Polypeptide-based star-block quadripolymers as unimolecular nanocarriers for the simultaneous encapsulation of hydrophobic and hydrophilic guests

► We design and synthesize two polypeptide-based star-block quadripolymers. ► Quadripolymers resemble amphiphilic unimolecular micelles. ► Quadripolymers solubilize hydrophobic molecules via hydrophobic interactions. ► Quadripolymers encapsulate hydrophilic drugs through electrostatic interactions. ► Quadripolymers entrap hydrophobic and hydrophilic guest molecules simultaneously in the site-isolated state.