Hyperbranched lysine-arginine copolymer for gene delivery

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Gene Delivery Systems

Background:

• Natural amino acids L-lysine and L-arginine possess reactive amine and carboxyl groups.
• Thermal polymerization enables the synthesis of hyperbranched lysine-arginine copolymers (P-lys-argX).

Purpose of the Study:

• To synthesize and characterize hyperbranched polylysine (P-lys) and its arginine-rich derivatives (P-lys-arg0.10, P-lys-arg0.20).
• To evaluate the potential of these copolymers as gene delivery vectors by assessing their DNA condensation and transfection efficiency.
• To investigate the effect of arginine content on polymer performance and cellular toxicity.

Main Methods:

• Synthesis of hyperbranched polylysine and lysine-arginine copolymers via thermal polymerization.
• Physicochemical characterization of polyplexes (DNA-polymer complexes) using agarose gel electrophoresis, dynamic light scattering, and zeta potential measurements.
• Assessment of in vitro transfection efficiency in COS-7, 293T, and HeLa cell lines.

Main Results:

• P-lys demonstrated limited DNA condensation and low transfection efficiency.
• Arginine-rich copolymers (P-lys-argX) significantly enhanced DNA condensation and transfection efficiency.
• Transfection efficiency correlated with arginine content and cell line; P-lys-arg0.20 showed superior performance and lower toxicity in COS-7 cells.

Conclusions:

• Hyperbranched lysine-arginine copolymers, particularly P-lys-arg0.20, are effective non-viral gene delivery vectors.
• Arginine incorporation is crucial for improving DNA binding and cellular uptake.
• These arginine-rich copolymers offer a promising platform for gene therapy with reduced cytotoxicity.