Fabrication of Size-Controllable mPEG-Decorated Microparticles Conjugating Optically Active Ketoprofen Based on Self-Assembly of Amphiphilic Random Copolymers

Novel size-controllable mPEG-decorated polymeric microparticles binding optically active ketoprofen were successfully fabricated based on chemoenzymatic synthesis and self-assembly of amphiphilic random polymer-ketoprofen conjugates with mPEG and (S)-ketoprofen as pendants. A series of mPEG(350)- or mPEG(1000)-functionalized amphiphilic random polymer-ketoprofen conjugates with drug loading capacity from 16.5% to 73.2% were easily prepared by combining enzymatic resolution with radical polymerization and characterized by Fourier Transform Infrared spectroscopy, H-1-NMR, and gel permeation chromatography. The formation of aggregates from the amphiphilic random polymer-ketoprofen conjugates was investigated by ultraviolet-visible absorption spectra using pyrene as the guest molecule. Transmission electron microscopy measurement revealed that the self-assemblies were well dispersed as spherical microparticles. The size of the self-assemblies could be widely tuned by varying the length of mPEG chains and the content of ketoprofen in the synthetic polymer-ketoprofen conjugates, and a series of mPEG-decorated (S)-ketoprofen-bound polymeric microparticles with average radius from 70 nm to 1.1 mu m were obtained. The successful preparation of the microparticles containing (S)-ketoprofen provided a new strategy for the design and fabrication of optically active drug delivery systems. (C) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 127: 3242-3248, 2013