Weakly acidic pH-responsive liposomal content release induced by histidine-modified agents.

Internal stimuli-responsive controlled release from liposomal vesicles is an innovative approach for site-specific delivery of therapeutic drugs. In this study, to enhance the endosomal pH control of drug release from liposomes, a series of histidine-modified pH-sensitive C-His ( = 8, 12, 18) agents were designed and utilized as triggers for liposomal content release. The pH-dependent properties of C-His-incorporated liposomes were characterized using dynamic light scattering, ζ-potential, and fluorescence spectroscopy.