Protein Transport Studied by a Model Asymmetric Membrane Army Arranged in a Dimple Chip

Reconstituted model membrane systems are powerful platforms to tackle interesting problems existing in membrane biology. One of the barriers to efficient drug delivery, as therapeutics to disease, is the physical membrane barrier of the cell. Small molecules can typically diffuse through the membrane; however, biomolecules such as proteins or nucleic acids cannot passively diffuse the bilayer and thus much research has been geared to engineering protein and/or nucleic acid delivery methods. One delivery method uses cell-penetrating peptides (CPPs). In this chapter, we introduce the model "membrane army" arranged in a dimple chip to study the delivery of β-galactosidase by a CPP known as Pep-1. This method uses droplet interface bilayer technology (DIB). It accelerates the speed to screen through the working conditions in CPP-assisted protein translocations because each chip provides dimples that can accommodate 36 pairs of droplets or 18 model bilayers. We will use one of the successful translocation conditions of β-galactosidase delivery as the example to illustrate how the model "membrane army" is built and utilized.