Bioreducible poly (β-amino esters)/shRNA complex nanoparticles for efficient RNA delivery

Area of Science:

• Biomaterials Science
• Gene Therapy
• Nanotechnology

Background:

• RNA interference (RNAi) is a powerful gene silencing tool for therapy.
• Developing efficient and safe non-viral vectors for RNA delivery remains a challenge.
• Existing vectors often struggle with high transfection efficiency and low cytotoxicity.

Purpose of the Study:

• To design and synthesize novel bioreducible poly(β-amine esters) (PAEs) as non-viral vectors.
• To evaluate the physicochemical properties and gene silencing efficacy of PAEs/shRNA nanoparticles (PAENs).
• To assess the in vitro and in vivo performance, including cytotoxicity and tumor targeting.

Main Methods:

• Synthesis of three novel PAEs via Michael addition polymerization.
• Characterization of PAENs size, surface charge, and stability.
• In vitro evaluation of cellular uptake, gene silencing (EGFP), and cytotoxicity in HEK-293 and U-87 MG cells.
• In vivo studies involving intravenous injection in tumor-bearing mice to assess biodistribution and gene silencing.

Main Results:

• PAEs successfully condensed shRNA into nanoparticles (60-200nm, >+10mV).
• PAENs demonstrated stability in physiological conditions and degradation in reductive environments.
• Efficient cellular uptake, EGFP silencing, and low cytotoxicity were observed in vitro.
• High PAEN accumulation in tumors and significant intra-tumor gene silencing were achieved in vivo.
• Polymer structure, particularly nitrogen density and disulfide bonds, influenced RNAi efficiency and cytotoxicity.

Conclusions:

• Novel bioreducible PAEs are effective non-viral vectors for shRNA delivery.
• PAENs exhibit promising characteristics for efficient and safe gene therapy applications.
• The developed PAEs represent a significant advancement in non-viral vector technology for RNAi.