The present disclosure provides compounds and nanostructures having one or more quaternary ammonium salts, compositions including the compounds and nanostructures, and methods useful for treating conditions using the compounds, nanostructures, and compositions. In at least one aspect, a compound is represented by formula (I): or a pharmaceutically acceptable salt thereof, wherein: Q is fluoro, chloro, bromo, or iodo； each of s, b, and n is independently an integer from about 10 to about 100； and each of v, j, p, z, q, x and m is independently an integer from 1 to about 20.
