Mechanical micronization of lipoaspirates for the treatment of hypertrophic scars

Immediate SVF-Gel Injection Reduced Incision Scar Formation: A Prospective, Double-Blind, Randomized, Self-control Trial

BACKGROUND

Skin incision scars are cosmetically displeasing; the effects of current treatments are limited, and new methods to reduce scar formation need to be found.

OBJECTIVE

We sought to determine whether immediate postoperative injection of stromal vascular fraction gel (SVF-gel) could reduce scar formation at skin incision sites.

METHODS

A prospective, randomized, double-blind, self-controlled trial was conducted in patients who underwent breast reduction. SVF-gel was intradermally injected into the surgical incision on one randomly selected side, with the other side receiving saline as a control. At the 6-month follow-up, the incision scars were evaluated using the Vancouver scar scale (VSS) and visual analog scale (VAS). Antera 3D camera was used for objective evaluation.

RESULTS

The VSS score and VAS score were significantly different between the SVF-gel-treated side (3.80 ± 1.37, 3.37±1.25) and the control side (5.25 ± 1.18, 4.94 ± 1.28). Moreover, the SVF-gel-treated side showed statistically significant improvements in scar appearance, based on evidences from Antera 3D camera.

LIMITATIONS

This was a single-center, single-race, and single-gender study. Furthermore, the results were available only for the 6-month interim follow-up period.

CONCLUSION

Postoperative immediate SVF-gel injection in surgical incisions can reduce scar formation, and exert a preventive effect on scars.

LEVEL OF EVIDENCE I

Evidence obtained from at least one properly designed randomized controlled trial. 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 .

Exploring Preclinical Experiments with Different Fat Types for Autologous Fat Grafting

BACKGROUND

Autologous fat transplantation has been a cornerstone of tissue regeneration for decades. However, there is no standardized selection system or criteria for fat graft selection, often relying heavily on the surgeon's experience.

OBJECTIVES

This study aimed to investigate various types of fat derivatives, both in vitro and in vivo at the same condition.

METHODS

We collected traditional fat granules of different sizes and SVF-gel, evaluating the viability of ADSCs isolated from them and their performance after grafting into mice.

RESULTS

Large fat granules exhibited more complete adipocyte structures, and the isolated ADSCs demonstrated superior differentiation, proliferation, and secretion capacities. They also showed excellent volume retention after 12 weeks. In contrast, ADSCs isolated from SVF-gel displayed lower vitality. However, grafts from SVF-gel exhibited the highest volume maintenance rate among the four groups after 12 weeks, closely resembling normal adipose tissue and displaying significant vascularization. Compared to large fat granule and SVF-gel group, medium and small fat granule grafts exhibited lower volume retention and less angiogenesis.

CONCLUSIONS

Through preclinical studies, the flexible clinical use of different fat grafts can be tailored to their unique characteristics.

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 .

One-step stromal vascular fraction therapy in osteoarthritis with tropoelastin-enhanced autologous stromal vascular fraction gel

Background: Osteoarthritis (OA) is a debilitating degenerative joint disease, leading to significant pain and disability. Despite advancements, current regenerative therapies, such as mesenchymal stem cells (MSCs), face challenges in clinical efficacy and ethical considerations. This study aimed to evaluate the therapeutic potential of stromal vascular fraction gel (SVF-gel) in comparison to available treatments like hyaluronic acid (HA) and adipose-derived stem cells (ADSCs) and to assess the enhancement of this potential by incorporating tropoelastin (TE). Methods: We conducted a comparative laboratory study, establishing an indirect co-culture system using a Transwell assay to test the effects of HA, ADSCs, SVF-gel, and TE-SVF-gel on osteoarthritic articular chondrocytes (OACs). Chondrogenic and hypertrophic markers were assessed after a 72-hour co-culture. SVF-gel was harvested from rat subcutaneous abdominal adipose tissue, with its mechanical properties characterized. Cell viability was specifically analyzed for SVF-gel and TE-SVF-gel. The in vivo therapeutic effectiveness was further investigated in a rat model of OA, examining MSCs tracking, effects on cartilage matrix synthesis, osteophyte formation, and muscle weight changes. Results: Cell viability assays revealed that TE-SVF-gel maintained higher cell survival rates than SVF-gel. In comparison to the control, HA, and ADSCs groups, SVF-gel and TE-SVF-gel significantly upregulated the expression of chondrogenic markers COL 2, SOX-9, and ACAN and downregulated the hypertrophic marker COL 10 in OACs. The TE-SVF-gel showed further improved expression of chondrogenic markers and a greater decrease in COL 10 expression compared to SVF-gel alone. Notably, the TE-SVF-gel treated group in the in vivo OA model exhibited the most MSCs on the synovial surface, superior cartilage matrix synthesis, increased COL 2 expression, and better muscle weight recovery, despite the presence of fewer stem cells than other treatments. Discussion: The findings suggest that SVF-gel, particularly when combined with TE, provides a more effective regenerative treatment for OA by enhancing the therapeutic potential of MSCs. This combination could represent an innovative strategy that overcomes limitations of current therapies, offering a new avenue for patient treatment. Further research is warranted to explore the long-term benefits and potential clinical applications of this combined approach.

Fat transplant: Amazing growth and regeneration of cells and rebirth with the miracle of fat cells

BACKGROUNDS AND OBJECTIVE

During fat transplantation, adipose tissue is removed from the body and injected into different areas under the skin. The goal of this review article is to look into the efficacy and applicability of fat transplantation in regenerative medicine and rejuvenation, including Nanofat, Microfat, and Millifat.

METHODS

As a search strategy and study selection, we searched the PubMed and Medline databases until 2023 using related keywords (e.g., Nanofat, Microfat and Millifat, Regenerative Medicine, and Rejuvenation).

