Rotating bed reactor setup for in situ formation, loading and handling of alginate beads and whole cell encapsulation
Video showing the formation of alginate beads under conditions mimicking whole cell encapsulation. The use of a SpinChem® rotating bed reactor (RBR) allowed easy collection, maturing and washing of the alginate beads. With the RBR setup, it was possible to immediately continue with filling of the reaction substrate into the same vessel, thus reducing the number of handling steps and facilitating bead recycling. The beads showed no signs of physical wear after use in the RBR.
Conditions: A SpinChem® S2 RBR with only outer filter was rotated at 50 rpm in an aqueous calcium chloride solution (200 mL, 50 mM) in a SpinChem® V2 flower-baffled reaction vessel, while an alginate solution (3.6%) mixed 1:1 with a simulated cell suspension consisting of 50 mM phosphate-buffered saline (PBS) coloured with methylene blue (100 mg/L), was added dropwise through a fine-tipped needle. The alginate beads formed instantaneously and were slowly drawn into the RBR where they were solidified for 10 min, after which the rotational speed was increased to 300 rpm and the vessel was drained from solution, washed with fresh aqueous calcium chloride solution and drained again. Pure water was added to mimic a substrate solution and finally the RBR was stopped and emptied from alginate beads which was observed to have an intact round morphology.