Folate-targeted gene transfer in vivo

Area of Science:

• Oncology
• Gene Therapy
• Nanomedicine

Background:

• Nonviral systemic delivery is crucial for cancer gene therapy.
• Cationic liposomes are commonly used but exhibit preferential lung accumulation and transfection after intravenous injection.
• Targeting strategies are needed to improve tumor-specific delivery and reduce off-target effects.

Purpose of the Study:

• To develop a method for targeted tumor gene delivery using folate-functionalized cationic liposomes.
• To evaluate the impact of polyethylene glycol (PEG)-lipids on the biodistribution and gene transfer efficiency of lipid-DNA complexes.
• To assess the efficacy of folate targeting in directing gene delivery to tumors and minimizing lung transfection.

Main Methods:

• Formulation of cationic lipid-DNA complexes.
• Modification of complexes with polyethylene glycol (PEG)-lipids, some functionalized with folic acid.
• Intravenous administration of complexes in vivo.
• Quantification of gene transfer in lung and tumor tissues.
• Assessment of lung accumulation and gene transfer reduction.

Main Results:

• Addition of PEG-lipids significantly reduced lung accumulation and gene transfer.
• Folate-targeted complexes showed restored gene transfer activity in tumors.
• Folate targeting reduced lung gene transfer by 50- to 100-fold compared to non-targeted complexes.
• Tumor accumulation was not significantly altered by the presence of folic acid on PEG-lipids.

Conclusions:

• Folate-targeted lipid-DNA complexes represent a viable strategy for achieving targeted tumor gene delivery.
• PEGylation with distal folate modification effectively redirects gene transfer to tumors and minimizes off-target lung transfection.
• This study provides the first in vivo proof of concept for targeted tumor gene delivery using this approach.