초록 |
Novel amphiphilic graft copolymers of poly(2-hydroxyethyl aspartamide) as a backbone and oligo(L-valine) as the grafted hydrophobic chain (PHEA-g-val) were successfully synthesized. The hydrophobic domains can adopt regular conformations that are insoluble in water, namely, crystalline β-sheets for oligo(L-valine). The hydrogel microparticles were prepared by a method similar to those used to obtain crew-cut (self-assembled) aggregates of amphiphilic polymers. In the process, PHEA-g-val was first dissolved in TFA, a good solvent for the polymer, and then a suitable amount of ddH2O was added dropwise into the TFA solution. When the water content reached a critical value, uniform hydrogel microparticles were obtained. Then, an excessive amount of water was added to quench the structure formed, and the suspension was dialyzed against water for 48h to remove TFA. The micro and nanoparticles were characterized with various techniques such as DLS, particle size analyzer and SEM. |