The proportion of CD73 and CD90 expressing cells was not decreased following TrypLE incubation, while the proportion of cells expressing CD105 was significantly reduced (p?0.001; Fig.?3fCh). [average 5.0 population doublings (PDL)], followed by bioreactor (4.0 PDL) and spinner flasks (3.3 PDL). Circulation cytometry confirmed MSC identity (CD73+, PKCC CD90+ and GANT61 CD105+) and lack of contaminating hematopoietic cell populations. Cultured MSCs did not display genetic aberrations and no difference in differentiation and immunomodulatory capacity was observed between tradition conditions. The response to IFN activation was related for cells from all tradition conditions, as was the capacity to inhibit T cell proliferation. Conclusions The new bioreactor technology can be used to tradition large amounts of cells with GANT61 characteristics equivalent to those cultured using traditional, flask centered, methods. Electronic supplementary material The online version GANT61 of this article (10.1186/s12967-019-1989-x) contains supplementary material, which is available to authorized users. Keywords: Bioreactor, Mesenchymal stromal cells, Cell therapy Background Cell-based therapies have the potential to become treatment options for many diseases , but efficient scale-out of these therapies has proven to be a major hurdle [2, 3]. The production of adherent cells for restorative purposes is particularly hard, due to the need for a large surface area to increase cells to clinically relevant numbers. Traditionally, adherent cell growth for clinical software involves cell tradition in large numbers of flasks in incubators installed in cleanroom facilities. This method requires heavy operator involvement as the tradition needs to become seeded, refreshed, passaged and harvested separately and by hand. The high costs of cell production in flasks poses a risk to the commercial viability of these cell-based therapies by jeopardizing the positive end result of a costCbenefit assessment, which is necessary for therapy reimbursement . As a result, the need for more efficient tradition methods that would enable a common deployment of cell therapies is definitely well established . Several alternatives that aim to address the specific problems associated with flask tradition have come to promote. These include stacked and multi-layered flask systems, as well as numerous bioreactor systems. The use of bioreactors reduces the amount of labour and allows more space-effective production. Moreover, the use of closed systems enables cell therapy medicinal product (CTMP) developing in environments with less stringent good developing practise (GMP) classification therefore reducing production costs, compared to growth using flasks. However, changing the tradition methods can expose changes to the characteristics and features of the cell products , as the properties of the cell product may switch upon small changes in cell manipulation. Therefore, it is crucial to investigate whether proposed fresh tradition methods result in a product that GANT61 is similar in terms of identity, safety and potency . Mesenchymal stromal cells (MSCs) are currently investigated for medical application in numerous trials rendering this adherent cell populace highly relevant for cell therapy developing using bioreactors. Here we investigate the possibility to efficiently generate MSCs using a novel, closed bioreactor system (Scinus), designed for automated cell growth. We compared the characteristics of MSC populations produced with three different tradition methods. We expanded MSCs on dissolvable microcarriers in the Scinus and in spinner flaskswhich are a down-scaled model for bioreactor tradition- and compared this to the traditional flask-based MSC production method. The assessment included MSC growth potential and important attributes of the producing cell populations. The growth potential was assessed in MSC ethnicities where the MSCs were expanded to restorative relevant figures (typically multiple infusions at a dose range of 1C2 millions of cells per kg of recipients body weight, amounting to several hundred millions of cells). MSCs have been attributed many practical properties ..