Accepted Article Histopathological Assessment of OASIS Ultra on critical sized wound healing: a pilot study Daniel Dante Yeh MD 1,2 *; Rosalynn M. Nazarian, MD 2,3 *; Leah Demetri, BA 2 ; Tomaz Mesar, MD 1,2 ; Suzan Dijkink, BSc 1 ; Andreas Larentzakis, MD 1,2 ; George Velmahos, MD, PhD 1,2 ; Karim Walid Sadik, MD, MPH 1,2 * Equally contributing authors 1 Department of Surgery, Division of Trauma, Emergency Surgery and Surgical Critical Care, Massachusetts General Hospital, Boston, Massachusetts, USA 2 Harvard Medical School, Boston, Massachusetts, USA 3 Department of Pathology, Dermatopathology Unit, Massachusetts General Hospital, Boston, Massachusetts, USA Financial Support: Smith & Nephew provided an unrestricted education grant and provided the investigational product used in this study Clinicaltrials.gov registration number: NCT01848821 Short running head: OASIS Ultra for critical sized wounds Financial Support: Smith & Nephew provided an unrestricted education grant and provided the investigational product used in this Investigator Initiated Trial. The sponsor had no role in the study design, conduct, data collection, or data analysis. None of the authors report any financial conflicts of interest. Key Words: Wound healing, fibrosis, acute inflammation, extracellular matrix, OASIS Corresponding Author: Daniel Dante Yeh, MD FACS 165 Cambridge St. #810 Boston, MA 02114 dyeh2@partners.org 617-724-8604 Fax: 617-726-9121 Abstract This article is protected by copyright. All rights reserved. This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1111/cup.12925