Synthesis And Self-Assembley Of Aie Amphiphilic Block Copolymer

Fluorescent polymersomes are interesting systems for cell/tissue imaging and in vivo study of drug distribution and delivery.In this thesis,the bright fluorescent polymersomes with aggregation-induced emission were reported,which self-assembled from a series of tetraphenylethylene(TPE)-containing amphiphilic biodegradable block copolymers.In these poylmers,the hydrophilic block was a polyethylene glycol,while the hydrophobic block was a TPE-substituted trimethylenecarbonate polymer P(TPE-TMC).Their self-assemblies were fabricated in water by nanoprecipitation using dioxane or tetrahydrofuran as co-solvent,and the self-assembling processes were studied in detail by cryo-electron microscopy,dynamic light scattering,and spectrofluorometer.The results showed that polymersomes were formed via the closure of bilayer lamellae self-assembled first by amphiphilic block copolymers.The polymersome membrane afforded a nanosize bright fluorescent system with self-assembly induced emission in the thickness scale of 10-15 nm.The control of the polymersome size was achieved by the co-solvents and a suitable hydrophilic/hydrophobic ratio of block copolymers.These polymersomes could be potentially used as stable fluorescent tools to monitor the transportation and distribution of drugs and bioconjugates in living cells.