A partially-aerated airlift bioreactor for expansion of microencapsulated stem cells

IntroductionDeveloping culture systems for production of required clinical amounts of stem cells from only a few initial harvested cells is crucial for medical applications .ObjectivesThe main goal of present study is to design an airlift bioreactor system to expand stem cells with minimal shear stress exertion. For this purpose, the aerated placed part way up cells to form an aerated and a non-aerated zone inside the bioreactor. Indeed, cells were microencapsulated to maintain them in non-aerated zone. Airlift bioreactor was used with height of 15 cm, diameter of 3 cm and total volume of 70 ml and airflow rate of 0.1 VVM. MethodsFibroblast and U937 cells as a model anchorage-dependent and suspension stem cells, were used and microencapsulated by alginate (1.25%) and gelatin (2%) with cell density of 106 cell/ml and were cultured for 7 days in the airlift bioreactor and T-flask. MTT assay was used for proliferation analysis and glucose and produced lactate were also evaluated. Culture medium also exchanged every 2 days. Results The microencapsulated U937 cells cultured in the bioreactor did not show a significant difference in cell expansion s compared to T-flask cultures, reaching to 16 million cells after 7 days. The microencapsulated fibroblast cells, however, proliferated 10% more when they were cultured in the bioreactor, reaching to 14.8 million after one week. ConclusionThe study demonstrated that the partially-aerated airlift bioreactor can be considered as a potential culture system for microencapsulated stem cells

Keywords:

Airlift bioreactor , Stem cell expansion , Partially-aerated