Impact of Long-term Storage in 4% Formaldehyde on Immunophenotypic Markers in Glutaraldehyde-treated Bovine Pericardium

• Published in: Applied immunohistochemistry & molecular morphology Vol. 32; no. 9; pp. 442 - 445
• Main Authors: Gewehr, Douglas M, Carvalho, Pedro E P, Izar, Fernanda P, Haddad, Alexandre G, Falkenbach Tenius, Victor D, Giovanini, Allan F, Kubrusly, Luiz F
• Format: Journal Article
• Language: English
• Published: United States 01-10-2024
• ISSN: 1541-2016; 1533-4058; 1533-4058
• DOI: 10.1097/PAI.0000000000001221

Bovine pericardium (BP) is widely used as a biomaterial for tissue engineering. Glutaraldehyde and formaldehyde are commonly employed in the reticulation processes to enhance the material's resistance and preservation. In this study, we assessed the impact of long-term storage in 4% formaldehyde on the quantitative expression of immunophenotypic markers in glutaraldehyde-treated BP. Histologic and immunohistochemical analyses were performed on 2 BP patches, manufactured in 2009 and 2020, respectively. Braile Biomédica provided the BP patches. Sections of BP were stained with H&E, Weigert, and picrosirius red, followed by immunolabeling for vimentin, laminin 5, collagen I, and collagen IV using a standardized protocol. Microscopic images were captured using light and polarized microscopy, and the area of the antibody signal was quantified using Image J Software. Histologic analysis showed no autolysis or significant changes in the patches. Immunohistochemical analysis revealed a diffuse distribution of collagen I and collagen IV throughout the connective tissue of the patches. The 2020 specimen exhibited higher expression levels of collagen I (21.36%) and collagen IV (24.67%) compared with the 2009 specimen (collagen I: 15.87%; collagen IV: 12.02%). Laminin did not show reactivity in either specimen. Notably, vimentin immunopositivity differed significantly between the patches, with a larger area of expression observed in the 2020 patch (54%) compared with the 2009 patch (13%). In summary, there were no substantial differences in immunophenotypic expression between the 2009 and 2020 BP patches, except for the higher vimentin expression in the 2020 BP patch.