Artificial water channels-toward biomimetic Aquaporins

Within biological systems, natural channels and pores transport metabolites across the cell membranes. Researchers have explored artificial ion-channel architectures as potential mimics of natural ionic conduction. All these synthetic systems have produced an impressive collection of alternative artificial ion-channels. Amazingly, researchers have made far less progress in the area of synthetic water channels. The development of synthetic biomimetic water-channels and pores could contribute to a better understanding of the natural function of protein channels and could offer new strategies to generate highly selective, advanced water purification systems. Despite the imaginative work by synthetic chemists to produce sophisticated architectures that confine water clusters, most synthetic water channels have used natural protein channels as the selectivity components, embedded in the diverse arrays of bio-assisted artificial systems. These systems combine natural proteins that present high water conductance states under natural conditions with artificial lipidic or polymeric matrixes. Experimental results have demonstrated that natural biomolecules can be used as bio-assisted building blocks for the construction of highly selective water transport through artificial membranes. A next step to further the potential of these systems was the design and construction of simpler compounds that maintain the high conduction activity obtained with natural compounds leading to fully synthetic artificial biomimetic channels. Such studies aim to use constitutional artificial desalination membranes for highly selective water transport to select functions similar to the natural structures. Moving to simpler water-channel systems offers a chance to better understand mechanistic and structural behaviors and to uncover novel artificial water-channels that might parallel those in biomolecular systems.