A Potentially Scalable Method for the Harvesting of hMSCs from Microcarriers: Initial Results
Conference Recording Aug 11, 2014
About the SpeakerHaving obtained his Masters in Engineering from University College London specialising in Biochemical Engineering, Qasim was part of the original cohort of the newly established Doctoral Training Centre in Regenerative Medicine at Loughborough University where he completed his PhD investigating the development of a standardised manufacturing process for the clinical-scale production of human mesenchymal stem/stromal cells (hMSCs) in collaboration with Lonza under the supervision of Professor Christopher Hewitt. Following a competitive process, Qasim was awarded a 2-year EPSRC E-TERM Landscape Research Fellowship where he is now investigating the use of the ambr automated bioreactor system as a process development tool for hMSC microcarrier culture as well as the utilisation of analytical tools (metabolomics, proteomics and metallomics) to improve hMSC yield and quality. Qasim also leads the hMSC team within the Cell Technologies group at Loughborough University.AbstractThe use of hMSCs for allogeneic therapies requiring lot sizes of billions of cells will necessitate large-scale culture techniques such as the expansion of cells on microcarriers in bioreactors. Whilst much research investigating hMSC culture on microcarriers has focused on growth, much less involves their harvesting for passaging or as a step towards cryopreservation and storage. A successful new harvesting method has recently been outlined for cells grown on SoloHill microcarriers in a 5 L bioreactor . Here, this new method is set out in detail, harvesting being defined as a two-step process involving cell ‘detachment’ from the microcarriers’ surface followed by the ‘separation’ of the two entities. The new detachment method is based on theoretical concepts originally developed for secondary nucleation due to agitation. Based on this theory, it is suggested that a short period (here 7 min) of intense agitation in the presence of a suitable enzyme should detach the cells from the relatively large microcarriers. In addition, once detached, the cells should not be damaged because they are smaller than the Kolmogorov microscale. Detachment was then successfully achieved using microcarrier/cell suspensions up to 100 mL in a spinner flask. Harvesting was completed by separating cells from microcarriers using a Steriflip® vacuum filter. The overall harvesting efficiency was > 95% and after harvesting, the cells maintained all the attributes expected of hMSC cells. The underlying theoretical concepts suggest that the method should be scalable.