Multi-liposomal containers

Area of Science:

• Biomaterials Science
• Nanotechnology
• Physical Chemistry

Background:

• Liposomes are versatile nanocarriers for drug delivery.
• Understanding liposome-polymer interactions is crucial for developing advanced delivery systems.
• Polycationic brushes offer unique properties for complexing liposomes.

Purpose of the Study:

• To investigate the molecular mechanisms of liposome complexation with spherical polycationic brushes (SPBs).
• To determine the structural integrity and lipid behavior within liposomes upon binding to SPBs.
• To explore the development of pH-sensitive, multi-liposomal drug delivery vehicles.

Main Methods:

• Electrophoretic mobility (EPM)
• Dynamic light scattering (DLS)
• Fluorescence spectroscopy
• Conductometry
• Differential scanning calorimetry (DSC)
• Cryogenic transmission electron microscopy (cryo-TEM)

Main Results:

• Liposome binding to SPBs induces anionic lipid flip-flop and lateral segregation.
• Anionic lipid geometry dictates the maximum molar fraction (ν) for liposome integrity (ν=0.3 for CL(2-), ν=0.5 for PS(1-)).
• The number of intact liposomes per SPB particle decreases with increasing ν.
• Multi-liposomal complexes with high loading capacity and controlled content ratios were prepared.
• pH-sensitive liposomes released contents upon pH reduction from 7.0 to 5.0 when complexed with SPBs.

Conclusions:

• Liposome structural reorganization is key to successful complexation with SPBs.
• Controlled liposome-polymer interactions enable the creation of efficient drug delivery systems.
• The developed multi-liposomal complexes show promise for targeted and triggered drug release.