Water Soluble Star‐block Copolypeptides: Towards Biodegradable Nanocarriers for Versatile and Simultaneous Encapsulation

The synthesis of water soluble star‐block copolypeptides and their encapsulation properties are described. The star‐block copolypeptides, obtained by ring‐opening polymerization of amino acid N‐carboxyanhydrides, consist of a PEI core, a hydrophobic polyphenylalanine or polyleucine inner shell, and a negatively charged polyglutamate outer shell. The encapsulation study showed that these water soluble, amphiphilic star‐block copolypeptides could simultaneously encapsulate versatile compounds ranging from hydrophobic to anionic and cationic hydrophilic guest molecules. Hydrophobic and hydrophilic amino acids are polymerized sequentially using a hyperbranched polymeric core as a macroinitiator to synthesize star‐block copolypeptides. The constructed water soluble, biodegradable and amphiphilic multishell architectures show simultaneous encapsulation of versatile compounds ranging from hydrophobic to anionic and cationic hydrophilic guest molecules.