Table 2.

Approaches for in vivo delivery of gene editors.

Viral Delivery	Pros	Cons
AAVs	Minimal risk of integration into the host genome Mild host immune responses Can be pseudotyped	Limited size of the cargo that can be packaged Continuous expression of editors, increasing risk of off-target effects Limited possibility to redose, due to the immune response
AdVs	Minimal risk of integration Not limited by the size of cargo	Undesirable immune responses Undesirable side effects Not suited for targeted delivery Continuous expression of editors, increasing risk of off-target effects
Lentiviruses	Can be pseudotyped Not limited by the size of cargo	Integrated into the host genome Continuous expression of editors, increasing risk of off-target effects
Non-viral delivery
LNPs	Minimal safety and immunogenicity concerns Possibility of re-dosing Can be targeted to specific cell populations Transient expression of editors, thus minimizing off-target effects	Low transfection efficiency

AdVs, adenoviruses; AAVs, adeno-associated viruses; LNPs, lipid-based nanoformulations.