Precise length and charge segmentation of billion-dalton supramolecular polymers.

Supramolecular polymers with precise micrometer-scale segments of opposite charge are challenging to synthesize as discrete assemblies in water. These systems could be used to pattern charged surfaces, interact with the membranes of cells, or form hierarchical structures. We report a living polymerization of fibrillar peptide assemblies with a central positively charged segment flanked by negative ones that can have a collective molar mass on the order of billions of daltons. The self-capping supramolecular polymerization required an untwisted β sheet core persisting along the entire length of the assembly as well as dormant ends in the absence of a monomer source. The positive domains of the segmented structures were anchored to the membranes of neurons, leaving the connected negative segments in a highly dynamic state near the cells through charge repulsion. The segmented architecture generated extensive neurite growth and synaptic activity.