Non-encapsidated miRNA contaminants found in AAV preparations

Adeno-associated virus (AAV) has been in clinical use for gene therapy applications for over a decade, with 6 FDA-approved drug products at the time of writing.1 However, this vector is manufactured in a complex biological system, and it is currently an elusive possibility to produce an AAV gene therapy product devoid of nucleic acid contaminants. In recent years, there has been extensive work profiling and understanding the unintended DNA molecules contained within preparations of AAV.2 This has increased awareness of the causes of these DNA impurities and innovation to minimize their encapsidation within AAV particles.