Thus, the objectives of this research were to: (1) reveal the time-dependent and dosage-dependent cellular uptake of LDH NPs, BSA-LDH NPs, and LCP NPs by EL4 cells; (2) understand the factors that affect the siRNA delivery efficacy in terms of target PD-1 mRNA silence and protein expression reduction in EL4; and, (3) confirm that the selected better system works on a human T cell, i.e., tumor infiltrating lymphocyte (TIL). This evidence concerns the gene PDCD1 and neoplasm.