Avaliação morfológica da resposta tecidual e da expressão de metaloproteinases ao implante subcutâneo de fragmentos de Luffa aegyptiaca mill em ratos

Abstract

Biomaterials are three-dimensional structures produced in the laboratory or extracted from nature that shows morphofunctional compatibility with animal tissues. They are used to replace or induce the regeneration of injured tissues and organs. Luffa aegyptiaca mill is a vegetable species, known as Loofah that has a porous and fibrous fruit, consisting of chitin. These characteristics give it a potential use as a support for cellular processes involved in tissue regeneration. Thus, this work aimed to evaluate, through the tissue response and the expression of MMPs (matrix metalloproteinases), the biocompatibility potential of the subcutaneous implant of Luffa aegyptiaca mill fragments in rats, in the periods of 15, 45, and 90 days. The tissues responses were assessed by analyzing the count of eosinophils and mast cells and by depositing collagen in the fibrous capsule using histological routine stains. The expression of MMP-2 and MMP-9 was analyzed by immunohistochemistry and zymography methods. The results showed statistical differences between the times evaluated for the number of eosinophils and mast cells present inside and outside the fibrous capsule. Still, it was observed the permanent presence of macrophages and multinucleated giant cells circumscribing the implants. A progressive increase in the deposition of collagen in the capsule was also detected, but there was a significant reduction in the time of 90 days, and also, visually, a reduction in the thickness of the fibrous capsule was observed during this period. The expression of MMP-9 was more specific in the multinucleated giant cells at all times evaluated, and the expression of MMP-2 was detected in fat cells present around the implants, mainly in the time of 90 days. Within the limits of this work, we can conclude that the tissue response process to the subcutaneous implantation of fragments of Luffa aegyptiaca mill in rats is within an acceptable level, without an intense foreign body granulomatous reaction and the fibrous capsule with a tendency to reduce its thickness and that the metalloproteinases may participate in this responses indicating potential biocompatibility between the plant loofah and the evaluated animal tissue.