Lanthanum-containing bioparticles are associated with the influence of lanthanum on high phosphate mediated bone marrow stromal cells viability.

Lanthanum (La)-based binder appears effective in reducing serum inorganic phosphate (Pi) levels among chronic dialysis patients, yet concern remains about La accumulation in bone during long-term oral administration. In this study, the effect of lanthanum chloride (LaCl) on bone marrow stromal cells (BMSCs) viability was investigated under high Pi situation. We found low concentration (10 M) of LaCl increased BMSCs viability, while high concentration (10 M) of LaCl not only inhibited BMSCs viability but also stimulated high Pi induced cell apoptosis. In addition, La-containing calcium phosphate (CaP) particles can be detected on cell surfaces and inside cells. We also found that inhibition of CaP formation by adding sodium pyrophosphate, a recognized inhibitor of hydroxyapatite formation, abrogated LaCl induced the BMSCs viability. For isolated La-containing CaP particles, the particle size increased and crystal phase switched with elevated concentration of LaCl. These results demonstrated that La-containing CaP particles were associated with the process of LaCl mediated BMSCs viability and the physicochemical properties of these particles played an important role in modulating BMSCs function.