Annealing of pDNA to Form the Single-Nucleobase-Terminal Complex for In Vivo Gene Expression

Area of Science:

• Biomaterials Science
• Gene Therapy
• Nanotechnology

Background:

• Polycationic carriers for plasmid DNA (pDNA) delivery face challenges with in vivo aggregation due to multiple cationic charges.
• Developing non-viral vectors that mitigate aggregation and enhance delivery efficiency is crucial for gene therapy applications.

Purpose of the Study:

• To synthesize and evaluate a novel nonionic, single-nucleobase end-modified poly(ethylene glycol) (Thy-PEG) complex for pDNA delivery.
• To investigate the potential of this Thy-PEG/pDNA complex as a cation-free platform for skeletal muscle gene delivery.

Main Methods:

• Synthesis of thymine end-modified poly(ethylene glycol) (Thy-PEG).
• Formation of Thy-PEG/pDNA complexes via hydrogen bonding between Thy-PEG and annealed pDNA.
• Local administration of Thy-PEG/pDNA complexes to the tibialis muscle of mice.

Main Results:

• The Thy-PEG/pDNA complex, a single-nucleobase-terminal complex (SNTC), showed no nonspecific aggregation in vivo.
• Local administration resulted in a tendency for a 14-fold increase in gene expression compared to annealed naked pDNA.
• The developed platform offers a unique cation-free approach for pDNA delivery.

Conclusions:

• Thy-PEG/pDNA complexes represent a promising nonionic, cation-free platform for skeletal muscle gene delivery.
• This approach overcomes the limitations of polycationic carriers, reducing in vivo aggregation.
• SNTCs offer a novel strategy for enhancing the efficiency of plasmid DNA delivery in vivo.