Synthesis of mRNA lipid nanoparticles for engineering GD2 CAR T and CAR NK cells against neuroblastoma

Engineering T and natural killer (NK) cells with chimeric antigen receptors (CAR) creates effective adoptive cell transfer therapies for cancer treatment. However, using viral transduction as a primary genetic modification method adds regulatory burdens and is expensive to produce at scale. Delivering mRNA encoding CAR via lipid nanoparticles (LNPs) has been explored as a potent non-viral method to generate CAR immune cells. Still, it has not been optimized for CAR treatment of neuroblastoma to date. An LNP formulation to deliver mRNA encoding a GD2 CAR into human T and NK cells was designed and characterized by dynamic light scattering for size distribution, z-average diameter, polydispersity index, and ζ potential. Fluorescent reporter detection persisted for more than 1 week after mRNA LNP transfection, without affecting T or NK cell viability. The potency of GD2 CAR T cells with 79.9% reporter positivity and GD2 CAR NK cells with 26.6% reporter positivity was assessed <i>in vitro</i> against the GD2 ⁺ neuroblastoma cell line CHLA20. GD2 CAR T or CAR NK cells could effectively target and kill neuroblastoma cells in a dose-dependent fashion, and GD2 CAR T cells showed increased IFNγ production. This study shows mRNA LNPs are a promising non-viral approach for generating GD2 CAR T and CAR NK cells, potentially offering a safer and more cost-effective alternative to current viral vector-based methods.