Nonphospholipid fluid liposomes with switchable photocontrolled release

Area of Science:

• Materials Science
• Biotechnology
• Nanotechnology

Background:

• Sterol-enriched nonphospholipid liposomes form stable large unilamellar vesicles (LUVs) with enhanced impermeability.
• Previous photosensitive liposomes often require a gel phase for light responsiveness.

Purpose of the Study:

• To create novel nonphospholipid photosensitive liposomes using a monoacylated azobenzene amphiphile (AzoC10N(+)) and cholesterol sulfate (Schol).
• To investigate light-induced payload release from these fluid liposomes and compare their photosensitivity to traditional phospholipid-based systems.

Main Methods:

• Preparation of fluid bilayers from AzoC10N(+)/Schol mixtures (25/75 molar ratio).
• Formation of LUVs using standard extrusion methods at room temperature.
• Characterization of azobenzene isomerization and light-induced leakage.

Main Results:

• Successfully prepared fluid AzoC10N(+)/Schol liposomes capable of forming LUVs.
• Demonstrated light-induced payload release via azobenzene photoconversion from trans to cis form.
• Achieved reversible, on-and-off control of release by photoisomerization back to the trans form.
• Observed limited passive release and responsiveness attributed to tight packing and conformational order.

Conclusions:

• AzoC10N(+)/Schol LUVs serve as effective nanocontainers with light-controlled and switchable release capabilities.
• These nonphospholipid liposomes offer a distinct advantage in photosensitive drug delivery due to their fluid nature and precise release control.