An In-Depth Analysis Approach Enabling Precision Single Chain Nanoparticle Design

The formation of single chain nanoparticles (SCNPs) is typically characterized by a shift towards higher elution volumes in SEC due to size decrease upon folding. However, a step-change in SCNP analysis is required for understanding of the nature of intramolecular SCNP folding. Herein, we exploit a unique combination of SANS, 19F NMR spectroscopy, and multidetection SEC to generate a systematic view of the folded morphology of poly(butyl acrylate) based-SCNPs as a function of their reactive group density and molar mass. In addition to detailed morphological insights, we establish that the primary factor dictating the compaction of SCNPs is their reactive group density, which is ineffective below 5 mol%, reaching maximum compaction close to 30 mol%. Above 20 kDa the molar mass of the precursor polymers has a minor impact on how an SCNP compacts.