Generation of Red Blood Cells From Human Embryonic Stem Cells (ES) with Increased Efficacy

Abstract 4334

It is estimated that for every unit of donated blood, two units are required in North America. The current rate of blood donation is stagnant while the need increases by 6–8% annually. In order to overcome this difficulty, we have developed an improved method to generate red blood cells from human embryonic stem cells (H9) with increased efficacy. In addition to xeno-free conditions and standard cytokine cocktail used for hematopoietic differentiation of human embryonic stem cells (Carrier et al. J Transl Med. 2009; Vol 7: 27), we have introduced a new method of improved growth and differentiation of human ES cells with hypoxia-induced mesenchymal stem cells, obtained from allogeneic adult bone marrow donors. This technique increased efficacy of red blood cell production by 5–25 fold.

We have developed a bioscaffold–> microsphere-based culture system with highly porous surface allowing culturing of a very large number of embryonic stem cells per one culture condition. This culture system avoids shear forces and damage to the cells, and facilitates removal and recycling of the microspheres. The in vitro obtained human ES-derived red blood cells are enucleated and do not produce tumors (efficacy of enucleation is 65–95%). The laser-based system is utilized to eliminate nucleated cells from the culture.

The problem with hES-derived red blood cells is that they are produced in small numbers and process is very costly. We are developing a 3-phase bioreactor with computerized programming, which will increase every step of the differentiation process and allow recycling of feeder cells and cytokines. In this system we will utilize iron-loaded microspheres coated with hypoxia-processed mesenchymal stem cells as a main culture unit. The in vitro generated human ES-derived red blood cells upscaled in a bioreactor will be used for the off-shelf production of red blood cells for clinical use.