Charge neutralized poly(β-amino ester) polyplex nanoparticles for delivery of self-amplifying RNA

Area of Science:

• Biotechnology
• Nanotechnology
• Molecular Biology

Background:

• Self-amplifying RNA (saRNA) offers therapeutic potential due to lower dosing requirements compared to mRNA.
• Effective delivery vehicles are crucial for saRNA protection and cellular transfection.
• Traditional polycationic delivery systems often cause cytotoxicity due to high positive charge density.

Purpose of the Study:

• To enhance the potency and tolerability of poly(β-amino ester)-based saRNA delivery vehicles.
• To investigate the effects of co-formulating polycationic saRNA polyplexes with anionic γ-polyglutamic acid (γ-PGA).

Main Methods:

• Preparation of poly(β-amino ester) from 1,6-hexanedioldiacrylate (HDDA) and 4-aminobutanol (ABOL).
• Formation and characterization of binary polyplexes (polymer and saRNA).
• Preparation and evaluation of ternary complexes incorporating γ-PGA, saRNA, and pHDDA-ABOL.

Main Results:

• γ-PGA integration significantly enhanced saRNA transfection efficacy in HEK293T and A431 cells.
• Ternary complexes showed reduced zeta potential and decreased toxicity in moDC, NIH3T3, and A431 cells.
• γ-PGA improved colloidal stability, maintaining low polydispersity index (PDI) after freeze-thaw cycles.

Conclusions:

• Co-formulating polycationic saRNA polyplexes with γ-PGA is a viable strategy to improve delivery.
• This approach enhances transfection efficiency and reduces cytotoxicity, addressing key challenges in saRNA delivery.
• The findings suggest a promising method for developing safer and more effective in vitro saRNA delivery formulations.