www.parjournal.net Original Article Open Access Yang et al. Plast Aesthet Res 2020;7:8 DOI: 10.20517/2347-9264.2019.63 Plastic and Aesthetic Research © The Author(s) 2020. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/ ), which permits unrestricted use, sharing, adaptation, distribution and reproduction in any medium or format, for any purpose, even commercially, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. Comparison of adipose particle size on autologous fat graft retention in a rodent model Xiaonan Yang 1,2,# , Francesco M. Egro 1,# , Taraneh Jones 3 , W. Vincent Nerone 1 , Michael Yousefpour 1 , Jeffrey A. Gusenoff 1 , J. Peter Rubin 1,4 , Lauren E. Kokai 1,4 1 Department of Plastic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA. 2 No.16 Department of Plastic Surgery, Plastic Surgery Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China. 3 Department of Chemical Engineering, University of Pittsburgh, Pittsburgh, PA 15213, USA. 4 McGowan Institute for Regenerative Medicine, Pittsburgh, PA 15219, USA. # Authors contributed equally. Correspondence to: Dr. Lauren E. Kokai, Department of Plastic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA. E-mail: kokail@upmc.edu How to cite this article: Yang X, Egro FM, Jones T, Nerone WV, Yousefpour M, Gusenoff JA, Rubin JP, Kokai LE. Comparison of adipose particle size on autologous fat graft retention in a rodent model. Plast Aesthet Res 2020;7:8. http://dx.doi.org/10.20517/2347-9264.2019.63 Received: 27 Nov 2019 First Decision: 17 Jan 2020 Revised: 3 Feb 2020 Accepted: 14 Feb 2020 Published: 27 Feb 2020 Science Editor: Jian-Xing Song Copy Editor: Jing-Wen Zhang Production Editor: Tian Zhang Abstract Aim: Unpredictable retention outcomes remain a significant issue in autologous fat grafting procedures. Liposuction cannula variation leads to variability in fat particle size. Recent data suggest that the size of fat particles is closely related to graft healing outcomes; however, this remains a point of contention due to potential confounding variables such as tissue trauma with harvest. The aim of this study was to compare autologous fat grafting outcomes with variable fat particle sizes in an animal model which isolated fat particle size as the primary experimental variable. The overall goal of this work was to determine if reducing fat particle size is an effective method for enhancing graft retention in autologous fat grafting. Methods: The range of fat particle diameter harvested by four common liposuction cannulas was quantified to define relevant small and large particle target diameters. To determine if particle size impacted nutrient and oxygen permeability, small and large particles were incubated in vitro in a spinner flask with an abundance of culture media and vascular endothelial growth factor secretion was measured with enzyme-linked immunosorbent assay. Finally, small and large fat grafts were prepared from subcutaneous mouse fat pads and grafted in syngeneic Balb/CJ mice. Weight and volume retention were evaluated at 1, 4, 8, and 12 weeks. Histological analysis with Masson’s trichrome and perilipin