Amphiphilic block copolymers : synthesis, self-assembly and applications

Self-assembly of amphiphilic block copolymers in aqueous solution is one of the most important nanotechnological methods to prepare nanocarriers for
different applications, such as drug delivery, biosensor, nanoreactor and so on. Synthesis of new types of amphiphilic block copolymers with novel
functionality and detailed characterization of self-assembly, influenced by self-assembly methods and different other parameters (molecular weight,
hydrophilic to hydrophobic ratio), are important. Especially, building up the relationship between the self-assembled nanomorphologies and molecule
constitution are helpful to understand amphiphilic block copolymer self-assemble theroy.
In this thesis, I present to you the influence of different parameters on the self-assembly nanostructures for the poly(dimethylsiloxane)-
block-poly(2-methyl-2-oxazoline) (PDMS-b-PMOXA) amphiphilic block copolymers.3D phase diagram clearly shows in which domain the PDMS-b-PMOXA
self-assemble into polymersome. The polymersome are possible for us to constribute the nano-sized based nanoreactor.
In addition, in order to develop more functional amphiphilic block copolymers and enlarge the potential application areas, another two types of
copolymers, grafted poly(2-methyl-2-oxazoline)-graft(ss)-poly(e-caprolactone) (PMOXA-graft(ss)-PCL) and linear poly(2-ethyl-2-oxazoline)-block-
poly(e-caprolactone)-ss-poly(L-lysine) (PEtOXA-b-PCL-ss-PLL), were designed and synthesized with reduction responsiveness, utilizing different
polymerization techniques, including ring openning polymerization and "graft-to" technology. Due to the amphiphilicity of these two types of
copolymers, nanoparticles are formed by them in aqueous solution. The primary evaluation of these two new type amphiphilic block copolymers
demonstrated that they can be promising candidates as smart nanocarries for the application of drug delivery.
In this dissertation, the result of our research have been comprehensivly compared with other publications and results from different groups.
We have new findingS. We find one new nano-object with 80-100 nm diameter, but without hollow aqueous cavity.
We also realize that basing on poly(2-ethyl-2-oxazoline)-block-poly(e-caprolactone)-ss-poly(L-lysine) (PEtOXA-b-PCL-ss-PLL) copolymer, it is possible
to synthesize more functional copolymer, for example introducing the pH-cleavable linker between PEtOXA and PCL, to mimic more closely the virus delivery
gene into cells.