Improved Long-Term Volume Retention of Stromal Vascular Fraction Gel Grafting with Enhanced Angiogenesis and Adipogenesis

Abstract

Stromal vascular fraction gel has a high long-term retention rate and a unique adipose regeneration mode, involving prompt inflammation and infiltration of immune cells, stimulating rapid angiogenesis and inducing host cell-mediated adipogenesis.

In vivo tissue engineering of an adipose tissue flap using fat grafts and Adipogel

“…Recent studies by other groups provide strong support for the hypothesis that when fat grafting is successful, this is explained by graft remodelling by stem cells rather than by adipocyte survival (Doi et al, 2015;Dong et al, 2015;Eto et al, 2012;Kato et al, 2014;Zhang et al, 2018). Furthermore, we have reported that the vast majority of grafted adipocytes dies when human fat grafts are implanted in a flow-through chamber model or subcutaneously in the scalp (Tang et al, 2018) in mice and yet new fat growth was seen in each case that was largely host derived.…”

“…It is becoming increasingly clear from a number of recent studies that if there is adipocyte survival in grafted fat, this is restricted to the very outermost (100-300 μm) layer (Doi et al, 2015;Dong et al, 2015;Eto et al, 2012;Kato et al, 2014;Tang et al, 2018;Zhang et al, 2018), termed the "survival zone" (Eto et al, 2012). We were unable to identify such a zone in our constructs, and indeed, both adipocytes and adipose-derived stem cells (ASCs; discussed below) throughout the graft showed very poor survival.…”

“…Adipogel could not be demonstrated to improve adipocyte survival in Group 2 compared with Group 1 (fat alone), although surgical complications leading to n = 2 only for the latter at 6 weeks made a strong comparison difficult (p = .11, one-way analysis of variance). That the bulk of graft adipocytes die is not surprising and has been demonstrated in numerous recent experimental studies (Doi et al, 2015;Dong et al, 2015;Eto et al, 2012;Kato et al, 2014;Stillaert et al, 2007;Tang et al, 2018;Zhang et al, 2018).…”

“…Vascularisation and adipogenesis are tightly coordinated events during both development and adulthood (Christiaens & Lijnen, 2010;Han et al, 2011), and vascularisation that is both timely and pervasive is a key aim in adipose tissue engineering (Debels et al, 2013;Kawaguchi et al, 1998;Zhang et al, 2018). When used by itself, Adipogel (Group 3) seemed to facilitate vascular invasion from the AV loop at the earliest time point, compared with Group 2 where the presence of necrotic adipocytes may have impeded invasion through the gel component.…”

Human adipose liquid extract induces angiogenesis and adipogenesis: a novel cell-free therapeutic agent

“…After centrifugation, we found that the processed lipoaspirates were separated into four parts (from top to bottom: lipid portion, lipid-devoid adipose tissue, liquid portion, and cell/tissue debris). The lipid-devoid adipose tissue, namely, extracellular matrix/stromal vascular fraction gel (SVF-gel), was found to have therapeutic ability in inducing angiogenesis and adipogenesis in vivo [20][21][22][23][24]. Unfortunately, the study of the liquid portion acquired from these physically processed lipoaspirates has been ignored.…”