Adipose-Derived Mesenchymal Stem Cell Treatments and Available Formulations

Regeneration of Two-Walled Infrabony Periodontal Defects in Swine After Buccal Fat Pad-Derived Dedifferentiated Fat Cell Autologous Transplantation

Mature adipocyte-derived dedifferentiated fat (DFAT) cells show proliferative capabilities and multipotency. Given that the buccal fat pad (BFP) serves as a readily available resource for DFAT cell isolation, BFP-derived DFAT (BFP-DFAT) cells are a promising candidate in orofacial tissue engineering. In this research, we assessed the regenerative capacity of the periodontium through autologous BFP-DFAT cell transplantation in adult swine (micro-minipigs; MMPs). The BFP-DFAT cells were transplanted into inflammation-inducing two-walled infrabony periodontal defects located on the mesial of the second mandibular premolar (n = 6). Twelve weeks post-transplantation, a remarkable attachment gain was noted in the DFAT group, based on probing depths and clinical attachment levels. Histological and immunohistochemical analyses indicated new continuous cellular cementum and alveolar bone formation within the created infrabony defect. Well-organized periodontal ligament-like fibers were embedded between newly formed cementum and the alveolar bone. Histometric analysis demonstrated that the DFAT group had a 2.2-fold increase in new alveolar bone length and a 2.2-fold enhancement in vascularization than those in the control group. Except for minor inflammation in the lungs, no teratomas were detected in the recipient MMPs. BFP-DFAT cells significantly enhanced periodontal tissue regeneration, thus representing an optimal source for tissue engineering applications in dentistry.

Role of micro‑fragmented adipose tissue in cartilage repair (Review)

Osteoarthritis (OA) is the most common degenerative joint disease, and one of the core factors in its development is articular cartilage damage. Due to the lack of vascular tissue in articular cartilage, if not treated in time, the damaged cartilage cannot regenerate spontaneously, thus leading to the occurrence of OA. Research has found that through a new type of fully enclosed device, lipogems®, micro-fragmented adipose tissue (MFAT) can be obtained by treating adipose tissue with mild mechanical force. MFAT does not require cell expansion, enzymatic treatment, or other major manipulations, and can maintain the complete stromal vascular niche. The present review discusses the latest research progress of the mechanism of MFAT in the repair of cartilage injury in OA, providing a new direction for the treatment of OA.

Advanced progress of adipose-derived stem cells-related biomaterials in maxillofacial regeneration

The tissue injury in maxillofacial region affects patients' physical function and specific mental health. This decade, utilizing regenerative medicine to achieve tissue regeneration has been proved a hopeful direction. Seed cells play a vital role in regeneration strategy. Among various kinds of stem cells that effectively to regenerate the soft and hard tissue of maxillofacial region, adipose-derived stem cells (ADSCs) have gained increasing interests of researchers due to their abundant sources, easy availability and multi-differentiation potentials in recent decades. Thus, this review focuses on the advances of ADSCs-based biomaterial in maxillofacial regeneration from the progress and strategies perspective. It is structured as introducing the properties of ADSCs, biomaterials (polymers, ceramics and metals) within ADSCs and the latest applications of ADSCs in maxillofacial regeneration, including temporomandibular joint (TMJ), bone, periodontal tissue, tooth, nerve as well as cosmetic field. In order to further facilitate ADSCs-based therapies as an emerging platform for regenerative medicine, this review also emphasized current challenges in translating ADSC-based therapies into clinical application and dissussed the strategies to solve these obstacles.

Adipose-derived stem cells and knee osteoarthritis: New perspectives, old concerns

In this editorial, we comment on the paper by Muthu et al published in the recent issue of the journal. This editorial review focusses on the use of adipose-derived stem cells (ADSCs) in knee osteoarthritis treatment. We discuss the differences between the stromal vascular fraction and microfragmented adipose tissue and highlight the results of clinical studies comparing both treatments and the use of hyaluronic acid, platelet-rich plasma, and bone marrow aspirate concentrate. The use of expanded ADSCs is also discussed; moreover, concerns regarding treatment with ADSCs, particularly the heterogeneity of published studies and the need to standardize protocols to explore clinical potential is explored.

