Jun 16, 2010
Self-assembled micelles for honokiol delivery
Honokiol (HK) loaded micelles have been prepared by self-assembly of PEG-PCL-PEG copolymer in aqueous solution triggered by the material's amphiphilic characteristics and assisted by ultrasonication (without any organic solvents, surfactants or vigorous stirring). The particle size of prepared micelles was approximately 58 nm, which is small enough to make the structure a candidate for intravenous drug delivery. Besides, the honokiol-loaded micelles could be lyophilized into powder without any adjuvant. The re-dissolved micelles are stable and homogeneous with a particle size of about 60 nm.
Researchers at Sichuan University, China, have proposed an improved method to prepare honokiol-loaded micelles, which is effective, stable and safe (organic solvent and surfactant free), as well as being easy to produce and scale up. In vitro release profiles show a significant difference between the rapid release of free honokiol and the much slower and sustained release of honokiol-micelles. Furthermore, the cytotoxicity results of blank micelles and honokiol-micelles show that the blank micelle behaved as a safe carrier and the encapsulated honokiol retained its potent anti-tumour effect. The group's results suggest that honokiol-micelles might be a promising carrier for the intravenous delivery of honokiol in cancer chemotherapy.
As shown in the image above, the scientists incorporated honokiol into PEG-PCL-PEG micelles using a self-assembly procedure assisted by ultrasonication. The appearance of prepared honokiol-micelles can be seen and the clear solution of blank or honokiol-loaded micelles can also be observed. Moreover, the honokiol loaded micelles can be lyophilized into a powder form without any adjuvant, and the re-dissolved honokiol-micelles are stable and homogeneous.
TEM analysis reveals that HK-micelles formed with PEG-PCL-PEG copolymer are monodispersed, thus confirming the spherical shape of micelles in solution. The nanostructure of the micelles observed by TEM, in combination with particle size analysis, indicates that the prepared HK-micelles are stable and could be well dispersed in water.
More information can be found in the journal Nanotechnology.
About the author
The study was conducted by the nano-biomaterials research team of the State Key Laboratory of Biotherapy at Sichuan University in Chengdu, PR China. The team is focused on advanced drug-delivery systems, containing nanotechnology, thermo- and pH-sensitive hydrogels, and non-viral gene vectors. Changyang Gong is a PhD student at the State Key Laboratory of Biotherapy, Sichuan University. His main focus is on the development and application of thermosensitive hydrogel and nanomedicine. Prof. Zhiyong Qian is head of the nano-biomaterials group at State Key Laboratory of Biotherapy. He is the associate editor of two international journals, including J Biomed Nanotechnology and Advanced Science Letter. Prof. Qian is in charge of a number of projects, including National High-Tech Project of China (863-Project, 2007AA021902), National Natural Science Foundation (NSFC20704027), Specialized Research Fund for the Doctoral Program of Higher Education (SRFDP 200806100065) and Sichuan Young Talents Program (2007Q14-033).