Application Of Adipose-derived Stem Cells Research Articles

A Preliminary Study Comparing Microfracture and Local Adherent Transplantation of Autologous Adipose-Derived Stem Cells Followed by Intraarticular Injection of Platelet-Rich Plasma for the Treatment of Chondral Defects in Rabbits.

Objective This study aimed to compare microfracture and application of adipose-derived stem cells (ADSCs) by local adherent technique enhanced by platelet-rich plasma (PRP) to provide a new approach for the repair of cartilage defect. Design Full-thickness cylindrical defects were created in the medial femoral condyle in 9 New Zealand White rabbits (5 months old, 4.65 ± 0.20 kg). Two groups of rabbits ( n = 3) were either treated with ADSCs (Group 1) or the microfracture technique (Group 2) following intraarticular injection of PRP 3 times in weekly intervals. Rabbits in control group ( n = 3) remained untreated. The outcome was assessed macroscopically, histologically, and immunohistochemically. Results At the end of week 12, Group 1 showed better defect filling compared with Group 2. Specimens treated with the combination of ADSCs and PRP exhibited significant differences from the other groups in all criteria of International Cartilage Repair Society macroscopic scoring system. Conclusions Intraarticular injection of autologous PRP in combination with transplantation of autologous ADSCs by local adherent technique enhances the quality of cartilage defect repair with better results in comparison with microfracture surgery in a rabbit model.

Skin Tissue Engineering: Application of Adipose-Derived Stem Cells.

Perception of the adipose tissue has changed dramatically over the last few decades. Identification of adipose-derived stem cells (ASCs) ultimately transformed paradigm of this tissue from a passive energy depot into a promising stem cell source with properties of self-renewal and multipotential differentiation. As compared to bone marrow-derived stem cells (BMSCs), ASCs are more easily accessible and their isolation yields higher amount of stem cells. Therefore, the ASCs are of high interest for stem cell-based therapies and skin tissue engineering. Currently, freshly isolated stromal vascular fraction (SVF), which may be used directly without any expansion, was also assessed to be highly effective in treating skin radiation injuries, burns, or nonhealing wounds such as diabetic ulcers. In this paper, we review the characteristics of SVF and ASCs and the efficacy of their treatment for skin injuries and disorders.

Tissue Source and Cell Expansion Condition Influence Phenotypic Changes of Adipose-Derived Stem Cells.

Stem cells derived from the subcutaneous adipose tissue of debrided burned skin represent an appealing source of adipose-derived stem cells (ASCs) for regenerative medicine. Traditional tissue culture uses fetal bovine serum (FBS), which complicates utilization of ASCs in human medicine. Human platelet lysate (hPL) is one potential xeno-free, alternative supplement for use in ASC culture. In this study, adipogenic and osteogenic differentiation in media supplemented with 10% FBS or 10% hPL was compared in human ASCs derived from abdominoplasty (HAP) or from adipose associated with debrided burned skin (BH). Most (95–99%) cells cultured in FBS were stained positive for CD73, CD90, CD105, and CD142. FBS supplementation was associated with increased triglyceride content and expression of adipogenic genes. Culture in hPL significantly decreased surface staining of CD105 by 31% and 48% and CD142 by 27% and 35% in HAP and BH, respectively (p < 0.05). Culture of BH-ASCs in hPL also increased expression of markers of osteogenesis and increased ALP activity. These data indicate that application of ASCs for wound healing may be influenced by ASC source as well as culture conditions used to expand them. As such, these factors must be taken into consideration before ASCs are used for regenerative purposes.

Adipose-derived stem cells in cartilage regeneration: current perspectives.

Repair of cartilage injuries represents a musculoskeletal medicine criticism because of the poor ability to self-renewal of adult cartilage. Therefore, research focuses on developing new regenerative strategies combining chondrocytes or stem cells, scaffolds and growth factors. Because of the low proliferation capability of explanted chondrocytes, new chondrogenesis models, employing human adipose-derived stem cells (ASCs), have been investigated. ASCs are readily accessible with no morbidity and display the capability to differentiate into several cell lineages, including the spontaneous chondrogenic differentiation when entrapped in collagen gel scaffolds. Recent studies also defined some biomolecular mechanisms involved in ASC chondrogenesis in vitro, and their regenerative properties in bioengineered scaffolds and in the presence of growth factors. However, further investigations are required to validate these exciting preclinical results for the application of bioenginereed ASCs in the clinical practice.

