Supplementation of fat grafts with adipose-derived regenerative cells improves long-term graft retention. Ann Plast Surg. 2010;64:222-228. [PMID: 20098110 DOI: 10.1097/sap.0b013e31819ae05c]

Adipose-derived stem cells in radiotherapy injury: a new frontier

Radiotherapy is increasingly used to treat numerous human malignancies. In addition to the beneficial anti-cancer effects, there are a series of undesirable effects on normal host tissues surrounding the target tumor. While the early effects of radiotherapy (desquamation, erythema, and hair loss) typically resolve, the chronic effects persist as unpredictable and often troublesome sequelae of cancer treatment, long after oncological treatment has been completed. Plastic surgeons are often called upon to treat the problems subsequently arising in irradiated tissues, such as recurrent infection, impaired healing, fibrosis, contracture, and/or lymphedema. Recently, it was anecdotally noted - then validated in more robust animal and human studies - that fat grafting can ameliorate some of these chronic tissue effects. Despite the widespread usage of fat grafting, the mechanism of its action remains poorly understood. This review provides an overview of the current understanding of: (i) mechanisms of chronic radiation injury and its clinical manifestations; (ii) biological properties of fat grafts and their key constituent, adipose-derived stem cells (ADSCs); and (iii) the role of ADSCs in radiotherapy-induced soft-tissue injury.

Uncultured autogenous adipose-derived regenerative cells promote bone formation during distraction osteogenesis in rats

BACKGROUND

Adipose-derived stem cells have recently shown differentiation potential in multiple mesenchymal lineages in vitro and in vivo. These cells can be easily isolated in large amounts from autologous adipose tissue and used without culturing or differentiation induction, which may make them relatively easy to use for clinical purposes; however, their use has not been tested in a distraction osteogenesis model.

QUESTION/PURPOSES

The question of this animal study in a rodent model of distraction osteogenesis was whether uncultured adipose-derived regenerative cells (ADRCs), which can easily be isolated in large amounts from autologous adipose tissue and contain several types of stem and regenerative cells, promote bone formation in distraction osteogenesis. We evaluated this using several tools: (1) radiographic analysis of bone density; (2) histological analysis of the callus that formed; (3) biomechanical testing; (4) DiI labeling (a method of membrane staining for postimplant celltracing); and (5) real-time polymerase chain reaction.

METHODS

Sixty rats were randomly assigned to three groups. Physiological saline (control group), Type I collagen gel (collagen group), or a mixture of ADRC and Type I collagen gel (ADRC group) was injected into the distracted callus immediately after distraction termination. To a rat femur an external fixator was applied at a rate of 0.8 mm/day for 8 days.

RESULTS

The bone density of the distracted callus in the ADRC group increased by 46% (p = 0.003, Cohen's d = 10.2, 95% confidence interval [CI] ± 0.180) compared with the control group at 6 weeks after injection. The fracture strength in the ADRC group increased by 66% (p = 0.006, Cohen's d = 1.32, 95% CI ± 0.180) compared with the control group at 6 weeks after injection. Real-time reverse transcription-polymerase chain reaction of the distracted callus from the ADRC group had higher levels of bone morphogenetic protein-2 (7.4 times higher), vascular endothelial growth factor A (6.8 times higher), and stromal cell-derived factor-1 (4.3 times higher). Cell labeling in the newly formed bone showed the ADRCs differentiated into osseous tissue at 3 weeks after injection.

CONCLUSIONS

The injection of ADRCs promoted bone formation in the distracted callus and this mechanism involves both osteogenic differentiation and secretion of humoral factors such as bone morphogenetic protein-2 or vascular endothelial growth factor A that promotes osteogenesis or angiogenesis.

CLINICAL RELEVANCE

The availability of an easily accessible cell source may greatly facilitate the development of new cell-based therapies for regenerative medicine applications in the distraction osteogenesis.

Implications for human adipose-derived stem cells in plastic surgery

Adipose-derived stem cells (ADSCs) are a subset of mesenchymal stem cells (MSCs) that possess many of the same regenerative properties as other MSCs. However, the ubiquitous presence of ADSCs and their ease of access in human tissue have led to a burgeoning field of research. The plastic surgeon is uniquely positioned to harness this technology because of the relative frequency in which they perform procedures such as liposuction and autologous fat grafting. This review examines the current landscape of ADSC isolation and identification, summarizes the current applications of ADSCs in the field of plastic surgery, discusses the risks associated with their use, current barriers to universal clinical translatability, and surveys the latest research which may help to overcome these obstacles.

Experimental and clinical methods used for fat volume maintenance after autologous fat grafting

Management of soft tissue deficits resulting from congenital abnormalities, trauma, systemic disease, and tumors is a particularly challenging field of plastic and reconstructive surgery. Fat grafting, a technique traditionally used in the correction of facial asymmetry, is commonly seen in aesthetic procedures which use the grafted fat for soft tissue augmentation and recontouring. Despite its widespread use in reconstruction and aesthetic surgery, therapeutic modalities applied in fat grafting are crude and the results of this intervention are unpredictable. The aim of this review was to present the most recent evidence regarding experimental studies and designs which confirmed or disproved fat volume expansion or fat maintenance after autologous fat grafting.

Paracrine mechanism of angiogenesis in adipose-derived stem cell transplantation

INTRODUCTION

Adipose-derived stem cells (ASCs) have shown potential for cell-based therapy in the field of plastic surgery. However, the fate of ASCs after transplantation and the mechanism(s) of their biologic capabilities remain unclear.

METHODS

We isolated and cultured ASCs from transgenic mice that express both luciferase and green fluorescent protein and injected the cells into the inguinal fat pads of wild-type mice. We tested 4 experimental groups, namely, ischemic fat pads with/without ASCs and control fat pads with/without ASCs.

RESULTS

Transplanted ASCs were tracked with bioluminescence imaging. The luminescence gradually decreased over 28 days, indicating cell death after transplantation. More ASCs were retained in ischemic fat pads on day 7 compared to control fat pads. On day 14, adipose tissue vascular density was higher in the ASC transplantation groups compared to those without ASCs. On day 28, there was decreased atrophy of adipose tissue in ASC-treated ischemic fat pads. Transplanted ASCs were detected as nonproliferating green fluorescent protein-positive cells, whereas native endothelial cells adjacent to the transplanted ASCs were proliferative. Protein analysis demonstrated higher expression of hepatocyte growth factor and vascular endothelial growth factor in the ASC transplantation groups, suggesting a paracrine mechanism, which was confirmed by in vitro experiments with conditioned media from ASCs.

