AAV Vectors in Regenerative Medicine and Cellular Reprogramming: Potential, Pitfalls, and Specificity Constraints
The adeno-associated virus (AAV) has become the vector of choice for gene therapy and experimental gene delivery, owing to its non-pathogenic nature and ability to achieve persistent gene expression across diverse tissues. AAV has emerged as a key platform in cellular reprogramming and regenerative medicine, with applications spanning transcription factor delivery for in vivo lineage conversion and tissue repair across the CNS, heart, and musculoskeletal systems. However, significant limitations remain, particularly in the context of induced pluripotent stem cell (iPSC) engineering. We assess barriers to efficient iPSC transduction including receptor-dependent entry deficits and activation of p53-dependent DNA damage responses. Although AAV is widely described as non-integrating, evidence indicates that integration events occur in rapidly proliferating and actively reprogramming cells. Critically, we synthesize evidence that cell-type-specific promoters lose fidelity when paired with neurogenic transgene payloads, a cross-tissue problem not addressed in existing AAV reviews, and that published in vivo reprogramming efficiencies may be substantially confounded by promoter leakage in the absence of formal lineage tracing. These aspects, underrepresented in recent platform-level reviews, are specifically emphasized here as a resource for researchers designing rigorous AAV-based reprogramming and gene therapy strategies.