Effects of Germanium embedded fabric on the chondrogenic differentiation of adipose derived stem cells

Osteoarthritis (OA) is a clinical state which is identified by the degeneration of articular cartilage. OA is a common condition (>500 millions of people affected worldwide), whose frequency is anticipated to continue to rise (> 110 % increase worldwide since 2019). The treatment for early-stage OA is based on a combination of therapeutic approaches, which can include regenerative medicine based on Adipose Derived Stem Cells (ADSCs). Germanium embedded Incrediwear® functional Cred40 fabric has been shown to have positive effects on OA clinically and is envisaged to give encouraging effects also on tissue regeneration. Still, the biological mechanisms underlying this therapeutic modality have not yet been fully defined. We tested the hypothesis that Germanium-embedded Incrediwear® functional Cred40 fabric could enhance chondrogenic differentiation. To this purpose, we applied Incrediwear® to human adipose-derived stem cells (hADSCs) induced to chondrogenic differentiation in vitro. Chondrogenic markers (ACAN, SOX9, RUNX2, COL2A1, COL10A1) were quantified following 21 days of treatment. We also assessed extracellular matrix (ECM) deposition (specifically Collagen and glycosaminoglycans (GAGs)) using Alcian Blue and Sirius Red staining. Here, we provide pilot data to demonstrate that Germanium-embedded Incrediwear® functional Cred40 fabric can enhance hADSCs chondrogenic differentiation and maturity and potentially induce events of cartilage regeneration.

Comparison of the Therapeutic Efficacy and Autophagy-Mediated Mechanisms of Action of Urine-Derived and Adipose-Derived Stem Cells in Osteoarthritis

BACKGROUND

Osteoarthritis (OA) is a prevalent and disabling disease that affects a significant proportion of the global population. Urine-derived stem cells (USCs) have shown great prospects in the treatment of OA, but there is no study that has compared them with traditional stem cells.

PURPOSE

This study aimed to compare the therapeutic efficacy and mechanisms of USCs and adipose-derived stem cells (ADSCs) for OA treatment.

STUDY DESIGN

Controlled laboratory study.

METHODS

We compared the biological properties of USCs and ADSCs using CCK-8, colony formation, EdU, adhesion, and apoptosis assays. We evaluated the protective effects of USCs and ADSCs on IL-1β-treated OA chondrocytes by chemical staining, immunofluorescence, and Western blotting. We assessed the effects of USCs and ADSCs on chondrocyte autophagy by transmission electron microscopy, immunofluorescence, and Western blotting. We also compared the therapeutic efficacy of intra-articular injections of USCs and ADSCs by gross, histological, micro-computed tomography, and immunohistochemical analyses in an OA rat model induced by anterior cruciate ligament transection.

RESULTS

USCs showed higher proliferation, colony formation, DNA synthesis, adhesion, and anti-apoptotic abilities than ADSCs. Both USCs and ADSCs increased the expression of cartilage-specific proteins and decreased the expression of matrix degradation-related proteins and inflammatory factors in OA chondrocytes. USCs had a greater advantage in suppressing MMP-13 and inflammatory factors than ADSCs. Both USCs and ADSCs enhanced autophagy in OA chondrocytes, with USCs being more effective than ADSCs. The autophagy inhibitor 3-MA reduced the enhanced autophagy and protective effects of USCs and ADSCs on OA chondrocytes.

CONCLUSION

To our knowledge, this is the first study to explore the efficacy of USCs in the treatment of knee OA and to compare them with ADSCs. Considering the superior properties of USCs in terms of noninvasive acquisition, a high cost-benefit ratio, and low ethical concerns, our study suggests that they may be a more promising therapeutic option than ADSCs for OA treatment under rigorous regulatory pathways.

CLINICAL RELEVANCE

USCs may be a superior cell source for stem cells to treat knee OA, and this study strengthens the evidence for the application of USCs.

Microfragmented adipose tissue versus platelet-rich plasma in the treatment of knee osteoarthritis: a systematic review and meta-analysis

