A random method for theoretical estimation of RBC osmotic damage in removing CPAs from cryopreserved blood with hollow fiber modules: Closed-loop blood flow mode

A theoretical method is developed to study the effect of the closed-loop blood flow mode on the osmotic damage of red blood cells (RBCs) during the removal of permeable cryoprotective agents (CPAs) from cryopreserved blood with a hollow fiber module. In this method, RBC suspension/blood with CPAs is divided into finite units, which randomly enter the lumen side of hollow fibers by using a random program code; washing solution/dialysate without CPAs is divided into infinite units entering the shell side of hollow fibers continuously. Mass transfer across cell and fiber membranes is calculated by the unsteady-state model proposed in previous study. By this random method, the closed-loop blood flow mode is simulated. Then the effects of blood flow rates, dialysate flow rates, hydraulic permeabilities and solute permeabilities of hollow fibers on the osmotic damage of RBCs are estimated statistically and the washing efficiencies of CPAs are investigated theoretically. The results show that in order to reduce the osmotic damage of RBCs and shorten the washing time of CPAs, choosing hollow fiber modules with low CPA permeabilities, increasing blood flow rates and decreasing dialysate flow rates are highly recommended.