CONCLUSIONS

Transplanted ASCs are preferentially retained in ischemic adipose tissue, although most of the cells eventually undergo cell death. They exert an angiogenic effect on adipose tissue mainly through a paracrine mechanism. Increased understanding of these effects will help develop ASCs as a tool for cell-based therapy.

Adipogenic differentiation potential of rat adipose tissue-derived subpopulations of stromal cells

Adipose-derived stromal cells (ASCs) are mostly isolated by enzymatic digestion, centrifugation and adherent growth resulting in a very heterogeneous cell population. Therefore, other cell types in the cell culture can comprise the differentiation and proliferation potential of the ASC population. Recent studies indicated that an antibody-aided isolation of distinct ASC subpopulations provides advantages over the conventional method of ASC isolation. The aim of this study was to investigate the adipogenic differentiation potential of CD29-, CD71-, CD73- and CD90-selected ASCs in vitro. The stromal vascular fraction (SVF) was obtained from rat adipose tissue by enzymatic digestion and centrifugation. Subsequently, CD29(+)-, CD71(+)-, CD73(+)- and CD90(+) cells were isolated by magnetic activated cell sorting (MACS), seeded into culture plates and differentiated into the adipogenic lineage. ASCs isolated by adherent growth only served as controls. Adipogenic differentiation was assessed by Oil Red O staining and quantification of the adiponectin and leptin concentrations in the cell culture supernatants. Statistical analysis was carried out using one-way analysis of variance (ANOVA) followed by the Scheffe's post hoc procedure. The results showed that different subpopulations with different adipogenic differentiation potentials can be isolated by the MACS procedure. The highest adipogenic differentiation potential was determined in the CD29-selected ASC population followed by the unsorted ASC population. The CD71-, CD73- and CD90-selected cells exhibited significantly the lowest adipogenic differentiation potential. In conclusion, the CD29-selected ASCs and the unsorted ASCs exhibited a similar adipogenic differentiation potential. Therefore, we do not see a clear advantage in the application of an anti-CD29-based isolation of ASCs over the conventional technique using adherent growth. However, the research on isolation/purification methods of adipogenic ASCs should continue in order to make this stem cell source even more attractive for future adipose tissue engineering applications.

Adipose stromal/stem cells assist fat transplantation reducing necrosis and increasing graft performance

Autologous fat transfer (AFT) is a procedure for adipose tissue (AT) repair after trauma, burns, post-tumor resections and lipodystrophies still negatively impacted by the lack of graft persistence. The reasons behind this poor outcome are unclear and seem to involve damages in either harvested/transplanted mature adipocytes or on their mesenchymal progenitors, namely adipose stromal/stem cells (ASC), and due to post-transplant AT apoptosis and involution. A rabbit subcutaneous AT regeneration model was here developed to first evaluate graft quality at different times after implant focusing on related parameters, such as necrosis and vasculogenesis. Standard AFT was compared with a strategy where purified autologous ASC, combined with hyaluronic acid (HA), assisted AFT. Five million of autologous ex vivo isolated CD29+, CD90+, CD49e+ ASC, loaded into HA, enriched 1 ml of AT generating an early significant protective effect in reducing AFT necrosis and increasing vasculogenesis with a preservation of transplanted AT architecture. This beneficial impact of ASC assisted AFT was then confirmed at three months with a robust lipopreservation and no signs of cellular transformation. By a novel ASC assisted AFT approach we ensure a reduction in early cell death favoring an enduring graft performance possibly for a more stable benefit in patients.

Award winner for outstanding research in the PhD category, 2014 Society for Biomaterials annual meeting and exposition, Denver, Colorado, April 16-19, 2014: Decellularized adipose matrix hydrogels stimulate in vivo neovascularization and adipose formation

Decellularization of tissues offers the ability to produce tissue-specific extracellular matrix (ECM) scaffolds that recreate many of the biochemical aspects of the tissue of interest. In this study, we describe the in vivo function of decellularized adipose ECM hydrogels for treating subcutaneous adipose deficits. Adipose ECM hydrogels were combined with either adipose-derived adult stem cells or a biocompatible cross-linker, injected subcutaneously into nude mice, and evaluated over the course of 1 month. These ECM hydrogels showed improved integration with the surrounding tissue in vivo compared to a clinical standard soft tissue filler, Juvederm, and stimulated neovascularization. More importantly, these adipose ECM hydrogels facilitated new adipose regeneration within the material at 1 month, a feature not seen with current clinical soft tissue fillers. These results contribute to the growing evidence that ECM-based materials are capable of stimulating subcutaneous adipose regeneration, suggesting that future soft tissue filler materials could incorporate ECM elements in order to restore function to adipose deficits instead of simply filling them with static materials.

Processing technique for lipofilling influences adipose-derived stem cell concentration and cell viability in lipoaspirate

BACKGROUND

Autologous fat grafting is a highly used technique in plastic and reconstructive surgery. Several fat-processing techniques have been described, with centrifugation frequently touted as the optimal method. Processing is one factor important for maximizing cell viability and adipose-derived mesenchymal stem cell (ADSC) concentrations. This study compared two methods of fat preparation (centrifugation vs Telfa-rolling) to determine which technique results in the greatest degree of cell viability and ADSC concentration.

METHODS

Abdominal fat was harvested from five patients. Equal aliquots were divided and processed by both centrifugation and Telfa-rolling. Samples were analyzed for ADSC proportions via flow cytometry and cell viability using methylene blue-based cell counting. Paired t tests were performed on all samples, and a P value lower than 0.05 was considered statistically significant.

RESULTS

Telfa-rolling processing resulted in a higher percentage of isolated ADSCs (P < 0.5 for 3 of 4 parameters) and a significantly higher number of viable cells (P < 0.05).

CONCLUSION

Telfa-rolling results in a higher proportion of ADSCs and greater cell viability than centrifugation for donor adipose graft preparation. Further studies are necessary to confirm whether optimal preparation translates to improved augmentation and cell take at the recipient site.

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 .

Prevalence of endogenous CD34+ adipose stem cells predicts human fat graft retention in a xenograft model

BACKGROUND

Fat grafting is a promising technique for soft-tissue augmentation, although graft retention is highly unpredictable and factors that affect graft survival have not been well defined. Because of their capacity for differentiation and growth factor release, adipose-derived stem cells may have a key role in graft healing. The authors' objective was to determine whether biological properties of adipose-derived stem cells present within human fat would correlate with in vivo outcomes of graft volume retention.

