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 ( f GaU ) and glucosidic units ( f GU ), 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.