title: Sterilization of Lung Matrices by Supercritical Carbon Dioxide.
abstract: Lung engineering is a potential alternative to transplantation for patients with end-stage pulmonary failure. Two challenges critical to the successful development of an engineered lung developed from a decellularized scaffold include (i) the suppression of resident infectious bioburden in the lung matrix, and (ii) the ability to sterilize decellularized tissues while preserving the essential biological and mechanical features intact. To date, the majority of lungs are sterilized using high concentrations of peracetic acid (PAA) resulting in extracellular matrix (ECM) depletion. These mechanically altered tissues have little to no storage potential. In this study, we report a sterilizing technique using supercritical carbon dioxide (ScCO2) that can achieve a sterility assurance level 10(-6) in decellularized lung matrix. The effects of ScCO2 treatment on the histological, mechanical, and biochemical properties of the sterile decellularized lung were evaluated and compared with those of freshly decellularized lung matrix and with PAA-treated acellular lung. Exposure of the decellularized tissue to ScCO2 did not significantly alter tissue architecture, ECM content or organization (glycosaminoglycans, elastin, collagen, and laminin), observations of cell engraftment, or mechanical integrity of the tissue. Furthermore, these attributes of lung matrix did not change after 6 months in sterile buffer following sterilization with ScCO2, indicating that ScCO2 produces a matrix that is stable during storage. The current study's results indicate that ScCO2 can be used to sterilize acellular lung tissue while simultaneously preserving key biological components required for the function of the scaffold for regenerative medicine purposes.
authors.affiliation: 1 Department of Biomedical Engineering, Yale University School of Medicine , New Haven, Connecticut.|2 Department of Anesthesiology, Yale University School of Medicine , New Haven, Connecticut.
authors.forename: Jenna L
authors.initials: JL
authors.lastname: Balestrini
authors.affiliation: 1 Department of Biomedical Engineering, Yale University School of Medicine , New Haven, Connecticut.
authors.forename: Angela
authors.initials: A
authors.lastname: Liu
authors.affiliation: 1 Department of Biomedical Engineering, Yale University School of Medicine , New Haven, Connecticut.
authors.forename: Ashley L
authors.initials: AL
authors.lastname: Gard
authors.affiliation: 3 NovaSterilis, Inc. , Lansing, New York.
authors.forename: Janet
authors.initials: J
authors.lastname: Huie
authors.affiliation: 3 NovaSterilis, Inc. , Lansing, New York.
authors.forename: Kelly M S
authors.initials: KM
authors.lastname: Blatt
authors.affiliation: 1 Department of Biomedical Engineering, Yale University School of Medicine , New Haven, Connecticut.
authors.forename: Jonas
authors.initials: J
authors.lastname: Schwan
authors.affiliation: 1 Department of Biomedical Engineering, Yale University School of Medicine , New Haven, Connecticut.
authors.forename: Liping
authors.initials: L
authors.lastname: Zhao
authors.affiliation: 4 Department of Cell Biology and Physiology, Washington University St. Louis , St. Louis, Missouri.
authors.forename: Tom J
authors.initials: TJ
authors.lastname: Broekelmann
authors.affiliation: 4 Department of Cell Biology and Physiology, Washington University St. Louis , St. Louis, Missouri.
authors.forename: Robert P
authors.initials: RP
authors.lastname: Mecham
authors.affiliation: 1 Department of Biomedical Engineering, Yale University School of Medicine , New Haven, Connecticut.
authors.forename: Elise C
authors.initials: EC
authors.lastname: Wilcox
authors.affiliation: 1 Department of Biomedical Engineering, Yale University School of Medicine , New Haven, Connecticut.|2 Department of Anesthesiology, Yale University School of Medicine , New Haven, Connecticut.
authors.forename: Laura E
authors.initials: LE
authors.lastname: Niklason
mesh_terms: D000072283:A549 Cells; D000818:Animals; D002245:Carbon Dioxide / Q000494:pharmacology*; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D008168:Lung / Q000187:drug effects / Q000502:physiology*; D055595:Mechanical Phenomena / Q000187:drug effects; D010463:Peracetic Acid / Q000494:pharmacology; D017207:Rats, Sprague-Dawley; D013242:Sterilization / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry
chemical_list: D002245:Carbon Dioxide; D010463:Peracetic Acid