RESULTS

Autologous fat transplantation has no risk of an allergic reaction or rejection of the transplant by the individual. Autologous adipose tissue is considered an ideal filler for facial rejuvenation and is suggested as the most biocompatible and non-immunogenic skin filler. Adipose tissue transplant may have semi-permanent to permanent effects. According to recent reports, adipose tissues possess a high percentage of mature stem cells. The effect of regenerating adipose tissue and its intrinsic cells can be described as an obvious process. Variations in the sizes of adipose tissues can result in different results depending on the surgical site. Based on topographic assessment, graft fats are assigned depending on the anatomical locations and the size such as Millifat (2-2.5 mm), Microfat (1 mm), and Nanofat (500 μm or less).

CONCLUSION

Some characteristics of fat tissue increase its effectiveness, such as increasing stem cells, growth factors, cytokines, and compounds effective in repair, regeneration, and rejuvenation.

A novel combined technology for treating hypertrophic scars: adipose tissue extract combined with fractional CO2 laser

Introduction: Owing to the need for liposuction and its unsuitability for allogeneic transplantation, the clinical application of stromal vascular fraction gel (SVF-gel) combined with fractional CO2 laser for scar treatment is limited. Adipose tissue extract (ATE), rich in cytokines and growth factors, offers a more convenient option for clinical practice as it can be easily prepared using purely physical methods and has low immunogenicity. We aimed to evaluate the effectiveness of ATE combined with fractional CO2 laser in the treatment of hypertrophic scars. Methods: ATE was prepared using discarded liposuction fluid from patients undergoing liposuction. A rabbit ear hypertrophic scar model was established and treated with ATE, fractional CO2 laser, or a combination. PBS was used as a control. The scar appearance and histological changes were observed. The immunohistochemistry method was used to evaluate the expression of α-SMA, while perilipin was detected using immunofluorescence. Additionally, the level of adipogenic signal C/EBPα and PPARγ mRNA was studied. Results: Following treatment, the volume of hypertrophic scar decreased, resulting in a softer texture and thinner dermis. Additionally, there was a decrease in the infiltration of inflammatory cells, and the collagen arrangement became looser and more regular, and the expression of α-SMA also decreased, with the combination of ATE and fractional laser showing the most significant improvement. Moreover, the combination group was found to promote subcutaneous fat regeneration and increase the expression of adipogenic signals C/EBPα and PPARγ. Conclusion: The combination of ATE and fractional CO2 laser treatment has been shown to inhibit the development of hypertrophic scars. This effect may be attributed to the enhancement of adipogenesis and decrease in collagen deposition.

Mechanical Fractionation of Adipose Tissue-A Scoping Review of Procedures to Obtain Stromal Vascular Fraction

Clinical indications for adipose tissue therapy are expanding towards a regenerative-based approach. Adipose-derived stromal vascular fraction consists of extracellular matrix and all nonadipocyte cells such as connective tissue cells including fibroblasts, adipose-derived stromal cells (ASCs) and vascular cells. Tissue stromal vascular fraction (tSVF) is obtained by mechanical fractionation, forcing adipose tissue through a device with one or more small hole(s) or cutting blades between syringes. The aim of this scoping review was to assess the efficacy of mechanical fractionation procedures to obtain tSVF. In addition, we provide an overview of the clinical, that is, therapeutic, efficacy of tSVF isolated by mechanical fraction on skin rejuvenation, wound healing and osteoarthritis. Procedures to obtain tissue stromal vascular fraction using mechanical fractionation and their associated validation data were included for comparison. For clinical outcome comparison, both animal and human studies that reported results after tSVF injection were included. We categorized mechanical fractionation procedures into filtration (n = 4), centrifugation (n = 8), both filtration and centrifugation (n = 3) and other methods (n = 3). In total, 1465 patients and 410 animals were described in the included clinical studies. tSVF seems to have a more positive clinical outcome in diseases with a high proinflammatory character such as osteoarthritis or (disturbed) wound healing, in comparison with skin rejuvenation of aging skin. Isolation of tSVF is obtained by disruption of adipocytes and therefore volume is reduced. Procedures consisting of centrifugation prior to mechanical fractionation seem to be most effective in volume reduction and thus isolation of tSVF. tSVF injection seems to be especially beneficial in clinical applications such as osteoarthritis or wound healing. Clinical application of tSVF appeared to be independent of the preparation procedure, which indicates that current methods are highly versatile.

Advancements in adipose-derived stem cell therapy for skin fibrosis

Pathological scarring and scleroderma, which are the most common conditions of skin fibrosis, pathologically manifest as fibroblast proliferation and extracellular matrix (ECM) hyperplasia. Fibroblast proliferation and ECM hyperplasia lead to fibrotic tissue remodeling, causing an exaggerated and prolonged wound-healing response. The pathogenesis of these diseases has not been fully clarified and is unfortunately accompanied by exceptionally high medical needs and poor treatment effects. Currently, a promising and relatively low-cost treatment has emerged-adipose-derived stem cell (ASC) therapy as a branch of stem cell therapy, including ASCs and their derivatives-purified ASC, stromal vascular fraction, ASC-conditioned medium, ASC exosomes, etc., which are rich in sources and easy to obtain. ASCs have been widely used in therapeutic settings for patients, primarily for the defection of soft tissues, such as breast enhancement and facial contouring. In the field of skin regeneration, ASC therapy has become a hot research topic because it is beneficial for reversing skin fibrosis. The ability of ASCs to control profibrotic factors as well as anti-inflammatory and immunomodulatory actions will be discussed in this review, as well as their new applications in the treatment of skin fibrosis. Although the long-term effect of ASC therapy is still unclear, ASCs have emerged as one of the most promising systemic antifibrotic therapies under development.

Microfat exerts an anti-fibrotic effect on human hypertrophic scar via fetuin-A/ETV4 axis

BACKGROUND

Hypertrophic scar is a fibrotic disease following wound healing and is characterized by excessive extracellular matrix deposition. Autologous microfat grafting proves an effective strategy for the treatment thereof as it could improve the texture of scars and relieve relevant symptoms. This study aims to explore the potential mechanisms underlying the anti-fibrotic effect of microfat on hypertrophic scars.

