Glutathione hybrid poly (beta-amino ester)-plasmid nanoparticles for enhancing gene delivery and biosafety

CRISPR/Cas9 gene editing technology has significantly advanced gene therapy, with gene vectors being one of the key factors for its success. Poly (beta-amino ester) (PBAE), a distinguished non-viral cationic gene vector, is known to elevate intracellular reactive oxygen species (ROS) levels, which may cause cytotoxicity and, consequently, impact gene transfection efficacy (T.E.).

To develop a simple but efficient strategy to improve the gene delivery ability and biosafety of PBAE both in vivo and in vitro.

We used glutathione (GSH), a clinically utilized drug with capability to modulating intracellular ROS level, to prepare a hybrid system with PBAE-plasmid nanoparticles (NPs). This system was characterized by flow cytometry, RNA-seq, Polymerase Chain Reaction (PCR) and Sanger sequencing in vitro, and its safety and efficacy in vivo was evaluated by imaging, PCR, Sanger sequencing and histology analysis.

The particle size of GSH-PBAE-plasmid NPs were 168.31 nm with a ζ-potential of 15.21 mV. An enhancement in T.E. and gene editing efficiency, ranging from 10 % to 100 %, was observed compared to GSH-free PBAE-plasmid NPs in various cell lines. In vitro results proved that GSH-PBAE-plasmid NPs reduced intracellular ROS levels by 25 %-40 %, decreased the total number of upregulated/downregulated genes from 4,952 to 789, and significantly avoided the disturbance in gene expression related to cellular oxidative stress-response and cell growth regulation signaling pathway compared to PBAE-plasmid NPs. They also demonstrated lower impact on the cell cycle, slighter hemolysis, and higher cell viability after gene transfection. Furthermore, GSH hybrid PBAE-plasmid NPs exhibited superior safety and improved tumor suppression ability in an Epstein-Barr virus (EBV)-infected murine tumor model, via targeting cleavage the EBV related oncogene by delivering CRISPR/Cas9 gene editing system and down-regulating the expression levels. This simple but effective strategy is expected to promote clinical applications of non-viral vector gene delivery.