Zn(ii) coordination to cyclen-based polycations for enhanced gene delivery

Area of Science:

• Biomaterials Science
• Gene Therapy
• Polymer Chemistry

Background:

• 1,4,7,10-Tetraazacyclododecane (cyclen) possesses a unique cyclic structure with cationic properties, facile modification, and strong cation coordination.
• Zinc(II) ions are essential for DNA binding and can coordinate with cyclen, making Zn(II)-cyclen complexes potential gene delivery agents.

Purpose of the Study:

• To synthesize and evaluate Zn(II)-polycations derived from cyclen as non-viral gene delivery vectors.
• To investigate the DNA binding, release, transfection efficiency, serum tolerance, and cytotoxicity of these novel polycations.

Main Methods:

• Ring-opening polymerization of diglycidyl ethers and cyclen to synthesize polycations.
• Complexation of polycations with Zn(NO3)2·6H2O to form Zn(II)-polycations.
• DNA conformational change analysis using UV absorption and circular dichroism.
• DNA binding and release assessment via agarose gel electrophoresis.
• In vitro transfection efficiency, serum tolerance, and cytotoxicity assays.

Main Results:

• Zn(II)-polycations induced DNA conformational changes, unlike polycations alone.
• Zn(II)-polycations showed slightly lower DNA binding but improved DNA release compared to polycations.
• Coordination of Zn(II) significantly enhanced gene transfection efficiency.
• The novel polycations, particularly Zn-cyclen-HD, demonstrated superior serum tolerance over PEI.
• Materials exhibited acceptable cytotoxicity at effective transfection dosages.

Conclusions:

• Zn(II)-polycations are effective non-viral gene delivery vectors with enhanced transfection efficiency and biocompatibility.
• The coordination of Zn(II) plays a crucial role in improving DNA interaction and transfection outcomes.
• These findings provide a foundation for developing advanced, high-performance non-viral gene delivery systems.