METHODS

In this study, we injected microfat into transplanted hypertrophic scars in mouse models and investigated the subsequent histological changes and differential expression of mRNAs therein. As for in vitro studies, we co-cultured microfat and hypertrophic scar fibroblasts (HSFs) and analyzed molecular profile changes in HSFs co-cultured with microfat by RNA sequencing. Moreover, to identify the key transcription factors (TFs) which might be responsible for the anti-fibrotic function of microfat, we screened the differentially expressed TFs and transfected HSFs with lentivirus to overexpress or knockdown certain differentially expressed TFs. Furthermore, comparative secretome analyses were conducted to investigate the proteins secreted by co-cultured microfat; changes in gene expression of HSFs were examined after the administration of the potential anti-fibrotic protein. Finally, the relationship between the key TF in HSFs and the microfat-secreted anti-fibrotic adipokine was analyzed.

RESULTS

The anti-fibrotic effect of microfat was confirmed by in vivo transplanted hypertrophic scar models, as the number of α-SMA-positive myofibroblasts was decreased and the expression of fibrosis-related genes downregulated. Co-cultured microfat suppressed the extracellular matrix production of HSFs in in vitro experiment, and the transcription factor ETV4 was primarily differentially expressed in HSFs when compared with normal skin fibroblasts. Overexpression of ETV4 significantly decreased the expression of fibrosis-related genes in HSFs at both mRNA and protein levels. Fetuin-A secreted by microfat could also downregulate the expression of fibrosis-related genes in HSFs, partially through upregulating ETV4 expression.

CONCLUSIONS

Our results demonstrated that transcription factor ETV4 is essential for the anti-fibrotic effect of microfat on hypertrophic scars, and that fetuin-A secreted by microfat could suppress the fibrotic characteristic of HSFs through upregulating ETV4 expression. Microfat wields an alleviative influence over hypertrophic scars via fetuin-A/ETV4 axis.

Mechanical Micronization of Lipoaspirates Combined with Fractional CO 2 Laser for the Treatment of Hypertrophic Scars

BACKGROUND

Treating hypertrophic scars remains challenging. Stromal vascular fraction (SVF) gel is produced by a purely mechanical process from lipoaspirates, rich in adipose-derived stem cells, and has showed therapeutic potential on scars. However, controversial effects on hypertrophic scars are emerging. This study aimed to assess the therapeutic effects of SVF gel combined with fractional CO 2 laser on hypertrophic scars.

METHODS

A rabbit ear hypertrophic scar model was established. SVF gel combined with fractional CO 2 laser was conducted for hypertrophic scars in rabbits. Scar alleviation in rabbits was observed based on the appearance and histology of scars, and the underlying mechanism was investigated by tissue immunologic analyses and quantitative real time polymerase chain reaction. At last, six patients with hypertrophic scar were treated by SVF gel combined with fractional CO 2 laser. Therapeutic effects were assessed using the Vancouver Scar Scale.

RESULTS

Following the treatments, hypertrophic scars became less apparent and softer, the dermis became thinner, and collagen fibers appeared looser and arranged in a more organized pattern. The SVF gel plus fractional CO 2 laser group showed the most obvious improvement. In addition, SVF gel combined with fractional CO 2 laser increased adipogenesis in scar tissue, and adipose tissue regeneration was observed. Hypertrophic scars in patients were alleviated after treatment with SVF gel combined with fractional CO 2 laser.

CONCLUSIONS

SVF gel transplantation combined with fractional CO 2 laser showed encouraging therapeutic effects on hypertrophic scars. Although further investigation is necessary, this technique has great potential for clinical application to treat hypertrophic scars.

CLINICAL RELEVANCE STATEMENT

This is a new technique for treating hypertrophic scars.

The Role of Verteporfin in Prevention of Periprosthetic Capsular Fibrosis: An Experimental Study

BACKGROUND

Capsular contracture (CC) characterized by excessive fibrosis is one of the most common complications after silicone implant surgery. Verteporfin (VP), an inhibitor of Yes-associated protein 1 (YAP1), has recently been found to reduce the fibrotic process.

OBJECTIVES

The aim of this study was to use an in vivo rabbit model to evaluate the efficacy of VP for the prevention of CC.

METHODS

Twenty-four New Zealand rabbits received 10-cc smooth saline silicone implants inserted in the dorsal skin and were randomly divided into 2 groups to receive 2 mL VP (1.5 mg/mL) or 2 mL phosphate-buffered saline solution instillation in the implant pocket. When the animals were killed on Day 60, capsule formation was observed both macroscopically and microscopically. Histologic evaluation included capsule thickness, fibrosis degree, and myofibroblast (α smooth muscle actin positive) content. In addition, the YAP1 expression level was examined by immunofluorescence staining. Transforming growth factor β1, collagen I, and connective tissue growth factor expression were measured by real-time quantitative polymerase chain reaction.

RESULTS

The VP-treated group exhibited thinner, more transparent capsules and less fibrosis than the control group at 60 days postsurgery (P < 0.05). Moreover, the VP treatment significantly reduced α smooth muscle actin, YAP1, transforming growth factor β1, collagen I, and connective tissue growth factor expression levels in the capsular tissues (P < 0.05).

CONCLUSIONS

VP reduced capsule formation after silicone implantation by inhibiting YAP1-mediated mechanical signaling, thereby attenuating excessive collagen deposition in the rabbit model. This preclinical study may provide a feasible strategy to prevent periprosthetic capsular fibrosis in clinical application.

Tissue Stromal Vascular Fraction Improves Early Scar Healing: A Prospective Randomized Multicenter Clinical Trial

BACKGROUND

Wound healing and scar formation depends on a plethora of factors. Given the impact of abnormal scar formation, interventions aimed to improve scar formation would be most advantageous. The tissue stromal vascular fraction (tSVF) of adipose tissue is composed of a heterogenous mixture of cells embedded in extracellular matrix. It contains growth factors and cytokines involved in wound-healing processes, eg, parenchymal proliferation, inflammation, angiogenesis, and matrix remodeling.