METHODS

Lipoaspirate from eight human subjects was processed using a standardized centrifugation technique and then injected subcutaneously into the flanks of 6-week-old athymic nude mice. Graft masses and volumes were measured, and histologic evaluation, including CD31+ staining for vessels, was performed 8 weeks after transplantation. Stromal vascular fraction isolated at the time of harvest from each subject was analyzed for surface markers by multiparameter flow cytometry, and also assessed for proliferation, differentiation capacity, and normoxic/hypoxic vascular endothelial growth factor secretion.

RESULTS

Wide variation in percentage of CD34+ progenitors within the stromal vascular fraction was noted among subjects and averaged 21.3 ± 15 percent (mean ± SD). Proliferation rates and adipogenic potential among stromal vascular fraction cells demonstrated moderate interpatient variability. In mouse xenograft studies, retention volumes ranged from approximately 36 to 68 percent after 8 weeks, with an overall average of 52 ± 11 percent. A strong correlation (r = 0.78, slope = 0.76, p < 0.05) existed between stromal vascular fraction percentage of CD34+ progenitors and high graft retention.

CONCLUSION

Inherent biological differences in adipose tissue exist between patients. In particular, concentration of CD34+ progenitor cells within the stromal vascular fraction may be one of the factors used to predict human fat graft retention.

The lipo-facelift: merging the face-lift and liposculpture: eight years experience and a preliminary observational study

BACKGROUND

Since the introduction of the classic submucosal aponeurotic system (SMAS) face-lift, the surgical approach to improve the changes of an aging face has evolved, and significant technical improvements have been made. However, several problems still have not been solved satisfactorily. These problems include facial lipodystrophy and changes in skin and skin texture.

METHODS

The Lipo-Facelift procedure consists of facial liposculpturing performed simultaneously with a biplanar, bivectorial SMAS face-lift procedure. The authors analyzed pre- and postsurgical photographs of 12 patients with a Lipo-Facelift after 3 and 12 months and analyzed their charts for complications. Furthermore, O2C measurement was performed to assess improved microcirculation. The longest follow-up period was 8 years.

RESULTS

The Lipo-Facelift demonstrated very satisfying results. Initial swelling and bruising were seen as well as two cases of wound-healing disorders, but no surgical intervention or revision was needed. The findings show lasting improvement of skin quality and a youthful appearance.

CONCLUSION

The Lipo-Facelift corrects age-related skin and SMAS changes as well as age-related lipodystrophy, improves skin circulation and skin revitalization, and provides a lasting and natural result. The skin quality resulting from simultaneous lipofilling can be explained by improved angiogenesis due to transferred growth factors in the lipoaspirate. Also, differentiation of progenitor cells to fibroblasts and increased production of collagen contribute to firmer skin.

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 .

Stem cells in plastic surgery: a review of current clinical and translational applications

BACKGROUND

Stem cells are a unique cell population characterized by self-renewal and cellular differentiation capabilities. These characteristics, among other traits, make them an attractive option for regenerative treatments of tissues defects and for aesthetic procedures in plastic surgery. As research regarding the isolation, culture and behavior of stem cells has progressed, stem cells, particularly adult stem cells, have shown promising results in both translational and clinical applications.

METHODS

The purpose of this review is to evaluate the applications of stem cells in the plastic surgery literature, with particular focus on the advances and limitations of current stem cell therapies. Different key areas amenable to stem cell therapy are addressed in the literature review; these include regeneration of soft tissue, bone, cartilage, and peripheral nerves, as well as wound healing and skin aging.

RESULTS

The reviewed studies demonstrate promising results, with favorable outcomes and minimal complications in the cited cases. In particular, adipose tissue derived stem cell (ADSC) transplants appear to provide effective treatment options for bony and soft tissue defects, and non-healing wounds. ADSCs have also been shown to be useful in aesthetic surgery.

CONCLUSIONS

Further studies involving both the basic and clinical science aspects of stem cell therapies are warranted. In particular, the mechanism of action of stem cells, their interactions with the surrounding microenvironment and their long-term fate require further elucidation. Larger randomized trials are also necessary to demonstrate the continued safety of transplanted stem cells as well as the efficacy of cellular therapies in comparison to the current standards of care.

Adipocyte regeneration after free fat transplantation: promotion by stromal vascular fraction cells

Our objective was to explore the mechanism of cell-assisted adipose transplantation by using freshly isolated human stromal vascular fraction (SVF) cells and to observe the dynamic changes of the graft after transplantation. The SVF was isolated from human liposuction aspirates, and 0.5 ml adipose tissue was mixed with 1 × 10(6) SVF cells or culture medium then injected to nude mice subcutaneously. At 1, 4, 7, 14, 30, 60, and 90 days after transplantation, samples were harvested for 1) general observation and retention rate; 2) whole-mount stain; 3) H&E stain; 4) immunohistochemical staining for S100, CD68, and CD34; 5) ELISA for VEGF and bFGF; 6) peroxisome proliferator-activated receptor-γ (PPARγ) fluorescence in situ hybridization. The retention rate in the experiment group was markedly higher than that in the control group. Whole-mount stain shows most of the cells in the center of the graft could not survive the ischemia until day 14. Histology showed new vessels on the surface of the graft at 3 days. However, in the control group, fewer newly formed vessels were detected until day 7. In the late stage of transplantation, gradual fibrosis was found in the graft, and the tissue was divided into a grid-like structure. A large number of round neonatal adipocytes with big nuclei in the center were found surrounding the new vessels, which were S100 and CD34 positive and CD68 negative. In the late stage of transplantation, most of the neonatal adipocytes were human PPARγ positive. Moreover, the SVF group showed a higher level of VEGF and bFGF. SVF assisting adipose transplantation could increase the retention rate of the graft through promoting adipose tissue regeneration via secretion of growth factors, promotion of angiogenesis, and increasing the density of mesenchymal stem cells.

Fat Ful'fill'ment: A Review of Autologous Fat Grafting

For more than a century, clinicians have attempted to utilise fat for the treatment of tissue deficiencies and contour abnormalities. Autologous fat transplantation for soft-tissue augmentation has become increasingly popular in recent years. The popularity of tumescent liposuction has brought renewed interest and accessibility of fat for transplantation. Newer techniques and approaches to augmentation have provided more predictable and reproducible results. Fat augmentation has become an effective, safe and reliable method for restoring volume and correcting the atrophy that accompanies senescence. In this review, the authors have described their approach to fat transplantation.

Adipose-derived regenerative cell (ADRC)-enriched fat grafting: optimal cell concentration and effects on grafted fat characteristics

Background

To overcome the absorption of traditional fat grafting, techniques for adipose-derived regenerative cell (ADRC)-enriched fat grafting are currently being adapted for practical application. The Celution®800/CRS (Cytori Therapeutics, San Diego, CA) has enabled rapid grafting of the patient’s own freshly harvested ADRCs without requiring a culturing step. However, the optimal cell concentration and the effects of ADRCs on the characteristics of grafted fat after free fat grafting remain unclear.

