Intravenous Delivery of Angiopep-Functionalized Polypropylenimine Dendriplex Enhances Gene Expression in the Brain

Area of Science:

• Nanotechnology
• Biomedical Engineering
• Neuroscience

Background:

• Gene therapy for neurological disorders faces challenges due to the blood-brain barrier (BBB).
• Angiopep-2 enhances therapeutic agent delivery across the BBB via receptor-mediated endocytosis.
• A novel nanocarrier is needed for effective brain-targeted gene delivery.

Purpose of the Study:

• To explore angiopep-2-conjugated generation-3 diaminobutyric polypropylenimine (DAB) dendrimer (DAB-Ang) as a nanocarrier.
• To evaluate DAB-Ang's potential for brain-targeted gene delivery.
• To assess the efficacy of DAB-Ang in enhancing gene expression in the brain.

Main Methods:

• Conjugation of angiopep-2 to DAB dendrimer.
• Characterization of DAB-Ang dendrimer (DNA condensation, particle size, surface charge, morphology).
• In vitro cellular uptake studies in bEnd.3 brain endothelial cells.
• In vivo gene expression evaluation in BALB/c mice following intravenous administration.

Main Results:

• DAB-Ang successfully condensed DNA into stable spherical dendriplexes (<240 nm, positive zeta potential).
• In vitro, DAB-Ang showed a 9-fold increase in cellular uptake by brain endothelial cells.
• In vivo, DAB-Ang significantly enhanced brain gene expression (1.8-3.2 fold increase) with minimal off-target effects.

Conclusions:

• Angiopep-2-conjugated DAB dendrimer (DAB-Ang) is effective for brain-targeted gene delivery.
• DAB-Ang demonstrates high specificity and efficacy for neurological disorder therapeutics.
• This nanocarrier platform holds promise for advancing gene therapy in the brain.