Mechanical Vibration-Extracted Stromal Vascular Fraction Improves Volume Retention after Autologous Fat Grafting

Poloxamer 188 washing of lipoaspirate improves fat graft survival: A comparative study in nude mice

BACKGROUND

Autologous fat transplantation is limited by the uncertainty of graft retention, impeding its application. Among the current strategies for processing lipoaspirates, high-density fat (HDF) is recommended owing to the enrichment of stem cells and washing before cotton concentration for simplicity of operation. Poloxamer 188 (P188) washing has been shown to repair the membranes of damaged cells. This study aimed to investigate the effect of P188-washing on fat graft survival and identify the best technique for processing lipoaspirates.

METHODS

Lipoaspirates were prepared using centrifugation to obtain HDF, which was then washed with saline or P188 followed by cotton concentration. Tissue integrity, adipocytic activity, and viability of stromal vascular fraction (SVF) in the samples from the 3 groups were assessed. Samples were sequenced in vitro using high-throughput RNA-seq, and differentially expressed genes were validated using qPCR and western blotting (WB). After transplantation under the dorsum of nude mice for 8 weeks, the grafts were extracted and examined for residual volume, histologic characteristics, and vascularization.

RESULTS

The HDF and P188 groups showed a higher survival rate of SVF, more Ki67-positive cells, intact tissue structure, and lesser fibrosis than the saline group. There were no significant differences in the density of SVF and residual volume of grafts. HDF showed significantly improved vascularization during 8 weeks. Through RNA-seq and bioinformatic analysis, notable changes in several related genes after transplantation were observed.

CONCLUSIONS

P188 treatment can prevent cells from apoptosis and preserve tissue viability, thereby improving graft quality. HDF contains large amounts of SVF and can be regarded as an excellent grafting material.

Strategies to Improve AFT Volume Retention After Fat Grafting

BACKGROUND

Autologous fat grafting has gained increasing popularity used in plastic surgery as a strategy to improve functional and aesthetic outcome. However, variable augmentation results have concerned surgeons in that volume loss of grafted fat reported fluctuates unsteadily.

AIM

An optimal technique that clinically maximizes the long-term survival rate of transplantation is in urgent need to be identified.

METHOD

The PubMed/MEDLINE database was queried to search for animal and human studies published through March of 2022 with search terms related to adipose grafting encompassing liposuction, adipose graft viability, processing technique, adipose-derived stem cell, SVF and others.

RESULTS

45 in vivo studies met inclusion criteria. The principal of ideal processing technique is effective purification of fat and protection of tissue viability, such as gauze rolling and washing-filtration devices. Cell-assisted lipotransfer including SVF, SVF-gel and ADSCs significantly promotes graft retention via differentiation potential and paracrine manner. ADSCs induce polarization of macrophages to regulate inflammatory response, mediate extracellular matrix remodeling and promote endothelial cell migration and sprouting, and differentiate into adipocytes to replace necrotic cells, providing powerful evidence for the benefits and efficacy of cell-assisted lipotransfer.

CONCLUSION

Based on the current evidence, the best strategy can not be decided. Cell-assisted lipotransfer has great potential for use in regenerative medicine. But so far mechanically prepared SVF-gel is conducive to clinical promotion. PRP as endogenous growth factor sustained-release material shows great feasibility.

LEVEL OF EVIDENCE IV

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 .

Comprehensive role of SARS-CoV-2 spike glycoprotein in regulating host signaling pathway

Since the outbreak of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, global public health and the economy have suffered unprecedented damage. Based on the increasing related literature, the characteristics and pathogenic mechanisms of the virus, and epidemiological and clinical features of the disease are being rapidly discovered. The spike glycoprotein (S protein), as a key antigen of SARS-CoV-2 for developing vaccines, antibodies, and drug targets, has been shown to play an important role in viral entry, tissue tropism, and pathogenesis. In this review, we summarize the molecular mechanisms of interaction between S protein and host factors, especially receptor-mediated viral modulation of host signaling pathways, and highlight the progression of potential therapeutic targets, prophylactic and therapeutic agents for prevention and treatment of SARS-CoV-2 infection.

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 .