Novel three-dimensional long-term bone marrow culture system using polymer particles with grafted epoxy-polymer-chains supports the proliferation and differentiation of hematopoietic stem cells

Abstract

Hematopoiesis occurs in the bone marrow, where primitive hematopoietic cells proliferate and differentiate in close association with a three-dimensional (3D) hematopoietic microenvironment composed of stromal cells. We examined the hematopoietic supportive ability of stromal cells in a 3D culture system using polymer particles with grafted epoxy polymer chains. Umbilical cord blood-derived CD34(+) cells were co-cultivated with MS-5 stromal cells. They formed a 3D structure in the culture dish in the presence of particles, and the total numbers of cells and the numbers of hematopoietic progenitor cells, including colony-forming unit (CFU)-Mix, CFU-granulocyte-macrophage, CFU-megakaryocyte and burst-forming unit-erythroid, were measured every seven days. The hematopoietic supportive activity of the 3D culture containing polymer particles and stromal cells was superior to that of 2D culture, and allowed the expansion and maintenance of hematopoietic progenitor cells for more than 12 weeks. Various types of hematopoietic cells, including granulocytes, macrophages and megakaryocytes at different maturation stages, appeared in the 3D culture, suggesting that the CD34(+) cells were able to differentiate into a range of blood cell types. Morphological examination showed that MS-5 stromal cells grew on the surface of the particles and bridged the gaps between them to form a 3D structure. Hematopoietic cells slipped into the 3D layer and proliferated within it, relying on the presence of the MS-5 cells. These results suggest that this 3D culture system using polymer particles reproduced the hematopoietic phenomenon in vitro, and might thus provide a new tool for investigating hematopoietic stem cell-stromal cell interactions.

A Human Hematopoietic Niche Model Supporting Hematopoietic Stem and Progenitor Cells In Vitro

“…To mimic the endosteal niche, hydrogels (e.g., Matrigel, collagen, Puramatrix, alginate, or PEG) or bone mimicking materials (e.g., βTCP, hydroxyapatite, or bioderived bone) have been used. In addition to these materials, models used either stromal cell lines or human primary cells as supportive cell sources. The primary cell sources are multipotent mesenchymal stromal cells (MSCs) or osteogenic differentiated MSCs (O‐MSCs) .…”

Co‐cultured hBMSCs and HUVECs on human bio‐derived bone scaffolds provide support for the long‐term ex vivo culture of HSC/HPCs

“…Therefore, it was failed to mimic the in vivo HSC niche described as a 3D microenvironment within BM, although to the knowledge of human HSC biology is unquestionable. In recent years, many studies have proved that 3D‐cultures of HSC/HPCs were obviously superior to bi‐dimensional (2D) culture . Unfortunately, so far, there was still neither a suitable HSC/HPCs culture system to provide a satisfied platform for studying cellular biology nor a system for exploring the in vivo counterpart for using in clinic.…”

“…In recent years, many studies have proved that 3D-cultures of HSC/HPCs were obviously superior to bi-dimensional (2D) culture. 2,15 Unfortunately, so far, there was still neither a suitable HSC/HPCs culture system to provide a satisfied platform for studying cellular biology nor a system for exploring the in vivo counterpart for using in clinic. Our previous study have demonstrated that the bio-derived bone scaffold (BDBS) made from human femur preserved natural spongy architecture of trabecular bones to more closely mimic HSC niche in vivo and showed excellent biocompatibility to feeder cells in vitro.…”

Stem‐Cell Niche Based Comparative Analysis of Chemical and Nano‐mechanical Material Properties Impacting Ex Vivo Expansion and Differentiation of Hematopoietic and Mesenchymal Stem Cells

“…Five main types of 3D scaffolds have been used in stem‐cell cultures: hydrogels,126 macroporous scaffolds,141, 142 fibrous mesh,62 interpenetrating networks143 and microspheres 64, 144. Each scaffold type has its own advantages over others in supporting ex vivo expansion and differentiation of stem cells.…”

“…When HSPCs were cultured in 3D culture systems (e.g., PET mesh, porous collagen microbeads and tantalum‐coated porous biomaterial), enhanced expansion of progenitor cells and longer ex vivo maintenance was obtained compared to cells in 2D cultures and on TCPS control surfaces 62, 64, 141, 142, 156, 157. The 3D environment can apparently synergize with other cues, including cytokines,158 ECMs62 and stromal cells,144 in supporting expansion of HSPCs. Cook et al developed another interesting and novel 3D culture system for HSPC expansion 159.…”