Methods

ADRCs were isolated and purified from human fat tissue using the Celution®800/CRS. Animals that received fat grafting without the addition of ADRCs were designated the control group (group A). The number of ADRCs per grafted fat volume (mL) was adjusted to 3 × 10⁵, 1.5 × 10⁶, and 3 × 10⁶ cells/mL (groups B, C, and D, respectively), mixed with free fat, and transplanted as ADRC-enriched fat grafting. These mixtures were transplanted subcutaneously into BALB/C Jcl-nu/nu mice. The volume of grafted fat was determined 5 months after transplantation, and histological assessments were performed.

Results

ADRC-enriched fat grafting resulted in decreased fat absorption and the formation of greater numbers of new blood vessels in the grafted fat. The optimal ADRC concentration in this study was found to be 3 × 10⁵ cells/mL (group B), with higher concentrations resulting in increased cyst and fibril formation in the grafted fat.

Conclusions

This study used the Celution®800/CRS for free fat grafting and demonstrated that the concentration of transplanted ADRCs affected the engraftment and quality of the grafted fat.

Enrichment of autologous fat grafts with ex-vivo expanded adipose tissue-derived stem cells for graft survival: a randomised placebo-controlled trial

BACKGROUND

Autologous fat grafting is increasingly used in reconstructive surgery. However, resorption rates ranging from 25% to 80% have been reported. Therefore, methods to increase graft viability are needed. Here, we report the results of a triple-blind, placebo-controlled trial to compare the survival of fat grafts enriched with autologous adipose-derived stem cells (ASCs) versus non-enriched fat grafts.

METHODS

Healthy participants underwent two liposuctions taken 14 days apart: one for ASC isolation and ex-vivo expansion, and another for the preparation of fat grafts. Two purified fat grafts (30 mL each) taken from the second liposuction were prepared for each participant. One graft was enriched with ASCs (20 × 10(6) cells per mL fat), and another graft without ASC enrichment served as a control. The fat grafts were injected subcutaneously as a bolus to the posterior part of the right and left upper arm according to the randomisation sequence. The volumes of injected fat grafts were measured by MRI immediately after injection and after 121 days before surgical removal. The primary goal was to compare the residual graft volumes of ASC-enriched grafts with those of control grafts. This study is registered at www.clinicaltrialsregister.eu, number 2010-023006-12.

FINDINGS

13 participants were enrolled, three of whom were excluded. Compared with the control grafts, the ASC-enriched fat grafts had significantly higher residual volumes: 23·00 (95% CI 20·57-25·43) cm(3) versus 4·66 (3·16-6·16) cm(3) for the controls, corresponding to 80·9% (76·6-85·2) versus 16·3% (11·1-21·4) of the initial volumes, respectively (p<0·0001). The difference between the groups was 18·34 (95% CI 15·70-20·98) cm(3), equivalent to 64·6% (57·1-72·1; p<0·0001). No serious adverse events were noted.

INTERPRETATION

The procedure of ASC-enriched fat grafting had excellent feasibility and safety. These promising results add significantly to the prospect of stem cell use in clinical settings, and indicate that ASC graft enrichment could render lipofilling a reliable alternative to major tissue augmentation, such as breast surgery, with allogeneic material or major flap surgery.

FUNDING

Danish Cancer Society, Centre of Head and Orthopaedics Rigshospitalet, and Moalem Weitemeyer Bendtsen.

Fat grafts supplemented with adipose-derived stromal cells in the rehabilitation of patients with craniofacial microsomia

BACKGROUND

Although first reports of the clinical use of adipose-derived stromal cells suggest that this approach may be feasible and effective for soft-tissue augmentation, there is a lack of randomized, controlled clinical trials in the literature. Thus, this study aimed to investigate whether a faster protocol for isolation of adipose-derived stromal cells and their use in combination with fat tissue improve the long-term retention of the grafts in patients with craniofacial microsomia.

METHODS

Patients with craniofacial microsomia (n = 14) were grafted either with supplementation of adipose-derived stromal cells (experimental group) or without supplementation of adipose-derived stromal cells (control group). The number of viable cells isolated before and after the supplementation of the grafts was calculated, and these cells were examined for mesenchymal cell surface markers using flow cytometry. Computed tomography was performed to assess both hemifaces preoperatively and at 6 months postoperatively.

RESULTS

The average number of viable cells isolated before and after the supplementation of the grafts was 5.6 × 10 and 9.9 × 10 cells/ml of fat tissue (p = 0.015). Flow cytometric analysis revealed that the adipose-derived stromal cells were positive for mesenchymal cell markers (>95 percent for CD73 and CD105). Surviving fat volume at 6 months was 88 percent for the experimental group and 54 percent for the control group (p = 0.003).

CONCLUSION

These results suggest that this strategy for isolation and supplementation of adipose-derived stromal cells is effective, safe, and superior to conventional lipoinjection for facial recontouring in patients with craniofacial microsomia.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, II.

Breast reconstruction with autologous fat graft mixed with platelet-rich plasma

BACKGROUND

The purpose of this study was to review the authors' experience of fat grafting, evaluating the effects related to the use of fat grafting with platelet-rich plasma (PRP) in the improvement of fat volume in breast reconstruction and comparing the results with a control group (only centrifuged fat grafting).

METHODS

A total of 50 patients aged between 19 and 60 years affected by breast soft-tissue defects were analyzed at the Plastic and Reconstructive Department of the University of Tor Vergata. They were treated with fat grafting + PRP. The control group (50 patients with breast soft-tissue defects) were treated with centrifuged fat grafting injection according to Coleman's procedure.

RESULTS

The patients treated with PRP added to the autologous fat grafts showed a 69% maintenance of the contour restoring and of 3-dimensional volume after 1 year, whereas the patients of the control group treated with centrifuged fat grafting showed a 39% maintenance.

CONCLUSION

PRP mixed with fat grafting leads to an improvement in maintaining breast volume in patients affected by breast soft-tissue defects.

Comparison of 3 techniques of fat grafting and cell-supplemented lipotransfer in athymic rats: a pilot study

BACKGROUND

Given the wide application of autologous fat grafting, a new emphasis on fat processing techniques has emerged in an effort to limit unpredictable degrees of resorption often seen with this procedure. With the growing interest in regenerative medicine, approaches to supplement fat grafts with adipose-derived stem cells are evolving in hopes of promoting vascularization and neoadipogenesis.

