AUTHOR=Hua Ziyi , Li Shuang , Liu Qianzi , Yu Minxuan , Liao Mengling , Zhang Hongmei , Xiang Xuerong , Wu Qingqing 

TITLE=Low-Intensity Pulsed Ultrasound Promotes Osteogenic Potential of iPSC-Derived MSCs but Fails to Simplify the iPSC-EB-MSC Differentiation Process

JOURNAL=Frontiers in Bioengineering and Biotechnology

VOLUME=Volume 10 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/bioengineering-and-biotechnology/articles/10.3389/fbioe.2022.841778

DOI=10.3389/fbioe.2022.841778

ISSN=2296-4185

ABSTRACT=Induced pluripotent stem cell (iPSC)-derived mesenchymal stem cells (iMSCs) is a promising cell source for bone tissue engineering. However, iMSCs were less osteogenic potential than BMSCs and the classical iPSC-EB-iMSC process to derive iMSCs from iPSCs is too laborious as it involves multiple in vitro steps. Low-intensity pulsed ultrasound (LIPUS) is a safe therapeutic modality used to promote osteogenic differentiation of stem cells. Whether LIPUS can facilitate osteogenic differentiation of iMSCs and simplify the iPSC-EB-iMSC process are unknown. We stimulated iMSCs with LIPUS at different output intensity (20, 40, and 60mW/cm2) and duty cycle (20%, 50%, and 80%). Results of ALP activity assay, osteogenic gene expression and mineralization quantification demonstrated that LIPUS was able to promote osteogenic differentiation of iMSCs, and it worked best at the intensity of 40mW/cm² and the duty circle of 50% (LIPUS40/50). Wnt/β-catenin signaling pathway was involved in LIPUS40/50-mediated osteogenesis. When cranial bone defects were implanted with iMSCs, LIPUS40/50 stimulation resulted in a significant higher new bone filling rate (72.63±17.04)% compared with the non-stimulated ones (34.85±4.53)%. Daily exposure to LIPUS40/50 may accelerate embryoid body (EB)-MSCs transition, but it failed to drive iPSCs or EB cells to an osteogenic lineage directly. This study is the first to demonstrate the pro-osteogenic effect of LIPUS on iMSCs. Although LIPUS40/50 failed to simplify the classical iPSC-EB-MSC differentiation process, our preliminary results suggest LIPUS with a more suitable parameter set may achieve the goal. LIPUS is a promising method to establish an efficient model for iPSCs application.