Chlorofluorocarbon interaction with DPPC vesicles: an ESR investigation

Area of Science:

• Biophysics
• Physical Chemistry
• Materials Science

Background:

• DPPC (dipalmitoylphosphatidylcholine) unilamellar vesicles are model systems for cell membranes.
• Chlorofluorocarbons (CFCs) are known environmental pollutants with potential biological effects.
• Understanding molecular interactions at interfaces is crucial for various scientific fields.

Purpose of the Study:

• To investigate the impact of halothane, a specific chlorofluorocarbon, on the physical properties of DPPC unilamellar vesicles.
• To characterize the thermotropic behavior of the vesicle interfacial region under varying halothane concentrations.
• To propose a model explaining the molecular interactions between halothane and phospholipids.

Main Methods:

• Electron Spin Resonance (ESR) spectroscopy was employed to probe the vesicle structure.
• X-band ESR was utilized to obtain high-resolution spectra.
• Experiments were conducted at various halothane concentrations to observe dose-dependent effects.

Main Results:

• ESR spectra exhibited significant thermotropic behavior, indicating changes in membrane fluidity and order.
• The observed changes were dependent on the concentration of halothane, highlighting its influence on the lipid bilayer.
• Distinct alterations in the interfacial region of the DPPC vesicles were detected.

Conclusions:

• Halothane demonstrably affects the structural and dynamic properties of DPPC unilamellar vesicles.
• The study provides evidence for molecular interactions between chlorofluorocarbons and phospholipid bilayers.
• A proposed model offers insights into the mechanism of halothane-phospholipid interactions.