Fast Biomimetic Phospholipid Assay for Modeling Brain Perfusion Kinetics of Drugs

DESCRIPTION (provided by applicant): We propose the development of a high-throughput analytic tool that can accurately assess passive permeability of drug-like molecules across the blood-brain barrier (BBB), using an artificial membrane measuring technique developed by plON. The parallel artificial membrane permeability assay (PAMPA) will incorporate a new, specially-designed permeability model based on the use of biomimetic membranes. The method will be suitable for screening large libraries of molecules, at about 1000 times lower cost than in vivo rodent-model measurements. The new PAMPA BBB barrier lipid will be optimized in composition, initially mimicking the lipid composition of endothelial cells, but "trained" to closely match available in situ brain perfusion data, derived from the "knockout" mouse (mdr1a(-/-)) model. To model the near zero thickness aqueous boundary layer environment in the brain microcapillaries, stirring will need to be performed on both sides of the membrane barrier in a specially-designed (plON) 96-well microtitre plate. We will use 39 identified drug molecules, whose highly-reliable knockout mouse in situ brain perfusion data are already available, as the training set for the new BBB-PAMPA model. With these, our aim in the new model is to reach the PAMPA vs. in situ linear-regression correlation coefficient, r2 > 0.9, without the use of in silico "booster" descriptors. However, as a backup, we will embrace the concept of in silicoenhanced measured data modeling, and will use this strategy as needed. The proposed high-throughput PAMPA BBB permeability technique is important to public health because it will allow large scale, low-cost compound screening producing data with enhanced downstream value earlier in discovery programs, thus eliminating molecules with questionable drugability characteristics sooner and help lower the current, estimated 98% attrition rate. This will contribute to the timely development of better medicines at lower cost.