Adipose-Derived Stem Cells Improve Collagenase-Induced Tendinopathy in a Rat Model

Background: Tendinopathy is a common and highly prevalent musculoskeletal disorder characterized by repetitive activity-related pain and focal tendon tenderness. Histopathologically, tendinopathic tissue mainly shows degenerative changes. Therefore, tendinopathy is not affected by anti-inflammatory therapies. A novel approach, including a stem cell–based therapy, may be beneficial for its treatment. Purpose/Hypothesis: The purpose of this study was to evaluate the effects of adipose-derived stem cells (ASCs) on tendon healing in a rat tendinopathy model. The hypothesis was that ASC transplantation would improve degeneration in collagenase-induced tendinopathy. Study Design: Controlled laboratory study. Methods: Sixteen F344/NSlc rats underwent collagenase injection into the Achilles tendon to induce tendinopathy. At 1 week after collagenase injection, 8 rats received ASCs (ASC group) and 8 received phosphate-buffered saline alone (PBS group). Animals were sacrificed at 4 or 12 weeks after ASC administration, and the degree of degeneration in each tendon was histologically evaluated according to the Bonar scale. The microstructure of healing tendons was observed by scanning electron microscopy. Reverse-transcription polymerase chain reaction (RT-PCR) was performed to measure the ratio of type III collagen messenger RNA (mRNA) to type I collagen mRNA in tendons. Results: The median Bonar scale score in the ASC and PBS groups was 2.5 and 5.33 at 4 weeks after treatment and 1.0 and 4.0 at 12 weeks after treatment, respectively. Histologically, the ASC group showed a significantly lower degree of tendon degeneration than the PBS group at both time points. In the RT-PCR analysis, the ratio of type III collagen to type I collagen was significantly lower in the ASC group than in the PBS group at 12 weeks after treatment. Moreover, this ratio decreased over time in the ASC group, whereas it increased over time in the PBS group. Conclusion: The study findings demonstrate that the application of ASCs results in significant improvement in the pathological findings associated with tendinopathy and the normalization of collagen ratios within the affected tendon. Clinical Relevance: Subcutaneous adipose tissue can be harvested easily, and ASC administration might have the potential to rapidly treat tendinopathy.

Autologous adipose-derived stem cells: Basic science, technique, and rationale for application in ulcer and wound healing.

Objectives The present review represents a translational boundary between basic research and surgery, particularly focusing on the promising application of adipose-derived stem cells harvested intra-operatively during debridement of venous leg ulcers. Methods We reviewed 830 out of 5578 articles on MEDLINE starting from 1997 and sorted by the relevance option. Results The technique currently used for adipose-derived stem cells intra-operative harvesting is presented, including a safety evaluation on a cohort of 5089 revised patients who underwent plastic surgery and maxillo-facial surgical procedures. Complications were reported in 169 cases (3.3%). One hundred and forty-one (2.77%) patients were classified as having minor complications, specifically: nodularity/induration 93 (1.83%), dysesthesia 14 (0.26%), hematoma 12 (0.23%), superficial infection 11 (0.21%), pain 7 (0.13%), poor cosmesis 3 (0.06%), and abnormal breast secretion 1 (0.02%), while 28 patients (0.55%) were classified as having major complications, specifically: deep infection 22 (0.43%), sepsis 3 (0.06%), abdominal hematoma 2 (0.04%), and pneumothorax 1 (0.02%). Application of cell therapy in venous leg ulcer is currently used only for patients not responding to the standard treatment. The review shows the lack of randomized clinical trials for application of adipose-derived stem cells among treatments for venous leg ulcer. Finally, adipose-derived stem cells implantation at the wound site promotes a new tissue formation rich in vascular structures and remodeling collagen. Conclusion Adipose-derived stem cells strategy represents a great opportunity for the treatment of chronic wounds, due to the simplicity of the technique and the application of cell treatment in the operating room immediately following debridement. However, clinical studies and data from randomized trials are currently lacking.