OBJECTIVE

The authors evaluated the outcomes of the most common processing techniques for fat grafting--decantation, washing, high-speed centrifugation--and stromal vascular cell-supplemented lipotransfer to determine which method yields a higher percentage of retention and better quality graft.

METHODS

A total of 32 subcutaneous injections of processed human lipoaspirate were carried out in 8 athymic rats. Each animal received all 4 processing conditions, with end points at 4, 8, and 12 weeks postinjection. Evaluation of graft survival included serial measurements of volume retention and histologic analysis.

RESULTS

At 12 weeks postinjection, cell-supplemented and centrifuged grafts showed the most consistent volume maintenance. Based on histologic analysis, cell-supplemented and washed grafts had higher scores of viability and vascularity, with the former presenting the least cystic necrosis and calcification as well as minimal inflammation.

CONCLUSIONS

Cell-supplemented lipotransfer had optimal outcomes for graft retention, viability, and vascularity, while washing resulted in high viability with a less intensive process. High-speed centrifugation resulted in consistent volume retention but lower viability. Each of these approaches is ideal under different circumstances and contributes to the versatility and reliability of fat grafting.

Grading lipoaspirate: is there an optimal density for fat grafting?

BACKGROUND

Clinical results of fat grafting have been unpredictable. In this article, the authors hypothesize that centrifugation creates "graded densities" of fat with varying characteristics that influence lipoaspirate persistence and quality.

METHODS

Aliquots of human female lipoaspirate (10 cc) were centrifuged for 3 minutes at 1200 g. The bloody and oil fractions were discarded. Subsequently, 1.0 cc of the highest density and lowest density fat was separated for lipoinfiltration or analysis. Highest density or lowest density fat grafted into adult FVB mice was harvested at 2 and 10 weeks to quantify short- and long-term persistence, respectively. Progenitor cell number and expression of vascular endothelial growth factor, stromal cell-derived factor-1α, platelet-derived growth factor, and adiponectin were analyzed by flow cytometry and enzyme-linked immunosorbent assay, respectively.

RESULTS

Greater percentages of highest density fat grafts remain at 2 and 10 weeks after injection compared with lowest density fat grafts (85.4 ± 1.9 percent versus 62.3 ± 0.1 percent, p = 0.05; and 60.8 ± 4.9 versus 42.2 ± 3.9, p < 0.05, respectively). Highest density fractions contain more progenitor cells per gram than lowest density fractions (2.0 ± 0.2-fold increase, p < 0.01). Furthermore, concentrations of vascular endothelial growth factor, stromal vascular fraction, platelet-derived growth factor, and adiponectin are all elevated in highest density compared with lowest density fractions (34.4 percent, p < 0.01; 34.6 percent, p < 0.05; 52.2 percent, p < 0.01; and 45.7 percent, p < 0.05, respectively).

CONCLUSIONS

Greater percentages of highest density fractions of lipoaspirate persist over time compared with lowest density fractions. A vasculogenic mechanism appears to contribute significantly, as highest density fractions contain more progenitor cells and increased concentrations of several vasculogenic mediators than lowest density fractions.

Adipose-Derived Stem Cells in Tissue Regeneration: A Review

In 2001, researchers at the University of California, Los Angeles, described the isolation of a new population of adult stem cells from liposuctioned adipose tissue. These stem cells, now known as adipose-derived stem cells or ADSCs, have gone on to become one of the most popular adult stem cells populations in the fields of stem cell research and regenerative medicine. As of today, thousands of research and clinical articles have been published using ASCs, describing their possible pluripotency in vitro, their uses in regenerative animal models, and their application to the clinic. This paper outlines the progress made in the ASC field since their initial description in 2001, describing their mesodermal, ectodermal, and endodermal potentials both in vitro and in vivo, their use in mediating inflammation and vascularization during tissue regeneration, and their potential for reprogramming into induced pluripotent cells.

New insights into lidocaine and adrenaline effects on human adipose stem cells

BACKGROUND

Adipose stem cells have gained great interest in plastic and reconstructive surgery with their ability to improve engraftment after fat transfer for soft tissue filling. It is therefore essential to know the effect of the drugs commonly used during the lipoaspiration procedure, such as lidocaine and adrenaline. Indeed, these drugs are infiltrated at the fat donor site for local anesthesia and for reduction of bleeding. This study analyzed the effects of these drugs on the viability of adipose-derived stem cells and on their inflammatory status.

METHODS

Adipose-derived stem cells from lipoaspirates were grown in culture before being treated with different clinical doses of lidocaine at different times of exposure (1-24 h), and with adrenaline (1 μg/mL). Cytotoxicity was measured by lactate dehydrogenase assay and by flow cytometry with annexin V/propidium iodide staining. In parallel, the secretion of the proinflammatory cytokines tumor necrosis factor-alpha (TNFα), interleukin-6 (IL-6), and monocyte chemotactic protein-1 (MCP-1) was tested by enzyme-linked immunoassay.

RESULTS

Lidocaine affected cell viability after 24 h, even when the cells were exposed for only 1 or 2 h. Apoptosis was not involved in lidocaine cytotoxicity. Regarding inflammation, no TNFα was produced, and lidocaine decreased the levels of IL-6 and MCP-1 in a dose-dependent manner. In contrast, adrenaline did not influence cell viability or cytokine secretions.

CONCLUSIONS

Adipose tissue should be handled appropriately to remove lidocaine and adrenaline, with such procedures as washing and centrifugation. This study provides new insights into the use of lidocaine and adrenaline for fat transfer or stem cell isolation from lipoaspirates.

LEVEL OF EVIDENCE II

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 .

Liposculpture and fat grafting for aesthetic correction of the gluteal concave deformity associated with multiple intragluteal injection of penicillin in childhood

BACKGROUND

The gluteal concave deformity, a complication of repeated intragluteal injections in childhood, is a relatively common complaint of many young women in China. This issue could be addressed by lipofilling, as the method could produce aesthetically acceptable results in correcting soft tissue contour defects.

METHODS

Twelve patients with bilateral gluteal concave deformities associated with repeated intragluteal injections were operated on from June 2006 to June 2010. The deformities were classified as major or minor. Overall satisfaction with body appearance after gluteal fat grafting and liposculpture was rated on a scale of 1 (poor), 2 (fair), 3 (good), 4 (very good), and 5 (excellent). The evaluation was performed at 3-44 months after surgery.

