Effects of microenvironmental engineering on the stemness of human umbilical cord mesenchymal stem cells

Table 1 Comparison of the ex vivo culture microenvironment and native in vivo microenvironment of human umbilical cord mesenchymal stem cells

Feature	In vivo native microenvironment	Ex vivo conventional culture	Consequences of ex vivo deviation
Oxygen tension	Physiological hypoxia (1%-5% O2)[21,22]	Atmospheric normoxia (21% O2)[22,23]	Oxidative stress, accelerated senescence, loss of stemness markers
ECM	Native 3D ECM rich in collagen, fibronectin, and hyaluronic acid; provides biochemical and topographical cues[9,21]	Rigid 2D plastic surface; absence of native ECM composition and architecture[6,9]	Disrupted cell-ECM interactions, altered mechanotransduction, spontaneous differentiation
Cell-cell interactions	Extensive cell-cell contacts within a 3D niche; paracrine signaling networks[8,19]	Limited to 2D monolayer contacts; reduced cell-cell communication[24,25]	Altered signaling pathways, reduced stemness maintenance
Mechanical cues	Soft tissue-specific stiffness (e.g., 0.1-1 kPa for soft tissues); dynamic mechanical forces[9,29]	Supraphysiological stiffness (GPa range of plastic); static, non-physiological substrate[9,29]	Activation of differentiation pathways (e.g., Yes-associated protein/transcriptional coactivator with PDZ-binding motif), loss of multipotency
Biochemical signals	Complex niche-derived soluble factors (growth factors and cytokines) from neighboring cells[7,8]	Simplified culture media; often supplemented with xenogeneic serum (fetal bovine serum)[34,35]	Altered signaling profiles, reduced immunomodulatory capacity
Physical architecture	3D spatial organization with native tissue structure[9,21]	2D planar culture with non-physiological geometry[24,25]	Loss of native cell morphology, altered cytoskeletal organization

ECM: Extracellular matrix; 3D: Three-dimensional; 2D: Two-dimensional.