OBJECTIVES

The aim of this study was to investigate the hypothesis that tSVF reduces postsurgical scar formation.

METHODS

This prospective, double-blind, placebo-controlled, randomized trial was conducted between 2016 and 2020. Forty mammoplasty patients were enrolled and followed for 1 year. At the end of the mammoplasty procedure, all patients received tSVF in the lateral 5 cm of the horizontal scar of 1 breast and a placebo injection in the contralateral breast to serve as an intrapatient control. Primary outcome was scar quality measure by the Patient and Observer Scar Assessment Scale (POSAS). Secondary outcomes were obtained from photographic evaluation and histologic analysis of scar tissue samples.

RESULTS

Thirty-four of 40 patients completed follow-up. At 6 months postoperation, injection of tSVF had significantly improved postoperative scar appearance as assessed by the POSAS questionnaire. No difference was observed at 12 months postoperation. No improvement was seen based on the evaluation of photographs and histologic analysis of postoperative scars between both groups.

CONCLUSIONS

Injection of tSVF resulted in improved wound healing and reduced scar formation at 6 months postoperation, without any noticeable advantageous effects seen at 12 months.

LEVEL OF EVIDENCE: 2

Managing Wound Healing with a High-Risk Patient: A Case Report

Wound healing is a complex, multi-step process. This process begins immediately after skin damage. The outcome of wound healing depends on the quality of each stage of this process: a normal or pathological scar. Violation of wound healing entails a decrease in the function of scar tissue as well as aesthetic dissatisfaction with the patient. This problem is especially important in aesthetic surgery. Patients who have come for beauty feel frustration, obtaining pathological scars. We have been dealing with the problem of wound healing after plastic surgery for about 10 years. Our approach includes the assessment of the risk of pathological wound healing and the treatment of high-risk patients. The risk assessment includes historical data on wound healing, signs of connective tissue dysfunction (especially patients with connective tissue dysplasia), and genetic polymorphisms of genes responsible for the structure of the components of the extracellular matrix of the skin. In the future, patients with a high risk of pathological scarring can be prescribed treatment after surgery. This article presents a clinical case in which we demonstrate our approach.

The Role of Extracellular Matrix in Skin Wound Healing

Impaired wound healing is one of the unsolved problems of modern medicine, affecting patients’ quality of life and causing serious economic losses. Impaired wound healing can manifest itself in the form of chronic skin wounds or hypertrophic scars. Research on the biology and physiology of skin wound healing disorders is actively continuing, but, unfortunately, a single understanding has not been developed. The attention of clinicians to the biological and physiological aspects of wound healing in the skin is necessary for the search for new and effective methods of prevention and treatment of its consequences. In addition, it is important to update knowledge about genetic and non-genetic factors predisposing to impaired wound healing in order to identify risk levels and develop personalized strategies for managing such patients. Wound healing is a very complex process involving several overlapping stages and involving many factors. This thematic review focuses on the extracellular matrix of the skin, in particular its role in wound healing. The authors analyzed the results of fundamental research in recent years, finding promising potential for their transition into real clinical practice.

A Retrospective Study of SVF-gel Compared With Nanofat Combined With High-density Fat in the Treatment of Early Periorbital Aging

PURPOSE

To compare the effectiveness of transplantation with stromal vascular fraction (SVF)-gel or nanofat combined with high-density fat prepared with the Coleman technique (nanofat+high-density fat) to restore volume in the periorbital region or for periorbital rejuvenation in early periorbital aging.

METHODS

This retrospective study included 103 patients who received a transplant of SVF-gel (n = 58) or nanofat+high-density fat (n = 45) to restore volume in the periorbital region (n = 85) or for periorbital rejuvenation (n = 18) in our hospital between January 2016 and January 2020. Patient satisfaction and the reoperation rate were evaluated.

RESULTS

All patients had improved periorbital contouring and augmentation. Among the patients that received treatment to restore volume in the periorbital region, 17% and 65.9% of patients administered SVF-gel were very satisfied or satisfied, and 5.3% and 44.7% of patients administered nanofat+high-density fat were very satisfied or satisfied.

PATIENTS

administered SVF-gel were significantly more satisfied than patients administered nanofat+high-density fat with improvements in periorbital contouring (p < 0.05). Among the patients that received treatment for periorbital rejuvenation, 54.5% and 27.3% of patients administered SVF-gel were very satisfied or satisfied, and 28.6% and 42.8% of patients administered nanofat+high-density fat were very satisfied or satisfied. There was no significant difference between groups (p > 0.05). Some patients underwent a second operation after 3 to 8 months. Patients administered SVF-gel to restore volume in the periorbital region had a significantly lower reoperation rate than patients administered nanofat+high-density fat (12.7% [6/47] vs. 34.2% [13/38]; p < 0.05). There was no significant difference in the reoperation rate in patients treated for periorbital rejuvenation (9.1% [1/11] vs. 14.3% [1/7]; p > 0.05).

CONCLUSION

SVF-gel and nanofat+high-density fat are effective for restoring volume in the periorbital region and for periorbital rejuvenation in early periorbital aging. The reoperation rate was significantly lower and patient satisfaction scores were significantly higher in patients administered SVF-gel to restore volume in the periorbital region compared with patients administered nanofat+high-density fat.

Comparison of Microfat, Nanofat, and Extracellular Matrix/Stromal Vascular Fraction Gel for Skin Rejuvenation: Basic Research and Clinical Applications

BACKGROUND

Over the past 2 decades, fat grafting has been extensively applied in the field of tissue regeneration.

OBJECTIVES

The aim of this study was to investigate the therapeutic potential of microfat, nanofat, and extracellular matrix/stromal vascular fraction gel (SVF-gel) in skin rejuvenation.

METHODS

Microfat was harvested by a cannula with multiple 0.8-mm smooth side holes and processed with a fat stirrer to remove fibers. Nanofat and SVF-gel were prepared according to previously reported methods, and their structure and viability were evaluated. Then, SVF cells from the 3 types of samples were isolated and characterized, and the cell viability was compared.

