Due to the high absorption rate of traditional autologous fat grafting, cell-assisted lipotransfer (CAL) and platelet-rich plasma (PRP)-assisted lipotransfer were developed. The purpose of this article was to evaluate the efficacy and safety of CAL and PRP in promoting the survival of autologous fat grafting through systematic review and meta-analysis. We searched Pubmed, Cochrane Library, Web of Science, and EMBASE for clinical studies on CAL and PRP-assisted lipotransfer published from January 2010 to January 2020. Then a meta-analysis was performed to assess the efficacy of CAL and PRP-assisted lipotransfer through data analysis of fat survival rate. We also assessed the incidence of complications and multiple operations to analyze their safety. A total of 36 studies (1697 patients) were included in this review. Regardless of the recipient area, CAL and PRP-assisted lipotransfer significantly improved the fat survival rate (CAL vs non-CAL: 71% vs 48%, P < 0.0001; PRP vs non-PRP: 70% vs 40%, P < 0.0001; CAL vs PRP: 71% vs 70%, P = 0.7175). However, in large-volume fat grafting, such as breast reconstruction, both increased the incidence of complications and did not decrease the frequency of multiple operations after lipotransfer. Further prospective studies are needed to evaluate the clinical benefits of CAL and PRP-assisted lipotransfer.

Background Mesenchymal stem cell-based acellular therapies have been widely exploited in managing hypertrophic scars. However, low maintenance dose and transitory therapeutic effects during topical medication remain a thorny issue. Herein, this study aimed to optimize the curative effect of adipose-derived stem cell conditioned medium (ADSC-CM) in the prevention of hypertrophic scarring. Methods In the present study, ADSC-CM was concentrated via the freeze-drying procedure. The efficacy of different dose groups (CM, CM5, CM10) was conducted on the proliferation, apoptosis, and α-smooth muscle actin (α-SMA) expression of human keloid fibroblasts (HKFs) in vitro. Incorporation of adipose-derived stem cell concentrated conditioned medium (ADSCC-CM) into polysaccharide hydrogel was investigated in rabbit ear, in vivo. Haematoxylin-eosin (H&E) and Masson’s trichrome staining were performed for the evaluation of scar hyperplasia. Results We noted that ADSCC-CM could downregulate the α-SMA expression of HKFs in a dose-dependent manner. In the rabbit ear model, the scar hyperplasia in the medium-dose group (CM5) and high-dose group (CM10) was inhibited with reduced scar elevation index (SEI) under 4 months of observation. It is noteworthy that the union of CM5 and polysaccharide hydrogel (CM5+H) yielded the best preventive effect on scar hyperplasia. Briefly, melanin, height, vascularity, and pliability in the CM5+H group were better than those of the control group. Collagen was evenly distributed, and skin appendages could be regenerated. Conclusions Altogether, ADSCC-CM can downregulate the expression of α-SMA due to its anti-fibrosis effect and promote the rearrangement of collagen fibres, which is integral to scar precaution. The in situ cross bonding of ADSCC-CM and polysaccharide hydrogel could remarkably enhance the therapeutic outcomes in inhibiting scar proliferation. Hence, the alliance of ADSCC-CM and hydrogel may become a potential alternative in hypertrophic scar prophylaxis.

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Background Small extracellular vesicles (sEVs) with genetic information secreted by cells play a crucial role in the cellular microenvironment. In this study, our purpose is to explore the characteristics of the small extracellular vesicles of human adipose-derived mesenchymal stromal cells (hADMSC-sEVs) and studied the role of hADMSC-sEVs in improving the survival rate of grafted fat. Methods In the present study, we used the transmission electron microscopy, nano-tracking analysis, nanoflow surface protein analysis, and zeta potential value to identify sEVs. SEVs’ trajectory was traced dynamically to verify whether hADMSC-sEVs can be internalized into human umbilical vein endothelial cells (HUVECs) in vitro at different times. The angiogenic property of hADMSC-sEVs was observed by measuring the volume, weight, and histological analysis of the grafted fats in nude mouse models. Results Our research showed that the hADMSC-sEVs were sEVs with double-layer membrane structure and the diameter of which is within 30–150 nm. hADMSC-sEVs exert biological influence mainly through internalization into cells. Compared with the control group, the hADMSC-sEVs group had a significantly higher survival rate of grafted fat, morphological integrity, and a lower degree of inflammation and fibrosis. And immunohistochemistry showed that hADMSC-sEVs significantly increased the neovascularisation and the expression of CD34, VEGFR2, and Ki-67 in the graft tissue. Conclusions As a potential nanomaterial, hADMSC-sEVs have been explored in the field of cell-free application of stem cell technology. hADMSC-sEVs promoted the survival of grafted fats by promoting the formation of new blood vessels, which is another promising progress in the field of regenerative medicine. We believe that hADMSC-sEVs will have a broad application prospect in the field of regenerative medicine in the future.