title: Prediction of heat-induced collagen shrinkage by use of second harmonic generation microscopy.
abstract: Collagen shrinkage associated with denaturation from thermal treatment has a number of important clinical applications. However, individualized treatment is hindered by the lack of reliable noninvasive methods to monitor the process of collagen denaturation. We investigate the serial changes of collagen denaturation from thermal treatment of rat tail tendons at 58 degrees C by use of second harmonic generation (SHG) microscopy. We find that rat tail tendon shrinks progressively from 0 to 9 min of thermal treatment, and remains unchanged in length upon further thermal treatment. The SHG intensity also decreases from 0 to 9 min of thermal treatment and becomes barely detectable from further thermal treatment. Collagen shrinkage and the SHG intensity are well correlated in a linear model. In addition, SHG imaging reveals a tiger-tail-like pattern of collagen denaturation. The bands of denatured collagen progressively widen from increased thermal treatment and completely replace the adjacent bands of normal collagen after 9 min of thermal treatment. Our results show that collagen denaturation in rat tail tendon from thermal treatment is inhomogeneous, and that SHG intensity can be used to predict the degree of thermally induced collagen shrinkage. With additional development, this approach has the potential to be used in biomedical applications.
authors.affiliation: National Taiwan University Hospital and College of Medicine, Department of Dermatology, Taipei.
authors.forename: Sung-Jan
authors.initials: SJ
authors.lastname: Lin
authors.forename: Wen
authors.initials: W
authors.lastname: Lo
authors.forename: Hsin-Yuan
authors.initials: HY
authors.lastname: Tan
authors.forename: Jung-Yi
authors.initials: JY
authors.lastname: Chan
authors.forename: Wei-Liang
authors.initials: WL
authors.lastname: Chen
authors.forename: Shiou-Han
authors.initials: SH
authors.lastname: Wang
authors.forename: Yen
authors.initials: Y
authors.lastname: Sun
authors.forename: Wei-Chou
authors.initials: WC
authors.lastname: Lin
authors.forename: Jau-Shiuh
authors.initials: JS
authors.lastname: Chen
authors.forename: Chih-Jung
authors.initials: CJ
authors.lastname: Hsu
authors.forename: Jeng-Wei
authors.initials: JW
authors.lastname: Tjiu
authors.forename: Hsin-Su
authors.initials: HS
authors.lastname: Yu
authors.forename: Shiou-Hwa
authors.initials: SH
authors.lastname: Jee
authors.forename: Chen-Yuan
authors.initials: CY
authors.lastname: Dong
mesh_terms: D000818:Animals; D003094:Collagen / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure*; D006358:Hot Temperature; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D018613:Microscopy, Confocal / Q000379:methods*; D011487:Protein Conformation / Q000528:radiation effects; D051381:Rats; D013710:Tendons / Q000737:chemistry* / Q000166:cytology* / Q000528:radiation effects
chemical_list: D003094:Collagen