Calcein Binding to Assess Mineralization in Hydrogel Microspheres.

We describe a method to assess mineralization by osteoblasts within microspheres using calcein. Fluorescence imaging of calcein bound to the calcium in hydroxyapatite permits assessment of the mineralized portion of the extracellular matrix. Colorimetric imaging of Alizarin Red S complexed with calcium also gives measures of mineralization, and in tissue cultures calcein and Alizarin Red S have been shown to bind to the same regions of mineral deposits.

The effect of low-magnitude, high-frequency vibration on poly(ethylene glycol)-microencapsulated mesenchymal stem cells.

Low-magnitude, high-frequency vibration has stimulated osteogenesis in mesenchymal stem cells when these cells were cultured in certain types of three-dimensional environments. However, results of osteogenesis are conflicting with some reports showing no effect of vibration at all. A large number of vibration studies using three-dimensional scaffolds employ scaffolds derived from natural sources.