Poly(l-lysine)-based star-block copolymers as pH-responsive nanocarriers for anionic drugs

► We design and synthesize poly(l-lysine)-based star-block copolymers. ► Copolymers show efficient encapsulation towards anionic drugs. ► Polymer-drug complexation is characterized by spectrophotometric titration. ► Polymer-drug complex is stable at physiological pH. ► Encapsulated drugs demonstrate accelerated release at higher or lower pH.