John Garner

mPEG-PCL used for genistein delivery micelle formation

Blog Post created by John Garner on Nov 11, 2015

PolySciTech Division of Akina, Inc. ( provides many block polymers including methoxy-poly(ethylene glycol)-poly(caprolactone) (mPEG-PCL). The methoxy serves as an inert blocking endcap, the PEG chain serves as a hydrophilic, water-soluble polymer to stabilize particles in aqeous solution and the PCL chain serves as a hydrophobic portion that can interact with poorly-water soluble drugs. Because of these properties, under the right conditions, this kind of polymer can self-assemble into micelles or nanoparticles which have a hydrophobic core for carrying medicinal molecules and hydrophilic PEG layer on the exterior to stabilize the particles in aqueous solutions. Recently, this kind of polymer was used by researchers at Jinan University to generate nano-carriers containing genistein, a poorly-soluble isoflavone that performs as a potent antitumor medicine, to improve the deliverability of this molecule. PolySciTech has recently launched a new mPEG-PCL product, AK105 (mPEG-PCL 5000-8000Da), which can be used for similar applications. Read more: Zhang, Tianpeng, Huan Wang, Yanghuan Ye, Xingwang Zhang, and Baojian Wu. "Micellar emulsions composed of mPEG-PCL/MCT as novel nano-carriers for systemic delivery of genistein: a comparative study with micelles." International journal of nanomedicine 10 (2015): 6175. Full-Text:


“Abstract: Polymeric micelles receive considerable attention as drug delivery vehicles, depending on the versatility in drug solubilization and targeting therapy. However, their use invariably suffers with poor stability both in in vitro and in vivo conditions. Here, we aimed to develop a novel nanocarrier (micellar emulsions, MEs) for a systemic delivery of genistein (Gen), a poorly soluble anticancer agent. Gen-loaded MEs (Gen-MEs) were prepared from methoxy poly(ethylene glycol)-block-(ε-caprolactone) and medium-chain triglycerides (MCT) by solvent-diffusion technique. Nanocarriers were characterized by dynamic light scattering, transmission electron microscopy, and in vitro release. The resulting Gen-MEs were approximately 46 nm in particle size with a narrow distribution. Gen-MEs produced a different in vitro release profile from the counterpart of Gen-ME. The incorporation of MCT significantly enhanced the stability of nanoparticles against dilution with simulated body fluid. Pharmacokinetic study revealed that MEs could notably extend the mean retention time of Gen, 1.57- and 7.38-fold as long as that of micelles and solution formulation, respectively, following intravenous injection. Furthermore, MEs markedly increased the elimination half-life (t1/2β) of Gen, which was 2.63-fold larger than that of Gen solution. Interestingly, Gen distribution in the liver and kidney for MEs group was significantly low relative to the micelle group in the first 2 hours, indicating less perfusion in such two tissues, which well accorded with the elongated mean retention time. Our findings suggested that MEs may be promising carriers as an alternative of micelles to systemically deliver poorly soluble drugs. Keywords: genistein, micellar emulsions, stability, pharmacokinetics, tissue distribution”