A Systematic Review on Extracellular Vesicles-Enriched Fat Grafting: A Shifting Paradigm

Role and therapeutic perspectives of extracellular vesicles derived from liver and adipose tissue in metabolic dysfunction-associated steatotic liver disease

The global epidemic of metabolic diseases has led to the emergence of metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH), which pose a significant threat to human health. Despite recent advances in research on the pathogenesis and treatment of MASLD/MASH, there is still a lack of more effective and targeted therapies. Extracellular vesicles (EVs) discovered in a wide range of tissues and body fluids encapsulate different activated biomolecules and mediate intercellular communication. Recent studies have shown that EVs derived from the liver and adipose tissue (AT) play vital roles in MASLD/MASH pathogenesis and therapeutics, depending on their sources and intervention types. Besides, adipose-derived stem cell (ADSC)-derived EVs appear to be more effective in mitigating MASLD/MASH. This review presents an overview of the definition, extraction strategies, and characterisation of EVs, with a particular focus on the biogenesis and release of exosomes. It also reviews the effects and potential molecular mechanisms of liver- and AT-derived EVs on MASLD/MASH, and emphasises the contribution and clinical therapeutic potential of ADSC-derived EVs. Furthermore, the future perspective of EV therapy in a clinical setting is discussed.

Evaluating the quality of studies reporting on clinical applications of stromal vascular fraction: A systematic review and proposed reporting guidelines (CLINIC-STRA-SVF)

Background

The stromal vascular fraction (SVF) has been widely explored in a number of therapeutic applications in several specialties. Its therapeutic potential is being increasingly demonstrated, although its mechanism of action is still unclear.

Objective

To evaluate the quality of studies reporting on clinical applications of SVF.

Method

This is a systematic literature review that followed the PRISMA guidelines with the search of the studies from December 1, 2012, to December 1, 2022, in the following databases: MEDLINE, LILACS and EMBASE. The level of evidence of the studies was assessed using the GRADE system, and the rigor used in the publication of the results was assessed in relation to adherence to the guidelines indicated by the EQUATOR Network Group. The CLINIC - STRA-SVF reporting guideline was developed after the completion of this systematic review.

Results

A total of 538 articles were found, and 77 articles were selected after reading the titles and abstracts and removing duplicates. Then, 15 studies were removed for not meeting the inclusion criteria, leaving 62 studies. The CLINIC - STRA-SVF was developed and consists of 33 items and two tables.

Conclusion

There is scientific evidence, although mostly with a low level of evidence, that the use of SVF in clinical applications is safe and effective. The information published in these studies should be standardized, and the CLINIC - STRA-SVF reporting guideline proposed in this study may assist in the design, conduct, recording and reporting of clinical trials and others clinical studies involving the SVF.

The preliminary study of exosomes derived from thymosin beta 4-treated adipose-derived stem cells in fat grafting

BACKGROUND

The retention rate in autologous fat grafting is an increasing concern for surgeons and patients. Our previous research verified that thymosin beta 4 (Tβ4) positively affected fat survival, while the mechanism was unknown. The endothelial cells (ECs) and exosomes derived from adipose-derived stem cells (ADSCs) were regarded to play a critical role in fat transplantation.

OBJECTIVE

This study aimed to evaluate the effect of exosomes derived from Tβ4-treated ADSCs on EC proliferation and to identify the exosomal microRNA (miRNA) profile compared with the Tβ4-untreated group. Additionally, this research intended to recognize the related molecules and signaling pathways in the Tβ4-treated group with potential roles in fat transplants.

METHODS

ADSCs were collected from patients who underwent liposuction surgery. Depending on whether the medium was supplemented with exogenous Tβ4 or not, exosomes derived from cultured ADSCs were divided into the Tβ4-Exos group and Con-Exos group. Exosome uptake and cell counting kit-8 (CCK-8) assays assessed the influence of Tβ4-Exos on EC proliferation. The exosomal miRNAs of the two groups were analyzed by next-generation sequencing. With the criteria at the |log₂ (fold change)| ≥ 1 and p-value < 0.05, up-regulated and down-regulated differentially expressed miRNAs (DEMs) were obtained. Prediction databases were used to predict the downstream mRNAs for DEMs. And then, overlapping genes for the up-regulated DEMs and the down-regulated were screened out, followed by enrichment analysis, protein-protein interaction network construction, and the gene cluster and hub gene identification.

RESULTS

ADSCs were obtained from four female patients. The exosome uptake and CCK-8 assays showed that the Tβ4-Exos could increase cell growth rate compared with the control group (DMEM-H + PBS). In Tβ4-Exos and Con-Exos groups, 2651 exosomal miRNAs were recognized, with 80 up-regulated and 99 down-regulated DEMs according to the criteria. After the prediction, 621 overlapping genes for the up-regulated and 572 for the down-regulated DEMs were screened. The subsequent bioinformatics analysis found specific molecules and pathways related to the positive effect on fat survival.

CONCLUSIONS

The exosomes derived from Tβ4-treated ADSCs probably positively affect EC proliferation. Compared with the Con-Exos group, several exosomal DEMs, genes, and pathways were distinguished. These findings of this exploratory study provide the potential direction for future in-depth research on fat grafting.

Oral and Maxillofacial Autologous Fat Transplantation: History, Clinical Application Status and Research Progress

After more than a century of development, autologous fat transplantation (AFT), a repair method for soft tissue defects and deformities, has the advantages of being simple, rapid, effective and safe, and it is increasingly favoured by plastic surgeons. This article reviews the developmental history of AFT, analyses its clinical application status in the oral and maxillofacial regions, and provides a preliminary summary and discussion of the research progress related to AFT. The hope is that that this technique could be widely applied for oral and maxillofacial diseases as well as facial rejuvenation indications. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. 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 .