Local Application of Isogenic Adipose-Derived Stem Cells Restores Bone Healing Capacity in a Type 2 Diabetes Model.

Bone regeneration is typically a reliable process without scar formation. The endocrine disease type 2 diabetes prolongs and impairs this healing process. In a previous work, we showed that angiogenesis and osteogenesis-essential steps of bone regeneration-are deteriorated, accompanied by reduced proliferation in type 2 diabetic bone regeneration. The aim of the study was to improve these mechanisms by local application of adipose-derived stem cells (ASCs) and facilitate bone regeneration in impaired diabetic bone regeneration. The availability of ASCs in great numbers and the relative ease of harvest offers unique advantages over other mesenchymal stem cell entities. A previously described unicortical tibial defect model was utilized in diabetic mice (Lepr(db-/-)). Isogenic mouse adipose-derived stem cells (mASCs)(db-/db-) were harvested, transfected with a green fluorescent protein vector, and isografted into tibial defects (150,000 living cells per defect). Alternatively, control groups were treated with Dulbecco's modified Eagle's medium or mASCs(WT). In addition, wild-type mice were identically treated. By means of immunohistochemistry, proteins specific for angiogenesis, cell proliferation, cell differentiation, and bone formation were analyzed at early (3 days) and late (7 days) stages of bone regeneration. Additionally, histomorphometry was performed to examine bone formation rate and remodeling. Histomorphometry revealed significantly increased bone formation in mASC(db-/db-)-treated diabetic mice as compared with the respective control groups. Furthermore, locally applied mASCs(db-/db-) significantly enhanced neovascularization and osteogenic differentiation. Moreover, bone remodeling was upregulated in stem cell treatment groups. Local application of mACSs can restore impaired diabetic bone regeneration and may represent a therapeutic option for the future. This study showed that stem cells obtained from fat pads of type 2 diabetic mice are capable of reconstituting impaired bone regeneration in type 2 diabetes. These multipotent stem cells promote both angiogenesis and osteogenesis in type 2 diabetic bony defects. These data might prove to have great clinical implications for bony defects in the ever-increasing type 2 diabetic patient population.

Adipose-Derived Stem Cell Delivery for Adipose Tissue Engineering: Current Status and Potential Applications in a Tissue Engineering Chamber Model.

In reconstructive surgery, there is a clinical need for adequate implants to repair soft tissue defects caused by traumatic injury, tumor resection, or congenital abnormalities. Adipose tissue engineering may provide answers to this increasing demand. This study comprehensively reviews current approaches to adipose tissue engineering, detailing different cell carriers under investigation, with a special focus on the application of adipose-derived stem cells (ASCs). ASCs act as building blocks for new tissue growth and as modulators of the host response. Recent studies have also demonstrated that the implantation of a hollow protected chamber, combined with a vascular pedicle within the fat flaps provides blood supply and enables the growth of large-volume of engineered soft tissue. Conceptually, it would be of value to co-regulate this unique chamber model with adipose-derived stem cells to obtain a greater volume of soft tissue constructs for clinical use. Our review provides a cogent update on these advances and details the generation of possible fat substitutes.

Chemically Defined and Xeno-Free Cryopreservation of Human Adipose-Derived Stem Cells.

