# Exosome-Mediated Enhancement of Fat Graft Retention: A Comparative Preclinical Study with Stromal Vascular Fraction

## TL;DR

Exosomes from fat cells improve fat graft survival better than cell-based methods in mice, offering a safer and more effective alternative for fat grafting.

## Contribution

Demonstrates that exosomes from adipose-derived cells enhance fat graft retention more effectively than stromal vascular fraction cells.

## Key findings

- Exosome-treated fat grafts showed significantly higher volume retention at weeks 4 and 8 compared to controls.
- Exosomes reduced inflammation and preserved more adipocytes while promoting angiogenesis better than SVF cells.
- The results suggest exosomes could be a superior non-cellular alternative to cell-based fat grafting techniques.

## Abstract

Cell-assisted lipotransfer (CAL) is a fat grafting technique that enhances graft survival by supplementing grafts with autologous stromal vascular fraction (SVF) or adipose-derived stromal cells (ASCs). However, its clinical translation has been hindered owing to inherent biological variability, potential cell viability issues, tumorigenic risk, and the complex regulatory landscape associated with cell-based therapies. To overcome these challenges, exosome has gained increasing attention as a promising non-cellular therapeutic modality capable of preserving key regenerative functions while minimizing relative concerns. This study aimed to compare the efficacy of SVF-enriched lipotransfer with fat co-transplanted with

exosomes from ASCs to identify a reliable and clinically applicable non-cellular strategy for optimizing fat graft outcomes.

In vivo, minced human fat tissue mixed with phosphate-buffered saline, SVF cells, or exosomes was grafted into nude mice. Grafts were evaluated through microcomputed tomography at weeks 4 and 8 post-grafting and histological analysis at weeks 1 and 8 post-grafting.

The exosome group showed a significantly higher volume retention rate than the control group at weeks 4 and 8 post-grafting. Histological analysis revealed that exosomes exhibited more pronounced effects in reducing inflammation, preserving perilipin-positive adipocytes, and promoting angiogenesis in the grafted fats compared with those of SVF cells.

Our findings highlight the potential of exosomes in improving fat graft retention and overall tissue regeneration, suggesting that fat co-transplanted with exosomes from ASCs could serve as a superior alternative to SVF-enriched lipotransfer.

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The online version contains supplementary material available at 10.1007/s00266-025-05350-5.