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

Abstract

A series of well-defined amphiphilic PDPA-b-P(NMS-co-OEG) diblock terpolymers were prepared via RAFT polymerization and self-assembled into non-cross-linked nanomicelles, and then shell-cross-linked micelles via cystamine-based in situ shell cross-linking.

Microwave Irradiation-Assisted Reversible Addition–Fragmentation Chain Transfer Polymerization-Induced Self-Assembly of pH-Responsive Diblock Copolymer Nanoparticles

“…The obtained results demonstrate that PSs at pH > p K a which points out to a higher ability to efficiently deliver the payload to the pH-specific site without higher amounts being released at pH 7.4. 61 , 62 These results are compatible with the release of payloads from systems based on the PDPA core observed by us 51 , 61 , 77 and others 78 , 79 In contrast, at pH < p K a , because of protonation of the PDPA block, the NPs undergo physical disassembly that lead to quick release of loaded NR. 61 It has already been reported by others that PSs show higher stability and slow release in buffered conditions than micelles.…”

“…Under neutral physiological conditions, PBS pH ∼ 7.4 at 4 h release reached 13 and 32% after 12 h (open blue circles). The obtained results demonstrate that PSs at pH > p K a which points out to a higher ability to efficiently deliver the payload to the pH-specific site without higher amounts being released at pH 7.4. , These results are compatible with the release of payloads from systems based on the PDPA core observed by us ,, and others , In contrast, at pH < p K a , because of protonation of the PDPA block, the NPs undergo physical disassembly that lead to quick release of loaded NR . It has already been reported by others that PSs show higher stability and slow release in buffered conditions than micelles. , It is important to highlight that the observed retardation of the NR release after an initial fast release at pH ∼ 4.0 is explained because the pH-induced disassembly at pHs lower than the pKa of the PDPA block leads to the presence of free chains that can reorganize in order to avoid as much as possible the contact with the polar solvent, water.…”

Smart Triboelectric Nanogenerators Based on Stimulus-Response Materials: From Intelligent Applications to Self-Powered Systems

“…pH-responsive materials have attracted much attention from academia and researchers in the past few decades. pH-responsive polymers are materials that respond sensitively to the pH of solution through changes in structural properties such as solubility, surface activity, configuration, and chain structure formation [99,100]. Polymer-based materials were widely used as pH response materials during their development because of their structurally weak acid/primary groups.…”

Crosslinked Polymer Nanoassemblies and Their Delivery Applications

“…[15] Our group recently developed a series of in-situ shell-crosslinked PDPA-b-P(NMS-co-OEG) diblock terpolymer micelles with pH-sensitive diisopropylamine and cystamine crosslinker, the micelles demonstrated remarkable pH/redox-dual responsive manners for Camptothecin (CPT) delivery application. [16] Although these progresses had been achieved, rationally in-situ incorporate crosslinkers into nanoassemblies to achieve low cytotoxicity, high drug loading efficiency, as well as dual, triple or multiple-stimuli responsive delivery manners is still a big challenge. Moreover, the structural characterization for the shell-crosslinked multi-stimuli responsive micelles needs to be further investigated.…”