Gene therapy aims to treat patients by altering or controlling gene expression. The field of gene therapy has had increasing success in recent years primarily using viral-based approaches, however, there is still significant interest towards the use of polymeric materials due to their potential as flexible, low-cost scaffolds for gene delivery that do not suffer the mutagenesis and immunogenicity concerns of viral vectors. To address the challenges of efficiency and biocompatibility, a series of zwitterion-like polyethylenimine derivatives (zPEIs) were produced via the succinylation of 2-11.5% of PEI amines. With increasing modification, zPEI polyplexes exhibited decreased serum protein aggregation and dissociate more easily in the presence of a competitor polyanion when compared to unmodified PEI. Surprisingly, the gene delivery mediated in the presence of serum showed that even succinylation of as few as 2% of PEI amines resulted in transgene expression 260- to 480-fold higher than that of unmodified PEI and 50- to 65-fold higher than that of commercial PEI-PEG2k in HEK293 and HeLa cells, respectively. Remarkably, the same zPEI also produced 16-fold greater efficiency of CRISPR/Cas9 gene knock-in compared to unmodified PEI in the presence of serum. In addition , we show that 2% succinylation does not significantly decrease polymer/DNA binding ability nor reduce serum protein interaction to a significant extent, yet this small modification is still sufficient to aid a remarkable transgene expression and gene knock-in in the presence of serum.

Enhanced gene delivery and CRISPR/Cas9 homology-directed repair in serum by minimally succinylated polyethylenimine

ACS Fall 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.