RESULTS

The average volume of fat injected was 196.9 ± 41.4 ml. No serious adverse events occurred. One patient with major deformity had one additional fat grafting procedure. One patient developed cellulitis in the feet and lower legs, upon which the grafted areas were incised and drained on suspicion of infection but with negative cultures. The patient recovered uneventfully with intravenous antibiotic application for 7 days. At the office visit nine cases judged that their appearance after the operation as "very good" (4) to "excellent" (5) and three cases responded that their contour was "good." Improvement in skin texture and alleviation of the pigmentation in the concave area were observed in all cases during the 3-44-month follow-up intervals after the fat grafting, and softening of the hypertrophic scar was also observed as early as 1 month after the fat grafting and continuously improved during the 12-month follow-up.

CONCLUSION

Autologous lipografting for gluteal concave deformity, combining a liposculpture procedure adjacent to the defects, accomplishes good aesthetic results with high patient satisfaction. The key to success is complete release of fibrosis adhesion, meticulous manipulation of fat grafts, and multitunnel and multiplane injections to ensure maximum take of the grafts.

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 .

Uncultured adipose-derived regenerative cells promote peripheral nerve regeneration

BACKGROUND

We examined whether or not peripheral nerves can be regenerated using uncultured adipose-derived regenerative cells (ADRCs). We also searched for humoral factors that might promote the proliferation or migration of Schwann cells.

METHODS

Thirty rats were randomly assigned to three groups. A 10 mm sciatic nerve defect was bridged using a silicon tube filled with physiological saline (control group), type I collagen gel (collagen group), and a mixture of ADRCs and type I collagen gel (ADRC group). The regenerated tissues were studied two weeks after surgery.

RESULTS

Continuity of regenerated tissue was observed in all rats in the control group and the ADRC group. In the collagen group, only two rats had a bridge of thin tissue, which was barely visible macroscopically. Protein gene product 9.5 staining confirmed significantly faster regeneration in the ADRC group. The distributions of the PKH-26 positive areas and the S-100 protein positive areas were different, suggesting that the transplanted cells had not differentiated into Schwann cells. In real-time RT-PCR, neuregulin-1 (Neu-1) and vascular endothelial growth factor A (VEGFA) expression were detected in uncultured ADRCs before transplantation. The regenerated tissue in the ADRC group had higher levels of Neu-1 and VEGFA expression than the control group.

CONCLUSIONS

ADRCs promote peripheral nerve regeneration. The mechanism does not involve the differentiation of transplanted cells into Schwann cells, but probably involves the secretion of some type of humoral factor such as Neu-1 or VEGFA that promotes the proliferation or migration of Schwann cells.

Mesenchymal markers on human adipose stem/progenitor cells

The stromal-vascular fraction (SVF) of adipose tissue is a rich source of multipotent stem cells. We and others have described three major populations of stem/progenitor cells in this fraction, all closely associated with small blood vessels: endothelial progenitor cells (EPC, CD45-/CD31+/CD34+), pericytes (CD45-/CD31-/CD146+), and supra-adventitial adipose stromal cells (SA-ASC, CD45-/CD31-/CD146-/CD34+). EPC are luminal, pericytes are adventitial, and SA-ASC surround the vessel like a sheath. The multipotency of the pericytes and SA-ASC compartments is strikingly similar to that of CD45-/CD34-/CD73+/CD105+/CD90+ bone marrow-derived mesenchymal stem cells (BM-MSC). Here, we determine the extent to which this mesenchymal pattern is expressed on the three adipose stem/progenitor populations. Eight independent adipose tissue samples were analyzed in a single tube (CD105-FITC/CD73-PE/CD146-PETXR/CD14-PECY5/CD33-PECY5/CD235A-PECY5/CD31-PECY7/CD90-APC/CD34-A700/CD45-APCCY7/DAPI). Adipose EPC were highly proliferative with (14.3 ± 2.8)% (mean ± SEM) having >2N DNA. About half (53.1 ± 7.6)% coexpressed CD73 and CD105, and (71.9 ± 7.4)% expressed CD90. Pericytes were less proliferative [(8.2 ± 3.4)% >2N DNA)] with a smaller proportion [(29.6 ± 6.9)% CD73+/CD105+, (60.5 ± 10.2)% CD90+] expressing mesenchymal associated markers. However, the CD34+ subset of CD146+ pericytes were both highly proliferative [(15.1 ± 3.6)% with >2N DNA] and of uniform mesenchymal phenotype [(93.3 ± 3.7)% CD73+/CD105+, (97.8 ± 0.7)% CD90+], suggesting transit amplifying progenitor cells. SA-ASC were the least proliferative [(3.7 ± 0.8)%>2N DNA] but were also highly mesenchymal in phenotype [(94.4 ± 3.2)% CD73+/CD105+, (95.5 ± 1.2)% CD90+]. These data imply a progenitor/progeny relationship between pericytes and SA-ASC, the most mesenchymal of SVF cells. Despite phenotypic and functional similarities to BM-MSC, SA-ASC are distinguished by CD34 expression.

Adipose tissue regeneration: a state of the art

Adipose tissue pathologies and defects have always represented a reconstructive challenge for plastic surgeons. In more recent years, several allogenic and alloplastic materials have been developed and used as fillers for soft tissue defects. However, their clinical use has been limited by further documented complications, such as foreign-body reactions potentially affecting function, degradation over time, and the risk for immunogenicity. Tissue-engineering strategies are thus being investigated to develop methods for generating adipose tissue. This paper will discuss the current state of the art in adipose tissue engineering techniques, exploring the biomaterials used, stem cells application, culture strategies, and current regulatory framework that are in use are here described and discussed.

Role of anti-TNF-α therapy in fat graft preservation

BACKGROUND/OBJECTIVE

In this study, we evaluated the role of antitumor necrosis factor-alpha (TNF-α) therapy in the decrease of adipocyte apoptosis and weight preservation of fat grafts in the rat model.

METHODS

A total of 64 rats were randomly divided into 2 groups, with 32 rats in each group. Autologous fat tissue was grafted subcutaneously on the back of each rat. For the experimental group, antirat TNF-α monoclonal antibody was injected into the fat grafts during operation. No treatment was given to the tissue in the control group. Eight rats in each group were killed respectively, at days 7, 14, 30, and 60 postoperatively and sampled for assessments of weight preservation, gene expression of TNF-α, histology, and adipocyte apoptosis.

RESULTS

There were no significant differences in the weight of fat tissues between the control group and the experimental group at days 7, 14, and 30 postoperatively (P > 0.05). However, the preservation ratio of the tissue was 65.36% ± 14.98% in the antirat TNF-α antibody-treated group when compared with the weight at transplantation, which was significantly higher than the control group (44.63% ± 10.39%) 60 days after the operation (P < 0.05). The numbers of apoptotic cells in the control group were 15.6 ± 3.17, 24.6 ± 4.34, 22.8 ± 2.42, and 27 ± 3.83 per field at different postoperative intervals. However, the numbers of apoptotic cells in the tissues treated with TNF-α antibody were significantly lower than that in the control group, which was 1 ± 0.63, 4 ± 1.41, 6 ± 2.08, and 7.2 ± 2.82 per field (P < 0.05). Gene expression showed that the expression of TNF-α was lower in the experimental group than the control group at days 7 and 14 postoperatively (P < 0.05).

