scAAV5-CAG-GFP

Recombinant adeno-associated virus (rAAV) vectors are a promising alternative to viral vectors and gene delivery systems because they are non-pathogenic, replication-defective, and can transduce both dividing and non-dividing cells. In addition, AAV is non-integrating compared to lentiviral vectors used in previous studies, thus improving its safety and regulatory compliance. AAV can effectively transduce a variety of cell types and tissues, including liver, muscle, lung, central nervous system, and bone marrow. In conventional AAV vectors, the genome is packaged as a linear single-stranded (ss) DNA molecule of approximately 4.7 kb in length. These single strands occur as either positive or negative strands. Prior to gene expression, the ssDNA needs to be converted to double-stranded (ds) DNA, either by annealing one positive and one negative strand, or by de novo synthesis of DNA. This is known to be one of the rate-limiting steps for efficient transduction. The use of self-complementary (sc) AAV vectors can completely circumvent this problem, as these vectors contain a dimeric inverted repeat genome that is able to fold into dsDNA. Compared with single-stranded vectors, the use of scAAV can bypass the rate-limiting step of second-strand synthesis, thereby improving transduction efficiency. This can be overcome by using higher ssAAV titers, thereby increasing the probability of annealing of two complementary single strands. However, compared with ssAAV, the use of scAAV can achieve sufficient gene expression levels with much lower vector titers. This can be accompanied by favorable effects: 1. Improved safety of gene delivery by reducing the risk of possible adverse reactions and immune responses to the vector; 2. Improved practicality and cost-effectiveness.