RESULTS

The microstructure of the 3 samples showed distinct differences. The microfat group showed a diameter of 100 to 120.0 μm under the microscope and presented a botryoid shape under calcein acetoxymethyl (calcein-AM)/propidium iodide staining. Scanning electron microscopy analysis showed that the microfat maintained an integral histologic structure. In the nanofat group, no viable adipocytes and no normal histologic structure were observed, but high levels of free lipids were noted. The SVF-gel group showed uniform dispersion of cells with different sizes and parts of the adipose histologic structure. Cell count and culture revealed that the number of viable SVF cells decreased distinctly in the nanofat group compared with the microfat group. In contrast, the number of viable SVF cells in the SVF-gel group increased moderately. Clinical applications with microfat showed marked improvements in skin wrinkles.

CONCLUSIONS

Microfat can preserve the integrity of the histologic structure and presents the advantages of subcutaneous volumetric restoration and improvement of skin quality in skin rejuvenation compared with the nanofat and SVF-gel.

LEVEL OF EVIDENCE: 5

A Reliable Method for Chin Augmentation by Mechanical Micronization of Lipoaspirates

BACKGROUND

Desire for improved aesthetic contour of the lower third of the face has resulted in an increase in chin augmentation. Although many fillers, including hyaluronic acid (HA), autologous fat and stromal vascular fraction gel (SVF-gel), have been used to improve facial morphology, chin augmentation requires fillers that provide greater support.

METHODS

The elastic and viscous moduli of SVF-gel and Coleman fat were assessed in vitro by rheological testing, whereas their elasticity were evaluated in vivo by ultrasonic elastography. Results in vitro were compared with those of highly elastic HA (HE-HA) and highly viscous HA (HV-HA), whereas results in vivo were compared with HE-HA. Changes in chin volume, SVF-gel retention rate and absorptivity for at least 12 months were measured by 3D white light scanning. Questionnaires were administered to assess patient satisfaction.

RESULTS

The elastic and viscous modulus of SVF-gel was, respectively, slightly lower than HE-HA and HV-HA but higher than the other two in vitro, with the elasticity of the three layers of SVF-gel lower than HE-HA but slightly higher than normal control in vivo. The average retention rate was 62.34±3.34% at 12 months. The absorptivity of 90% of the samples was <3% from 6 to 12 months, which was considered stable. Patients expressed satisfaction with their results.

CONCLUSION

SVF-gel has ideal rheologic characteristics in vitro, which has slightly higher elasticity than normal fat tissue of chin in vivo, and could keep well retention rate for chin augmentation in clinic.

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 .

Effect of Co-transplanting Stromal Vascular Fraction-Gelatin and Platelet-Rich Fibrin on the Long-Term Maintenance of Fat Volume

OBJECTIVE

In the present study, we aimed to investigate the survival of stromal vascular fraction-gelatin (SVF-gel) grafts and determine whether co-transplantation of SVF-gel and platelet-rich fibrin (PRF) improves long-term maintenance of fat volume (Wei et al. in Oncotarget 8:68542-68556, 2017) in a rabbit model.

METHODS

SVF-gel was transplanted into the ears of 12 rabbits with (experimental group) or without PRF (control group). Transplantation retention was evaluated based on weight, histology, and immunohistochemistry.

RESULTS

In the 2nd and 4th weeks, the volume of fat was larger in the experimental group than in the control group. In the 6th week, the absorption of fat was noticeable in both groups, and there was no significant difference in the fat survival rate between the two groups (experimental group: 1.051 ± 0.144 and control group: 0.789 ± 0.232, P > 0.05). HE staining results: At week 2, adipocytes were observed in the experimental group and tended to mature over time. These adipocytes also exhibited an ordered arrangement. Adipocytes with abnormal morphology appeared in the control group in the 4th week. At different weeks, there were more inflammatory cells and fibroblasts in the experimental group than in the control group, and they were arranged in an ordered fashion. Immunohistochemical results: More brown areas were observed in the experimental group than in the control group, and the morphology and distribution of adipocytes in the experimental group were better than those in the control group. The distribution of fibrocytes was also more regular in the experimental group than in the control group.

CONCLUSION

SVF-gel cannot maintain long-term filling in rabbit ears. The addition of PRF has no influence, although PRF can induce SVF-gel to transform into adipocytes, and the anti-inflammatory effect is noticeable in the early period following the procedure. Co-transplantation also helped to ensure orderly arrangement of fibrin. There were no "volume preservation differences in this experimental model" perhaps there are differences if other models/methodology are employed. No Level Assigned 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 Table of Contents or online Instructions to Authors - www.springer.com/00266 .

An Efficacy Study of a New Radical Treatment for Acne Vulgaris Using Fat Injection

BACKGROUND

Fat grafting is a popular operative approach for rejuvenation. Some patients requiring facial fat grafting also have acne. Fat grafting may improve acne in some patients.

OBJECTIVES

The aim of this study was to assess whether fat grafting can improve acne and to analyze the mechanism of action by which such improvement occurs.

METHODS

Preoperative and postoperative digital photographs were examined retrospectively in 229 patients who underwent fat grafting to compare the numbers of inflammatory acne lesions. In addition, 18 patients with acne who were treated by injection of subdermal stromal vascular fraction gel (SVF-gel) were examined prospectively. The numbers of inflammatory acne lesions before and after treatment were measured, and changes in the levels of CD4+ T-cell infiltration were determined from immunohistochemical staining.

RESULTS

Of the 229 retrospectively evaluated patients who underwent fat grafting, 22 had acne and had complete follow-up data; in these patients, the numbers of acne lesions were significantly lower after than before treatment. The 18 patients who received subdermal SVF-gel injection showed evident improvements in inflammatory lesions after more than 1 year of follow-up. CD4+ T-cell infiltration was significantly decreased at week 4.

CONCLUSIONS

Facial fat grafting can improve inflammatory acne lesions, perhaps because adipose-derived stem cells, which are plentiful in SVF-gel, reduce CD4+ T-cell-mediated inflammation responses.

