Maintenance and expansion of hematopoietic stem/progenitor cells in biomimetic osteoblast niche

Abstract

In this study, we employed bio-derived bone scaffold and composited with the marrow mesenchymal stem cell induced into osteoblast to replicate a "biomimetic niche." The CD34(+) cells or mononuclear cells (MNC) from umbilical cord blood were cultured for 2-5 weeks in the biomimetic niche (3D system) was compared with conventional two dimensional cultures (2D system) without adding cytokine supplement. After 2 weeks in culture, the CD34(+) cells from umbilical cord blood in the 3D system increased 3.3-4.8 folds when compared with the initial CD34(+) cells. CD34(+)/CD38(-) cells accounted for 82-90% of CD34(+) cells. After 5 weeks, CD34(+)/CD38(-) cells in the 3D system increased when compared with initial (1.3 ± 0.3 × 10(3) vs. 1.0 ± 0.5 × 10(4), p < 0.05), but were decreased in the 2D system (1.3 ± 0.3 × 10(3) vs. 2.5 ± 0.7 × 10(2), p < 0.05). The CFU progenitors were produced more in the 3D system than in the 2D system (4.6-9.3 folds vs. 1.0-1.5 folds) after 2 weeks in culture, and the colony distribution in the 3D system manifested higher percentage of BFU-E and CFU-GEMM, but in the 2D system was mainly CFU-GM. The LTC-ICs in the 3D system showed 5.2-7.2 folds increase over input at 2 weeks in culture, and maintain the immaturation of hematopoietic progenitor cells (HPCs) over 5 weeks. In conclusion, this new 3D hematopoietic progenitor cell culture system is the first to utilize natural cancellous bone as scaffold with osteoblasts as supporting cells; it is mimicry of natural bone marrow HSC niche. Our primary work has demonstrated it could maintain and expand HSC/HPC in vitro.

In Vitro Modeling of Tissue-Specific 3D Microenvironments and Possibile Application to Pediatric Cancer Research

“…Several 3D models have been developed in order to mimic normal BM niches [171][172][173]. Artificial analogues of BM can accelerate the understanding of hematopoiesis in humans or can be suitable for ex vivo simulation of some aspects of human immune response.…”

Artificial Hematopoietic Stem Cell Niches-Dimensionality Matters

“…The CFU progenitors were more abundant in the 3D-system compared to the 2D-system (4.6-9.3 fold vs. 1.0-1.5 fold) after 2 weeks in culture, and the colony distribution in the3D-system showed a higher percentage of BFU-E and CFU-GEMM, whereas the 2D-system was mainly comprised of CFU-GM colonies. The LTC-ICs in the 3D-system showed 5.2-7.2 fold increase over 2 weeks and maintained the immature state of the hematopoietic progenitor cells (HPCs) over 5 weeks [112]. In an attempt to generate blood progenitor cells, agarose was modified with vascular endothelial growth factor.…”

Skeletal Stem Cell Niche of the Bone Marrow

“…Overall, these spheroid cultures formed submicroenvironments that were recognised differentially by HSCs, thus influencing their positioning near the hypoxic insides and inducing quiescence. Another study used a 3D hematopoietic progenitor cell culture system utilizing natural cancellous bone as a scaffold, seeded with osteoblasts and other bone marrow stromal cells [144]. In this system, certain parts of the ECM of the scaffold were still preserved, and the system demonstrated that it could maintain and expand haematopoietic progenitors efficiently.…”