Bone Marrow Stem Cells in Response to Intervertebral Disc-Like Matrix Acidity and Oxygen Concentration

Study Design. In vitro culture of porcine bone marrow stem cells (BMSCs) in varying pH microenvironments in a threedimensional hydrogel system. Objective. To characterize the response of BMSCs to varying pH environments (blood [pH 7.41, healthy intervertebral disc (IVD) (pH 7.1), mildly degenerated IVD (pH 6.8), and severely degenerated IVD (pH 6.5) in three-dimensional culture under normoxic (20%) and hypoxic (5%) conditions. Summary of Background Data. The IVD is an avascular organ relying on diffusion of essential nutrients through the cartilaginous endplates (CEPs) thereby creating a challenging microenvironment. Within a degenerated IVD, oxygen and glucose concentrations decrease further (<5% oxygen, <5 mmol/L glucose) and matrix acidity (