Synthesis of crosslinkable diblock terpolymers PDPA- b -P(NMS- co -OEG) and preparation of shell-crosslinked pH/redox-dual responsive micelles as smart nanomaterials.

Crosslinked polymer nanomaterials have attracted great attention due to their stability and highly controllable drug delivery; herein, a series of well-defined amphiphilic PDPA- b -P(NMS- co -OEG) diblock terpolymers (P1-P3) were designed and prepared via RAFT polymerization and were self-assembled into non-cross-linked (NCL) nanomicelles, which were further prepared into shell-cross-linked (SCL) micelles via cystamine-based in situ shell cross-linking. Using P3 as an optimized polymer, SCL-P3 micelles were prepared, which demonstrated remarkable pH/redox-dual responsive behaviour. For drug delivery, camptothecin (CPT)-loaded SCL-P3 micelles were prepared and showed much higher CPT-loading capability than their NCL-P3 counterparts. Notably, the SCL-P3 micelles showed good synergistic pH/redox-dual responsive CPT release properties, making them potential "smart" nanocarriers for drug delivery.