Osteoinductive Properties of Secretome of Human Mesenchymal Stem Cells, Obtained with Automatic Cell Culture System

Abstract

The secretome of human mesenchymal stem cells (MSCs) after osteogenic differentiation of FetMSC cells in vitro was obtained to develop tissue engineering technologies for bone tissue. For standard secretome samples a large number of FetMSC cells (7 × 108 cells) were cultured in serum-free conditioned medium (SFCM). All steps of cell processing were performed in the CompacT SelecT automatic system (Sartorius, United Kingdom). The SFCM was concentrated by ultrafiltration, then subjected to dialysis and dried in a vacuum rotary evaporator. The osteoinductive properties of SFCM concentrate (SFCMC) were tested on FetMSC cells by means of adding it to the growth medium at different concentrations. There were no changes in cell morphology during cultivation in the presence of SFCMC. Analysis of the transcription factors Runx2 and YAP1 (markers of osteogenic differentiation) expression using immunofluorescence staining and real-time polymerase chain reaction (RT-PCR) showed an increase in their level of expression in the presence of SFCMC. These findings demonstrate that it is possible to use SFCMC obtained from osteogenic MSCs to induce differentiation of other (undifferentiated) MSCs. The results are useful for the development of cell therapy products for bone restoration based on MSCs secretome.