LEVEL OF EVIDENCE: 4

Systematic review: Advances of fat tissue engineering as bioactive scaffold, bioactive material, and source for adipose-derived mesenchymal stem cells in wound and scar treatment

Fat tissue (FT) has been used for many years in regenerative surgery as a bioactive material through the lipofilling/fat graft (F-GRF)-nano-fat technique, as a bioactive scaffold when it was enriched with adipose-derived mesenchymal stem cells (AD-MSCs) contained in the stromal vascular fraction (SVF), and as a direct source of AD-MSCs used in wound healing (WH) and scar treatment (ST). This systematic review aims to describe the advances in FT engineering applied to regenerative surgery (from bench to clinic), through the use of AD-MSCs, SVF contained in F-GRF in WH and ST. The work has been performed by assessing in the selected studies autologous graft of AD-MSCs, SVF, and F-GRF compared to any control for ST and WH. The protocol was developed following the Preferred Reporting for Items for Systematic Reviews and Meta-Analyses-Protocols (PRISMA-P) guidelines. A multistep search of the PubMed, MEDLINE, Embase, PreMEDLINE, Ebase, CINAHL, PsycINFO, Clinicaltrials.gov , Scopus database, and Cochrane databases has been performed to identify papers on AD-MSCs, SVF, and F-GRF use in WH and ST in which FT was used as bioactive material-scaffold and source of AD-MSCs. Of the 714 articles initially identified, 453 articles focusing on regenerative strategies in WH and ST were selected and, consequently, only 84 articles that apparently related to AD-MSC, SVF, and F-GRF were analyzed. Of these, 61 articles identified as pre-clinical, experimental, and in vitro, and 5 articles identified as a comment and systematic review were excluded. Only 18 original articles which strictly and exclusively focused on autologous AD-MSCs, SVF, and F-GRF in ST and WH were analyzed. The included studies had to match predetermined criteria according to the PICOS (patients, intervention, comparator, outcomes, and study design) approach. The identified studies described microscopic and clinical outcomes in patients treated with AD-MSCs, SVF, and F-GRF. Collected data confirmed the safety and efficacy of FT both as bioactive material-scaffold and source of AD-MSCs in WH and ST without major side effects.

Extracellular Vesicles Derived From Human Adipose-Derived Stem Cell Prevent the Formation of Hypertrophic Scar in a Rabbit Model

Preventing scar formation during wound healing has important clinical implications. Numerous studies have indicated that adipose-derived stem cell culture mediums, which are rich in cytokines and extracellular vesicles (EVs), regulate matrix remodeling and prevent scar formation after wound healing. Therefore, using a rabbit scar model, we tried to demonstrate which factor in adipose-derived stem cell culture mediums plays a major role in preventing scar formation (EVs or cytokines), as well as revealing the underlying mechanism.

Adipose-Derived Mesenchymal Stem Cells (AD-MSCs) against Ultraviolet (UV) Radiation Effects and the Skin Photoaging

The skin is a natural barrier against the ultraviolet (UV) radiation of sunlight. The long-term and/or repetitive exposure to the sunlight and related UV radiation may change the skin structure, decreasing collagen production, promoting premature skin aging, which is termed "photoaging". The signs of photoaging include wrinkle formation, mottled pigmentation, and/or cancerous changes. For many years, adipose-derived mesenchymal stem cells (AD-MSCs) and fat grafting (F-GRF) have been used to combat photoaging signs, wrinkles, loss of elasticity, and face soft tissue defects. Several studies have analyzed in vitro actions of AD-MSCs against photoaging's effects, thanks to their migratory activity, paracrine actions, and related in vivo-ex vivo outcomes. In fact, AD-MSCs act against skin photoaging in vitro via activation of dermal fibroblast proliferation, antioxidant effect, and matrix metalloproteinases (MMPs) reduction. In vivo and ex vivo outcomes regard the local injection of AD-MSCs, F-GRF, and/or enriched-F-GRF with AD-MSCs directly in the wrinkles and the face's soft tissue defects. This concise review summarizes the most recent in vitro, in vivo and ex vivo outcomes and developments on the effects of AD-MSCs and F-GRF against photoaging.

Therapeutic Strategies by Regulating Interleukin Family to Suppress Inflammation in Hypertrophic Scar and Keloid

Hypertrophic scar (HS) and keloid are fibroproliferative disorders (FPDs) of the skin due to aberrant wound healing, which cause disfigured appearance, discomfort, dysfunction, psychological stress, and patient frustration. The unclear pathogenesis behind HS and keloid is partially responsible for the clinical treatment stagnancy. However, there are now increasing evidences suggesting that inflammation is the initiator of HS and keloid formation. Interleukins are known to participate in inflammatory and immune responses, and play a critical role in wound healing and scar formation. In this review, we summarize the function of related interleukins, and focus on their potentials as the therapeutic target for the treatment of HS and keloid.

Not Stromal Vascular Fraction (SVF) or Nanofat, but Total Stromal-Cells (TOST): A New Definition. Systemic Review of Mechanical Stromal-Cell Extraction Techniques

The most important and greatest source in the body for regenerative cells is fat tissue. Obtaining regenerative cells from adipose tissue can be done in two ways: Enzymatic and mechanical. The regenerative cell cocktail obtained by the enzymatic method, including stem cells, is called Stromal vascular fracture (SVF). In the literature, there is no clear definition of regenerative cells obtained by mechanical method. We systematically searched the techniques and definitions for stromal cells obtained from adipose tissue by scanning different databases. To evaluate the mechanical stromal-cell isolation techniques and end products from adipose tissue. Systematic review of English and non-English articles using Embase, PubMed, Web of Science and Google scholar databases. Search terms included Nanofat, fragmented fat, mechanical stromal / stem cell, mechanical SVF, SVF gel. We screened all peer-reviewed articles related with mechanical stromal-cell isolation. Author performed a literature query with the aforementioned key words and databases. A total of 276 publications containing the keywords we searched were reached. In these publications, there are 46 different definitions used to obtain mechanical stromal cells. The term SVF is only suitable for enzymatic methods. A different definition is required for mechanical. The most used term nanofat is also not suitable because the product is not in both "fat" and in "nanoscale". We think that the term total stromal-cells would be the most appropriate definition since both extracellular matrix and all stromal cells are protected in mechanical methods.

