Multifunctional Polypeptide-Based Nanoconjugates for Targeted Mitochondrial Delivery and Nonviral Gene Therapy

Area of Science:

• Nanomedicine
• Bioconjugate Chemistry
• Molecular Biology

Background:

• Developing multifunctional nanocarriers for targeted subcellular delivery and gene therapy is challenging.
• Existing nanomedicine approaches often lack the specificity for simultaneous targeting and therapeutic delivery.
• Efficient endosomal escape and intracellular trafficking remain critical hurdles in nanocarrier design.

Purpose of the Study:

• To design, synthesize, and evaluate a novel multifunctional polypeptide-based nanoconjugate for sequential delivery, combining mitochondrial targeting and nonviral gene therapy.
• To engineer a poly-l-ornithine-based, polyethylene glycol-modified carrier incorporating a custom-designed trivalent compound (TRV3).
• To assess the nanoconjugate's potential as a nonviral vector for gene therapy, particularly in cancer models.

Main Methods:

• Synthesis of a polypeptide-based nanocarrier modified with polyethylene glycol and conjugated to a trivalent compound (TRV3) via a redox-sensitive disulfide linker.
• Incorporation of triphenylphosphonium moiety (TPP) for mitochondrial targeting and Cy5 fluorophore as a model drug into TRV3.
• Evaluation of nanoconjugate (C-TRV3-A) for endosomal escape, mitochondrial localization, and formulation of plasmid DNA polyplexes with optimized stability using an anionic polypeptide coating (VLC-3).
• Assessment of transfection efficiency in triple-negative breast cancer cell culture models.

Main Results:

• The engineered nanoconjugate (C-TRV3-A) demonstrated efficient endosomal escape and successful mitochondrial localization.
• The nanoconjugate's endosomolytic properties were leveraged for nonviral gene delivery applications.
• Optimized plasmid DNA polyplexes exhibited enhanced stability and transfection efficiency in triple-negative breast cancer cell lines.
• The developed nanocarrier platform shows promise for simultaneous subcellular targeting and gene delivery.

Conclusions:

• A novel multifunctional polypeptide-based nanoconjugate was successfully developed, enabling sequential delivery for combined mitochondrial targeting and gene therapy.
• The nanoconjugate exhibits efficient endosomal escape and mitochondrial localization, crucial for intracellular therapeutic delivery.
• This chemically versatile platform offers a promising strategy for targeted cancer treatments and other pathologies requiring precise subcellular gene delivery.