Lima Verde Maria Elisa Quezado, Ferreira-Júnior Antonio Ernando Carlos, de Barros-Silva Paulo Goberlânio, Miguel Emilio de Castro, Mathor Monica Beatriz, Lima-Júnior Edmar Maciel, de Moraes-Filho Manoel Odorico, Alves Ana Paula Negreiros Nunes
Post Graduate Program in Dentistry, Faculty of Pharmacy, Dentistry and Nursing, Federal University of Ceará, Fortaleza, Ceará, Brazil; Drugs Research and Development Center, Federal University of Ceará, Fortaleza, Ceará, Brazil.
Analytical Center, Physics Department, Science Center, Federal University of Ceará, Fortaleza, Ceará, Brazil.
Acta Histochem. 2021 Sep;123(6):151762. doi: 10.1016/j.acthis.2021.151762. Epub 2021 Jul 29.
Nile tilapia (Oreochromis niloticus) skin is a well-known biomaterial used as an occlusive dressing for burn treatment. It is also an inexpensive and important source of collagen. This study aims to describe the ultrastructural aspects of Nile tilapia skin, assess its collagen amount and organization, and compare quantitative methods of histochemical and immunohistochemical analysis (in all sterilization steps for use in burn dressings). One sample (0.5 × 0.5 cm) of ten different fish skins was divided in four groups: in natura skin (IN), chemical sterilization (CH), additional irradiation (30 kGy) (IR), and skins used in burn treatment (BT) to compare histochemical and immunohistochemical findings of collagen amount and describe ultrastructural aspects through scanning electron microscopy. The amount of type I collagen decreased during sterilization and clinical use owing to gradual reduction of immunostaining (anti-collagen-I) and decreasing fiber thickness of the collagen, when compared to type III (Picrosirius-red-polarized light). The collagen fibers were rearranged at each sterilization step, with a low collagen percentage and large structural disorganization in BT. The amount of type-I collagen was further reduced after BT (p < 0.05). Both the methods did not exhibit a quantified value difference (p = 0.247), and a positive correlation (r = 0.927; 95 % CI = 0.720-0.983) was observed between them, with concordance for collagen quantification in similar samples, presenting a low systematic error rate (Dalberg coefficient: 6.70). A significant amount of type-I collagen is still observed despite sterilization, although clinical application further reduces type I collagen. Its quantification can be performed both by immunohistochemistry and/or Picrosirius Red reliably.
尼罗罗非鱼（Oreochromis niloticus）皮是一种知名的生物材料，用作烧伤治疗的封闭敷料。它也是胶原蛋白的一种廉价且重要的来源。本研究旨在描述尼罗罗非鱼皮的超微结构特征，评估其胶原蛋白的含量和组织结构，并比较组织化学和免疫组织化学分析的定量方法（用于烧伤敷料的所有灭菌步骤）。将十个不同鱼皮的样本（0.5×0.5厘米）分为四组：天然皮肤（IN）、化学灭菌（CH）、额外照射（30千戈瑞）（IR）和用于烧伤治疗的皮肤（BT），以比较胶原蛋白含量的组织化学和免疫组织化学结果，并通过扫描电子显微镜描述超微结构特征。与III型胶原蛋白（天狼星红偏振光）相比，在灭菌和临床使用过程中，I型胶原蛋白的含量由于免疫染色（抗胶原蛋白-I）逐渐减少和胶原蛋白纤维厚度降低而减少。在每个灭菌步骤中，胶原蛋白纤维都会重新排列，BT组中胶原蛋白百分比低且结构紊乱严重。BT后I型胶原蛋白的含量进一步降低（p<0.05）。两种方法均未显示出定量值差异（p = 0.247），且两者之间存在正相关（r = 0.927；95%CI = 0.720 - 0.983），在相似样本中胶原蛋白定量具有一致性，系统误差率低（达尔伯格系数：6.70）。尽管经过灭菌处理，但仍观察到大量的I型胶原蛋白，不过临床应用会进一步减少I型胶原蛋白。其定量可通过免疫组织化学和/或天狼星红可靠地进行。
