| 초록 |
G4 PAMAM dendrimers grafted with poly(ethylene glycol) (PEG) of different sizes (Mw = 550 and 5000) and grafting densities (12-94% of surface terminals) were simulated using the coarse-grained (CG) force fields previously developed and reparametrized in this work. The Rg of the fully PEG(Mw = 5000)-grafted dendrimer agrees well with experiment. Longer PEG chains with higher grafting density yield PEG-PEG crowding, which stretches dendrimer terminals toward water more strongly, leading to larger size and a dense-shell structure of the dendrimer. Long PEG chains at high grafting densities also penetrate into the dendrimer core, while short ones do not, which might help explain the reduced encapsulation of hydrophobic compounds seen experimentally in dendrimers that are 75%-grafted with long PEG’s (Mw = 5000). These results show PEG penetration into the core of the dendrimer to which the PEG is attached. |
