Versatile delivery.

Electroporation offers diverse modes of administration, (in vitro, in vivo, ex vivo), and has been used successfully for several different applications. In 2019, Wiesinger et al. (Wiesinger et al. 2019) used Bio-Rad’s Gene Pulser Xcell Electroporation System to produce CAR-T cells via mRNA targeting of melanomas at clinical scale. Notably, this was achieved under full good manufacturing practice (GMP) compliance. Similarly, Krug et al. also used electroporation to generate CAR-T cells under GMP compliance (Krug et al. 2014).

While electroporation to date has mainly been used in vitro, new electroporation technologies have enabled transfection-based application of epidermal DNA vaccines. Currently, late-stage clinical trials are evaluating this electroporation technique in vivo for inducing immune protection against MERS and SARS-CoV-2, HIV, and other infectious diseases (Xu et al. 2020 and INOVIO Pharmaceuticals 2021). As of November 2021, a DNA vaccine candidate targeting SARS-CoV-2 is set to begin phase 3 clinical trials in the US (INOVIO Pharmaceuticals 2021).

Improved safety.

Electroporation can be used to avoid the toxicity and immunogenicity risks associated with adenoviral and lentiviral vectors (BCC Research 2022 and Raper et al. 2003) in gene therapy for both in vitro and ex vivo settings. Therapeutic cells generated using electroporation have improved tolerance and can enable repeat dosing with lower risk for patients (Timmins et al. 2021).

They are also safer to produce, as there is no risk for viral exposure by laboratory or manufacturing personnel (Schumann et al. 2015).  

Flexibility for easier optimization.

Parameter optimization is a challenging, time consuming, and iterative process necessary to achieve the highest efficiency and viability possible for delivery of a molecule to a particular cell type. Electroporation instruments that offer the ability to deliver parameters to a multi-sample well set aid in quicker optimization, and even more so if they are unique parameters. Additionally, some instruments, like the Gene Pulser Xcell Electroporation System, allow users the flexibility to manually adjust parameter settings (e.g., waveform, electric field, and pulse length) to optimize parameters for a variety of cell types.

Scalability.

Electroporation devices have a variety of features that can impact their use in manufacturing. For example, electroporation systems with the necessary throughput can facilitate easy and fast parameter optimization. Moreover, those that can scale into larger volumes without parameter re-optimization also facilitate the scalability needs of manufacturing. Taken as a whole, the quicker optimization of viability and efficiency parameters and the ability to scale-up enable the large volume processing required by manufacturing.

Host cell versatility.

Transfection by electroporation is far less dependent on cell type compared to viral or chemical transfection methods.  When applied to a high concentration of viable cells, electroporation can quickly enable molecule delivery through transient pores in the cell membrane without the need to target specific cell proteins or the limitation of cell tropism. It can efficiently transfer nucleic acids or other molecules into almost any cell type, including primary cells of the immune system (T cells, dendritic cells) and CAR T cells (Atsavapranee et al. 2021). 

Given these advantages, several pre-clinical adoptive T-cell therapies use electroporation technology. Notable examples include allogenic T-cell therapies with demonstrated anti-tumor activity both in vitro and in vivo, as well as T-cell antigen coupler (TAC-T cell) adoptive immunotherapy for the treatment of HER2-overexpressing cancers (Triumvira Immunologics 2021 and Guo 2021).

More cargo types and capacity.

In many cases, electroporation can efficiently deliver larger and complex payloads, such as CRISPR/Cas9 systems, DNA vectors, short hairpin RNA, microRNA, small interfering RNA, oligonucleotides, and even small molecules, to a variety of cell types (Timmins et al. 2021). Electroporation can also accommodate larger loads with multiple molecules simultaneously, including ribonucleoproteins (RNPs) and mRNAs, making it more flexible and effective than viral-based delivery methods which are limited to the viral-vector insert size. 

Decreased development cost and time.

Electroporation is an attractive alternative to viral-based delivery methods because it can reduce the cost and time associated with manufacturing infrastructure needs and skilled personnel, whether vector-based development is done in-house or outsourced. (Pires de Mello et al. 2016). Additionally, it can facilitate easier and quicker scale-up (as described above), thereby reducing time to investigational new drug approval by the U.S. Food and Drug Administration (Bulcha 2021, Srivastava 2021, and Timmins et al. 2021).  This can be critical for companies operating in the fast-paced, high-stakes field of cell and gene therapy, where time to market is crucial for success.

Improved control of CRISPR-Cas9–based genome edits.

Several studies have demonstrated the utility of electroporation for delivering CRISPR-Cas9 DNA, mRNA, and RNPs to a variety of cell types, including difficult to transfect cells (Kim 2014 and Razeghian 2021). Electroporation is increasingly used to deliver CRISPR-Cas9 systems in the context of immune oncology and hematologic disorders because they offer better control over the duration of CRISPR-Cas9 components in cells and reduce off-target effects and toxicity. Additionally, electroporation approaches can directly deliver CRISPR-Cas9 components without requiring the transcription and translation steps necessary with viral CRISPR-Cas9 delivery (Stadtmauer 2020).