Enhancing repair of full-thickness excisional wounds in a murine model: Impact of tissue-engineered biological dressings featuring human differentiated adipocytes Pascal Morissette Martin a,b , Amandine Maux a,b , Véronique Laterreur a,b,d , Dominique Mayrand a,b , Valérie L. Gagné a,b , Véronique J. Moulin a,b,c , Julie Fradette a,b,c,⇑ a Laval University Tissue Engineering Laboratory/LOEX, Québec, QC, Canada b Division of regenerative medicine, CHU de Quebec Research Centre, Québec, QC, Canada c Department of Surgery, Faculty of Medicine, Laval University, Québec, QC, Canada d Department of Mechanical Engineering, Faculty of Sciences and Engineering, Laval University, Québec, QC, Canada article info Article history: Received 29 November 2014 Received in revised form 18 April 2015 Accepted 23 April 2015 Available online 29 April 2015 Keywords: Skin Wound healing Adipose-derived stem cells Adipocytes Tissue engineering abstract Promotion of skin repair for acute or chronic wounds through the use of tissue-engineered products is an active field of research. This study evaluates the effects mediated by tissue-engineered biological dress- ings containing human in vitro-differentiated adipocytes and adipose-derived stromal cells (ASCs). Re-epithelialization, granulation tissue formation and neovascularization of full-thickness cutaneous wounds were specifically assessed using a murine model featuring a fluorescent epidermis. In comparison with wounds that did not receive an adipocyte-containing biological dressing, treated wounds displayed a slight but significantly faster wound closure based on macroscopic observations over 18 days. Non-invasive imaging of GFP-expressing keratinocytes determined that the kinetics of re-epithelialization were similar for both groups. Treated wounds featured thicker granulation tissues (1.7-fold, P < 0.0001) enriched in collagens (1.3-fold, P < 0.0104). In addition, wound cryosections labeled for detection of CD31-expressing cells indicated a 2.2-fold (P < 0.0002) increased neovascularization for the treated wounds at the time of terminal biopsy. This is in accordance with the secretion of pro-angiogenic factors detected in media conditioned by the dressings. Taken together, these results establish that a new type of engineered substitutes featuring a mixture of adipocytes and ASCs can pro- mote cutaneous healing when applied as temporary dressings, suggesting their potential relevance for chronic wound management studies. Ó 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. 1. Introduction Chronic wounds and skin ulcers are major burdens for health care systems, in particular in the context of aging populations with an increasing proportion of diabetic patients [1]. During their life- time, 15–25% of diabetic patients will develop at least one diabetic foot ulcer [2]. Among innovative methods developed to promote cutaneous healing, strategies relying on the therapeutic properties of mesenchymal stem/stromal cells (MSCs) are actively investi- gated (reviewed in [3]). Indeed, preclinical studies reported that MSCs derived from bone-marrow [4–6], cord blood and cord stroma [7,8], amniotic fluid [9,10] and adipose tissue (AT) [11,12] contribute to wound healing by acting upon the complex repair processes mediating wound closure, which comprise re-epithelialization, granulation tissue formation and angiogenesis. In particular, the paracrine effects of MSCs after their injection/implantation were reported to enhance repair in various contexts of tissue injury through the secretion of growth factors and angiogenic modulators [13,14]. Among MSCs, human adipose-derived stromal/stem cells (ASCs) are excellent candidates for cell-based therapies and tissue-engineering applications. Indeed, subcutaneous AT is abun- dant and easily harvested using a syringe or a minimally invasive lipoaspiration procedure. http://dx.doi.org/10.1016/j.actbio.2015.04.036 1742-7061/Ó 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. ⇑ Corresponding author at: CMDGT/LOEX, Aile-R, CRCHU de Québec – Hôpital Enfant-Jésus, 1401, 18e Rue, Québec, QC G1J 1Z4, Canada. Tel.: +1 418 990 8255x1713 (office); fax: +1 418 990 8248. E-mail addresses: pascal.morissette-martin.1@ulaval.ca (P. Morissette Martin), am.maux@gmail.com (A. Maux), veronique.laterreur.1@ulaval.ca (V. Laterreur), dominique.mayrand.1@ulaval.ca (D. Mayrand), valerie.l-gagne.1@ulaval.ca (V. L. Gagné), veronique.moulin@chg.ulaval.ca (V.J. Moulin), julie.fradette@chg. ulaval.ca (J. Fradette). URL: http://www.loex.qc.ca (J. Fradette). Acta Biomaterialia 22 (2015) 39–49 Contents lists available at ScienceDirect Acta Biomaterialia journal homepage: www.elsevier.com/locate/actabiomat