초록 |
Nano-sized self-assemblies formed with amphiphilic block and graft copolymers have been extensively studied for targeted drug delivery. This study reports novel strategy to prepare self-assemblies with unique morphology by varying packing structure of beta sheets. Specifically, the amphiphilic graft copolymers composed of poly(2-hydroxyehtyl aspartamide) (PHEA) as the hydrophilic backbone and oligo(L-valine) as the grafted hydrophobic chain were synthesized by a ring-opening polymerization of the Val-NCA to backbone polymer. Then, the effect of degree of substitution (DS) and polymerization (DP) on self-assemblies of PHEA-g-oligo(L-valine)s were investigated in an aqueous solution. This study discovered that the beta-sheets of polymers are formed favorably by increasing of DS, while the structural transition of self-assemblies is influenced dominantly by DP. |