Nonclinical safety assessment of iPSC-PLTs. (A) Profiles of novel drugs in the test batches. All substances were a less-than-lifetime limit of 120 μg per day for administration of up to 1 month. (B) A table summarizing in vivo general toxicity tests. For the single-dose study in NOG mice, the mice were observed for general condition, weight, and feeding amount, and underwent blood tests. On days 14 and 28, half of the mice in each group were sacrificed for autopsy for macroscopic observation of the organs, organ weight, and histopathology. For single and repeated administration tests on rats, the rats were observed for general condition, weight, and feeding amount and underwent blood, urine, and ophthalmological tests for 2 weeks after the last dose. They were then sacrificed for autopsy for macroscopic observation of the organs, organ weight, and histopathology. Formulation buffer and saline of the same volume were used as controls. For repeated tests, samples were administered twice a week 4 times. (C) Hematoxylin and eosin–stained histology sections of day 14 NOG mice injected IV with a 0.1 mL suspension of 2 × 108 platelets or formulation buffer of the same volume. (D) In vitro tumorigenicity test. (i) imMKCLs, iPSCs, or HL60 cells were cultured with or without the same nonirradiated cell type in 90-mm culture dishes. The number of grown colonies per dish was counted and averaged. (ii) An iPSC-PLT product of 2 mL and nonirradiated imMKCLs or HL60 cells were cultured in different combinations in suspension culture condition in 90-mm culture dishes. Similarly, an iPSC-PLT product of 2 mL and nonirradiated HeLa cells were cultured in different combinations in adherent culture condition in 90-mm culture dishes. The number of grown colonies per dish was counted and averaged.