CONCLUSION

The results indicate that antirat TNF-α monoclonal antibody can preserve the quality of the transplanted fat tissue.

Importance of mesenchymal stem cells in autologous fat grafting: a systematic review of existing studies

Autologous fat grafting (lipofilling) enables repair and augmentation of soft tissues and is increasingly used both in aesthetic and reconstructive surgery. Autologous fat has several advantages, including biocompatibility, versatility, natural appearance, and low donor site morbidity. The main limitation is unpredictable graft resorption, which ranges from 25%-80%, probably as a result of ischaemia and lack of neoangiogenesis. To obviate these disadvantages, several studies have searched for new ways of increasing the viability of the transplanted tissue. One promising approach has been to enrich the fat graft with adipose tissue-derived mesenchymal stem cells (ASC) before transplantation. We have reviewed original studies published on fat transplantation enriched with ASC. We found four murine and three human studies that investigated the subject after a sensitive search of publications. In the human studies, so-called cell assisted lipotransfer (CAL) increased the ASC concentration 2-5 times compared with non-manipulated fat grafts, which caused a questionable improvement in survival of fat grafts, compared with that of traditional lipofilling. In contrast, in two of the murine studies ASC-concentrations were increased 1250 and 6250 times, respectively, by ASC ex vivo expansion, which resulted in considerably improved fat transplant survival as well as quality. This effect of high-level enrichment with ASC is thought to have been caused by paracrine signalling, cellular differentiation, or both. The surgical and tissue handling techniques used in lipofilling are well proved, but the added effect of high-level enrichment with ex vivo expanded ASC still needs to be investigated properly in human lipofilling studies, combined with a thorough follow up and matched control groups. In conclusion, ASC-enriched lipofilling theoretically has the potential for transforming lipofilling from a relatively unpredictable intervention into one in which the resorption rate, quality of tissue, and safety can be predicted, and possibly superior to prosthetic implantation.

Cotransplantation of adipose-derived mesenchymal stromal cells and endothelial cells in a modular construct drives vascularization in SCID/bg mice

A modular approach to adipose tissue engineering was explored by embedding adipose-derived mesenchymal stromal cells (adMSC) in sub-mm-sized collagen rods or "modules" and coating with human microvascular endothelial cells (HMEC). After subcutaneous injection into a SCID/Bg mouse, HMEC on modules containing embedded adMSC appeared to detach from the modules to form vessels as early as day 3, as confirmed by the human EC-specific UEA-1 lectin stain, and these vessels persisted for up to 90 days. Vessel numbers decreased over 14 days, but vessel size increased suggesting a maturing of the vasculature. Vessel perfusion with the host was confirmed at 21 days by microCT. HMEC on modules without embedded adMSC remained attached to the module surface at day 3 and UEA-1 staining disappeared over 14 days suggesting cell death. It appeared that cotransplantation with adMSC had an anti-apoptotic and proangiogenic effect on HMEC. The early revascularization strategy may be successful in supporting adMSC viability and differentiation, as a preliminary study suggests progressive fat accumulation in the HMEC+adMSC implants: ∼60% of the implant area stained positive for Oil Red O by day 90. adMSC-embedded modules without HMEC surface coating did not show similar levels of Oil Red O staining. All implant volumes decreased over the time course of the experiment, yet HMEC+adMSC module implants were larger than adMSC-only implants at day 90. Collagen gel is mechanically weak and contracts in vivo making it unsuitable as a biomaterial for adipose tissue engineering where volume maintenance is critical. When combined with an appropriate biomaterial, the modular approach to adipose tissue engineering may represent a successful strategy to engineer soft tissue substitutes of clinical relevance.

Fat grafting versus adipose-derived stem cell therapy: distinguishing indications, techniques, and outcomes

With adipose-derived stem cells (ASCs) at the forefront of research and potential clinical applications, it is important that clinicians be able to distinguish them from the fat grafting currently used clinically and to understand how the two approaches relate to one another. At times, there has been confusion in clinically considering the two therapies to be the same. This report is aimed at distinguishing clearly between fat grafting and ASC therapy with regard to the indications, harvesting, processing, application techniques, outcomes, and complications. Findings have shown that autologous fat transfer, a widely used procedure for soft tissue augmentation, is beneficial for reconstructive and cosmetic procedures used to treat patients with volume loss due to disease, trauma, congenital defects, or the natural process of aging. On the other hand, ASCs have been identified as an ideal source of cells for regenerative medicine, with the potential to serve as soft tissue therapy for irradiated, scarred, or chronic wounds. Recent advances in tissue engineering suggest that the supplementation of fat grafts with ASCs isolated in the stromal vascular fraction may increase the longevity and quality of the fat graft. Research suggests that ASC supplementation may be a great clinical tool in the future, but more data should be acquired before clinical applications.

A comparative translational study: the combined use of enhanced stromal vascular fraction and platelet-rich plasma improves fat grafting maintenance in breast reconstruction

The use of autologous fat grafting is ideal in breast reconstruction. However, published data on long-term outcomes and instrumental results of fat grafting to the breast are lacking. The purpose of this study was to review the authors' experience of fat grafting, evaluating the effects related to the use of enhanced stromal vascular fraction (e-SVF) and fat grafting with platelet-rich plasma (PRP) in the maintenance of fat volume in breast reconstruction, comparing the results with a control group. Twenty-three patients aged 19-60 years affected by breast soft tissue defects were analyzed at the Plastic and Reconstructive Department of the University of Rome Tor Vergata. Ten patients were treated with SVF-enhanced autologous fat grafts, and 13 patients were treated with fat grafting + platelet-rich plasma. The patients in the control group (n = 10) were treated with centrifuged fat grafting injection according to Coleman's procedure. The patients treated with SVF-enhanced autologous fat grafts showed a 63% maintenance of the contour restoring and of three-dimensional volume after 1 year compared with the patients of the control group treated with centrifuged fat graft, who showed a 39% maintenance. In those patients who were treated with fat grafting and PRP, we observed a 69% maintenance of contour restoring and of three-dimensional volume after 1 year. As reported, the use of either e-SVF or PRP mixed with fat grafting produced an improvement in maintenance of breast volume in patients affected by breast soft tissue defect.

