Transplantation of beige adipose organoids fabricated using adipose acellular matrix hydrogel improves metabolic dysfunction in high-fat diet-induced obesity and type 2 diabetes mice.

Transplantation of brown adipose tissue (BAT) is a promising approach for treating obesity and metabolic disorders. However, obtaining sufficient amounts of functional BAT or brown adipocytes for transplantation remains a major challenge. In this study, we developed a hydrogel that combining adipose acellular matrix (AAM) and GelMA and HAMA that can be adjusted for stiffness by modulating the duration of light-crosslinking. We used human white adipose tissue-derived microvascular fragments to create beige adipose organoids (BAO) that were encapsulated in either a soft or stiff AAM hydrogel. We found that BAOs cultivated in AAM hydrogels with high stiffness demonstrated increased metabolic activity and upregulation of thermogenesis-related genes. When transplanted into obese and type 2 diabetes mice, the HFD + BAO group showed sustained improvements in metabolic rate, resulting in significant weight loss and decreased blood glucose levels. Furthermore, the mice showed a marked reduction in nonalcoholic liver steatosis, indicating improved liver function. In contrast, transplantation of 2D-cultured beige adipocytes failed to produce these beneficial effects. Our findings demonstrate the feasibility of fabricating beige adipose organoids in vitro and administering them by injection, which may represent a promising therapeutic approach for obesity and diabetes.

Mesenchymal Stem Cells-Derived Apoptotic Extracellular Vesicles (ApoEVs): Mechanism and Application in Tissue Regeneration.

Mesenchymal stem cells (MSCs) are commonly used as a source for cellular therapy owing to their strong immunosuppressive and regenerative effects. However, MSCs undergo extensive apoptosis within a short period after transplantation. During apoptosis, MSCs generate several apoptotic extracellular vesicles (MSCs-ApoEVs). MSCs-ApoEVs are rich in miRNomes, metabolites, and proteomes. They are critical intercellular communication mediators that can exert different regulatory effects on recipient cells. MSCs-ApoEVs have been shown to promote regeneration in the skin, hair, bone, muscle, and vascular system, etc. This review describes the production, release, isolation, and functionality of ApoEVs in detail. Furthermore, we summarize the existing mechanisms of MSCs-ApoEVs used for tissue regeneration and evaluate the possible strategies for their clinical application.

Brown adipose tissue transplantation improves skin fibrosis in localized scleroderma.

Adipose tissue transplantation shows great therapeutic potential in reversing localized scleroderma-associated skin fibrosis. Brown adipose tissue (BAT) can specifically secrete various cytokines against fibrosis, but its therapeutic potential in improving skin fibrosis has not yet been demonstrated. In this study, we have demonstrated the superior therapeutic efficacy of BAT transplantation for sclerotic skin by transplanting two distinct types of adipose tissue. In comparison to the white adipose tissue (WAT) group, mice treated with BAT transplantation exhibited a significant reduction in dermal thickness. BAT transplantation effectively reverses skin sclerosis through mechanisms involving inflammation reduction, promotion of angiogenesis, inhibition of myofibroblast accumulation, and collagen deposition. This therapeutic effect can be attributed to its unique paracrine effects. Furthermore, transcriptome sequencing (RNA-Seq) revealed upregulation of pathways associated with lipogenesis and fatty acid metabolism in BAT while downregulating pathways are related to transforming growth factor ß(TGF-ß), epithelial-mesenchymal transition (EMT), and inflammatory response. These findings suggest that BAT transplantation holds great promise as a novel approach for localized scleroderma treatment.

Combining High-Density Fat and Condensed Low-Density Fat Injections for Precise Facial Rejuvenation.

