Development of poly(amino ester glycol urethane)/siRNA polyplexes for gene silencing

Area of Science:

• Biotechnology
• Polymer Chemistry
• Gene Therapy

Background:

• Nonviral vectors offer safer alternatives for siRNA therapy due to low immunogenicity and pathogenicity.
• Poly(ester urethane)s functionalized with tertiary amines and polyethylene glycol (PEG) were previously developed as DNA transfection reagents.
• The need for effective nonviral carriers for small interfering RNA (siRNA) delivery remains a key challenge in gene silencing.

Purpose of the Study:

• To develop and optimize poly(amino ester glycol urethane) (PaE(G)U)/siRNA polyplexes for efficient gene silencing.
• To characterize the properties of PaE(G)U/siRNA polyplexes and compare them with PaE(G)U/DNA polyplexes.
• To evaluate the gene silencing efficacy of the developed PaE(G)U/siRNA polyplexes in a cellular model.

Main Methods:

• Synthesis of soluble poly(amino ester glycol urethane) (PaE(G)U) incorporating tertiary amines and PEG.
• Formation and characterization of PaE(G)U/siRNA polyplexes, including size determination.
• Visualization of cellular uptake using fluorescently labeled siRNA and assessment of gene silencing via luciferase reporter assay.

Main Results:

• PaE(G)U/siRNA polyplexes were successfully formed with an optimized mass ratio of 80/1, resulting in an average diameter of 540 nm.
• Cellular uptake of PaE(G)U/siRNA polyplexes was visualized and optimized.
• Transient silencing of constitutive luciferase expression up to 92% was achieved in HT-1080 fibroblasts using anti-luciferase siRNA delivered by PaE(G)U/siRNA polyplexes.

Conclusions:

• PaE(G)U/siRNA polyplexes are effective nonviral carriers for gene silencing applications.
• The engineering of soluble, biodegradable polymers with specific functional units (amino, ester, PEG, urethane) is a promising strategy for designing novel siRNA carriers.
• Optimized PaE(G)U/siRNA polyplexes demonstrate potential for safer and efficient siRNA-based gene therapy.