CRISPR-Cas9 engineering of CAR-T cells: Can non-viral nanoparticles unlock safer and scalable genome editing?

CAR-T cell therapy has revolutionized the treatment of hematologic malignancies. Still, durable activity in tumors remains limited by antigen heterogeneity and escape, immunosuppressive tumor microenvironment, and restricted persistence. Genome engineering with CRISPR-Cas systems offers a powerful route to reprogram CAR-T cells; however, translation increasingly depends on how editing payloads are delivered. Viral vectors remain a benchmark for efficient gene transfer, cargo constraints, insertional risk, immunogenicity, and manufacturing complexity motivate the development of safer, more scalable non-viral platforms. In this review, we provide an overview of CAR designs, clinical use, and current ex vivo manufacturing workflow; compare viral and non-viral delivery routes while distinguishing established ex vivo editing from emerging in vivo T cell programming; and outline genome-engineering strategies organized by therapeutic goals. We highlight feasibility trade-offs and discuss how nanoparticles could enable transient, non-viral delivery of genome editors, while noting that robust T cell targeting and standardized potency/safety assays remain key bottlenecks.