BACKGROUND: Facial aging involves ptosis, adipose atrophy, and skeletal resorption. Depletion of adipose tissue primarily affects the deep facial fat compartment, leading to facial depression or ptosis, accompanied by atrophy of the superficial compartment. Restoring volume in the deep fat compartment is crucial for facial rejuvenation, while enhancing its supportive properties is also important. The superficial fat compartment contains small-sized adipocytes, and autologous fat grafting is a popular approach. However, variability in fat retention, homogeneity, and processing methods can impact outcomes, necessitating careful selection of a suitable fat processing material for precise facial fat grafting. METHOD: A retrospective study was conducted on 50 patients who underwent facial augmentation using combined transplantation of high-density fat (HDF) and condensed low-density fat (CLDF) and 25 patients who underwent conventional Coleman fat grafting. Coleman fat was harvested by standard technique and the adipose tissue was divided into HDF and CLDF fractions through centrifugation. Subsequently, the low-density fat fraction was subjected to a process involving physical disruption followed by additional centrifugation to obtain CLDF. The CLDF fraction was consequently injected into the pre-SMAS subcutaneous layer of the superficial fat compartments. Patient satisfaction was evaluated using a typical Likert scale. Photographs were taken and imageological examinations were performed before and after treatment. RESULT: The CLDF+HDF grafting group demonstrated a significantly shorter duration of swelling (6.0 ± 1.2 to 12.6 ± 3.3 days) and higher level of patient satisfaction when compared to the Coleman fat group. No serious complications were observed among all the patients who received the injections. CONCLUSION: The use of this new treatment approach allows for precise fat transplantation in facial regions. The use of high-concentration fat filling for deep facial layers and CLDF filling for superficial layers is a safe and effective treatment plan for facial rejuvenation. 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 .

Type IV Collagen Promotes Adipogenic Differentiation of Adipose Stem Cells.

Type IV collagen is a major component of the extracellular matrix in adipose tissue. It is secreted during the lipogenic differentiation of mesenchymal stem cells, but its direct impact and mechanism on the differentiation of adipose-derived stem cells (ASCs) into lipids are unclear. In this study, ASCs were obtained from human liposuction samples and cultured. Lipogenic induction of ASCs was achieved using lipogenic induction medium. Immunofluorescence analysis revealed differential expression of type IV collagen during the early and late stages of adipogenic induction, displaying a distinct morphological encapsulation of ASCs. Silencing of type IV collagen using siRNA resulted in a significant decrease in adipogenic capacity, as indicated by reduced lipid droplet formation and downregulation of adipogenic-related gene transcription. Conversely, supplementation of the culture medium with synthetic type IV collagen demonstrated enhanced adipogenic induction efficiency, accompanied by upregulation of YAP/TAZ protein expression and its downstream target gene transcription. Furthermore, inhibition of the YAP/TAZ pathway using the inhibitor Blebbistatin attenuated the functionality of type IV collagen, leading to decreased lipid droplet formation and downregulation of adipocyte maturation-related gene expression. These findings highlight the crucial role of type IV collagen in promoting adipogenic differentiation of ASCs and suggest its involvement in the YAP/TAZ-mediated Hippo pathway.No Level Assigned This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. 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 .

The fates of different types of adipose tissue after transplantation in mice.

Fat grafting is one of the most commonly applied procedure for soft-tissue repair. However, it remains unclear whether the type of adipose tissue would have any effects on fat graft survival. The present study aimed to determine fates of fat grafting of three different types of fat tissue. In this study, mice were randomly divided into three groups, white adipose tissue (WAT) group, beige adipose tissue (beige AT) group and brown adipose tissue (BAT) group. Before transplantation, donor mice were injected with rosiglitazone or phosphate-buffered saline (PBS). The WAT and BAT were obtained from PBS-treated mice while beige AT was obtained from the rosiglitazone-treated mice. Three types of fat tissue (150 mg each) were transplanted in three groups, respectively, and harvested at 2, 4 or 12 weeks. The BAT and beige AT contained smaller adipocytes and expressed higher level of uncoupling protein-1 gene. The retention rate of the transplanted fat was significantly higher for beige than for white fat, but was significantly lower for brown than for white fat. Transplanted brown fat was characterized by upregulated inflammation and high endoplasmic reticulum stress. By contrast, fat grafts in beige AT group showed the best adipogenic capacity, moderate inflammation level and superior angiongenesis. In vitro, under hypoxic condition, fewer apoptotic cells were found in beige adipocyte group than that in brown and white adipocyte group. Conditioned medium from brown adipocytes induced M1 polarization of RAW 264.7 macrophages while that from beige adipocytes effectively promoted M2 polarization. Therefore, we suggest that beige AT provides a new potential choice for fat grafting because of low inflammation and superior survival but BAT might not be ideal for fat grafting due to its poor survival.

