Self-assembly And Drug-load Study Of Amphiphilic Dendritic Copolymer

In this paper, the dendritic copolymer poly(l, lactide)-dendron-poly(ethylene glycol)-dendron-poly(l, lactide) was used as research object to study the self-assembly in solution, and its drug-loading applications.Polymeric micelles were prepared by adding water into the tetrahydrofuran (THF) solution of poly(l, lactide)- dendron- poly(ethylene glycol)- dendron- poly(l, lactide). The experimental results reveal that the copolymer micelle is a vesicle has hollow construction. By changing the structure of dendritic copolymer, and controling self-assembly conditions (initial solution concentration, temperature, stirring intensity), we get the micelles have different size.Staying micellar solution of the dendritic copolymer at 30℃, it’s growing into visible filamentous macro-aggregates in the solution. When stay at 60℃, it’s growing into visible film. Through a variety of detection experiments, we know that the visible filamentous was a network-like structure formed by hollow tubes. And the hollow tube is aggregated by micelles through the second self-assembling, the protruding structure shall on the wall of tube was the ball crown formed by the micelles fused together. In the process of micellar aggregation, the micelles were integration and transfixion along the growing direction of tube; while at the horizontal side, the micelles were not fully integrated fuse together, just sharing one side of the micelle wall. The observation of the films reveal that:there are uniform size and dense spherical protrusions arranged on the surface of thin-film. We propose the formation of self-assembly mechanism of film, the micellar aggregation is not fully integrated, through the formation of sharing micellar wall, the hollow micelles connect with each other and form thin-films.Select dialysis method, using dendritic copolymer as the research object, the successful preparation of rapamycin drug-loaded micelles. The results showed that:Rh of micelles prepared by dialysis method, in general increases, with the increasing of generation, and with increasing molecular weight of a single PLLA. Comparison of uncoated drug micelle micelles and packages drugs, the average particle size of micelles increased. As the generation increases, the release rate of drug is more slowly.