L2C, Univ Montpellier, CNRS, Montpellier, France.
MMDN, Univ Montpellier, EPHE, INSERM, Montpellier, France; IUF, Intitut Universitaire de, France, Paris.
Nanomedicine. 2023 Sep;53:102699. doi: 10.1016/j.nano.2023.102699. Epub 2023 Aug 11.
Spinal cord injury is a dramatic disease leading to severe motor, sensitive and autonomic impairments. After injury the axonal regeneration is partly inhibited by the glial scar, acting as a physical and chemical barrier. The scarring process involves microglia, astrocytes and extracellular matrix components, such as collagen, constructing the fibrotic component of the scar. To investigate the role of collagen, we used a multimodal label-free imaging approach combining multiphoton and atomic force microscopy. The second harmonic generation signal exhibited by fibrillar collagen enabled to specifically monitor it as a biomarker of the lesion. An increase in collagen density and the formation of more tortuous fibers over time after injury are observed. Nano-mechanical investigations revealed a noticeable hardening of the injured area, correlated with collagen fibers' formation. These observations indicate the concomitance of important structural and mechanical modifications during the fibrotic scar evolution.
脊髓损伤是一种严重的疾病，会导致严重的运动、感觉和自主功能障碍。损伤后，轴突再生部分受到神经胶质瘢痕的抑制，神经胶质瘢痕充当物理和化学屏障。瘢痕形成过程涉及小胶质细胞、星形胶质细胞和细胞外基质成分，如胶原，构成瘢痕的纤维性成分。为了研究胶原的作用，我们使用了一种多模式无标记成像方法，结合多光子和原子力显微镜。纤维状胶原产生的二次谐波信号使其能够作为病变的生物标志物进行特异性监测。损伤后，胶原密度增加，纤维变得更加扭曲。纳米力学研究表明，损伤区域的硬度明显增加，与胶原纤维的形成有关。这些观察结果表明，在纤维性瘢痕演变过程中存在重要的结构和力学变化。
