Liposome-encapsulated polyethylenimine/oligonucleotide polyplexes prepared by reverse-phase evaporation technique

Area of Science:

• Biotechnology
• Materials Science
• Nanotechnology

Background:

• Liposome-encapsulated polyplexes are promising for delivering oligonucleotide therapeutics like siRNA and asODN.
• Existing methods for preparing these systems require optimization for efficiency and stability.

Purpose of the Study:

• To develop a novel method for preparing liposome-encapsulated cationic polymer/oligonucleotide polyplexes.
• To characterize the resulting particles for their stability, loading efficiency, and protective capabilities.

Main Methods:

• Polyplexes of polyethylenimine and oligonucleotide were formed in aqueous buffer.
• Anionic phospholipids were used in organic media to form inverted micelle-like particles with polyplex cores.
• Reverse-phase evaporation with hydrophilic polymer-grafted lipids yielded stable, lipid-coated particles.

Main Results:

• Transmission electron microscopy confirmed spherical particles with polyplex cores and lipid coats.
• The lipid-coated polyplex particles demonstrated colloidal stability.
• Complete protection of oligonucleotide molecules from enzymatic degradation was observed.
• High loading efficiency exceeding 80% was achieved.

Conclusions:

• The novel reverse-phase evaporation method provides an effective way to create liposome-encapsulated polyplexes.
• This technique offers a viable alternative for producing lipid-coated polyplex particles for oligonucleotide therapeutics delivery.