Skeletal muscle provides a pro-browning microenvironment for transplanted brown adipose tissue to maintain its effect to ameliorate obesity in ob/ob mice.

Brown adipose tissue (BAT) transplantation is a promising means of increasing whole-body energy metabolism to ameliorate obesity. However, the changes in BAT following transplantation and the effects of the microenvironment of the recipient site on graft function have yet to be fully characterized. Therefore, we aimed to determine the effects of transplanting BAT from C57BL/6 mice into the dorsal subcutaneous region or deep to the quadriceps femoris muscle of leptin-deficient ob/ob mice. Subcutaneously transplanted BAT lost features of BAT and demonstrated greater inflammatory cell infiltration and more oil cysts 16 weeks following transplantation. By contrast, the sub-muscularly transplanted BAT maintained features of BAT and was more highly vascularized. Interestingly, sub-muscular BAT transplantation led to a significant increase in oxygen consumption and less inflammation in subcutaneous fat, which was associated with long-term reductions in insulin resistance and body mass gain, whereas the subcutaneous transplants failed after 16 weeks. These results demonstrate that the beneficial effects of BAT transplantation depend upon the microenvironment of the recipient site. Skeletal muscle may provide a microenvironment that maintains the inherent features of BAT grafts over a long period of time, which facilitates a reduction in obesity and improvements in glucose homeostasis.

Condensing of Low-Density Fat by Mechanical Process Improves Fat Retention and Reduces Oil Cyst Formation in Breast Reconstruction.

BACKGROUND: Although autologous fat grafting is a useful adjunct for breast reconstruction, its indications remain limited as large-volume fat grafting results in high absorption and complication rates. Low-density fat includes small numbers of viable cells and considerable oil, resulting in nodules and oil cysts. This study evaluated the volumization effect and complications with combined fat grafting of condense low-density fat and high-density fat. METHODS: This retrospective, single-center study included 25 patients who underwent combined grafting of condensed low-density fat and high-density fat (CLDF + HDF) and 20 patients who underwent conventional Coleman fat grafting for breast reconstruction from December 2017 to January 2022. Retention rates and complications were evaluated by magnetic resonance imaging and ultrasound rates. Patient satisfaction was evaluated using a typical Likert scale. Photographs were taken and imageological examinations were performed before and after treatment. OUTCOMES: Graft retention rate was higher in patients who underwent CLDF + HDF than Coleman fat grafting for breast reconstruction (38.40 ± 4.41% vs. 31.43 ± 5.43%, p <0.05). One patient in the CLDF + HDF grafting group, compared with twelve in the Coleman fat grafting group, developed oil cysts exceeding 1 cm. Patient satisfaction rate was higher in the CLDF + HDF grafting group. CONCLUSIONS: Mechanical processes can concentrate the cellular content of LDF and remove oil, condensing LDF to the level of HDF. Combined grafting of CLDF optimized by mechanical processing and HDF is effective for breast reconstruction, with a higher retention rate and a lower incidence of complications than conventional Coleman fat grafting. 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 .

mTORC1 promotes mineralization via p53 pathway.

