A novel expansion medium, termed the CTSâ„¢ StemProâ„¢ HSC Expansion Medium, has been shown to enhance the expansion of ex vivo human hematopoietic stem cells.
In a collaborative study between Thermo Fisher Scientific (MD, USA) and the University of Maryland School of Medicine (MD, USA), scientists have developed a xeno-free, serum-free medium which could overcome the issues associated with the ex vivo expansion of harvested human hematopoietic stem-progenitor cells (HSPCs).
Our ability to grow human HSPC cells ex vivo is limited, as the rapid differentiation of HSPCs results in the loss of primitive pluripotent hematopoietic stem cells (HSCs). A culture system to promote pluripotent HSCs would therefore greatly benefit clinical HSC applications.
The team’s research, presented at the American Society of Gene & Cell Therapy (ASGCT) 23rd annual meeting, describes CTSâ„¢ StemProâ„¢ HSC Expansion Medium, a novel tool to overcome these barriers.
In the study, standard primary human CD34+ cells immunopurified from cord blood, mobilized peripheral blood and bone marrow were cultured in the novel HSC Expansion Medium supplemented with FLT3L, SCF, TPO, IL3 and IL6 (FKT36). This produced a higher number of immunophenotype-defined HSPCs when compared to uncultured cells or cells cultured in industry-standard culture media containing FKT36.
Importantly, the team found that CD34+ cells expanded with this medium displayed long-term engraftment potential and multilineage chimerism at 6 months post-transplant in a murine model.
The medium was also found to support gene modifying CD34+ cells with CRISPR-Cas9 gene editing tools — further supporting the potential clinical application of this technique.¯
Source: Becker AH, Moses S, Kim MJ et al. Optimized Culture Medium for Enhanced Ex Vivo Expansion of Human Hematopoietic Stem Cells. ASGCT 2020 Annual Meeting (12-15 May 2020). Abstract: 422.