An in vitro nerve agent brain poisoning transwell model for convenient and accurate antidote evaluation

Nerve agent (NA) can inhibit acetylcholinesterase (AChE) causing seriously injury at extremely low doses. However, the cruel reality is that the lack of effective cerebral antidotes for treatment of NA poisoning. There is an urgent requirement for the large-scale evaluation and screening of antidotes. An effective NA antidote should include two characteristics: a) to permeate the blood-brain barrier (BBB); 2) to reactivate the inhibited AChE in brain. Existing methods for evaluating reactivators in vitro can only examine the reactivation effect, while the current Transwell model can only evaluate the drug penetration performance for crossing the barrier. In this work, brain microvascular endothelial cells (RBMECs) were inoculated to establish a Transwell model. AChE, NAs and antidotes of reactivators were added into the different chambers to simulate central poisoning and peripheral drug administration. This method can evaluate the reactivation ability and brain penetration ability of compounds at same time, which is a rapidly and accurately way for drug preliminary screening. In addition to small-molecule drugs, a liposomal nanoantidote loaded with the reactivator Asoxime chloride (HI-6)was prepared. This nanoantidote show high reactivation rate against the NA (sarin), evaluated by both this modified model in vitro and animal test, gaining the consistence results.