However, the maximum AAV packaging capacity of ∼4.5 kb limits the donor size.
Trans-splicing AAV (tsAAV) vectors double AAV packaging capacity but their transduction efficiency has been too low to be useful.
The most promising gene delivery vehicles, viral vectors, suffer from several limitations, including immunogenicity, loss of therapeutic gene expression, and a limited packaging capacity.
Limited packaging capacity has hampered adeno-associated virus (AAV -mediated gene therAAV -mediatedcommon genetherapyeases such as cystic forrosis (CF) and Duchenne manyular dystrophy (DMD).
Expression vectors are often composed of multiple genes (e.g. a therapeutic, a marker gene, a suicide gene and a reporter gene) some of which can be large surface proteins, which may tax the vector packaging capacity and transcriptional efficiency.
Because of the various properties of each viral vector, the definition of their application range depends on factors such as packaging capacity, host range, cell- or tissue-specific targeting, replication competency, genome integration and duration of transgene expression.
While gene transfer approach is being tested for several of these diseases, such strategies can be hampered when the size of the corresponding complementary DNA (cDNA) exceeds the packaging capacity of adeno-associated virus vectors.
When the enterprise began turning away orders due to lack of storage and packaging capacity, the founders knew they needed a new facility quickly, before the opportunities slipped away, but Common Market was still too small to qualify for the $1.3 million mortgage loan required.
It should be noted though that AAV has a limited packaging capacity of roughly 5 kb of exogenous DNA [37].
3) The size of exogenous DNA that can be included into rAAV targeting vectors is limited by the packaging capacity of rAAV up to 4.8 kb [64].
