title: The discrimination of type I and type II collagen and the label-free imaging of engineered cartilage tissue.
abstract: Using excitation polarization-resolved second harmonic generation (SHG) microscopy, we measured SHG intensity as a function of the excitation polarization angle for type I and type II collagens. We determined the second order susceptibility (χ((2))) tensor ratios of type I and II collagens at each pixel, and displayed the results as images. We found that the χ((2)) tensor ratios can be used to distinguish the two types of collagen. In particular, we obtained χ(zzz)/χ(zxx) = 1.40 ± 0.04 and χ(xzx)/χ(zxx) = 0.53 ± 0.10 for type I collagen from rat tail tendon, and χ(zzz)/χ(zxx) = 1.14 ± 0.09 and χ(xzx)/χ(zxx) = 0.29 ± 0.11 for type II collagen from rat trachea cartilage. We also applied this methodology on the label-free imaging of engineered cartilage tissue which produces type I and II collagen simultaneously. By displaying the χ((2)) tensor ratios in the image format, the variation in the χ((2)) tensor ratios can be used as a contrast mechanism for distinguishing type I and II collagens.
authors.affiliation: Department of Physics, National Taiwan University, Taipei 106, Taiwan.
authors.forename: Ping-Jung
authors.initials: PJ
authors.lastname: Su
authors.forename: Wei-Liang
authors.initials: WL
authors.lastname: Chen
authors.forename: Tsung-Hsien
authors.initials: TH
authors.lastname: Li
authors.forename: Chen-Kuan
authors.initials: CK
authors.lastname: Chou
authors.forename: Te-Hsuen
authors.initials: TH
authors.lastname: Chen
authors.forename: Yi-Yun
authors.initials: YY
authors.lastname: Ho
authors.forename: Chi-Hsiu
authors.initials: CH
authors.lastname: Huang
authors.forename: Shwu-Jen
authors.initials: SJ
authors.lastname: Chang
authors.forename: Yi-You
authors.initials: YY
authors.lastname: Huang
authors.forename: Hsuan-Shu
authors.initials: HS
authors.lastname: Lee
authors.forename: Chen-Yuan
authors.initials: CY
authors.lastname: Dong
mesh_terms: D000818:Animals; D002356:Cartilage / Q000166:cytology / Q000502:physiology*; D024042:Collagen Type I / Q000378:metabolism*; D024043:Collagen Type II / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008954:Models, Biological; D051381:Rats; D013194:Staining and Labeling; D013710:Tendons / Q000166:cytology; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D024042:Collagen Type I; D024043:Collagen Type II