Molecular dynamics simulations and neutron scattering provide an atomistic level understanding of the self-assembly of poloxamines*

By integrating molecular dynamics simulations and neutron scattering, we have studied different poloxamines (Tetronics), a family of star-shaped block copolymers that show promise as controlled release drug delivery agents. Their amphiphilicity and the basicity of their central diamine unit control their pH-sensitive self-assembly into supramolecular complexes.

We have studied Tetronic 904 (T904), a medium-sized poloxamine, and Tetronic 304 (T304), a smaller analogue, by all-atom molecular dynamics simulations and neutron scattering. While it is well-known that T904 readily forms micelles over a range of temperatures and concentrations, T304 has previously been found to have a more limited ability to self-assemble. Together, our simulations and experiments provide a detailed microscopic picture of the structure, dynamics and hydration of the self-assembled structures formed by both T904 and T304, and for the first time have uncovered the mechanisms that typically hinder T304 self-assembly.