Nature Nanotech. http://doi.org/v7k (2014)

In most drug delivery systems comprising nanomaterials or macromolecules as carriers, the carrier entities fulfil the role of targeting the associated therapeutic drug to the required site in the body, but provide no therapeutic effects themselves. Now, Joo Eun Chung, Motoichi Kurisawa and colleagues synthesize micellar nanocomplexes in which antitumour proteins are self-assembled with macromolecular derivatives of an ingredient of green tea known to have anticancer properties, and show that the resultant nanocomplexes cause a considerably higher anticancer effect in vivo than the free antitumour protein and drug-free micellar complexes. The binding properties of the green tea derivative, (−)-epigallocatechin-3-O-gallate (EGCG), with proteins, are the driving force for the assembly of the micellar nanocomplex. The core of the nanocomplex contains oligomerized EGCG assembled with the antitumour protein, Herceptin, and the shell consists of poly(ethylene glycol)–EGCG. The nanocomplex remains in blood circulation for a longer time period as well as demonstrating a 2.3-fold higher accumulation within the tumour compared with free Herceptin.