Comblike Polyethylenimine-Based Polyplexes: Balancing Toxicity, Cell Internalization, and Transfection Efficiency via...

Area of Science:

• Biomaterials Science
• Gene Therapy
• Polymer Chemistry

Background:

• Gene delivery vectors are crucial for genetic therapies.
• Polyethylenimines are widely studied for gene delivery due to their buffering capacity.
• Developing safe and efficient gene delivery systems remains a challenge.

Purpose of the Study:

• To evaluate comblike polyethylenimines with varied structures as gene delivery vectors.
• To investigate the relationship between polymer topology and gene delivery efficiency.
• To assess the safety and stability of polyethylenimine-DNA complexes (polyplexes).

Main Methods:

• Synthesis of comblike polyethylenimines with controlled polymerization and grafting density.
• Condensation of linear and plasmid DNA into polyplex nanoparticles.
• Characterization of polyplex size, surface potential, and colloidal stability.
• Cytotoxicity assessment using WISH cells.
• Analysis of cellular uptake pathways via lysosomal fluorescence staining.

Main Results:

• Polyethylenimines condensed DNA into nanosized polyplexes (130-330 nm) with variable surface potentials (-30 to +15 mV) based on the amine/phosphate (N/P) ratio.
• Polyplexes exhibited moderate colloidal stability, with broad size distribution (PDI > 0.2) and structural polymorphism.
• Low cytotoxicity was observed for both polymers and polyplexes (cell viability > 60%).
• Transfection efficiency correlated with polymer chain topology and cellular internalization pathways.

Conclusions:

• Comblike polyethylenimines are capable of forming stable DNA nanoparticles for gene delivery.
• Polymer structure significantly influences polyplex stability, cellular uptake, and transfection efficiency.
• Vector systems based on densely structured polymers demonstrate potential as effective gene transfection agents in eukaryotic cells.