Binary-Stabilized Morphological Control of Cationic Oligochitosan Nano-Objects in Polymerization-Induced Self-Assembly

Preparing functional nano-objects by polymerization-induced self-assembly (PISA) from polyelectrolyte-based stabilizers has remained challenging due to strong electrostatic interactions that prevent morphological evolution beyond spherical assemblies. To overcome this limitation, we developed a binary stabilization strategy combining cationic oligochitosan (OCS) and neutral dextran (Dex) stabilizers in a photoinitiated reversible addition–fragmentation chain transfer polymerization-induced self-assembly (photo-RAFT PISA) approach. By fine-tuning the molar fraction of glucosamine units (fGaU) and glucosidic units (fGU), we successfully unlocked morphology transitions, forming complex nanostructures. Our results demonstrate that this dual stabilization mechanism effectively balances electrostatic and steric repulsions, thereby enabling controlled self-assembly in polyelectrolyte-driven PISA. This work provides a scalable and bioinspired strategy for engineering complex polysaccharide-based nanostructures with promising applications in drug delivery and biomaterial design.