The stromal compartment of adipose tissue harbors multipotent cells known as adipose-derived stem cells (ASCs). These cells can differentiate into various lineages including osteogenic, chrondrogenic, adipogenic, and neurogenic; this cellular fraction may be easily obtained in large quantities through a clinically safe liposuction procedure. Therefore, ASCs offer exceptional opportunities for tissue engineering and regenerative medicine. However, current practices involving ASCs typically use fetal bovine serum (FBS)-based cryopreservation solutions that are associated with risks of immunological reactions and of transmitting infectious diseases and prions. To realize clinical applications of ASCs, serum- and xeno-free defined cryopreservation methods are needed. To this end, an animal product-free chemically defined cryopreservation medium was formulated by adding two antioxidants (reduced glutathione and ascorbic acid 2-phosphate), two polymers (PVA and ficoll), two permeating cryoprotectants (ethylene glycol and dimethylsulfoxide), a disaccharide (trehalose), and a calcium chelator (EGTA) to HEPES-buffered DMEM/F12. To limit the number of experimental groups, the concentration of trehalose, both polymers, and EGTA was fixed while the presence of the permeating CPAs and antioxidants was varied. ASCs suspended either in different versions of the defined medium or in the conventional undefined cryopreservation medium (10% dimethylsulfoxide+10% DMEM/F12+80% serum) were cooled to -70°C at 1°C/min before being plunged into liquid nitrogen. Samples were thawed either in air or in a water bath at 37°C. The presence of antioxidants along with 3.5% concentration of each penetrating cryoprotectant improved the freezing outcome to the level of the undefined cryopreservation medium, but the plating efficiency was still lower than that of unfrozen controls. Subsequently, increasing the concentration of both permeating cryoprotectants to 5% further improved the plating efficiency to the level of unfrozen controls. Moreover, ASCs cryopreserved in this defined medium retained their multipotency and chromosomal normality. These results are of significance for tissue engineering and clinical applications of stem cells.

Adipose derived stem cells application results in plastic and reconstructive surgery (review)

Experience of adipose derived stem cells clinical application for soft tissue defects reconstruction is given in the form of a review. Research is focused on details of diff erent research data of adipose derived stem cells application for tissue defects reconstruction, formed aft er the removal of a malignant tumor, and in the topographic anatomy recovery of human body parts for cosmetic purposes in terms of their functional viability under new (post-operative) conditions. Based on the results of many experts and discussed issues and unsolved problems of clinical application of adipose derived stem cells in plastic and reconstructive surgery, possible ways of addressing them through targeted representative prospective studies are considered. Refs 45.

Adipose-Derived Stem Cells for Tissue Engineering and Regenerative Medicine Applications.

Adipose-derived stem cells (ASCs) are a mesenchymal stem cell source with properties of self-renewal and multipotential differentiation. Compared to bone marrow-derived stem cells (BMSCs), ASCs can be derived from more sources and are harvested more easily. Three-dimensional (3D) tissue engineering scaffolds are better able to mimic the in vivo cellular microenvironment, which benefits the localization, attachment, proliferation, and differentiation of ASCs. Therefore, tissue-engineered ASCs are recognized as an attractive substitute for tissue and organ transplantation. In this paper, we review the characteristics of ASCs, as well as the biomaterials and tissue engineering methods used to proliferate and differentiate ASCs in a 3D environment. Clinical applications of tissue-engineered ASCs are also discussed to reveal the potential and feasibility of using tissue-engineered ASCs in regenerative medicine.

Human adipose stem cell and ASC-derived cardiac progenitor cellular therapy improves outcomes in a murine model of myocardial infarction

BackgroundAdipose tissue is an abundant and potent source of adult stem cells for transplant therapy. In this study, we present our findings on the potential application of adipose-derived stem cells (ASCs) as well as induced cardiac-like progenitors (iCPs) derived from ASCs for the treatment of myocardial infarction.Methods and resultsHuman bone marrow (BM)-derived stem cells, ASCs, and iCPs generated from ASCs using three defined cardiac lineage transcription factors were assessed in an immune-compromised mouse myocardial infarction model. Analysis of iCP prior to transplant confirmed changes in gene and protein expression consistent with a cardiac phenotype. Endpoint analysis was performed 1 month posttransplant. Significantly increased endpoint fractional shortening, as well as reduction in the infarct area at risk, was observed in recipients of iCPs as compared to the other recipient cohorts. Both recipients of iCPs and ASCs presented higher myocardial capillary densities than either recipients of BM-derived stem cells or the control cohort. Furthermore, mice receiving iCPs had a significantly higher cardiac retention of transplanted cells than all other groups.ConclusionOverall, iCPs generated from ASCs outperform BM-derived stem cells and ASCs in facilitating recovery from induced myocardial infarction in mice.

