Amphiphilic cylindrical copolypeptide brushes as potential nanocarriers for the simultaneous encapsulation of hydrophobic and cationic drugs

Cylindrical copolypeptide brushes PLLF-g-(PLF-b-PLG) with poly(L-lysine-co-L-phenylalanine) (PLLF) as the backbone and poly(L-phenylalanine)-b-poly(L-glutamic acid) (PLF-b-PLG) as the side chains have been synthesized and evaluated as drug delivery carriers. The synthesized copolypeptide brushes were characterized by H-1 NMR, gel permeation chromatography (GPC), and transmission electron microscopy (TEM). In aqueous solution, the copolypeptide brushes adopt cylindrical morphologies and resemble unimolecular polymeric micelles with a hydrophobic poly(L-phenylalanine) core and a hydrophilic poly(L-glutamate) shell. An encapsulation study demonstrated that these water soluble, biodegradable copolypeptide brushes encapsulate hydrophobic compounds and cationic hydrophilic guest molecules simultaneously. Furthermore, the encapsulated cationic model compounds exhibit a pH-responsive releasing property. (C) 2012 Elsevier B.V. All rights reserved.