Saponin conjugation improves p-CRISPR delivery by polyethylenimine modified carbon dots

Introduction: Non-toxic and efficient delivery platforms are important for gene editing applications. In this report, the preparation of saponin-conjugated low molecular weight polyethyleneimine (PEI1.8kDa) modified carbon dots (CD-PEI-Sap) is described. Methods: Polyethyleneimine modified carbon dots (CD-PEI1.8kDa), were synthesized by one-step microwave-mediated pyrolysis of citric acid (CA) and PEI1.8kDa to produce non-toxic fluorescent particles. When saponin was added at this stage followed by microwave treatment a completely clear solution of CD-PEI-Sap was produced. Results: These 80 nm nanoparticle vectors not only transfected green fluorescent protein plasmid (p-GFP) (3 kb) with 60% expression in human embryonic kidney (HEK 293T) cells, and>60% in hard to transfect human breast adenocarcinoma cells (MCF7), but could also transfect a large clustered regularly interspaced short palindromic repeat plasmid (p-CRISPR) with 5-fold higher efficiency (50%) than the gold standard reagent, branched PEI MWt 25 kDa (PEI25kDa). Moreover, the CD-PEI-Sap system produced good transfection with a low concentration of p-CRISPR and in the presence of 30% fetal bovine serum (FBS). Conclusion: This system demonstrated efficient transfection and serum resistance, making it a promising tool for future gene editing research.