Anionic liposomes prepared without organic solvents for effective siRNA delivery

Area of Science:

• Biotechnology
• Materials Science
• Drug Delivery

Background:

• Traditional anionic liposome preparation for siRNA delivery relies on organic solvents, posing challenges in removal and stability.
• Residual organic solvents can be hazardous and negatively impact liposome integrity.

Purpose of the Study:

• To develop a novel, efficient, and safe method for preparing anionic liposomes using glycerol as a physiologically compatible medium.
• To evaluate the efficacy of glycerol-prepared anionic liposomes for siRNA encapsulation, delivery, and therapeutic potential.

Main Methods:

• Anionic liposomes were prepared using glycerol to promote lipid dispersion and liposome formation, avoiding organic solvents.
• Small interfering RNA (siRNA) encapsulation was achieved using calcium ions (Ca2+), with encapsulation efficiency optimized.
• Cell viability assays and studies on siRNA resistance to degradation were performed.

Main Results:

• Spherical anionic liposomes with an average particle size of 188.9 nm were successfully synthesized using glycerol.
• A maximum siRNA encapsulation efficiency of 91% was achieved at 2.4 mM Ca2+.
• Calcium phosphate formation facilitated endosomal escape, anionic liposomes enhanced siRNA stability, and demonstrated effective gene knockout with no significant cytotoxicity.

Conclusions:

• Glycerol provides a safe, efficient, and solvent-free method for anionic liposome preparation, suitable for siRNA delivery.
• These liposomes represent a promising platform for delivering siRNA and other nucleic acid therapeutics, enhancing stability and efficacy.