title: Mechanical compliance and immunological compatibility of fixative-free decellularized/cryopreserved human pericardium.
abstract: BACKGROUND
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Laboratorio di Ingegneria Tissutale Cardiovascolare, Centro Cardiologico Monzino-IRCCS, Milan, Italy.
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Vinci
authors.forename: Giulio
authors.initials: G
authors.lastname: Tessitore
authors.forename: Laura
authors.initials: L
authors.lastname: Castiglioni
authors.forename: Francesca
authors.initials: F
authors.lastname: Prandi
authors.forename: Monica
authors.initials: M
authors.lastname: Soncini
authors.forename: Rosaria
authors.initials: R
authors.lastname: Santoro
authors.forename: Filippo
authors.initials: F
authors.lastname: Consolo
authors.forename: Francesca
authors.initials: F
authors.lastname: Colazzo
authors.forename: Barbara
authors.initials: B
authors.lastname: Micheli
authors.forename: Luigi
authors.initials: L
authors.lastname: Sironi
authors.forename: Gianluca
authors.initials: G
authors.lastname: Polvani
authors.forename: Maurizio
authors.initials: M
authors.lastname: Pesce
mesh_terms: D000818:Animals; D003187:Compliance / Q000187:drug effects; D015925:Cryopreservation / Q000379:methods*; D005404:Fixatives / Q000494:pharmacology*; D006801:Humans; D007121:Immunocompetence / Q000187:drug effects; D020007:Implants, Experimental; D008422:Materials Testing; D051379:Mice; D010496:Pericardium / Q000166:cytology* / Q000187:drug effects / Q000276:immunology*; D013314:Stress, Mechanical; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D005404:Fixatives