Microfluidic systems are increasingly used in neuroprotection research, but their clearest value may be to show why candidate compounds fail before costly downstream models. This critical framework review examines CNS-relevant microfluidic studies through a within-program triage logic linking chemistry-aware prescreening, blood-brain barrier/neurovascular unit (BBB/NVU) filtering, and timed validation in neuronal ischemia/reperfusion models, and treats non-CNS organ-on-a-chip and analytical microfluidic studies as engineering analogies only. The available evidence most strongly supports BBB/NVU chips as exposure- and safety-aware filters and compartmentalized neuronal oxygen-glucose deprivation platforms as timing-sensitive validation tools; droplet microfluidics contributes mainly upstream through dense dose mapping, aggregation assays and counterscreens for assay interference. A compound-centered reading also suggests that apparent activity often fails for distinct reasons, including timing mismatch, poor solubility, surface adsorption, optical artifact, inadequate multicellular context, or loss of efficacy under transport-aware testing. Taken together, the literature supports a cautious, within-program triage logic in which microfluidics is used not as a universal disease model, but as an operational framework for exposing transport, barrier, timing and assay liabilities early in neuroprotective discovery.
Anchimowicz et al. (2026) studied this question.