One of the paradigms of tissue engineering is cell transplantation (discussed in cant), for example, to restore failed liver function.
Since the human body does not have any 'spare' hepatocylee, allogeneic' liver cells are to be encapsulated and implanted into patients.
In designing the cell-encapsulation process, it is important that the cells receive enough oxygen to survive. Suppose Met we encapsulated a hepatocme aggrega. of 150um M diameter in a layer of a hiocompatible hydrogel and kept the capsule in a well-mixed cell-culture media.
Determine the maximum layer of the hydrogel membrane that would result in an oxygen concentration of at least 1.104 mol/mL everywhere in the capsule.
Assume that the diffusivity of oxygen in the hydrogel is similar to that in the cells (2x10-5 cm2/s) and that the bulk oxygen concentration is 3.5 x 10-8 mol/mL/s.
The maximum uptake ate of oxygen by the cells is 3.5 x 10-8 moL/mL/s. You may assume steady stale and zero order reaction kinetics.
Take the critical oxygen concentration needed as 6.10-8 mol/mL.