Getting peptide drugs to work as oral medicine is genuinely hard. The gut breaks them down, and what survives rarely crosses the intestinal wall in useful amounts. Sodium caprate — a fatty acid compound already approved as a permeation enhancer — has shown real promise here, but how it actually behaves inside the intestine, at the structural level, was still largely a blank. That gap was the starting point for this project.
The work combined coarse-grained molecular dynamics simulations with small-angle scattering experiments to track how sodium caprate organizes itself under conditions that mimic the intestinal environment. Small-angle neutron scattering with contrast variation was especially useful: by adjusting which molecular components the neutron beam “sees,” it became possible to map the internal architecture of sodium caprate aggregates in the presence of intestinal fluids, peptide drugs, and charged polymers — environments that shift its self-assembly in ways X-ray scattering alone cannot fully resolve. The simulations then provided a molecular-level explanation of what the scattering patterns described.
What emerged is a validated framework for studying how amphiphiles self-assemble in complex biological settings — one that trades trial-and-error for structural understanding. The insights are directly applicable to the design of better oral peptide formulations, and the methodology itself extends well beyond sodium caprate to other lipid-based delivery systems.