A novel high throughput screening platform reveals an optimised cytokine formulation for human hematopoietic progenitor cell expansion.

The main limitations of hematopoietic cord blood (CB) transplantation, viz. low cell dosage and delayed reconstitution, can be overcome by ex-vivo expansion. CB expansion under conventional culture causes the rapid cell differentiation and depletion of hematopoietic stem/progenitor cells (HSPC) responsible for engraftment. Here, we use combinatorial cell culture technology (CombiCult®) to identify media formulations that promote CD133+ CB HSPC proliferation while maintaining their phenotypic characteristics. We employed second generation CombiCult® screens that use electro-spraying technology to encapsulate CB cells in alginate beads. Our results suggest that, not only the combination, but also the order of addition of individual components has a profound influence on expansion of specific HSPC populations. Top protocols identified by the CombiCult® screen were used to culture human CD133+ CB HSPCs on nanofiber scaffolds and validate the expansion of the phenotypically defined CD34+CD38lo/-CD45RA-CD90+CD49f+ population of hematopoietic stem cells and their differentiation into defined progeny