DIFFERENCES IN THE EXTRACELLULAR MATRIX OF BOVINE PERICARDIALS TREATED WITH GLUTARALDEHYDE RELATED TO THE STORAGE TIME IN FORMALDEHYDE (Atena Editora)

Abstract

INTRODUCTION: Bovine pericardium is a xenogeneic membrane that requires pre-treatment to be used as an implant in humans. In order to do this, these membranes are treated with a warm solution of deglutaraldehyde, which cross-linking action reduces the immunogenicity of the xenograft and guarantees satisfactory biomechanical properties. These membranes are marketed under the name of "bovine pericardium patches", which are immersed in an aqueous formaldehyde solution as a preservative medium. OBJECTIVES: To evaluate the structure of the extracellular matrix and the microbiological properties of bovine pericardium previously treated with glutaraldehyde and stored in formaldehyde for more than 10 years. To analyze and quantify the presence of collagen fibers (I and IV), laminin and cementin in bovine pericardium from 2009 in comparison with the 2020 bovine pericardium.METHODS: Two patches of bovine pericardium were used. One, which consists of the control group, was produced in the year 2020 and the other, object of study, was produced in the year 2009. After treatment, the membranes were rolled, immersed in 10% formaldehyde, and embedded in paraffin to make the blocks. Cuts of 3um thick were obtained and subjected to HE staining and immunohistochemistry using the technique of streptovidin-perodixed for anti-patches I and IV, anti-vimentin and anti-laminin to ascertain these proteins in the patches. Digital images of the slides were taken, inserted into Photoshop for Windows, and through the image J program. RESULTS: No structural changes were detected when comparing the microscopic aspects between the membranes of 2009 and 2020. Collagen I occupied an area of 21.36% for the 2020 patch and 15.87% for the 2009 patch. Collagen IV occupied 24.67% and 12.02%, respectively, for the 2020 and 2009 patches. Vimentin was identified both in fusiform cells in the middle of the membrane and in areas compatible with vascular membranes.The percentage in cellular content was 54.34% for the 2020 patch and only 13% for the 2009 patch.Alaminin was not reacted among specimens and both membranes were negative for the presence of this protein. CONCLUSION: Although there are no important morphological alterations between the membranes, in this pilot study we can see that the 2009 membrane loses important proteins of sustentation and cellularity, suggesting loss of functional substrate that provides its use.