Scar-Free Healing: Current Concepts and Future Perspectives

Every year, millions of people develop scars due to skin injuries after trauma, surgery, or skin burns. From the beginning of wound healing development, scar hyperplasia, and prolonged healing time in wound healing have been severe problems. Based on the difference between adult and fetal wound healing processes, many promising therapies have been developed to decrease scar formation in skin wounds. Currently, there is no good or reliable therapy to cure or prevent scar formation. This work briefly reviews the engineering methods of scarless wound healing, focusing on regenerative biomaterials and different cytokines, growth factors, and extracellular components in regenerative wound healing to minimize skin damage cell types, and scar formation.

Autologous Fractionated Adipose Tissue as a Natural Biomaterial and Novel One-Step Stem Cell Therapy for Repairing Articular Cartilage Defects

Articular cartilage damage remains a tough challenge for clinicians. Stem cells have emerged promising biologics in regenerative medicine. Previous research has widely demonstrated that adipose-derived mesenchymal stem cells (ADSCs) can promote cartilage repair due to their multipotency. However, enzymatic isolation and monolayer expansion of ADSCs decrease their differentiation potential and limit their clinical application. Here, a novel adipose tissue-derived product, extracellular matrix/stromal vascular fraction gel (ECM/SVF-gel), was obtained by simple mechanical shifting and centrifugation to separate the fat oil and concentrate the effective constituents. This study aimed to evaluate the therapeutic effect of this natural biomaterial on the repair of articular cartilage defects. Scanning electron microscopy showed that the fibrous structure in the ECM/SVF-gel was preserved. ADSCs sprouted from the ECM/SVF-gel were characterized by their ability of differentiation into chondrocytes, osteoblasts, and adipocytes. In a rabbit model, critical-sized cartilage defects (diameter, 4 mm; depth, 1.5 mm) were created and treated with microfracture (MF) or a combination of autologous ECM/SVF-gel injection. The knee joints were evaluated at 6 and 12 weeks through magnetic resonance imaging, macroscopic observation, histology, and immunohistochemistry. The International Cartilage Repair Society score and histological score were significantly higher in the ECM/SVF-gel group than those in the MF-treated group. The ECM/SVF-gel distinctly improved cartilage regeneration, integration with surrounding normal cartilage, and the expression of hyaline cartilage marker, type II collagen, in comparison with the MF treatment alone. Overall, the ready-to-use ECM/SVF-gel is a promising therapeutic strategy to facilitate articular cartilage regeneration. Moreover, due to the simple, time-sparing, cost-effective, enzyme-free, and minimally invasive preparation process, this gel provides a valuable alternative to stem cell-based therapy for clinical translation.

Role of stable hydrogen isotope variations in water for drug dissolution managing

In the present work, we provide the results of defining by utilizing Laser diffraction spectroscopy, the kinetic isotopic effect of solvent and constant of dissolution rate κ, s−1 of аn active pharmaceutical ingredient (API) in water with a different content of a stable 2 1 H _2^1{\rm{H}} isotope on the basis of the laws of first-order kinetics. This approach is based on the analysis of the light scattering profile that occurs when the particles of the dispersion phase in the aquatic environment are covered with a collimated laser beam. For the first time, the dependence of the rate of dissolution is demonstrated not only on the properties of the pharmaceutical substance itself (water solubility mg/ml, octanol–water partition coefficient log P oct/water, topological polar surface area, Abraham solvation parameters, the lattice type), but also on the properties of the solvent, depending on the content of stable hydrogen isotope. We show that the rate constant of dissolution of a sparingly hydrophobic substance moxifloxacin hydrochloride (MF · HCl) in the Mili-Q water is: k=1.20±0.14∙10−2 s−1 at 293.15 K, while in deuterium depleted water, it is k=4.24±0.4∙10−2 s−1. Consequently, we have established the development of the normal kinetic isotopic effect (kH/kD >1) of the solvent. This effect can be explained both by the positions of the difference in the vibrational energy of zero levels in the initial and transition states, and from the position of water clusters giving volumetric effects of salvation, depending on the ratio D/H. The study of kinetic isotopic effects is a method that gives an indication of the mechanism of reactions and the nature of the transition state. The effect of increasing the dissolution of the API, as a function of the D/H ratio, we have discovered, can be used in the chemical and pharmaceutical industries in the study of API properties and in the drug production through improvement in soluble and pharmacokinetic characteristics.

Strategies to prevent hypertrophic scar formation: a review of therapeutic interventions based on molecular evidence

Once scar tissues mature, it is impossible for the surrounding tissue to regenerate normal dermal tissue. Therefore, it is essential to understand the fundamental mechanisms and establish effective strategies to inhibit aberrant scar formation. Hypertrophic scar formation is considered a result of the imbalance between extracellular matrix synthesis and degradation during wound healing. However, the underlying mechanisms of hypertrophic scar development are poorly understood. The purpose of this review was to outline the management in the early stage after wound healing to prevent hypertrophic scar formation, focusing on strategies excluding therapeutic agents of internal use. Treatment aimed at molecular targets, including cytokines, will be future options to prevent and treat hypertrophic scars. More basic studies and clinical trials, including combination therapy, are required to investigate the mechanisms and prevent hypertrophic scar formation.

Fat Grafting for Facial Rejuvenation Using Stromal Vascular Fraction Gel Injection

This study used stromal vascular fraction gel (SVF-gel), a mechanically processed fat-derived product, to treat eye bag and tear trough deformity. SVF-gel is prepared by a process of centrifugation and intersyringe shifting and is particularly rich in SVF cells and native adipose extracellular matrix. SVF-gel injection is used alone or combined with transconjunctival eye bag removal. High satisfaction was noted among patients treated with SVF-gel injection for periorbital rejuvenation with fairly low complication rates. SVF-gel injection is a good alternative to assist transconjunctival lower eyelid blepharoplasty and correct the palpebromalar groove, tear trough deformity, and supraorbital hollow.

