P-LM421E8, the heparan sulfate chain-conjugated laminin-421-E8 fragment, drives differentiation of human induced pluripotent stem cells into hematopoietic progenitor cells comparable to basic fibroblast growth factor in a chemically defined system

populations comparable to those produced with bFGF treatment. Furthermore, we observed that HPCs generated on P‑LM421E8‑coated surfaces exhibited superior natural killer (NK) cell differentiation potential. Although both P-LM421E8 and bFGF supported HPC differentiation, no significant additive effects were observed when used together. This suggests that P-LM421E8 can effectively support HPC differentiation without the need for exogenous bFGF, possibly through enhanced interaction with endogenous FGFs. The structural properties of P-LM421E8, which facilitate retention and presentation of FGFs via HS chains on its D1, may contribute to its effectiveness in promoting HPC development. Our findings establish P‑LM421E8 as a potent matrix for HPC differentiation and highlight its promise for refining hematopoietic protocols and advancing cell‑based immunotherapies.