Electrochemicolor imaging of endogenous alkaline phosphatase and respiratory activities of mesenchymal stem cell aggregates in early-stage osteodifferentiation

Mesenchymal stem cells (MSCs) have received great attention for tissue engineering. In the present study, the early stage of osteogenesis of MSC aggregates was monitored by electrochemicolor imaging using an electrode array device that can simultaneously detect multiple redox species. Electrochemicolor imaging was used to evaluate the cells' endogenous alkaline phosphatase (ALP) and respiratory activities. High ALP activity was observed in the aggregates after osteomedium (OM) treatment, with hydroxyapatite addition inducing early-stage osteogenesis in large aggregates. In small aggregates, OM treatment decreased the respiratory activity. To the best of our knowledge, this is the first report to use electrochemical imaging of ALP and respiratory activities to evaluate osteogenesis in MSC aggregates.