No abstract

No abstract

Background: Autologous fat grafting is an efficient procedure in plastic surgery. However, its long-term tissue absorption is variable and technique-dependent. Platelet-rich plasma positively affects fat-grafting outcomes but still has shortcomings, and platelet-rich fibrin has been reported to have efficacy in fat transplantation. Here, we compared the effects of platelet-rich fibrin and platelet-rich plasma in fat grafting using histologic analysis. Methods: Twenty rabbits were divided randomly into two groups. In each group, the groin region fat pads were cut into 1-mm3 granules. Platelet-rich fibrin–treated or platelet-rich plasma–treated fat granules were transplanted into one ear, whereas the contralateral ear was transplanted with normal saline–treated fat granules. Histologic characteristics and capillary density of grafted tissue were analyzed 12 weeks after fat grafting. Results: The grafted fat in the platelet-rich fibrin–treated group showed higher tissue retention than that in the control group [weight retention, 19.57 percent (interquartile range, 13.87 to 29.93 percent) versus 9.04 percent (interquartile range, 6.16 to 16.80 percent), p < 0.05; and volume retention, 18.00 percent (interquartile range, 10.50 to 26.50 percent) versus 8.00 percent (interquartile range, 5.75 to 13.25 percent), p < 0.05] and higher neovascularized capillary density than that in the platelet-rich plasma–treated and control groups. The platelet-rich plasma–treated group showed higher vessel density without superior tissue retention compared with the control group. Conclusion: Platelet-rich fibrin increased tissue retention, quality, and vascularization of grafted fat compared with the control group and showed effects similar to those of platelet-rich plasma on tissue retention and histologic graft improvement.

Stem cells play a key role in tissue regeneration due to their self-renewal and multidirectional differentiation, which are continuously regulated by signals from the extracellular matrix (ECM) microenvironment. Therefore, the unique biological and physical characteristics of the ECM are important determinants of stem cell behavior. Although the acellular ECM of specific tissues and organs (such as the skin, heart, cartilage, and lung) can mimic the natural microenvironment required for stem cell differentiation, the lack of donor sources restricts their development. With the rapid development of adipose tissue engineering, decellularized adipose matrix (DAM) has attracted much attention due to its wide range of sources and good regeneration capacity. Protocols for DAM preparation involve various physical, chemical, and biological methods. Different combinations of these methods may have different impacts on the structure and composition of DAM, which in turn interfere with the growth and differentiation of stem cells. This is a narrative review about DAM. We summarize the methods for decellularizing and sterilizing adipose tissue, and the impact of these methods on the biological and physical properties of DAM. In addition, we also analyze the application of different forms of DAM with or without stem cells in tissue regeneration (such as adipose tissue), repair (such as wounds, cartilage, bone, and nerves), in vitro bionic systems, clinical trials, and other disease research.

Results of this study suggest that browning of subcutaneous white adipose tissue participates in adaptive tissue remodeling following grafting and contributes to adipose tissue repair.

Background: Mechanical stretch is utilized to promote skin regeneration during tissue expansion for reconstructive surgery. Although mechanical stretch induces characteristic morphological changes in the skin, the biological processes and molecular mechanisms involved in mechanically induced skin regeneration are not well elucidated.Methods: A male rat scalp expansion model was established and the important biological processes related to mechanical stretch-induced skin regeneration were identified using Gene Ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, and gene set enrichment analysis (GSEA). Analysis was also conducted by constructing a protein–protein interaction (PPI) network, identifying key modules and hub genes, determining transcription factor (TF)-mRNA regulatory relationships, and confirming the expression pattern of the TFs and hub genes.Results: We identified nine robust hub genes (CXCL1, NEB, ACTN3, MYOZ1, ACTA1, TNNT3, PYGM, AMPD1, and CKM) that may serve as key molecules in skin growth. These genes were determined to be involved in several important biological processes, including keratinocyte differentiation, cytoskeleton reorganization, chemokine signaling pathway, glycogen metabolism, and voltage-gated ion channel activity. The potentially significant pathways, including the glucagon signaling pathway, the Wnt signaling pathway, and cytokine–cytokine receptor interaction, were distinguished. In addition, we identified six TFs (LEF1, TCF7, HMGA1, TFAP2C, FOSL1, and ELF5) and constructed regulatory TF–mRNA interaction networks.Conclusion: This study generated a comprehensive overview of the gene networks underlying mechanically induced skin regeneration. The functions of these key genes and the pathways in which they participate may reveal new aspects of skin regeneration under mechanical strain. Furthermore, the identified TF regulators can be used as potential candidates for clinical therapeutics for skin pretreatment before reconstructive surgery.

