Access to Different Nanostructures via Self-Assembly of Thiourea-Containing PEGylated Amphiphiles

Readily water‐soluble PEGylated amphiphiles containing bis‐thiourea‐based molecular recognition units at the interface of hydrophobic and hydrophilic blocks are developed. Self‐assembly of these amphiphiles is found to be dependent on the exact chemical composition of the hydrophobic component. Elongated, spherical, and disk‐like micelles are formed with the change in hydrophobic group from stearyl (2A), oleyl (2B), and dodecanol (2C), respectively. The length of the rod‐like elongated micelles formed by 2A could be tuned by thermal treatment as well. Synthesis and detailed structural characterization of these amphiphiles by TEM, DSC, synchrotron SAXS techniques are reported. Organic solvent‐free direct aqueous encapsulation of doxorubicin, an anticancer drug into these nanostructures is demonstrated. Different nanostructural morphologies are accessed by simply dissolving readily water‐soluble thiourea‐containing PEGylated amphiphiles. Both the chemical composition and the nature of packing (due to thermal treatment) affect the morphology and the dimension of nanostructures. These nanostructures can potentially be used for the delivery of a variety of therapeutics as well as tissue engineering.