Figure 1.

NK expansion process. PBMCs were obtained from peripheral blood (approximately 50 mL) of each cancer patient. The plasma was prepared, and the lymphocytes were separated using human lymphocyte separation solution. The lymphocytes were resuspended in NK cell culture medium and cultured. For the first week, the cells were cultured in a T175 culture flask. From day 8, the cells were cultured in a 2-L cell culture bag. The first sterility test was performed on day 8, while the quality control (cell viability ≥80%, NK cell purity ≥80%, endotoxin ≤1 EU/mL, and bacteria, fungi, and mycoplasma culture-negative) and sterility tests were performed on day 12. On day 13, approximately 3–5×10⁹ HANK cells were harvested into a blood transfusion bags each day for infusion at a concentration of approximately 2×10⁷/mL.

Abbreviations: NK, natural killer; PBMC, peripheral blood mononuclear cell; HANK, highly activated natural killer.