ROS-responsive fluorinated polycations as non-viral gene vectors.

Area of Science:

• Biomaterials Science
• Gene Therapy
• Polymer Chemistry

Background:

• Polycation carriers are promising for gene therapy but face challenges with cytotoxicity and transfection efficiency.
• Developing safe and effective non-viral gene delivery vectors remains a critical research area.

Purpose of the Study:

• To synthesize and evaluate novel fluorobenzene-substituted and thioacetal-containing polycations (TAEA-S-xF) as gene delivery vectors.
• To investigate the structure-activity relationship, focusing on the impact of fluorine content and reactive oxygen species (ROS) responsiveness on vector performance.

Main Methods:

• Synthesis of a series of TAEA-S-xF polycations with varying fluorine substitution.
• Characterization of DNA condensation, nanoparticle formation, ROS-responsive degradation (NMR, gel electrophoresis, DLS), in vitro transfection, serum tolerance, and cytotoxicity assays.
• Mechanism studies involving cellular uptake and endosome escape.

Main Results:

• TAEA-S-xF polycations efficiently condensed DNA into nanoparticles with suitable size and surface potential.
• Transfection efficiency and serum tolerance were significantly influenced by the degree of fluorine substitution.
• ROS-responsive degradation was confirmed, and polycations exhibited good biocompatibility, especially in ROS-rich cancer cells.
• The polycation with the highest fluorine content demonstrated up to 54-fold higher transfection efficiency compared to polyethyleneimine (PEI) 25 kDa.

Conclusions:

• Fluorobenzene-substituted, ROS-responsive polycations represent a promising class of non-viral gene vectors.
• Optimized fluorine content enhances transfection efficiency and serum tolerance.
• These novel polycations offer a safer and more effective alternative for gene therapy applications due to their biocompatibility and efficient gene delivery capabilities.