β-Tricalcium Phosphate Micron Particles Enhance Calcification of Human Mesenchymal Stem Cells In Vitro

Abstract EN

β-Tricalcium phosphate (β-TCP) micron particles whose diameters range from 1 μm to 10 μm have been recently developed, however, their biological effects remain unknown.

We investigated the biological effects of β-TCP micron particles on proliferation, cytotoxicity, and calcification of human synovial mesenchymal stem cells (MSCs).

MSCs were cultured without dexamethasone, β-glycerophosphate, or ascorbic acid.

1.0 mg/mL β-TCP micron particles inhibited proliferation of MSCs significantly and increased dead cells.

In the contact condition, 0.1 mg/mL β-TCP micron particles promoted calcification of MSCs evaluated by alizarin red staining and enhanced mRNA expressions of runx2, osteopontin, and type I collagen.

In the noncontact condition, these effects were not observed.

0.1 mg/mL β-TCP micron particles increased calcium concentration in the medium in the contact condition, while 1.0 mg/mL β-TCP micron particles decreased calcium and phosphorus concentrations in the medium in the noncontact condition.

By transmission electron microscopy, β-TCP micron particles were localized in the phagosome of MSCs and were dissolved.

In conclusion, β-TCP micron particles promoted calcification of MSCs and enhanced osteogenesis-related gene expressions in vitro.