| 초록 |
We designed poly(ethylene glycol) derivatives of polypeptide to introduce thermosensitivity to the polypeptide. The PEG-PP aqueous solution showed a lower critical solution temperature (LCST). By controlling the ratio of the hydrophilic PEG to the hydrophobic Phe group, transition temperature of the PEG-PP could be controlled to 30 ~ 40 oC. The higher the number of hydrophilic PEG grafts, the higher the LCST of the PEG-PP aqueous solution. Dynamic light scattering shows the PEG-PPs form micelles in water with an average radius of 10 nm below LCST. Interestingly, the precipitated PEG-PPs form nanoparticles with an average radius of 100 nm above LCST. The nanoparticles were not aggregated, but existed as a stable colloidal suspension. The nanoparticle formation at above LCST suggests the possibility of solvent-free nanoparticle preparation for hydrophobic drug delivery. The transition of nanoparticle to micelle solution was reversible. |
