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 1 H 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.