Gold Nanoparticles Enhanced Electroporation for Mammalian Cell Transfection

Abstract

Electroporation figured prominently as an effective nonviral gene delivery approach for its balance on the transfection efficiency and cell viability, no restrictions of probe or cell type, and operation simplicity. The commercial electroporation systems have been widely adopted in the past two decades while still carry drawbacks associated with the high applied electric voltage, unsatisfied delivery efficiency, and/or low cell viability. By adding highly conductive gold nanoparticles (AuNPs) in electroporation solution, we demonstrated enhanced electroporation performance (i.e. better DNA delivery efficiency and higher cell viability) on mammalian cells from two different aspects: the free, naked AuNPs reduce the resistance of the electroporation solution so that the local pulse strength on cells was enhanced; targeting AuNPs (e.g., Tf-AuNPs) were brought to the cell membrane to work as virtual microelectrodes to porate cells with limited area from many different sites. The enhancement was confirmed with leukemia cells in both a commercial batch electroporation system and a home-made flow-through system using pWizGFP plasmid DNA probes. Such enhancement depends on the size, concentration, and the mixing ratio of free AuNPs/Tf-AuNPs. An equivalent mixture of free AuNPs and Tf-AuNPs exhibited the best enhancement with the transfection efficiency increased 2-3 folds at minimum sacrifice of cell viability. This new delivery concept, the combination of nanoparticles and electroporation technologies, may stimulate various in vitro and in vivo biomedical applications which rely on the efficient delivery of nucleic acids, anticancer drugs, or other therapeutic materials.

Direct Permeation of Nanoparticles across Cell Membrane: A Review

“…These NPs include DNAconjugated gold NPs with 100 to 200 nm diameter Kawano et al, 2006;Zu et al, 2014), silver NPs with 80 nm diameter (Lin et al, 2009), and hollow metal NPs coated with mesoporous silica layer with 65 nm diameter (Kim et al, 2011). These experimental studies demonstrated significant enhancement of delivery efficacy of NPs with the electroporation treatment.…”

“…Meanwhile, an increase in cellular mortality can often be a great concern in these physical methods, if cells are subjected to the excess stress derived from the applied external forces. With regard to the direct delivery of NPs, the electroporation Kawano et al, 2006;Kim et al, 2011;Lin et al, 2009;Zu et al, 2014) and sonoporation (Carrasco et al, 2016;Wang et al, 2014;Yang et al, 2011) have been utilized in recent. In the following, these studies will be reviewed.…”

“…These experimental studies demonstrated significant enhancement of delivery efficacy of NPs with the electroporation treatment. Huang et al (2014) and Zu et al (2014) showed that with the electroporation treatment the dominant NP delivery pathway into cells shifted from the endocytosis to the direct permeation. It should be noted that even NPs with relatively large particle size (ca.…”

“…To overcome this disadvantage, some efforts have been reported. Zu et al (2014) found that both of high delivery efficacy of DNA-conjugated NPs and low cell mortality can be achieved by adding pristine gold NPs as an additive. They considered that this is due to decreasing the electric resistance of the medium with highly conducting gold NPs, resulting in much lower applied intensity required for the delivery.…”

“…The physical methods were originally developed for gene transfer into cells. Recently, these are exploited for the direct delivery of NPs (Carrasco et al, 2016;Huang et al, 2014;Kawano et al, 2006;Kim et al, 2011;Lin et al, 2009;Wang et al, 2014;Yang et al, 2011;Zu et al, 2014).…”