Laboratorio di Ingegneria Tissutale Cardiovascolare, Centro Cardiologico Monzino-IRCCS, Milan, Italy.
PLoS One. 2013 May 21;8(5):e64769. doi: 10.1371/journal.pone.0064769. Print 2013.
The pericardial tissue is commonly used to produce bio-prosthetic cardiac valves and patches in cardiac surgery. The procedures adopted to prepare this tissue consist in treatment with aldehydes, which do not prevent post-graft tissue calcification due to incomplete xeno-antigens removal. The adoption of fixative-free decellularization protocols has been therefore suggested to overcome this limitation. Although promising, the decellularized pericardium has not yet used in clinics, due to the absence of proofs indicating that the decellularization and cryopreservation procedures can effectively preserve the mechanical properties and the immunologic compatibility of the tissue.
The aim of the present work was to validate a procedure to prepare decellularized/cryopreserved human pericardium which may be implemented into cardiovascular homograft tissue Banks. The method employed to decellularize the tissue completely removed the cells without affecting ECM structure; furthermore, uniaxial tensile loading tests revealed an equivalent resistance of the decellularized tissue to strain, before and after the cryopreservation, in comparison with the fresh tissue. Finally, immunological compatibility, showed a minimized host immune cells invasion and low levels of systemic inflammation, as assessed by tissue transplantation into immune-competent mice.
Our results indicate, for the first time, that fixative-free decellularized pericardium from cadaveric tissue donors can be banked according to Tissue Repository-approved procedures without compromising its mechanical properties and immunological tolerance. This tissue can be therefore treated as a safe homograft for cardiac surgery.
心包组织通常用于心脏手术中生物假体心脏瓣膜和补片的制作。制备这种组织的方法包括用醛处理，但由于不完全去除异种抗原，不能防止移植后组织钙化。因此，建议采用无固定剂的去细胞化方案来克服这一限制。尽管有前景，但去细胞化心包尚未在临床上使用，因为缺乏证据表明去细胞化和冷冻保存程序可以有效地保持组织的机械性能和免疫相容性。
本研究旨在验证一种制备去细胞/冷冻保存的人心包的方法，该方法可用于心血管同种异体组织库。所采用的方法可彻底去除细胞，而不影响 ECM 结构；此外，与新鲜组织相比，单向拉伸试验表明，冷冻保存前后，去细胞组织的应变阻力相当。最后，通过组织移植到免疫功能正常的小鼠中，免疫相容性显示出宿主免疫细胞入侵减少和全身炎症水平低。
我们的结果首次表明，来自尸体供体的无固定剂去细胞心包可以按照组织库批准的程序储存，而不会损害其机械性能和免疫耐受性。因此，这种组织可以作为心脏手术的安全同种异体移植物进行处理。
