Cryoconserved shielded and EGF receptor targeted DNA polyplexes: cellular mechanisms

Area of Science:

• Biotechnology
• Molecular Biology
• Nanomedicine

Background:

• Polyethylene glycol (PEG)-shielded and epidermal growth factor receptor (EGFR)-targeted polyplexes (EGF+ polyplexes) were previously engineered for tumor-directed DNA transfer.
• EGFR is a key target for cancer therapy due to its overexpression in various tumors.

Purpose of the Study:

• To analyze the specificity and kinetics of EGFR-mediated cellular uptake of EGF+ polyplexes.
• To evaluate the impact of EGFR-targeting on DNA transfection efficiency and cell association.

Main Methods:

• Utilized HUH-7 hepatoma and Renca-EGFR renal carcinoma cells.
• Compared EGF+ polyplexes with polyplexes lacking EGF (EGF- polyplexes).
• Assessed cell association and transfection efficiency over time and in the presence of free EGF. Employed fluorescence microscopy to visualize polyplex-cell interactions.

Main Results:

• EGF+ polyplexes significantly enhanced transfection efficiency compared to EGF- polyplexes.
• Rapid cell association of EGF+ polyplexes was observed within 30 min, with significantly higher binding after 4 h.
• Reduced cell association and transfection efficiency in the presence of free EGF confirmed EGFR-mediated uptake.
• Fluorescence microscopy showed aggregation of cell-associated EGF+ polyplexes, indicative of receptor clustering.

Conclusions:

• EGFR-targeting accelerates and increases cell association of polyplexes.
• Polyplex aggregation upon binding enhances transfection efficiency.
• These findings support the potential of EGFR-targeted polyplexes for tumor-specific gene delivery.