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Updated: Feb 14, 2026

Microfluidic Production of Lysolipid-Containing Temperature-Sensitive Liposomes
Published on: March 3, 2020
Hierarchical drug release of pH-sensitive liposomes encapsulating aqueous two phase system
Xunan Zhang1, Wei Zong1, Hongmei Bi2
1State Key Laboratory of Urban Water Resource and Environment, School of Chemical Engineering and Technology, Harbin Institute of Technology, 92 West Da-Zhi Street, China.
Abstract:
As promising drug delivery vehicles, previous investigations of liposomes as carriers are primarily focused on insertion and modification of lipid membrane interfaces. The utility of the inner core seems to be overlooked. Herein, we developed pH-sensitive liposomes (PSLs) containing an aqueous two phase system (ATPS), and intriguingly discovered their hierarchical release under acidic stimuli. ATPS containing two polymers (poly(ethylene glycol) (PEG) and dextran) is homogeneous above phase transition temperature when producing ATPS-liposomes, and separated into PEG-rich phase and dextran-rich phase after cooling down to room temperature. The overall release time of ATPS-liposomes is divided into two stages and prolonged compared to simple aqueous liposomes. The unique release profile is due to the disproportional distribution of drugs in two phases. Doxorubicin (DOX) is loaded in the ATPS-liposomes, and their half maximum inhibition concentration on HeLa cells is 0.018 μmol L-1, which means 27.5 fold increase in inhibition efficiency over free DOX.
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