Synthesis of amphiphilic pseudopolyamino acid-containing ABC-triblock copolymers and micellar characterizations



This study describes the synthesis of amphiphilic ABC-triblock copolymers comprising a central pseudopoly(4-hydroxy-L-proline) segment and terminal hydrophilic poly(ethylene glycol)methyl ether as well as hydrophobic poly(ε-caprolactone) blocks. Differential scanning calorimetry, 1H-NMR spectroscopy, and gel permeation chromatography are used to characterize the copolymers. The thermal properties (Tg and Tms) of the triblock copolymers depend on the composition of polymers. Larger amounts of ε-CL incorporated into the macromolecular backbone increased Tg and Tms. Fluorescence spectroscopy, transmission electron microscopy, and dynamic light scattering are utilized to investigate their micellar characteristics in the aqueous phase. Observations showed a higher critical micelle concentration with higher hydrophilic components in the copolymers. The micelle exhibited a core-shell-corona and/or vesicle shape, and the average size was less than 300 nm. Drug entrapment efficiency and drug loading of micelles depending on the composition of block polymers are also described. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010