Lineage Specific Differentiation of Magnetic Nanoparticle-Based Size Controlled Human Embryoid Body

Human embryonic stem cells (hESCs) possess unique properties in terms of self-renewal and differentiation, which make them particularly well-suited for use in tissue engineering and regenerative medicine. The differentiation of hESCs in the form of human embryoid bodies (hEBs) recapitulates early embryonic development, and hEBs may provide useful insight into the embryological development of humans. Herein, cell-penetrating magnetic nanoparticles (MNPs) were utilized to form hEBs with defined sizes and the differentiation patterns were analyzed. Through intracellular delivery of MNPs into the hESCs, suspended and magnetized hESCs efficiently clustered in to hEBs driven by magnetic pin-based external magnetic forces. The hEB size was controlled by varying the suspended cell numbers that were applied in the magnetic pin system. After 3 days of differentiation in a suspended condition, ectodermal differentiation was observed to have been enhanced in the small hEBs (150 μm in diameter) while endodermal and mesodermal differentiation were enhanced in large hEBs (600 μm in diameter). This indicates that the size of the hEBs plays an important role in the early lineage commitment of hESCs, and MNP-based control of the hEB size would be a novel, useful methodology for lineage-specific hESC differentiation.