Producing platelet from umbilical cord blood stem cells by bioreactor

Abstract

Objectives: The platelet component play key role in the treatment of thrombocytopenia. Today, Platelets are only obtained through blood donation. However, due to the limitations in preparation and storage, they are produced in laboratories, especially through bioreactors, which convert megakaryocytes from stem cells into large-scale injectable platelets. Material/methods: In this study, the CD34+ cells, isolated from cord blood, were differentiated into megakaryocytes. A new bioreactor which consisted of six compartments and a two-layer scaffold made of collagen and natural tragacanth gum and several ECM factors, and human cryopreciptate were used to mimic the structure of the bone marrow. After adding megakaryocytes to the scaffold, the platelets were produced due to the flow pressure and from the interaction between the scaffold structure and factors. Results: CD41 + cells were expanded 100 times as much as CD34 + cord blood stem cells. Each megakaryocyte that was loaded into the scaffold collagen produced 17.8 platelets and from the scaffold collagen-tragacanth and the pure tragacanth scaffold, it produced 23.46 and 9.44 platelets, respectively The mean platelet release from one megakaryocyte in pure collagen scaffold was 17.42 platelets, by adding fibrin, fibronectin, hyaluronic acid and cryopreciptate to collagen it was 21.4, 22.4, 23.9 and 27.37 respectively, with the simultaneous addition of three factors to collagen (CFFH) 30.52 platelets, and by adding 4 factors (CFFHC) the number of platelets reached to 34. Conclusion: Functional platelets can be produced on a large scale with a multi-chamber bioreactor using a collagen-tragacanth scaffold and combination of ECM and cryopreciptate with collagen scaffolding. It can be said that this scaffold and bioreactor design can be efficient in bone marrow simulation to produce large-scale injectable platelets. Keywords: Bioreactor, Scaffold, Tragacanth, Megakaryocyte, Platelet, cryopreciptate, Umbilical cord blood stem cell