Department of Plastic and Reconstructive Surgery, Kindai University Faculty of Medicine, Osaka-sayama, Japan.
J Biomed Mater Res B Appl Biomater. 2023 Jan;111(1):16-25. doi: 10.1002/jbm.b.35128. Epub 2022 Jul 14.
Among various biomaterials, we focused on nanofiber-based polyglycolic acid (PGA) fabric and examined the dynamics of cells that migrate within the non-woven fabric after implantation. The efficacy of nano-PGA as a tissue reinforcement in the process of subcutaneous tissue repair was immunohistochemically investigated. Two types of clinically available PGA non-woven sheet (nano-PGA: fiber diameter = 2.0 μm, conventional PGA: fiber diameter = 14.2 μm) were used and subcutaneously implanted in rats. Samples were collected 3 days, and 1, 2, 3, and 4 weeks after the implantation to perform histological and immunohistochemical (CD68, CD163, α-SMA, Type I collagen, CD34, MCP-1, IL-6, TNF-α, TGF-β, VEGF, IgG) examinations to assess the expression of molecules related to inflammation or tissue repair. Immunohistochemical analysis in nano-PGA revealed that the intensity and positive cells (CD68, MCP-1, IL-6, TNF-α) significantly increased which indicated an early inflammatory response. This was followed by phagocytosis of nano-PGA with foreign body giant cells and CD68+ macrophages. Finally, the number of proliferating cells (CD163, α-SMA, TGF-β) and angiogenesis (CD34, VEGF) for tissue repair promoted the formation of collagen fibers (type I collagen). Unlike nano-PGA, implantation of conventional PGA sheet resulted in a prolonged inflammatory response and was characterized by the presence of discontinuous collagen fibers with many foreign body giant cells, which did not lead to tissue repair. Nano-PGA sheets demonstrated a better tissue compatibility compared with conventional PGA by inducing early polarization to M2 phenotype macrophages, which triggered subsequent angiogenesis and tissue repair in the subcutaneous tissue.
在各种生物材料中，我们专注于基于纳米纤维的聚乙醇酸（PGA）织物，并研究了细胞在植入后的非织造织物中的迁移动力学。通过免疫组织化学研究了纳米 PGA 作为皮下组织修复过程中组织增强的效果。使用了两种临床可用的 PGA 无纺片（纳米 PGA：纤维直径=2.0μm，常规 PGA：纤维直径=14.2μm），并将其植入大鼠皮下。在植入后 3 天、1 周、2 周、3 周和 4 周收集样本，进行组织学和免疫组织化学（CD68、CD163、α-SMA、I 型胶原、CD34、MCP-1、IL-6、TNF-α、TGF-β、VEGF、IgG）检查，以评估与炎症或组织修复相关分子的表达。纳米 PGA 的免疫组织化学分析表明，强度和阳性细胞（CD68、MCP-1、IL-6、TNF-α）显著增加，表明早期炎症反应。随后是纳米 PGA 的吞噬作用，伴有异物巨细胞和 CD68+巨噬细胞。最后，增殖细胞（CD163、α-SMA、TGF-β）和血管生成（CD34、VEGF）的数量增加促进了胶原蛋白纤维（I 型胶原蛋白）的形成。与纳米 PGA 不同，常规 PGA 片的植入导致炎症反应延长，其特征是存在许多异物巨细胞的不连续胶原蛋白纤维，这不会导致组织修复。纳米 PGA 片通过诱导早期向 M2 表型巨噬细胞极化，表现出比常规 PGA 更好的组织相容性，从而触发随后的血管生成和皮下组织修复。
