Dose–response of top-performing LNPs from libraries A and B confirm enhanced mRNA delivery to a T cell line (Jurkat) over a standard LNP formulation and lipofectamine. (A) Luciferase expression and viability of Jurkat cells treated with S2, A16, or B10 LNPs for 48 h, confirming the relative performance of each formulation. Luminescence and viability were normalized to untreated cells and compared within each dose using a one-way ANOVA with post hoc t tests using Holm’s correction. *p < 0.05, ***p < 0.001 as compared to S2, n = 3 biological replicates, error bars = standard deviation. (B) Luciferase expression and viability of Jurkat cells treated with B10 LNPs or lipofectamine for 48 h showing the ability of B10 LNPs to achieve increased mRNA delivery with no increase in cytotoxicity. Luminescence and viability were normalized to untreated cells, and the treatment groups were compared within each dose using a t test with post hoc t tests using Holm’s correction. **p < 0.01, n = 3 biological replicates, error bars = standard deviation.