Study of the drug release kinetics in nanoscale micelle to micelle system

A new drug delivery model is proposed in vitro in a micelle to micelle system. Gold nanoparticles can be encapsulated by micelles of amphiphilic diblock copolymers; it provides an environment to incorporate drug molecules, forming the Au@polymer-drug conjugates. Gold nanoparticles are fluorescent quenchers, allowing the release kinetics of fluorescent probes from nanoparticles to be followed by fluorescence spectroscopy. Herein, we synthesized the Au@PSPAA-dye conjugates, and investigated the release kinetics in pure water and empty polymeric micelle aqueous solution with fluorescence spectroscopy. The results show that the release kinetics is a fast and diffusion-controlled process in the presence of empty micelles; while the water is not the ultimate acceptor in the absence of perfect sedimentation. The homogeneous mixed micelle to micelle release system avoids the material transfer in bulk phase, which may real reflect the release mechanism in vivo.