Standardization and Optimization for the Use of Human Adipose-Derived Stem Cells on an Extracellular Matrix

PURPOSE: Extracellular matrix (ECM) use in breast reconstruction surgery has gained popularity with utilization in 56% of tissue-expander based and/or implant-based surgical procedures.1 Combining adipose-derived stem cells (ASC) with an ECM has demonstrated improved tissue incorporation and increased strength of repair in hernia repair.2 Obtaining sufficient ASC number and improving ASC attachment to ECM are two key limiting factors for clinical treatments utilizing ASC on an ECM. With this study, we hope to establish (1)a safe and efficacious population doubling (PD) range under which in vitro expansion doesn’t affect ASC population doubling time (PDT) and/or differentiation capacity (DC); and determine if (2)human platelet rich plasma (PRP) can be used to promote the attachment and proliferation of ASC on an ECM. METHODS: Freshly isolated ASC from 3 individuals were cultured at 4 different seeding densities (n=4) ranging from 500 cells/cm2 to 5000 cells/cm2. Cell numbers were determined at 90% confluence to calculate PDT and PD. Osteogenic, chondrogenic, and adipogenic DC were measured by Alizarin red, Alcian blue, and Oil red O staining, respectively. Freshly isolated PRP from 3 individuals (n=3) or phosphate-buffered saline (PBS) (n=3) was pre-incubated on ECM before seeding with ASC. MTT assays were utilized to assess cell attachment at day 1 and cell proliferation at day 7. RESULTS: ASC were cultured for 9 to 31 days prior to 90% confluence and no significant differences in growth rates were observed among individual specimens and overall for PD 1.6 to 6.2 (n=4, p=0.184)(Fig. 1). The DC over PDs 1.6 to 6.2 also showed no significant changes (osteogenic, n=3, p=0.472; chondrogenic, n=3, p=0.878; adipogenic, n=3, p=0.256). PRP treatment significantly increased cell attachment on ECM (P<0.001) and also significantly increased proliferation compared to the PBS controls across all samples (P<0.001)(Fig. 2).Figure 1: Cell Growth Rate: Population doubling time (PDT) observed among seeding densities 500 cells/cm2 to 5000 cells/cm2 (n=4, p=0.184).Figure 2: Cell Attachment and Proliferation: Significantly increased MTT readings across all groups (PBS:PBS, PRP:PRP, All:All) (n=3, P<0.001). Significantly increased cell presence demonstrated after 7 days (n=3, P<0.001).CONCLUSION: Our results demonstrate that in vitro expansion of ASC within the PD range 1.6 to 6.2 causes no significant change in cell growth rate or regenerative capacity. This suggests in vitro expansion prior to clinical application in this PD range is both safe and effective. Also, PRP treatment was shown to significantly improve ADSC attachment and proliferation on an ECM. We hope that this information will benefit ASC application to ECM in future in vivo studies and clinical applications.

Application of adipose-derived stem cells in heart disease.

Therapy with mesenchymal stem cells is one of the promising tools to improve outcomes after myocardial infarction. Adipose-derived stem cells (ASCs) are an ideal source of mesenchymal stem cells due to their abundance and ease of preparation. Studies in animal models of myocardial infarction have demonstrated the ability of injected ASCs to engraft and differentiate into cardiomyocytes and vasculature cells. ASCs secrete a wide array of angiogenic and anti-apoptotic paracrine factors such as vascular endothelial growth factor, hepatocyte growth factor, and insulin-like growth factor 1. ASCs are capable of enhancing heart function, reducing myocardial infarction, promoting vascularization, and reversing remodeling in the ischemically injured hearts. Furthermore, several ongoing clinical trials using ASCs are producing promising results for heart diseases. This article reviews the isolation, differentiation, immunoregulatory properties, mechanisms of action, animal models, and ongoing clinical trials of ASCs for cardiac disease.

Application of adipose-derived stem cells on scleral contact lens carrier in an animal model of severe acute alkaline burn.

