Biohybrid hematopoietic niche for expansion of hematopoietic stem/progenitor cells by using geometrically controlled fibrous layers

The expansion of hematopoietic stem/progenitor cells (HSPCs), which can give rise to all types of mature blood cells, is one of the actual challenges of regenerative medicine. In this study, we propose a construction of a 3D hematopoietic niche for the coculture of HSPCs and mesenchymal stem cells, which was prepared from geometrically controlled electrospun fibrous layers. The proliferation activity, retention of CD34(+)CD38(-) immunophenotype and multipotency of the HSPCs in the artificial hematopoietic niche were analyzed by FACS and colony-forming unit assay. Results showed that the 3D biohybrid hematopoietic niche has a capacity to support self-renewal of HSPCs, maintaining their primitive phenotype and accommodate a large number of expanded cells. The geometry of the artificial niche served as a physical cue that controlled chemical signals to facilitate successful in vitro expansion and retention of HSPCs potential to differentiate into various lineages.