Highly permeable artificial water channels that can self-assemble into two-dimensional arrays

Bioinspired artificial water channels aim to combine the high permeability and selectivity of biological aquaporin (AQP) water channels with chemical stability. Here, we carefully characterized a class of artificial water channels, peptide-appended pillar[5]arenes (PAPs). The average single-channel osmotic water permeability for PAPs is 1.0(\ub1 0.3) 7 10(-14) cm(3)/s or 3.5(\ub1 1.0) 7 10(8) water molecules per s, which is in the range of AQPs (3.4 3c 40.3 7 10(8) water molecules per s) and their current synthetic analogs, carbon nanotubes (CNTs, 9.0 7 10(8) water molecules per s). This permeability is an order of magnitude higher than first-generation artificial water channels (20 to 3c 10(7) water molecules per s). Furthermore, within lipid bilayers, PAP channels can self-assemble into 2D arrays. Relevant to permeable membrane design, the pore density of PAP channel arrays ( 3c 2.6 7 10(5) pores per \u3bcm(2)) is two orders of magnitude higher than that of CNT membranes (0.1 3c 2.5 7 10(3) pores per \u3bcm(2)). PAP channels thus combine the advantages of biological channels and CNTs and improve upon them through their relatively simple synthesis, chemical stability, and propensity to form arrays