AAV capsid design: A Goldilocks challenge

Trends Mol Med. 2022 Mar;28(3):183-193. doi: 10.1016/j.molmed.2022.01.003. Epub 2022 Jan 29.


In vivo therapeutic gene transfer has emerged as a novel class of medicines. Its feasibility relies on the safe and efficacious delivery of genetic cargo to the appropriate targets. The adeno-associated virus (AAV) vector manifested itself as a preferred gene delivery vehicle enabling therapeutic gene expression for several clinical indications. Here, we cover the recent trends in AAV capsid engineering to enhance its targeting specificity, safety, and endurance. While each and every desirable trait can be individually remodeled, combining several attributes in one capsid amounts to a significant engineering challenge. Taking advantage of virion structure and phylogenetics, harnessing directed evolution, sequence analyses, and machine learning, researchers develop novel capsid variants to realize the goals of safe and enduring gene therapy.

Keywords: adeno-associated virus vector; directed evolution; gene therapy; machine learning.

Publication types

  • Review

MeSH terms

  • Capsid Proteins / genetics
  • Capsid*
  • Dependovirus* / genetics
  • Genetic Therapy
  • Genetic Vectors / genetics
  • Humans
  • Transduction, Genetic


  • Capsid Proteins