College of Photonics, National Yang Ming Chiao Tung University, Tainan, Taiwan.
Orthopaedic Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan.
Sci Rep. 2022 Nov 2;12(1):18453. doi: 10.1038/s41598-022-21876-z.
In this study, we extend on the three parameter analysis approach of utilizing a noninvasive dual-liquid-crystal-based polarization-resolved second harmonic generation (SHG) microscopy to facilitate the quantitative characterization of collagen types I and II in fracture healing tissues. The SHG images under various linear and circular polarization states are analyzed and quantified in terms of the peptide pitch angle (PA), SHG-circular dichroism (CD), and anisotropy parameter (AP). The results show that the collagen PA has a value of 49.26° after 2 weeks of fracture healing (collagen type II domination) and 49.05° after 4 weeks (collagen type I domination). Moreover, the SHG-CD and AP values of the different collagen types differ by 0.05. The change tendencies of the extracted PA, SHG-CD, and AP parameters over the healing time are consistent with the collagen properties of healthy nonfractured bone. Thus, the feasibility of the proposed dual-liquid-crystal-based polarization-SHG method for differentiating between collagen types I and II in bone fracture healing tissue is confirmed.
在这项研究中，我们扩展了利用基于双液晶体的无侵入性偏振分辨二次谐波产生（SHG）显微镜的三参数分析方法，以促进对骨折愈合组织中 I 型和 II 型胶原的定量特征分析。我们根据肽间距角（PA）、SHG-圆二色性（CD）和各向异性参数（AP），对各种线性和圆偏振状态下的 SHG 图像进行分析和量化。结果表明，骨折愈合后 2 周的胶原 PA 值为 49.26°（II 型胶原主导），4 周后为 49.05°（I 型胶原主导）。此外，不同类型胶原的 SHG-CD 和 AP 值相差 0.05。提取的 PA、SHG-CD 和 AP 参数随愈合时间的变化趋势与健康非骨折骨的胶原特性一致。因此，证实了基于双液晶体的偏振-SHG 方法在区分骨骨折愈合组织中 I 型和 II 型胶原的可行性。
