Abstract-Terahertz spectroscopy of human skin tissue models with different melanin content

Xomalin G. Peralta, Dawn Lipscomb, Gerald J. Wilmink, and Ibtissam Echchgadda

Fig. 1 Human skin tissue model. (a) Schematic illustration of the wells used for culturing skin tissue models. (b-d) Top down digital photographs of (b) Asian, (c) Black, and (d) Caucasian skin tissue models on Day 16.

https://www.osapublishing.org/boe/abstract.cfm?uri=boe-10-6-2942

Terahertz imaging has been proposed for burns and skin cancer identification. However, the role of melanocytes, melanosomes, melanin content and distribution in determining the terahertz optical properties of human skin has not been investigated. We use terahertz time domain spectroscopy to measure the optical properties of in vitro pigmented human skin tissue models from Asian, Black, and Caucasian donors. Spectra were collected at various time intervals and used to extract the absorption coefficient and index of refraction at terahertz frequencies. Our results indicate that the degree of cell differentiation and type of donor both contribute to the measured terahertz optical properties.

Abstract-Microfluidic Devices for Terahertz Spectroscopy of Live Cells Toward Lab-on-a-Chip Applications

Qi Tang 1

, Min Liang 1

, Yi Lu 2

, Pak Kin Wong 2

, Gerald J. Wilmink 3

, Donna D. Zhang 4

 and Hao Xin 1,* 

1 Department of Electrical and Computer Engineering, University of Arizona, Tucson, AZ 85721, USA2 Department of Biomedical Engineering, Pennsylvania State University, University Park, PA 16802, USA3 WiseWear Corporation, New York, NY 10018, USA4 College of Pharmacy, University of Arizona, Tucson, AZ 85721, USA

* Author to whom correspondence should be addressed.

http://www.mdpi.com/1424-8220/16/4/476

THz spectroscopy is an emerging technique for studying the dynamics and interactions of cells and biomolecules, but many practical challenges still remain in experimental studies. We present a prototype of simple and inexpensive cell-trapping microfluidic chip for THz spectroscopic study of live cells. Cells are transported, trapped and concentrated into the THz exposure region by applying an AC bias signal while the chip maintains a steady temperature at 37 °C by resistive heating. We conduct some preliminary experiments on E. coli and T-cell solution and compare the transmission spectra of empty channels, channels filled with aqueous media only, and channels filled with aqueous media with un-concentrated and concentrated cells.