Mechanical process prior to cryopreservation of lipoaspirates maintains extracellular matrix integrity and cell viability: evaluation of the retention and regenerative potential of cryopreserved fat-derived product after fat grafting

Background

Cryopreservation of fat grafts facilitates reinjection for later use. However, low temperature and thawing can disrupt tissues and cause lipid leakage, which raises safety concerns. Here, we compared the cryopreservation potential of stromal vascular fraction (SVF) gel processed from lipoaspirate with that of fat.

Methods

Human SVF gel and fat were cryopreserved at − 20 °C without cryoprotectant for 1 month. Fresh SVF gel and fat were used as controls. Tissue viability, adipose-derived stem cell (ASC) function, and the extracellular content were evaluated. At 3 months after transplanting the specimens to immunocompromised mice subcutaneously, the grafts were examined for retention, tissue engraftment, and inflammatory levels. The regenerative effect of cryopreserved SVF gel was evaluated in a murine ischemic wound healing model.

Results

At 1 month, the cell death rate in the SVF gel group was 36 ± 2%. The survived ASCs not only could be isolated via explant culture but also preserved colony-forming and differentiation. However, prolonged cryopreservation exacerbated apoptosis. Assessment of recovered tissues showed that the morphology, cell viability, and extracellular protein enrichment were better in SVF gel-preserved tissues than in frozen fat. At 3 months after lipotransfer, the retention ability of 1-month cryopreserved fat was 41.1 ± 9% compared to that of 1-month cryopreserved SVF gel. Immunostaining results showed that adipose tissue regeneration and integrity in the 1-month cryopreserved SVF gel group were superior to those of the cryopreserved fat group. The cryopreserved SVF gel also accelerated healing of the ischemic wound, compared with cryopreserved fat.

Conclusion

Cryopreserved SVF gel maintained tissue integrity and cell viability and resulted in a better long-term retention rate than that of cryopreserved fat. Cryopreserved SVF gel also showed superior regenerative potential and improved ischemic wound healing.

Human adipose liquid extract induces angiogenesis and adipogenesis: a novel cell-free therapeutic agent

BACKGROUND

Taking advantage of cellular paracrine mechanisms, the secretome of adipose-derived stem cells (ADSCs) and adipose tissue has been demonstrated to induce tissue repair and regeneration in various ischemic and impaired conditions. However, these cell-based therapies have been hindered by issues, such as inherent safety and cost-efficiency for clinical applications. In this study, we prepared a liquid cell-free extract from human adipose tissue [adipose liquid extract (ALE)] and evaluated its potential therapeutic efficacy.

METHODS

ALE was prepared from human subcutaneous adipose tissue using a rapid and physical approach, and the protein components in ALE were identified using mass spectrometry analysis. In vivo, the therapeutic effect of this agent was investigated on wound healing in C57BL/6 mice, and wound healing rate, vessel density, and neo-adipocyte formation in wounded skins were measured at days 3, 7, 11, and 14. In vitro, the effect of ALE on the viability of human ADSCs, tube formation of human umbilical vein endothelial cells (HUVECs), and adipogenic differentiation of ADSCs were tested.

RESULTS

The results demonstrated that ALE contained a variety of growth factors and did not affect cell viability. ALE-treated wounds exhibited accelerated wound healing with increased vessel density and formation of neo-adipocytes compared to that of control wounds. Moreover, when added as a cell culture supplement, ALE effectively induced tube formation of HUVECs and lipid accumulation in ADSCs. ALE-treated ADSCs also exhibited elevated levels of adipogenic gene expression.

CONCLUSIONS

ALE is a novel growth-rich therapeutic agent that is cell-free and easy to produce. Besides, it is also able to induce angiogenesis and adipogenesis both in vitro and in vivo, thus indicating that it could be used for wound repair and soft tissue regeneration.

Intralesional Injection of Botulinum Toxin Type A Compared with Intralesional Injection of Corticosteroid for the Treatment of Hypertrophic Scar and Keloid: A Systematic Review and Meta-Analysis

Background

The optimal treatment for hypertrophic scar and keloid remains controversial. Therefore, the aim of this systematic review and meta-analysis was to compare the effectiveness of intralesional injection of botulinum toxin type A compared with placebo and intralesional injection of corticosteroid compared with placebo in patients with hypertrophic scar and keloid.

Material/Methods

Six databases were searched using Medical Subject Headings (MeSH) keywords and included Web of Science, PubMed, EMBASE, the Cochrane Library, WanFang, and CNKI from their inception to March 1 2019, without language restriction. Randomized controlled trials (RCTs) and prospective controlled trials (PCTs) were identified that compared intralesional injection of botulinum toxin type A with placebo and corticosteroid with placebo in hypertrophic scar and keloid. The quality of controlled trials was assessed by the Newcastle-Ottawa Scale (NOS).

Results

Comparison of intralesional botulinum toxin type A and corticosteroid showed significant differences in the Visual Analog Scale (VAS) (P<0.001) (WMD, −4.30; 95% CI, −4.44 to −4.16) and effective rate (P=0.012) (RR=0.82; 95% CI, 0.70–0.96). Intralesional injection of botulinum toxin type A compared with placebo showed significant differences in the VAS (P<0.001) (WMD, 1.41; 95% CI, 1.21–1.62), the width of scar (P=0.00) (WMD, −0.15; 95% CI, −0.19 to −0.10) and Vancouver Scar Scale (VSS) (P=0.003) (WMD, −0.69; 95% CI, −1.14 to −0.23).

Conclusions

Systematic review and meta-analysis showed that injection of intralesional botulinum toxin type A was more effective in the treatment of hypertrophic scar and keloid than injection of intralesional corticosteroid or placebo.