The objectives of our study were to investigate the roles of mTORC1 in odontoblast proliferation and mineralization and to determine the mechanism by which mTORC1 regulates odontoblast mineralization. In vitro, MDPC23 cells were treated with rapamycin (10 nmol/L) and transfected with a lentivirus for short hairpin (shRNA)-mediated silencing of the tuberous sclerosis complex (shTSC1) to inhibit and activate mTORC1, respectively. CCK8 assays, flow cytometry, Alizarin red S staining, ALP staining, qRT-PCR, and western blot analysis were performed. TSC1-conditional knockout (DMP1-Cre+ ; TSC1f/f , hereafter CKO) mice and littermate control (DMP1-Cre- ; TSC1f/f , hereafter WT) mice were generated. H&E staining, immunofluorescence, and micro-CT analysis were performed. Transcriptome sequencing analysis was used to screen the mechanism of this process. mTORC1 inactivation decreased the cell proliferation. The qRT-PCR and western blot results showed that mineralization-related genes and proteins were downregulated in mTORC1-inactivated cells. Moreover, mTORC1 overactivation promoted cell proliferation and mineralization-related gene and protein expression. In vivo, the micro-CT results showed that DV/TV and dentin thickness were higher in CKO mice than in controls and H&E staining showed the same results. Mineralization-related proteins expression was upregulated. Transcriptome sequencing analysis revealed that p53 pathway-associated genes were differentially expressed in TSC1-deficient cells. By inhibiting p53 alone or both mTORC1 and p53 with rapamycin and a p53 inhibitor, we elucidated that p53 acts downstream of mTORC1 and that mTORC1 thereby promotes odontoblast mineralization. Taken together, our findings demonstrate that the role of mTORC1 in odontoblast proliferation and mineralization, and confirm that mTORC1 upregulates odontoblast mineralization via the p53 pathway.

Ischemic flap survival improvement by composition-selective fat grafting with novel adipose tissue derived product - stromal vascular fraction gel.

BACKGROUND: Flap necrosis due to insufficient blood supply is a common postoperative complication in random pattern flaps. Stem cell therapies have emerged as promising biologics for tissue ischemia. A novel fat derived product, stromal vascular fraction gel (SVF-gel), can be prepared with lipoaspirate through simple mechanical processing, removing only the lipid content. SVF-gel enriches adipose-derived stem cells and potentially beneficial for flap necrosis. METHODS: Nude mice ischemic flaps were treated with human SVF-gel, stromal vascular fraction (SVF) cell suspension or saline (n = 10). They were injected to the flap recipient beds, and necrosis and vascularization was assessed on postoperative day 14. We harvested the necrosis-free distal to evaluated skin healthiness and neovasculogenesis by Masson's trichrome stain and immunofluorescence, etc. Pro-angiogenic factors were assessed with tissue qRT-PCR. Finally, we traced the grafted human tissue with immunofluorescence. RESULTS: SVF-gel-treated flaps have the smallest necrotic zones (22.05% ± 0.0438) compared with the saline controls (53.78% ± 0.1412) or SVF-treated ones (35.54% ± 0.0850, p = 0.039). Numerous functional musculocutaneous perforators were developed around SVF-gel grafts. The SVF-gel-treated skin had the best fat restoration (231.3 ± 48.1 µm) among three groups (F = 10.83, p = 0.0102) while saline-treated flap distal appeared fibrotic. SVF-gel-treated flaps also had ∼43% more CD31 + capillaries (p = 0.0152) with ∼3 folds more gene expression of angiogenic cytokines of VEGF and bFGF (p = 0.0310 and 0.0303, respectively) than saline-treated controls. Furthermore, we found hSVF-gel cells (hGolgi+) had directly engrafted as vessel component (α-smooth muscle actin, α-SMA+) to the flap. CONCLUSION: Adipose cellular matrix enhanced flap neovascularization partly by direct incorporation, improved flap survival and fat restoration. The composition-selective fat grafting with SVF-gel demonstrated efficacy comparable with stem cell therapy and is especially valuable for clinical translation.

Adipose Stromal Vascular Fraction Gel Grafting: A New Method for Tissue Volumization and Rejuvenation.

