Cytotoxicity of PVPAC‐treated bovine pericardium: A potential replacement for glutaraldehyde in biological heart valves

Abstract

Acellular biological tissues, including bovine pericardium (BP), have been proposed as biomaterial for tissue engineering. BP is usually modified chemically to improve mechanical and biological properties using glutaraldehyde, the standard reagent for preservation of fresh bioprosthetic materials. Glutaraldehyde-fixed BP (Glut-BP), the most widely used material in heart valve manufacture, has been associated with calcification in vivo. In an attempt to reduce this issue and maintain its biocompatibility, this study assesses the physical properties and cytotoxicity of lyophilized BP treated with poly (vinylpyrrolidone-co-acrolein) (PVPAC-BP), a novel copolymer, as a substitute for glutaraldehyde. For that, PVPAC-BP surface ultrastructure, elastic function, water uptake and tissue calcification were evaluated. For the analysis of biocompatibility, fibroblasts (3T3-L1) and endothelial cells (HUVEC) were cultured on PVPAC-BP, Untreated-BP and Glut-BP. Nitric oxide (NO) release assay, fluorescence and SEM images of endothelial cells adhered on scaffolds were also performed. As results, the data show some advantages of PVPAC-BP over the Glut-BP. The PVPAC-BP maintains partially the original ultrastructure and elastic properties, improves scaffold hydration, and presents less calcium phosphate deposits. The cells demonstrated strong attachment, high proliferation rate, and formation of a monolayer on PVPAC-BP. Attached cells were also able to release NO de-monstrating regular metabolism. In conclusion, PVPAC may be considered as a promising alternative to BP treatment improving the efficiency of cell attachment and proliferation and also avoid immunogenicity.

Biological Characterization of Human Autologous Pericardium Treated with the Ozaki Procedure for Aortic Valve Reconstruction

“…After having ascertained the absence of toxic effects of the residual GA in the treated autologous pericardium, in the last part of our work we wanted to assess whether the physiological endothelialization of the post-Ozaki samples was affected by the chemical treatment. To answer this question, endothelial cells were seeded on the fibrous layer of the GA-treated pericardium, which in the native valve is the most proximal layer contacting blood [29]. Then, the number of cells was compared to that of HUVEC adhering on the BP control membranes after 4 days of culture, as performed by others on bovine pericardium substrates [30,31].…”

Postfunctionalization of biological valve leaflets with a polyphenol network and anticoagulant recombinant humanized type III collagen for improved anticoagulation and endothelialization

“…3 The common commercial BHVs, crosslinked with glutaraldehyde (GLUT), have the advantages of improved mechanical properties and reduced immunogenicity. 4,5 However, GLUT-crosslinked BHVs without further treatment would suffer from severe thrombosis, violent inflammation, calcification, and delayed endothelialization. Among these ailments, the coagulation response specifically exacerbates subsequent calcification and impedes the endothelialization process.…”