Spatial structural integrity is important for adipose regeneration after transplantation

Abstract

Advances in structural fat transplantation technology have significantly improved the survival rate and stability of grafts. This study investigated the importance of the spatial structural integrity of adipose tissue for adipose regeneration after fat transplantation. We sought to enhance understanding of structural fat transplantation and optimize procedures used for the clinical acquisition, purification, and transplantation of adipose tissue. In an inactivated structuration adipose tissue model established by freezing at -20 °C for 3 days, nearly all cells were dead but the structure was intact. We transplanted this adipose tissue model (group A) or non-treated adipose tissue (group B) into GFP-expressing mice. Group B showed a higher graft survival percentage and less fibrosis than group A. The macrophage infiltration (F4/80) peak period was longer in group A than in group B. The change in vessel density (CD31) was similar in the two groups: it peaked at 4 weeks after transplantation and decreased thereafter. In both groups, the number of Ki67+ cells showed a similar trend. In comparison to group B, group A had more Ki67+ cells at 4-8 weeks after transplantation, but fewer of these cells at 12 weeks after transplantation. The intact spatial structure of adipose tissue, which is supported by adipocytes and extracellular matrix, provides a niche for adipogenesis and angiogenesis after fat transplantation.

Autologous fat grafting: Harvesting techniques

“…Autologous fat grafting has become increasingly used as a method for multiple volume filling applications. The major obstacle to the widespread of its clinical use is the lack of standardized guidelines during harvesting, processing and implantation steps [ 91 ]. Indeed, many authors have recognized that there is no universally accepted methodology for fat grafting [ 92 , 93 ].…”

Autologous Fat Grafting: The Science Behind the Surgery

“…64 In fact, it has recently been shown that decellularized fat may serve as a scaffold and be repopulated and revascularized after implantation, demonstrating the importance of the mechanical aspects of the adipose-specific niche. 65 The biomechanics of fat transfer therefore should not be ignored, and represent an appropriate lens through which to view the effects of fat procurement, processing, and placement.…”

Phenotypic and Cellular Characteristics of a Stromal Vascular Fraction/Extracellular Matrix Gel Prepared Using Mechanical Shear Force on Human Fat

“…The activity of adipocytes is affected by fat preparation and processing methods (Oranges et al, 2019;Sese et al, 2019;Wei et al, 2019). The key factor contributing to the fat retention rate is the extent of retainment of the integrity and activity of the adipocyte structure in the fat graft (Yuan et al, 2015). In recent years, Kato et al (2014) proposed the three-zone theory of fat transplantation, based on two older theories: the cell survival theory, which states that only one to three layers of mature adipocytes could survive in grafts due to the lack of early blood supply and oxygen content, and the host cell replacement theory, indicating that new adipocytes are formed almost exclusively by the differentiation of ASCs (Billings and May, 1989).…”