Frame Guided Assembly

During last decades, self-assembly of amphiphiles has attracted more and more attention. It has been found that the morphology of the assemblies is closely connected to the structure of the amphiphiles and the environment. Though many efforts have been taken to control the morphology in molecular design and developing assembly methods, obtaining amphiphilic assemblies with customized shapes and sizes is still a significant challenge in this field. Inspired by the cytoskeletal-membrane protein-lipid bilayer system that determines the shape of eukaryotic cells, we have developed a frame guided assembly(FGA) process as a general strategy to prepare customized hetero-vesicles.Firstly, we have realized a first example of the FGA in a dendron system to prove its feasibility. DNA modified gold nanoparticles(AuNPs) have been utilized as the scaffold and the poly(arylether) dendron has been chosen as the leading hydrophobic group(LHG). The discontinuous, pre-positioned LHGs outline the fringe of the frame structures and guide G2Cl-18 to fill in the gap between LHGs, finally leading to the formation of hetero-vesicles whose final morphology would be determined by the frames. The shape controllability and size controllability of the FGA have also been proved by applying different scaffolds.Secondly, the generality of the FGA has also been proved by realizing FGA in different molecular systems. We have employed cholesterol as LHGs, and proved that small amphiphilic molecule, sodium dodecyl sulfate(SDS), could also obey the rule and form hetero-vesicles. With thermally responsive poly(propylene oxide)(PPO) as LHGs, FGA of DNA-b-PPO block copolymers has also been achieved. We have also proved the shape controllability and size controllability in these new molecular systems. Meanwhile, the dynamic process has been discussed which would improve further understanding of FGA.Thirdly, DNA nanotechnology has been introduced to FGA to construct DNA scaffold. We have applied DNA Cube through DNA origami strategy as the scaffold, and the poly(arylether)dendron and G2Cl-18 are selected to serve as the LGH and assembly molecules. Following the FGA process, cubic assemblies have been achieved. The dumbbell shape assemblies have also been achieved with the careful design of DNA scaffold. Furthermore, different molecular systems including the SDS and DNA-b-PPO have also been realized with different LHGs. These results prove that the compatibility between FGA and DNA nanotechnology is good enough for further potential applications.