Metabolically stabilized long-circulating PEGylated polyacridine peptide polyplexes mediate hydrodynamically...

Area of Science:

• Biotechnology
• Molecular Biology
• Gene Therapy

Background:

• Gene therapy requires efficient and safe delivery of genetic material to target cells.
• Current gene delivery vectors face challenges including immunogenicity, instability, and limited targeting efficiency.
• Polyacridine peptides offer a novel scaffold for DNA complexation and delivery.

Purpose of the Study:

• To develop and evaluate novel PEGylated polyacridine peptides as in vivo gene transfer agents.
• To assess the DNA binding affinity, stability, and pharmacokinetic properties of these peptides.
• To determine the efficacy of PEGylated polyacridine peptides in mediating gene expression in the mouse liver.

Main Methods:

• Synthesis of PEGylated polyacridine peptides with varying repeat units.
• Complexation of plasmid DNA (pGL3) with the optimal peptide to form polyplexes.
• In vivo administration of polyplexes followed by a hydrodynamic boost in mice.
• Quantification of luciferase gene expression in the liver as a measure of transfection efficiency.

Main Results:

• An optimal peptide, (Acr-Lys)(6)-Cys-PEG, demonstrated high affinity for plasmid DNA via polyintercalation.
• PEGylated polyacridine peptide polyplexes stabilized DNA against DNase degradation and extended DNA's circulatory half-life to 2 hours.
• A combination of peptide polyplexes and a hydrodynamic boost resulted in high-level luciferase expression in the mouse liver, comparable to direct hydrodynamic gene delivery.

Conclusions:

• PEGylated polyacridine peptides represent a novel and effective class of gene delivery vectors.
• These peptides facilitate reversible DNA binding, protect DNA from degradation, and enhance in vivo circulation.
• The developed system shows significant potential for high-level gene expression in the liver upon hydrodynamic stimulation.