tested it for a specified context of use, the assessment of lineage-specific toxicity. Results: We demonstrated the accuracy of our multicolour flow cytometry set-up to determine cell type and maturity, and the viability of a "repeated measures" design where we sample from chips repeatedly for increased scalability and robustness. Importantly, we demonstrated an optimal way to arrange technical confounders. Accounting for these confounders in a mixed-model analysis pipeline increased power, which meant that the expected lineage-specific toxicities following treatment with olaparib or carboplatin were detected earlier and at lower doses. Furthermore, we performed a sample size analysis to estimate the appropriate number of replicates required for different effect sizes. This experimental design-based approach will generalise to other MPS set-ups. Discussion: This design of experiments approach has established a groundwork for a reliable and reproducible in vitro analysis of BM toxicity in a MPS, and the lineage-specific toxicity data demonstrate the utility of this model for BM toxicity assessment. Toxicity data demonstrate the utility of this model for BM toxicity assessment.  a1663-9812