BACKGROUND: The clinical outcomes of fat grafting vary and are technique-dependent. Stromal vascular fraction (SVF) gel is a novel, mechanically processed fat product with high concentrations of adipose tissue-derived stem cells and other SVF cells. This study evaluated the volumization and rejuvenation effects of SVF-gel. OBJECTIVE: This study evaluated the volumization and rejuvenation effects of SVF-gel. METHODS: This retrospective, single-center study included 126 patients who underwent SVF-gel grafting and 78 who underwent conventional lipoinjection for various indications from March 2015 to February 2017. Patient satisfaction and secondary surgery rates were evaluated. Samples of transferred SVF-gel were harvested and examined histologically. RESULTS: All patients showed improvements in facial augmentation and contour. Patients in the SVF-gel group experienced mild postoperative swelling and a low secondary surgery rate (10.9%). Assessment of patient-rated satisfaction on a 5-point Likert scale found that 77.3% of patients in the SVF-gel group were satisfied (54.5%) or very satisfied (22.8%) with their outcomes. By comparison, 53.8% of patients who underwent conventional lipoinjection were satisfied (48.7%) or very satisfied (5.1%). Moreover, SVF-gel showed effective antiwrinkle and skin rejuvenation effects. Hematoxylin-eosin staining showed a normal adipose tissue structure in transferred SVF-gel. CONCLUSION: Stromal vascular fraction gel is effective for both volumization and rejuvenation, and may be superior to conventional lipoinjection for facial recontouring.

Challenges and opportunities in obesity: the role of adipocytes during tissue fibrosis.

Obesity is a chronic disease that affects the energy balance of the whole body. In addition to increasing fat mass, tissue fibrosis occurred in white adipose tissue in obese condition. Fibrosis is the over-activation of fibroblasts leading to excessive accumulation of extracellular matrix, which could be caused by various factors, including the status of adipocytes. The morphology of adipocytes responds rapidly and dynamically to nutrient fluctuations. Adaptive hypertrophy of normal adipocytes protects peripheral organs from damage from lipotoxicity. However, the biological behavior of hypertrophic adipocytes in chronic obesity is abnormally altered. Adipocytes lead to fibrotic remodeling of the extracellular matrix by inducing unresolved chronic inflammation, persistent hypoxia, and increasing myofibroblast numbers. Moreover, adipocyte-induced fibrosis not only restricts the flexible expansion and contraction of adipose tissue but also initiates the development of various diseases through cellular autonomic and paracrine effects. Regarding anti-fibrotic therapy, dysregulated intracellular signaling and epigenetic changes represent potential candidate targets. Thus, modulation of adipocytes may provide potential therapeutic avenues for reversing pathological fibrosis in adipose tissue and achieving the anti-obesity purpose.

Adipose Component Transplantation: An Advanced Fat-Grafting Strategy for Facial Rejuvenation.

BACKGROUND: Autologous fat grafting is frequently used for volume augmentation and tissue regeneration. The uniform physical and biological characteristics of fat grafts, however, limit their optimal effects in various situations. Subjecting fat tissue to different mechanical processes results in adipose-derived products with distinct biological components and physical features. The present study describes a novel facial fat-grafting strategy, adipose component transplantation (ACT), that yields different adipose products that can be applied to specific injection sites. METHODS: All patients who underwent ACT were evaluated retrospectively. Fat tissue samples were fractionated into high-density fat, adipose matrix complex, stromal vascular fraction gel, and adipose collagen fragment, as described. Each of these fractions was processed and injected into indicated recipient sites. Additional SVF gel was cryopreserved and, if necessary, injected during the following 3 months. Patients were followed up after 1, 2, 3, and 6 months, and annually thereafter. RESULTS: From March of 2020 to September of 2021, 78 patients underwent whole face fat grafting using the ACT strategy. All operations and secondary injections of cryopreserved SVF gel were uneventful. There were no major complications, and final aesthetic results were satisfactory in 91% of patients. CONCLUSIONS: The ACT strategy allows specific adipose products to be applied to specific injection sites, as warranted. Adipose matrix complex is indicated for sufficient rigid support, high-density fat when large volumes are required, SVF gel for precise injection and cryopreservation, and ACF as mesotherapy for skin rejuvenation. The ACT strategy optimizes the biological functions and physical features of different adipose-derived products. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

The browning and mobilization of subcutaneous white adipose tissue supports efficient skin repair.

