Evaluating the Homing Potential of Adipose-Derived Stromal Cells Following Dorsal Subcutaneous Injection in a Rat Fat Graft Model.

Abstract

BACKGROUND: Cell-assisted lipotransfer is a fat-grafting technique that uses adipose tissue from lipoaspirates mixed with adipose-derived stromal cells (ASCs) to enhance fat graft survival. Intravenously injected ASCs migrate to the fat graft site via circulatory system; however, a large portion of circulatory ASCs can get trapped in the lungs, reducing the amount of available ASCs for fat graft. The molecular and cellular mechanisms modulating ASC homing remain unclear. We aimed to investigate the migration and infiltration of ASCs to adjacent fat graft when injected subcutaneously. METHODS: A fat graft was implanted on the dorsal side of Sprague-Dawley rats without genetic modification. Green fluorescent protein (GFP)-ASCs were harvested from genetically engineered Sprague-Dawley rats and injected subcutaneously cephalically away from the fat graft at 0, 1, and 2 cm. The migration and fate of the injected GFP-ASCs in relation to fat grafts were monitored using an in vivo imaging system for 4 weeks, and GFP fluorescence in fat graft was examined under a microscope. RESULTS: Cell migration was observed at both 1 and 2 cm from the fat graft. However, ASC infiltration to the fat graft was greater at a distance of 1 cm away from the graft than at 0 and 2 cm. CONCLUSION: ASC migration into fat grafts was observed after subcutaneous injection. ASCs injected at a distance of 1 cm showed positive retention rates ASCs those mixed directly with the fat graft or those injected at a greater distance (2 cm) from the fat graft. ASCs successfully migrated to fat grafts, with greater infiltration observed when the injection site was closer This migration capacity underscores the importance of injection site proximity in optimizing ASC delivery We provide a novel approach to enhance fat graft survival NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.