Background Vascular embolism is the most severe complication after autologous fat grafting. With a worldwide increase in fat grafting, there has been a rise in severe vascular complications, such as ophthalmic artery embolism, cerebral artery embolism, and even death. This article aims to review the role of fat in causing severe vascular complications and the association between fat grafting and severe vascular complications. Methods A critical review was conducted by appraising the cases of severe vascular complications associated with facial fat grafting reported globally. Repeated cases that were reported in multiple publications were further screened. Results The final search yielded 50 publications in English that met the inclusion criteria for review. A total of 113 cases of fat-induced severe vascular complications in the literature were identified. The number of cases reported yearly has increased over time, with even more significant increases since 2010. The glabella and temple are the most common sites of severe vascular complications described in the literature. In addition, only one case of ophthalmic artery embolism and one case of cerebral artery embolism have been treated successfully. Conclusions Given the increase in reported cases of severe vascular complications, both doctors and patients should pay careful attention to the risks of facial fat grafting. Because of the unclear mechanism of vascular embolism and the lack of guidelines for prevention and treatment, the effective cure rate is unsatisfactory. We propose that preventing vascular embolism is a priority in fat grafting and that timely, multidisciplinary treatment should be performed when severe vascular complications occur. It is necessary in future studies to explore the mechanisms of vascular embolism and effective treatment strategies to promote the development of fat grafting.

Background: Silicone implants are widely used in the field of plastic surgery for wound repair and cosmetic augmentation. However, molecular mechanisms and signaling pathways underlying the foreign body reaction (FBR) of a host tissue to the silicone require further elucidation. The purpose of this study was to identify key FBR-related transcription factors (TFs) and genes through transcriptome analysis.Methods: We used a rat model with a subcutaneous silicone implant in the scalp and performed high throughput sequencing to determine the transcriptional profiles involved in the FBR. The function was analyzed by Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway-enrichment analysis. A protein-protein interaction (PPI) network of differentially expressed mRNAs (DEmRNAs) was constructed to identify the hub genes and key modules and to determine the regulatory TF-mRNA relationships. In addition, the hub gene and transcript expression levels were determined by Quantitative Reverse Transcription polymerase Chain Reaction (qRT-PCR). Myofibroblasts differentiation and macrophage recruitment were identified by immunofluorescence. The protein expression of MMP9 was detected by immunohistochemistry and Western blot.Results: We identified ten hub genes (Fos, Spp1, Fn1, Ctgf, Tlr2, Itgb2, Itgax, Ccl2, Mmp9, and Serpine1) and 3 TFs (FOS, IRF4, and SPI1) that may be crucial (particularly FOS) for the FBR. Furthermore, we identified multiple differentially expressed genes involved in several important biological processes, including leukocyte migration, cytokine‒ cytokine receptor interaction, phagocytosis, extracellular matrix (ECM) organization, and angiogenesis. We also identified potentially significant signaling pathways, including cytokine‒cytokine receptor interaction, phagosome, ECM‒receptor interaction, complement and coagulation cascades, the IL-17 signaling pathway, and the PI3K‒Akt signaling pathway. In addition, qRT-PCR confirmed the expression patterns of the TFs and hub genes, Western blot and immunohistochemistry validated the expression patterns of MMP9.Conclusion: We generated a comprehensive overview of the gene networks underlying the FBR evoked by silicone implants. Moreover, we identified specific molecular and signaling pathways that may perform key functions in the silicone implant-induced FBR. Our results provide significant insights into the molecular mechanisms underlying silicone-induced FBR and determine novel therapeutic targets to reduce complications related to silicone implantation.