Formulation of a peptide nucleic acid based nucleic acid delivery construct

Area of Science:

• Biomaterials Science
• Gene Therapy
• Nanotechnology

Background:

• Efficient nuclear delivery of plasmid DNA is crucial for gene delivery biomaterials.
• Current polycation-based DNA packaging faces challenges with cytotoxicity and limited in vivo transfection efficiency.

Purpose of the Study:

• To explore an alternative DNA packaging approach using peptide nucleic acids (PNAs) for enhanced gene delivery.
• To synthesize and characterize DNA-PNA-peptide-PEG (DP3) conjugates and their complexes with poly(ethylenimine) (PEI).

Main Methods:

• Synthesized DNA-PNA-peptide-PEG (DP3) conjugates.
• Self-assembled DP3 conjugates with poly(ethylenimine) (PEI) to form polyplexes.
• Characterized polyplex size and N/P ratio dependence.
• Evaluated transfection efficiency and cytotoxicity in Chinese hamster ovary (CHO) cells.

Main Results:

• Formed homogeneous polyplexes (30-50 nm) with minimal size dependence on N/P ratio.
• Achieved tighter DNA compaction in PEI-DP3 complexes compared to PEI-DNA complexes.
• Demonstrated comparable transfection efficiencies with reduced cytotoxicity for PEI-DP3 complexes.
• Showed maintained cellular activity of PEI-DP3 complexes after free PEI removal.

Conclusions:

• DNA prePEGylation via a PNA-based strategy can improve polyplex homogeneity and reduce aggregation.
• This approach circumvents cytotoxicity and formulation issues associated with PEI-based gene delivery.
• The PNA-based strategy offers a promising alternative for effective and safer in vivo gene delivery.