Adipose stem cell-based soft tissue regeneration

INTRODUCTION

Since their isolation and characterization nearly a decade ago, adipose-derived stem cells (ASCs) have become one of the most popular adult stem cell populations for research in soft tissue engineering and regenerative medicine applications. Compared with other stem cell sources, ASCs offer several advantages including an abundant autologous source, minor invasive harvesting (liposuction), significant proliferative capacity in culture and multi-lineage potential. Numerous preclinical studies have been pursued, with early clinical data appearing in the literature.

AREAS COVERED

Autologous fat grafting has gained tremendous momentum in clinical practice over the past several years due to its potential applications in trauma and reconstructive surgery. This review focuses on the published clinical and pre-clinical (i.e., animal) data to date using ASCs for soft tissue reconstruction, with particular attention to experimental models and methodologies. Future directions for rendering soft tissue reconstructive therapies more effective are discussed.

EXPERT OPINION

Although standardization of ASC harvesting and processing techniques, as well as long-term results of existing clinical studies, remains to be addressed, the known biological properties of ASCs suggest a potential role in enhancing fat graft retention and facilitating minimally invasive reconstructive treatments. While clinical applications are being reported, well controlled clinical studies are needed to demonstrate safety and efficacy.

Influence of age and body mass index on the yield and proliferation capacity of adipose-derived stem cells

BACKGROUND

Adipose tissue is commonly used for volume restoration. It is also a source of adipose-derived stem cells (ASCs), easy to obtain in large quantities by liposuction or resection techniques. The aim of this study was to determine the influence of body mass index (BMI) and age on the number (yield) and proliferation capacity of ASCs.

METHODS

A prospective study was conducted in 42 women. They were divided into two groups: age ≤ 40 or >40 and BMI ≤ 25 or >25. Fat tissue was harvested via manual lipoaspiration always from the abdominal region. After centrifugation in the OR, the harvested fat (100 cc) was sent to the laboratory for isolation and cultivation of ASCs. The yield of viable ASCs was evaluated by the trypan blue exclusion test. Viable ASCs were cultured and their proliferation capacity was evaluated by the growth kinetics assay. Results were statistically analyzed.

RESULTS

The average cell yield was 0.380 × 10(6)/ml. Cell yield and proliferation capacity did not show statistically significant correlation to the age and BMI of patients, with regression lines showing null correlation. There was no significant difference between the cell yield and proliferation capacity between the different groups.

CONCLUSION

The results from this study suggest that there is no statistically significant correlation between ASC yield and proliferation capacity and age and BMI.

Staged stem cell-enriched tissue (SET) injections for soft tissue augmentation in hostile recipient areas: a preliminary report

BACKGROUND

Autologous fat transplantation is frequently used for a variety of cosmetic treatments and difficult reconstructive indications such as involutional disorders, hemifacial atrophy, sequelae of radiation therapy, or similar problems. However, the limitations of fat transplantation are well known in such difficult cases, particularly the long-term unpredictability of volume maintenance. The ideal method of preparing autologous fat grafts optimizes tissue survival and reduces the variability of outcomes. We propose that enriching traditionally prepared fat grafts with adipose-derived regenerative cells (ADRCs) represents one such method.

METHODS

Using a staged approach, we performed cell-enriched fat transfer by injecting autologous ADRCs into soft tissue that was recently grafted using traditional methods of fat transfer. Over a 3-year period, data were prospectively collected from 29 patients who underwent a single session of stem cell-enriched tissue injections (SET).

RESULTS

Cell-enriched grafts ranged in volume from 10 to 390 cc per recipient area and were obtained by manual or automated processes. The mean follow-up period was 10 months. Postoperative atrophy of the injected tissue was minimal and subjectively did not change after 8 weeks. Of note, historically reported rates of atrophy range from 20 to 80%. All patients were satisfied with the primary result with no need for a secondary session except for the cosmetic cases.

CONCLUSION

These preliminary results suggest that SET is safe and may provide superior results compared to traditional fat grafting. By performing the procedure in a staged approach, operating room expenses are minimized, which ultimately decreases the cost of the procedure. Adipose-derived regenerative cells may mitigate early ischemia by increasing angiogenesis, decreasing apoptosis, and modulating the local inflammatory response. This technique may be of particular value to the surgeon when grafting high volumes of fat or when faced with hostile recipient area conditions, including fibrosis and post radiation.

Fat Augmentation of the Anterior Vaginal Wall: A Novel Use of Fat Augmentation in Enhancing the Female Sexual Experience

This is a case series of 2 female patients with long-standing histories of decreased sexual function and pelvic organ prolapse who underwent augmentation of the anterior vaginal wall using autologous fat grafting, in conjunction with other cosmetic procedures. Fat augmentation of the anterior vaginal wall with its enhanced permanence could be a safe and long-lasting alternative to improve female sexual function in this group.

Effects of expanded human adipose tissue-derived mesenchymal stem cells on the viability of cryopreserved fat grafts in the nude mouse

Adipose-derived mesenchymal stem cells (AdMSCs) augment the ability to contribute to microvascular remodeling in vivo and to modulate vascular stability in fresh fat grafts. Although cryopreserved adipose tissue is frequently used for soft tissue augmentation, the viability of the fat graft is poor. The effects of culture-expanded human adipose tissue-derived mesenchymal stem cells (hAdMSCs) on the survival and quality of the cryopreserved fat graft were determined. hAdMSCs from the same donor were mixed with fat tissues cryopreserved at -70 °C for 8 weeks and injected subcutaneously into 6-week-old BALB/c-nu nude mice. Graft volume and weight were measured, and histology was evaluated 4 and 15 weeks post-transplantation. The hAdMSC-treated group showed significantly enhanced graft volume and weight. The histological evaluation demonstrated significantly better fat cell integrity compared with the vehicle-treated control 4 weeks post-transplantation. No significant difference in graft weight, volume, or histological parameters was found among the groups 15 weeks post-transplantation. The hAdMSCs enhanced the survival and quality of transplanted cryopreserved fat tissues. Cultured and expanded hAdMSCs have reconstructive capacity in cryopreserved fat grafting by increasing the number of stem cells.

Adipose-derived stem cells for clinical applications: a review

The use of stem cells derived from adipose tissue as an autologous and self-replenishing source for a variety of differentiated cell phenotypes, provides a great deal of promise for reconstructive surgery. In this article, we review available literature encompassing methods of extraction of pluripotent adipose stem cells (ASCs) from lipoaspirate locations, their storage, options for culture, growth and differentiation, cryopreservation and its effect on stem cell survival and proliferation, and new technologies involving biomaterials and scaffolds. We will conclude by assessing potential avenues for developing this incredibly promising field.