Exosomes Are Comparable to Source Adipose Stem Cells in Fat Graft Retention with Up-Regulating Early Inflammation and Angiogenesis
Jiankun Cao, Ran Xiao
Abstract
Sir: We read the article entitled “Exosomes Are Comparable to Source Adipose Stem Cells in Fat Graft Retention with Up-Regulating Early Inflammation and Angiogenesis” by Chen et al.1 published in Plastic and Reconstructive Surgery. The effects of stem cell–enriched fat grafting have been evaluated by many experiments since cell-assisted lipotransfer was first introduced by Matsumoto et al.2 A meta-analysis involving 387 cases demonstrated that cell-assisted lipotransfer had better efficacy than non–cell-assisted lipotransfer.3 In the article by Chen et al., exosomes and source adipose stem cells showed similar effects in boosting fat retention with the underlying mechanisms, including up-regulation of early inflammation and angiogenesis. This study confirmed that exosomes could be used as a cell-free alternative strategy in fat grafting. We appreciate the work and want to discuss some questions with the authors. The authors stated that at the first injection, 1 × 104 cells of adipose-derived stem cells or 40 μg of adipose-derived stem cell–derived exosomes were injected under the mouse skin. Why did they use 40 μg of exosomes? Were 40 μg of adipose-derived stem cell–derived exosomes comparable to 1 × 104 adipose-derived stem cells? If the doses are not comparable, should the conclusion be different? Besides, at the second and third injections, the exosome groups were injected with adipose-derived stem cell–derived exosomes, whereas cell-assisted lipotransfer groups were injected with phosphate-buffered saline. Why were cell-assisted lipotransfer groups not injected with adipose-derived stem cells? In conclusion, the authors presented an excellent study regarding the effects of exosomes, which may have great therapeutic potential in tissue repair and regenerative medicine. We expect further studies to provide more information. DISCLOSURE Neither author has a financial interest to declare in relation to the content of this communication.