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

• Main Authors: Yusuke Nakagawa, Takeshi Muneta, Kunikazu Tsuji, Shizuko Ichinose, Yasuharu Hakamatsuka, Hideyuki Koga, Ichiro Sekiya
• Format: Article
• Language: English
• Published: Hindawi Limited 2013-01-01
• Series: Journal of Nanomaterials
• Online Access: http://dx.doi.org/10.1155/2013/426786

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.