Human mesenchymal stem cell (hMSC) differentiation towards cardiac cells using a new microbioanalytical method.

Stem cells (SCs) are more and more often applied in tissue engineering and cell therapies, e.g. in regenerative medicine. Standard methods of SC differentiation are time consuming and ineffective. Therefore, new bioanalytical methods (i.e. Lab-on-a-Chip systems) are develop to improve such type of studies. Although, microtechnology is a rapidly growing research area, there are so far not too many works which present SC differentiation into cardiomyocytes in the microsystems. Therefore, we present new microbioanalytical method of SC differentiation towards cardiac cells using a newly developed digitally controlled microdispenser integrated with a Heart-on-a-chip system. Seven-day culture of human mesenchymal stem cells (hMSCs) and their differentiation using biochemical factors such as 5-AZA (2 μM, 24 h) and VEGF (20 ng ml, 72 h) were investigated in the microsystem which was automatically operated using smartphone software. hMSC differentiation into the cardiac cells was confirmed using immunostaining of cardiac markers (α-actinin and troponin T). The usage of the microsystem allowed shortening the time of hMSC differentiation in comparison to macroscale method. We showed that the microsystem, in which the in vivo microenvironment is mimicked and dynamic conditions are provided by a microdispenser, favorably affect hMSC differentiation towards cardiac cells. Based on the presented research we can conclude that the developed digitally controlled microsystem could be successfully utilized as a new microbioanalytical method for stem cells differentiation and analysis of their function under dynamic conditions. In the future, this could be a helpful tool for scientists working on regenerative medicine.