Designing magnetic microcapsules for cultivation and differentiation of stem cell spheroids.

Human pluripotent stem cells (hPSCs) represent an excellent cell source for regenerative medicine and tissue engineering applications. However, there remains a need for robust and scalable differentiation of stem cells into functional adult tissues. In this paper, we sought to address this challenge by developing magnetic microcapsules carrying hPSC spheroids. A co-axial flow-focusing microfluidic device was employed to encapsulate stem cells in core-shell microcapsules that also contained iron oxide magnetic nanoparticles (MNPs). These microcapsules exhibited excellent response to an external magnetic field and could be held at a specific location. As a demonstration of utility, magnetic microcapsules were used for differentiating hPSC spheroids as suspension cultures in a stirred bioreactor. Compared to standard suspension cultures, magnetic microcapsules allowed for more efficient media change and produced improved differentiation outcomes. In the future, magnetic microcapsules may enable better and more scalable differentiation of hPSCs into adult cell types and may offer benefits for cell transplantation.