Table 3.

Different methods for transduction of the CAR construct to the NK cells

Vector	Advantages	Disadvantages	References
Retroviral (α-RV and γ-RV)	High transduction efficacy Can integrate into the transcriptionally active site and transcription factor-binding site Used for transportation of CAR genome to PBMC Can be enhanced by transduction enhancers (such as polybrene, retronectine, and protamine sulfate, etc.) Can be used for the transduction of the CAR to different sources	Mutagenesis Can integrate only into dividing cells in the mitosis stage Harmful effect on NK cell viability	[66, 133]
Lentiviral	Can integrate into the transcriptionally active site and transcription factor-binding site Can integrate into both dividing and non-dividing cells High transduction efficacy Safer than retroviral transduction	Mutagenesis risk Lower transduction efficacy than retroviral vectors	[53, 74]
Electroporation with mRNA	Transient expression (only for 3–5 days) No risk of mutagenesis Simple and cost-effective High transduction efficacy	High cell death rate (due to cell membrane destruction) Lower efficacy in UCB and PBMC-derived NK cells Cannot integrate into the genome	[53, 234]
Electroporation with DNA (PiggyBac (PB) and Sleeping Beauty (SB))	Transient expression No risk of mutagenesis Simple and cost-effective Can transfer large gene sequence The possibility of permanent expression of the CAR using PB and SB Less off-target effect	High cell death rate (due to cell membrane destruction) Lower efficacy in UCB and PBMC-derived NK cells Cannot integrate into the genome	[50, 80, 235, 236]
CRISPR/Cas9	The genetic sequence is transduced using Adeno-associated virus (AAV), electroporation, or gold nano-particles Precision insertion of the transgene to the genome High success rate (68%)	Expensive Requiring high technology Difficult transduction method	[103]