Characterization of Decellularized Human Pericardium for Tissue Engineering and Regenerative Medicine Applications.

BACKGROUND: Pericardium tissue allograft can be used for surgical repair in several procedures. One of the tissue engineering strategies is the process of decellularization. This process decreases immunogenic response, but it may modify the natural extracellular matrix composition and behavior. OBJECTIVE: The aim of this study was to evaluate the effectiveness of cell removal, maintenance of extracellular matrix properties and mechanical integrity of decellularized human pericardium using a low concentration solution of sodium dodecyl sulfate. METHODS: Decellularization was performed with sodium dodecyl sulfate and ethylenediaminetetraacetic acid. Histological analysis, DNA quantification, evaluation of glycosaminoglycans and collagen were performed. Biomechanical assay was performed using tensile test to compare the decellularization effects on tissue properties of tensile strength, elongation and elastic modulus. P < 0.05 was considered significant. RESULTS: There was reduction in visible nuclei present in pericardium tissue after decellularization, but it retained collagen and elastin bundles similar to fresh pericardium. The DNA contents of the decellularized pericardium were significantly reduced to less than 511.23 ± 120.4 ng per mg of dry weight (p < 0.001). The biomechanical assay showed no significant difference for fresh or decellularized tissue. CONCLUSION: The decellularization process reduces cell content as well as extracellular matrix components without changing its biomechanical properties.

Characterization of Decellularized Human Pericardium for Tissue Engineering and Regenerative Medicine Applications / Caracterização do Pericárdio Humano Descelularizado para Engenharia de Tecidos e Aplicações de Medicina Regenerativa

Abstract Background: Pericardium tissue allograft can be used for surgical repair in several procedures. One of the tissue engineering strategies is the process of decellularization. This process decreases immunogenic response, but it may modify the natural extracellular matrix composition and behavior. Objective: The aim of this study was to evaluate the effectiveness of cell removal, maintenance of extracellular matrix properties and mechanical integrity of decellularized human pericardium using a low concentration solution of sodium dodecyl sulfate. Methods: Decellularization was performed with sodium dodecyl sulfate and ethylenediaminetetraacetic acid. Histological analysis, DNA quantification, evaluation of glycosaminoglycans and collagen were performed. Biomechanical assay was performed using tensile test to compare the decellularization effects on tissue properties of tensile strength, elongation and elastic modulus. P < 0.05 was considered significant. Results: There was reduction in visible nuclei present in pericardium tissue after decellularization, but it retained collagen and elastin bundles similar to fresh pericardium. The DNA contents of the decellularized pericardium were significantly reduced to less than 511.23 ± 120.4 ng per mg of dry weight (p < 0.001). The biomechanical assay showed no significant difference for fresh or decellularized tissue. Conclusion: The decellularization process reduces cell content as well as extracellular matrix components without changing its biomechanical properties.

Resumo Fundameto: O enxerto de pericárdio pode ser usado em muitos procedimentos de correção cirúrgica. Uma das estratégias da engenharia tecidual é o processo de descelularização. No entanto, embora esse processo diminua a resposta imunogênica, a descelularização pode modificar tanto o comportamento como a composição da matriz extracelular natural. Objetivos: Avaliar a eficácia da descelularização usando baixa concentração de dodecil sulfato de sódio na remoção celular, na manutenção das propriedades da matriz extracelular e na integridade mecânica do pericárdio humano descelularizado. Métodos: A descelularização foi realizada com dodecil sulfato de sódio e ácido etilenodiamino tetra-acético. Foi realizada análise histológica, quantificação de DNA, e avaliação de glicosaminoglicanos e colágeno. O estudo biomecânico foi conduzido pelo teste de tração para comparar os efeitos da descelularização sobre as propriedades teciduais de resistência à tração, alongamento e módulo de elasticidade. Foi considerado um valor de p < 0,05 como estatisticamente significativo. Resultados: Observou-se uma redução na quantidade de núcleos presentes no pericárdio após a descelularização, apesar de manter quantidades similares de feixes de elastina e de colágeno. As concentrações de DNA do pericárdio descelularizado foram significativamente reduzidas para menos que 511,23 ± 120,4 ng por mg de peso seco (p < 0,001). O teste biomecânico não apontou diferenças entre os tecidos fresco e descelularizado. Conclusão: A descelularização reduziu a concentração de células bem como os componentes da matriz extracelular sem afetar suas propriedades biomecânicas.

In vitro evaluation of bovine pericardium after a soft decellularization approach for use in tissue engineering.

Pericardial membrane derived from bovine heart tissues is a promising source of material for use in tissue-engineering applications. However, tissue processing is required for its use in humans due to the presence of animal antigens. Therefore, the purpose of this study was to evaluate the structural integrity and biocompatibility of the bovine pericardium (BP) after a soft decellularization process with a 0.1% sodium dodecyl sulfate (SDS) solution, with the aim to remove xenoantigens and preserve extracellular matrix (ECM) bioactivity. The decellularization process promoted a mean reduction of 77% of the amount of DNA in the samples in which cell nuclei staining was undetectable. The ECM content was maintained as mostly preserved after decellularization as well as its biomechanical properties. In addition, the decellularization protocol has proven to be efficient in removing the xenoantigen alpha-gal, which is responsible for immune rejection. The decellularized BP was noncytotoxic in vitro and allowed human adipose-derived stem cell (hASC) adhesion. Finally, after 7 days in culture, the tissue scaffold became repopulated by hASCs, and after 30 days, the ECM protein pro-collagen I was seen in the scaffold. Together, these characteristics indicated that soft BP decellularization with 0.1% SDS solution allows the acquirement of a bioactive scaffold suitable for cell repopulation and potentially useful for regenerative medicine.