Bile Salts Trigger Deformability in Liposomal Vesicles through Edge-Activating Action

Area of Science:

• Biochemistry
• Materials Science
• Physical Chemistry

Background:

• Liposomes are crucial drug delivery vehicles.
• Modulating liposome mechanical properties is key for enhanced biological barrier penetration.
• Bile salts are known to interact with lipid bilayers.

Purpose of the Study:

• To investigate the impact of bile-salt-based edge activators (EAs) on liposome mechanical properties and deformability.
• To elucidate the effect of specific bile salts (sodium cholate, NaC; sodium deoxycholate, NaDC; and sodium taurocholate, NaTC) on liposomes composed of l-α-phosphatidylcholine (SPC).

Main Methods:

• Liposome formulation via thin-film hydration.
• Characterization using scattering, spectroscopic, and atomic force microscopy (AFM).
• Force-deformation and force-indentation experiments to assess mechanical properties.

Main Results:

• Bile salts altered liposome hydrodynamic diameter, morphology, and mechanical characteristics.
• Deformability and Young's modulus followed the order NaDC ≥ NaC > NaTC.
• Fourier-transformed infrared spectroscopy (FTIR) confirmed hydrophobic interactions and enhanced hydrogen bonding with increased bile salt concentration.

Conclusions:

• Sodium deoxycholate (NaDC) significantly improves liposome mechanical properties and deformability.
• Enhanced liposome elasticity and reduced Young's modulus were observed with NaDC.
• These findings suggest potential for improved biological barrier penetration in drug delivery applications.