ABC | Volume 113, Nº1, July 2019

Short Editorial Lima et al. Decellularization of human pericardium Arq Bras Cardiol. 2019; 113(1):18-19 1. Hacker MC, Krieghoff J, Mikos AG, Synthetic Polymers. In Principles of Regenerative Medicine , 3 ed. Atala A, Ed. Academic Press: 2018; p. 1428. 2. Hench LL, Polak JM. Third-Generation Biomedical Materials. Science. 2002;295(5557):1014-7. 3. Griffiths LG, Choe LH, Reardon KF, Dow SW, Christopher Orton E. Immunoproteomic identification of bovine pericardium xenoantigens. Biomaterials. 2008;29(26):3514-20. 4. Gilbert TW, Sellaro TL, Badylak SF. Decellularization of tissues and organs. Biomaterials. 2006; 27 (19):3675-83. 5. Vinci MC, Tessitore G, Castiglioni L, Prandi F, Soncini M, Santoro R, et al. Mechanical compliance and immunological compatibility of fixative-free decellularized/cryopreservedhumanpericardium. PLoSOne. 2013; 8 (5):e64769. 6. Inoue H, Iguro Y, Matsumoto H, Ueno M, Higashi A, Sakata R. Right hemi- reconstructionoftheleftatriumusingtwoequinepericardialpatchesforrecurrent malignantfibroushi stiocytoma:Reportofacase.SurgToday .2009;39(8):710-2. 7. Ma B, Wang X, Wu C, Chang J. Crosslinking strategies for preparation of extracellular matrix-derived cardiovascular scaffolds. Regen Biomater. 2014; 1 (1):81-9. 8. SchoenFJ,LevyRJ.Calcificationoftissueheartvalvesubstitutes:progresstoward understanding and prevention. Ann Thorac Surg. 2005; 79 (3): 1072-80. 9. Gilpin A, Yang Y. Decellularization Strategies for Regenerative Medicine: From ProcessingTechniquestoApplications. BiomedResInt.2017Apr;2017:9831534. 10. Wollmann L, Suss P, Mendonça J, Luzia C, Schittini A, Rosa GW. Caracterização do Pericárdio Humano Descelularizado para  Engenharia de Tecidos e Aplicações deMedicina Regenerativa. Arq Bras Cardiol. 2019; 113(1):11-17 . 11. Scarritt ME, Pashos NC, Bunnell BA. A Review of Cellularization Strategies for Tissue Engineering of Whole Organs. Front Bioeng Biotechnol. 2015 Mar;3:43. 12. Akhyari P, Aubin H, Gwanmesia P, Barth M, Hoffmann S, Huelsmann J, et al. The quest for an optimized protocol for whole-heart decellularization: a comparison of three popular and a novel decellularization technique and their diverse effects on crucial extracellular matrix qualities. Tissue Eng Part C Methods. 2011;17(9):915-26. 13. de Souza FR, Dalboni MA, Kaasi A, Pestana JO, Vieyra, AR, de Souza NK. Rapid Protocol of Porcine Kidney Decellularization . Journal of Biomimetics, Biomaterials and Biomedical Engineering. 2018 Aug;38:67-74. 14. Poornejad N, Momtahan N, Salehi AS, Scott DR, Fronk CA, Roeder BL, et al. Efficient decellularization of whole porcine kidneys improves reseeded cell behavior. Biomed Mater. 2016;11(2):025003. 15. Ashcraft TM, Jones K, Border WL, Eghtesady P, Pearl JM, Khoury PR, et al. Factorsaffecting long-termriskofaorticarchrecoarctationaftertheNorwood procedure. Ann Thorac Surg. 2008;85(4):1397-401; discussion 1401-2. 16. Hussein KH, Park KM, Kang KS, Woo HM. Biocompatibility evaluation of tissue-engineered decellularized scaffolds for biomedical application. Mater Sci Eng C Mater Biol Appl. 2016 Oct;67:766-778. 17. WorldHealthOrganization. (WHO).WorldHeart Day. Scale up prevention of heart attack and stroke, 2017 [ cited in 2017 Sep 29 ]. Available from: https://www.who.int/cardiovascular_diseases/world-heart-day/en/ References This is an open-access article distributed under the terms of the Creative Commons Attribution License is performed using SDS detergent (revised by Scarritt et al. 11 ). Despite the structural changes with respect to GAGs, the biomechanical behavior of the matrix was similar to that of fresh tissue, and this enables use in the treatment of tissues that suffer intense mechanical loads, such as those encountered in the cardiovascular system. We observe that one of the field’s great challenges is to unmask the best method of obtaining intact scaffolds. For that purpose, the concentration of the reagents can be modulated to guarantee the ideal ECM composition, and when it is optimized on the basis of the philosophy of “less is more”, the reagents fail considerably in removing completely cell debris, containing cellular DNA. Conversely, when the concentrations used are higher, the opposite is true. 12 . Considering that the success of the techniques of decellularization is directly associated to minimal change in composition, structure and mechanics of tissues, the work of Wollmann et al. 10 is in line with the requirements of perfecting the methods of obtaining decellularized pericardium. In the article, Wollmann et al. 10 investigate mainly the effect of a concentration of SDS described as “low”, of 0.1% (w/v). That concentration is unquestionably low compared to the concentration of 1% used in, for example, decellularization of porcine kidneys. 13 Other authors have adopted the descriptor “low concentration” for 0.5%, also for porcine kidneys. 14 The concept of “low concentration” should be understood in the context of the tissue to be decellularized. For example, 0.1% may be a low concentration for a sub-millimetric tissue, such as pericardium, whereas 0.5% may equally be low for a centrimetric organ, such as the kidney. In addition to the challenge of customizing the concentration to the tissue to be decellularized, the variability between donors hampers the standardization of a scalable decellularization process and suggests that the path to clinical translation requires a customized and not necessarily standardized approach. The use of patches in cardiac surgery is already a well‑established practice, however, the most widely used biological material is of xenogeneic origin and is not submitted to the process of decellularization, increasing the risk of surgical reinterventions. 3,15 The prospect of employing a decellularized pericardial patch, whose structural components are satisfactorily preserved and the antigenic molecules properly eliminated, is consequently of great interest for clinical application. These characteristics have the potential to enhance the signaling in the tissue for the recruitment and adhesion of cells from the recipient patient’s own tissue, to maintain ideal mechanical characteristics, in addition to reducing the immunogenicity of the graft. 16 All this would elevate the durability of the graft, favor adequate tissue regeneration and reduce the propensity to fibrosis and calcification, improving the quality of life of the patient. Considering that cardiovascular disease is the driver of the main causes of death worldwide (31%), 17 developing strategies that lead to products biocompatible for this application and more similar to natural tissue is of great importance to regenerative medicine and, as a consequence, new alternatives are emerging in the quest for an ideal cardiac biomaterial. 19