Adipocytes in dermis are considered to be important participants in skin repair and regeneration, but the role of subcutaneous white adipose tissue (sWAT) in skin repair is poorly understood. Here, we revealed the dynamic changes of sWAT during wound healing process. Lineage-tracing mouse studies revealed that sWAT would enter into the large wound bed and participate in the formation of granulation tissue. Moreover, sWAT undergoes beiging after skin injury. Inhibition of sWAT beiging by genetically silencing PRDM16, a key regulator to beiging, hindered wound healing process. The transcriptomics results suggested that beige adipocytes in sWAT abundantly express neuregulin 4 (NRG4), which regulated macrophage polarization and the function of myofibroblasts. In diabetic wounds, the beiging of sWAT was significantly suppressed. Thus, adipocytes from sWAT regulate multiple aspects of repair and may be therapeutic for inflammatory diseases and defective wound healing associated with aging and diabetes.

Hypoxia preconditioned human adipose derived mesenchymal stem cells enhance angiogenic potential via secretion of increased VEGF and bFGF.

Mesenchymal stem cells (MSCs) are adult multipotent cells found in bone marrow, adipose tissue, and other adult tissues. MSCs improve regeneration of injured tissues in vivo, but the mechanisms remain unclear. Typically, MSCs are cultured under ambient or normoxic conditions (21% O2 ). However, the physiological niches of MSCs have much lower oxygen tension. When used as a therapeutic tool to repair tissue injuries, MSCs cultured in standard conditions must adapt from 21% O2 in culture to <1% O2 in ischemic tissue. We have examined the effects of hypoxia preconditioning (1% O2 ) in human adipose derived mesenchymal stem cells (AD-MSCs) to discover the conditions that best enhance their tissue regenerative potential. We demonstrate that AD-MSCs respond positively to hypoxia compared with normoxia preconditioning, show decreased apoptosis even in severe microenvironmental conditions (such as a low-serum medium), and an increased expression of the angiogenic factors, vascular endothelial growth factor and basic fibroblast growth factor. Human umbilical vein endothelial cells have higher vitality and lower apoptosis when cultured in medium taken from hypoxia-preconditioned AD-MSCs, as well as significantly increased capillary-like structures with this medium on Matrigel. The data suggest that hypoxia preconditioned AD-MSCs can improve tissue regeneration.

Supplementing fat grafts with adipose stromal cells for cosmetic facial contouring.

BACKGROUND: Numerous methods have been proposed to enhance the survival of fat grafts, but no definitive treatment is available. Stromal vascular fraction (SVF)-assisted cell therapy offers new perspectives for improving fat graft survival. OBJECTIVES: To determine whether SVF supplementation could improve graft retention in patients undergoing autologous fat grafting for cosmetic improvement of facial contour. METHODS: We retrospectively analyzed data from 38 women who underwent fat transplantation with SVF (n = 26) or fat grafting alone (n = 12) between October 2010 and January 2012. Each patient underwent computed tomography, and photographs were taken before and 6 months after surgery. The Philips Extended Brilliance Workspace was used for analysis of volume augmentation. RESULTS: All patients showed cosmetic improvements, but the degree varied. No complications were evidenced during follow-up. Fat survival was higher with SVF (64.8 ± 10.2%) than fat grafting alone (46.4 ± 9.3%) (p < .01). SVF supplementation resulted in better clinical improvement than fat grafting alone. CONCLUSION: Supplementing fat grafts with SVF for cosmetic facial contouring can improve the survival of fat grafts over fat grafting alone and provides satisfactory outcomes without major complications. Autologous fat grafting has been used for various cosmetic treatments and difficult reconstructive indications such as temporal depression, wrinkles of nasolabial folds, and hemifacial atrophy, with no incisional scar or complications associated with foreign materials, although problems such as a low rate of graft survival because of early resorption remain. (Aesthet Plast Surg, 14, 1990 and 127) Despite many innovations to overcome these problems, (Dermatol Surg, 26, 2000 and 1159); (Ann Plast Surg, 60, 2008 and 594); (Dermatol Surg, 27, 2001 and 819); (Dermatol Surg, 28, 2002 and 987) we lack a definitive method of fat processing that ensures maximal graft take and viability. (Plast Reconstr Surg, 115, 2005 and 197); (Dermatol Surg, 37, 2011 and 619).

