Influence of Phase Transitions on Diffusive Molecular Transport Across Biological Membranes
Abstract
Phase transitions of lipid bilayer membranes should affect passive transport of molecules. While this hypothesis has been used to design drug‐releasing thermosensitive liposomes, the effect has yet to be quantified. Herein, we use time‐resolved second harmonic light scattering to measure transport of a molecular cation across membranes of unilamellar liposomes composed of the total lipid extract of E. coli from 9 °C to 36 °C, in which two distinct phase transitions (gel to liquid‐disordered phase) have been identified. While the transport rate slowly increases with temperature as a diffusion process, dramatic jumps are observed at 14.7 °C and 27.6 °C, the known phase transitions. The transport rate constant measured as (7.3±0.8)×10−3 s−1 in the liquid‐disordered phase at 36 °C is 35‐times faster than (2.1±0.2)×10−4 s−1 of the gel phase at 9 °C. For the mixed‐phase between these two phases, the measured rates are consistent with a structure of gel domains among a liquid‐disordered bulk.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Sep 14, 2022
- Source ID
- 10.1002/ange.202205608
Entities
People
- Hai-Lung Dai
- Jianqiang Ma
- Michael J. Wilhelm
- Tong Wu
- Yuhao Wu
- Yujie Li
Organizations
- Air Force Office of Scientific Research
- Pacific Northwest National Laboratory
- Temple University