To evaluate the therapeutic effect of human adipose-derived stem cells (hASCs) overlaid on a scleral contact lens (SCL) carrier in a rabbit model of ocular alkaline burn. After inducing alkaline burn in 11 New Zealand white rabbits, hASCs cultured on SCLs were placed on the right eye of 5 rabbits, SCLs without cells were used in 5, and no treatment was applied in 1 eye. Each eye was examined and photographed for corneal vascularization, opacities, and epithelial defect in week 1, 2, and 4 after surgery. After 1 month, rabbits were killed and the corneas were removed and cut in half for electron and light microscopy examination. Human adipose-derived stem cells were attached to SCL surface and confluent easily. Human adipose-derived stem cells on SCL eyes showed smaller epithelial defect, less corneal opacity, corneal neovascularization relative to SCL eyes. Both groups showed no symblepharon. However, the cornea in the untreated eye was melted in 2 weeks and developed severe symblepharon. Human adipose-derived stem cells on SCL can reduce inflammation and corneal haziness in severe ocular alkaline burn injury in rabbits.

Healing of grafted adipose tissue: current clinical applications of adipose-derived stem cells for breast and face reconstruction.

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 soft tissue engineering and regenerative medicine applications. Compared with other stem cell sources, ASCs offer several advantages including abundant autologous source, minor invasive harvesting (liposuction), significant proliferative capacity in culture, and multilineage potential. In this mini review, we focus on some of the more salient published clinical and preclinical data to date regarding ASC treatment for breast and facial soft tissue reconstruction.

Transplantation of adipose-derived stem cells combined with decellularized cartilage ECM: A novel approach to nasal septum perforation repair

Nasal septal perforation, a defect of the nasal mucoperichondrium and cartilage, may induce epistaxis, persistent rhinorrhea and nasal obstruction. Cell-based tissue engineering is a promising therapeutic method for the treatment of nasal septal perforation. However, lack of an adequate source of cells and unsuitable biomaterials greatly hinder the development of cell-based therapy. In this paper, we proposed the application of adipose-derived stem cells combined with decellularized cartilage ECM as a potential graft for the damaged nasal septum, which could help to repair the mucosal and cartilage tissues in the treatment of nasal septal perforation. This new technology could play a novel role in the repair of nasal septal perforation, and in regeneration of damaged nasal cartilage.

Fair or Foul: Time for Standard Protocols for Potential Application of Adipose-Derived Stem Cells?

Adipose tissue derived stem cells (ASC) has currently been highly attracted as a new source for regenerative medicine as well as promising avenue of investigation for the delivery of adjuvant therapies in various disease. A criticized standard protocol of generating purified good quality and quantity of ASCs is emergent in need.

Current applications of adipose-derived stem cells and their future perspectives

Adult stem cells have a great potential to treat various diseases. For these cell-based therapies, adipose-derived stem cells (ADSCs) are one of the most promising stem cell types, including embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). ESCs and iPSCs have taken center stage due to their pluripotency. However, ESCs and iPSCs have limitations in ethical issues and in identification of characteristics, respectively. Unlike ESCs and iPSCs, ADSCs do not have such limitations and are not only easily obtained but also uniquely expandable. ADSCs can differentiate into adipocytes, osteoblasts, chondrocytes, myocytes and neurons under specific differentiation conditions, and these kinds of differentiation potential of ADSCs could be applied in regenerative medicine e.g., skin reconstruction, bone and cartilage formation, etc. In this review, the current status of ADSC isolation, differentiation and their therapeutic applications are discussed.

ADIPOSE-DERIVED STEM CELLS IN TISSUE ENGINEERING: LABORATORY TO BEDSIDE

Human adipose tissue has been recognized as an alternative source of adult stem cells. The abundance and ease of harvest of adipose tissue has made it suitable for use in regenerative medicine and tissue engineering. Adipose-derived stem cells isolated from human adipose tissue are able to differentiate into several mesenchymal lineages and secrete growth factors that exhibit therapeutic potential. Protein profiles have been established using various isolation methods, which has expanded researchers' understanding of adipose-derived stem cells in clinical applications. This review highlights the properties, isolation methods, immunophenotype and clinical applications of adipose-derived stem cells.