Selection of donor site for fat grafting and cell isolation.

BACKGROUND: Autologous fat grafting has rapidly become an important treatment for soft tissue defects in cosmetic and reconstructive surgery. However, consensus is lacking on the ideal donor site for harvesting and isolating stromal vascular fraction (SVF) cells to improve survival of fat grafts. We aimed to determine the best donor site for tissue harvesting and isolation of SVF cells for fat graft survival. METHODS: Adipose tissue samples were harvested from six women who underwent an aesthetic procedure. The samples were harvested by needle aspiration of five commonly used donor sites: flank, upper and lower abdomen, and lateral and inner thigh. The adipose tissue was injected subcutaneously into nude mice and grafts were harvested at 12 weeks. We evaluated graft volume, weight, and histologic parameters of the grafts: integrity, cysts/vacuoles, inflammation, fibrosis, and neovascularization. SVF cells isolated from donor sites were counted and assayed by flow cytometry. RESULTS: At 12 weeks post-transplantation, weight, volume, and histologic parameters did not differ among the grafts from the five tissue donor sites. Also, SVF and levels of cell surface markers did not differ by donor site. CONCLUSIONS: This study revealed no ideal tissue donor site for fat grafting and SVF isolation. Choosing a site should be based on ease and safety of access and the preference and request of the patient. LEVEL OF EVIDENCE I: 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 .

Corynebacterium bovis infection after autologous fat grafting in breast augmentation: a case report.

In this report, we present a case study of a rare human bacterium, Corynebacterium bovis, which caused an infection in a patient who had undergone autologous fat-based breast augmentation using cryopreserved fat. This infection occurred during a secondary fat grafting procedure. To identify the bacteria causing the infection, we used high-throughput DNA sequencing technology since this bacterium is seldomly reported in human infections. The patient was successfully treated with intravenous imipenem. We also discuss potential factors that may have contributed to this unusual bacterial infection and propose that DNA sequencing can be a useful tool in cases where standard culture techniques fail to identify the causative agent. Additionally, we highlight the importance of further research on the cryopreservation of fat. In summary, this case highlights the possibility of rare bacterial infections occurring after fat grafting procedures and emphasizes the importance of identifying the causative agent through advanced techniques such as DNA sequencing. Further research is needed to improve our understanding of the risks associated with cryopreservation of fat and to identify ways to prevent these types of infections in the future.

Dedifferentiated fat cells: current applications and future directions in regenerative medicine.

Stem cell therapy is the most promising treatment option for regenerative medicine. Therapeutic effect of different stem cells has been verified in various disease model. Dedifferentiated fat (DFAT) cells, derived from mature adipocytes, are induced pluripotent stem cells. Compared with ASCs and other stem cells, the DFAT cells have unique advantageous characteristics in their abundant sources, high homogeneity, easily harvest and low immunogenicity. The DFAT cells have shown great potential in tissue engineering and regenerative medicine for the treatment of clinical problems such as cardiac and kidney diseases, autoimmune disease, soft and hard tissue defect. In this review, we summarize the current understanding of DFAT cell properties and focus on the relevant practical applications of DFAT cells in cell therapy in recent years.