Quantitative correlations among human mesenchymal stem cell mechanical properties and biological function

Abstract

Mesenchymal stem cells (MSCs) are derived from bone marrow, and are capable of proliferating and differentiating along multiple pathways such as osteoblasts, chondrocytes and adipocytes. MSCs offer the means for regenerative therapies not possible with conventional small molecule/antibody/ nucleic acid therapeutics. However, all MSCs are not equivalent. Adult MSCs (aMSCs) derived from infant or adult sources are heterogeneous, exhibit poor overall integration in host tissues, and their differentiation and proliferation capacities are limited by ex vivo culture. On the other hand, fetal MSCs (fMSCs) derived from fetuses are more homogeneous, plastic and grow faster than aMSCs. However, they face serious ethical and practical issues that limit their applications. For these reasons, we hypothesized that aMSC populations contain a subpopulation with similar biophysical and biological properties to fMSCs. To verify this thesis, we studied aMSC size distribution, aMSC migration velocity and aMSC mechanical properties. We explain later in this work why we chose these characteristics. We were then able to find a subpopulation of aMSCs with similar size distribution to fMSCs. We were not able to find a subpopulation of aMSCs with similar migration velocity to fMSCs. At last, we were able to prove the existence of a subpopulation of aMSCs with similar mechanical properties to fMSCs.