多核巨细胞在人发生物材料降解中的超微观察

Ultrastructural observation of multinuclear giant cell during the process of degeneration and clearing of human hair

目的:在超微结构水平观察人发生物材料修复周围神经缺损过程中自身的降解与多核巨细胞的关系。方法:制备SD大鼠坐骨神经缺损模型,用人发生物材料来桥接缺损的坐骨神经,电镜观察巨噬细胞与多核巨细胞对降解的人发生物材料吞噬消化过程。结果:术后3周,巨噬细胞聚集在人发周围,毛小皮已经开始剥脱断裂;6周时,人发周围出现由多个巨噬细胞融合形成的多核巨细胞,均质状的崩解颗粒及部分毛小皮碎片被巨噬细胞吞噬;12周时,有些皮质颗粒已降解为角蛋白细丝,巨噬细胞内含有大量颗粒。结论:在人发生物材料的降解过程中,多核巨细胞作为屏障隔离了材料和宿主组织细胞,毛小皮断裂的碎片和疏松的皮质颗粒,被巨噬细胞所吞噬,然后在大量溶酶体酶的水解下,完成对人发生物材料的清除。

Objective： To observe the changes ofmultinuclear giant cell during the process of degeneration and elimination of human hair in repairing injured peripheral nerve. Methods： To prepare the SD rat model of sciatic nerve damage, and implant the human hair. Electronic microscopy was performed to explore the ultrastructural changes ofmultinuclear giant cell during the process of degeneration and clearing of human hair. Results： The hair cuticle was denudated and degraded at the 3rd week. The human hair was surrounded by many macrophages. At the 6th week after the human hair implantation, the human hair biomaterial was surrounded by multinuclear giant cells fused by many macrophages. Human hair cortex was homogenous and began to collapse. The fragments of human hair were surrounded and wrapped by macrophages. At the 12th week, some human hair was degenerated into filament and granules which were wrapped and degenerated by macrophages. Conclusions： During the process of degeneration of human hair, multinuclear giant cells isolate the biomaterial and the host organization cell as the barrier. The deciduous fragments of human hair are wrapped, digested and eliminated by lysosomal enzyme in macrophages.