抄録
The establishment of non-invasive evaluation of cartilage tissue is indispensable for clinical applications of tissue-engineered cartilage. About 70% of cartilage tissue is water. Water is separated into "free water" and "bound water", and bound water is thought to be bound to extracellular matrix (ECM) in the case of living tissues. The mechanical properties of cartilage tissue depend on the interaction between water and ECM. Hence, focusing on water is valid for the evaluation of cartilage tissue. Terahertz time domain spectroscopy (THz-TDS) spectra are sensitive to the properties of water and bio-molecules. In this research, investigation of the relationship between THz-TDS spectra, mechanical and biochemical properties was carried out with three type cartilage samples (non-treated, proteoglycan-depletion (guanidine hydrochloride-treated) and chondroitinase-treated samples). Mechanical and biochemical properties are evaluated by equilibrium stress test normalized by peak values and amount of ECM, respectively. The difference in THz-TDS spectra between non-treated and proteoglycan-depletion samples showed two peaks at 0.85THz and 1.55THz. In the chondroitinase-treated samples, the THz-TDS absorbance at 1.55THz related to both mechanical and biochemical properties. It was suggesting that 1.55THz might be related to the absorbance spectra peak of bound water bounded to proteoglycan. Therefore, the possibility of the application of terahertz time domain spectroscopy for non-invasive evaluation of cartilage tissue might be achieved by focusing on this band of frequency.
