Abstract-Determination of tenogenic differentiation in human mesenchymal stem cells by terahertz waves for measurement of the optical property of cellular suspensions

Yasuyuki Morita, Kosuke Azuchi, Yang Ju, Satoshi Suzuki, Baiyao Xu and Shuhei Yamamoto

http://iopscience.iop.org/0957-0233/25/6/065703/article
ju@mech.nagoya-u.ac.jp

Department of Mechanical Science and Engineering, Graduate School of Engineering, Nagoya University, Nagoya, Japan
 

Yasuyuki Morita et al 2014 Meas. Sci. Technol. 25 065703. doi:10.1088/0957-0233/25/6/065703
Received 18 November 2013, accepted for publication 28 March 2014. Published 12 May 2014.
© 2014 IOP Publishing Ltd

Abstract

Technology for identifying stem cell-to-tenocyte differentiation that is non-contact and non-destructive in vitro is essential in tissue engineering. It has been found that expression of various RNA and proteins produced by differentiated cells is elevated when human bone marrow mesenchymal stem cells (hBMSCs) differentiate into tenocytes. Also, such biomolecules have absorption bands in the terahertz range. Thus, we attempted to evaluate whether terahertz waves could be used to distinguish hBMSC-to-tenocyte differentiation. Terahertz time-domain spectroscopy (THz-TDS) using femtosecond laser pulses was used for terahertz measurements. HBMSCs differentiated into tenocytes with mechanical stimulation: 10% cyclical uniaxial stretching at 1 Hz for 24 or 48 h. Cellular suspensions before and after differentiation were measured with terahertz waves. Complex refractive index, consisting of a refractive index (real) and an extinction coefficient (imaginary) obtained from the transmitted terahertz signals, was evaluated before and after differentiation at 1.0 THz. As a result, the THz-TDS system enabled discrimination of hBMSC-to-tenocyte differentiation due to the marked contrast in optical parameter before and after differentiation. This is the first report of the potential of a THz-TDS system for the detection of tenogenic differentiation using a non-contact and non-destructive in vitro technique.