A facile entrapment approach to construct PEGylated polyplexes for improving stability in physiological condition

Area of Science:

• Biomaterials Science
• Gene Delivery Systems
• Nanotechnology

Background:

• PEGylation enhances DNA complex stability but can impede DNA complexation.
• Existing methods for PEGylated polyplexes face challenges in balancing stability and complexation efficiency.

Purpose of the Study:

• To develop a facile and effective method for constructing stable PEGylated polyplexes.
• To investigate the impact of CPEG addition sequence on polyplex stability and transfection efficiency.
• To explore the potential of entrapping CPEG into polyplexes for improved non-viral gene delivery.

Main Methods:

• Constructing PEGylated polyplexes by entrapping poly(ethylene glycol) cholesterol ether (CPEG) into poly(ethyleneimine) (PEI)/DNA complexes.
• Comparing the "CPEG first" method (pre-mixing CPEG and PEI before adding DNA) with adding CPEG to pre-formed polyplexes.
• Evaluating polyplex stability in physiological salt concentrations and assessing transfection efficiency.

Main Results:

• The "CPEG first" method resulted in PEI(25k)/CPEG/DNA polyplexes with excellent anti-aggregation properties in physiological conditions.
• This method significantly enhanced transfection efficiency compared to adding CPEG after polyplex formation.
• Hydrophobic interactions between CPEG's cholesterol group and the polyplex core facilitate stable PEGylation.

Conclusions:

• The "CPEG first" entrapment strategy offers a facile and effective approach to prepare highly stable PEGylated polyplexes.
• This method overcomes the limitations of traditional PEGylation conjugation reactions, improving both stability and transfection efficiency.
• The developed PEGylated polyplexes show significant potential for advancing non-viral gene delivery applications.