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

Org Biomol Chem. 2024 Apr 3;22(14):2844-2850. doi: 10.1039/d4ob00216d.

Abstract

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 Cn-His (n = 8, 12, 18) agents were designed and utilized as triggers for liposomal content release. The pH-dependent properties of Cn-His-incorporated liposomes were characterized using dynamic light scattering, ζ-potential, and fluorescence spectroscopy. The liposomes maintained a relatively uniform size across all pH conditions. However, the ζ-potential exhibited positive values at endosomal acidic pH levels and neutral or negative values at physiological pH levels. Furthermore, acidic pH-dependent release of both polar content (carboxyfluorescein) and nonpolar content (Nile red) was observed from the Cn-His-incorporated liposomes. Notably, with C12-His as the pH sensitizer, the pH dependence of liposomal content release was significantly evident. This work establishes endosomal pH-controllable liposome platforms, laying the groundwork for developing clinically applicable triggered release formulations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Drug Delivery Systems / methods
  • Endosomes
  • Histidine*
  • Hydrogen-Ion Concentration
  • Liposomes* / chemistry
  • Polymers / chemistry

Substances

  • Liposomes
  • Histidine
  • Polymers