The thermal disruption of collagen I in rat tail tendon is investigated with second-harmonic generation (SHG) microscopy. We investigate its effects on SHG images and intensity in the temperature range 25°-60°C. We find that the SHG signal decreases rapidly starting at 45°C. However, SHG imaging reveals that breakage of collagen fibers is not evident until 57°C and worsens with increasing temperature. At 57°C, structures of both molten and fibrous collagen exist, and the disruption of collagen appears to be complete at 60°C. Our results suggest that, in addition to intensity measurement, SHG imaging is necessary for monitoring details of thermally induced changes in collagen structures in biomedical applications.
© 2005 Optical Society of America
Sung-Jan Lin, Chih-Yuan Hsiao, Yen Sun, Wen Lo, Wei-Chou Lin, Gwo-Jen Jan, Shiou-Hwa Jee, and Chen-Yuan Dong, "Monitoring the thermally induced structural transitions of collagen by use of second-harmonic generation microscopy," Opt. Lett. 30, 622-624 (2005)