This meta-analysis focuses on the controversial efficacy and safety of microfragmented adipose tissue (MFAT) as compared with platelet-rich plasma (PRP) in the clinical treatment of knee osteoarthritis (KOA). We have attempted to provide an evidence-based medicine protocol for the conservative treatment of KOA. Researchers collected and compared randomized controlled trials (RCTs) that used microfragmented adipose tissue and platelet-rich plasma to treat knee osteoarthritis. We searched CNKI, Wanfang Database, CMJD, PubMed, Sinomed, Cochrane Library, and Embase for studies published up to May 31, 2023. Two investigators independently screened literature, extracted data, and assessed bias risk using the Cochrane bias risk tool. The researchers then performed a meta-analysis using Revman 5.4 statistics software provided by the Cochrane Library. A total of 4 randomized controlled trials involving 266 patients (326 knees) were included. There were 161 knees in the MFAT group and 165 knees in the PRP group. Meta-analysis showed a statistically significant difference in VAS scores between the MFAT group and the PRP group at 12 months after treatment [MD=0.99, 95% CI (0.31, 1.67), P=0.004]. This result showed that VAS scores were lower in the PRP group than in the MFAT group, and that PRP injection reduced pain more effectively than MFAT injection. At 6 months after treatment, Tegner activity scale scores in the MFAT group were higher than that in the PRP group [MD=0.65, 95% CI (0.11, 1.19), P=0.02], and the difference was statistically significant. There were no significant differences in the remaining indicators between the two groups. Based on this meta-analysis, PRP appears to be more effective than MFAT in treating KOA in terms of long-term pain relief. However, MFAT was superior to PRP in improving short-term activity function. Overall, there was no significant difference between MFAT and PRP in the treatment of KOA. In addition, MFAT does not increase the risk of adverse events compared to PRP. However, at present, there are few clinical studies on MFAT and PRP, which need to be verified by more rigorously designed clinical trials.

Arthroscopy With Adipose-Derived Stromal Vascular Fraction Using a Selective Tissue Engineering Photo-Stimulation Technique for the Treatment of Mild to Moderate Knee Osteoarthritis

Osteoarthritis (OA) is characterized by articular cartilage degeneration, synovial inflammation, and subchondral bone thickening, affecting the synovial joint as an organ and leading to pain and disability. Subcutaneous stromal vascular fraction is safe and relieves pain, improves function, and repairs cartilage defects in patients with knee OA. Our goal is to describe step-by-step the arthroscopic treatment of mild to moderate knee OA with photo-stimulated stromal vascular fraction harvested from the thigh using a selective tissue engineering photo-stimulation ("One S.T.E.P.") technique.

Regenerative mechanisms of stem cells and their clinical applications for degenerative eye diseases

There are different types of treatment for eye diseases. Although the majority of eye diseases are curable with primary treatments and surgery, some of degenerative eye damages need regeneration that is not gained by conventional procedures. Stem cells, such as mesenchymal stem cells, human embryonic stem cell-derived retinal pigmented epithelium, and inducible pluripotent stem cells, are now considered one of the most important and safe methods for regeneration of various damaged tissues or organs. However, how will stem cell therapy contribute to regeneration and overcome degenerative eye diseases? This review discusses the regenerative mechanisms, clinical applications, and advantages of different types of stem cells for restoring degenerative eye diseases.

New method to induce neurotrophin gene expression in human adipose-derived stem cells in vitro

Rosemary leaf extract, a well-known medicinal plant, can induce neurotrophin gene expression and proliferation in stem cells. Human adipose-derived stem cells (hASCs) with high proliferation and differentiation capacity are easily accessible and can be extracted with the least damage. This study evaluated the effect of rosemary extract (RE) on neurotrophin gene expression at 48 h postinduction in hASCs. hASCs were isolated from healthy female donors, aged 28-35 years, who had undergone abdominal liposuction. Passage-4 stem cells were cultured and treated with different doses of RE (from 30 to 70 µg/ml) containing 40% carnosic acid for 48 h. Reverse transcription-polymerase chain reaction was used to check the expression of neurotrophin genes. The expression of NTF3, NTF4, and nerve growth factor genes in cells treated with 40-60 µg/ml and the expression of GDNF in cells treated with 50-70 µg/ml of RE for 48 h showed a significant increase compared to cells cultured in serum-containing medium. However, different doses of RE showed no effect on brain-derived neurotrophic factor gene expression in the treated cells. RE (50, 60 µg/ml) leads to an increase of neurotrophin gene expression in hASCs as compared to routine cell culture. Hence, this protocol can be used to prepare ideal cell sources for cell therapy.

Intra-Articular Application of Autologous, Fat-Derived Orthobiologics in the Treatment of Knee Osteoarthritis: A Systematic Review

The aim of this study was to review the current literature regarding the effects of intra-articularly applied, fat-derived orthobiologics (FDO) in the treatment of primary knee osteoarthritis over a mid-term follow-up period. A systematic literature search was conducted on the online databases of Scopus, PubMed, Ovid MEDLINE, and Cochrane Library. Studies investigating intra-articularly applied FDO with a minimum number of 10 knee osteoarthritis patients, a follow-up period of at least 2 years, and at least 1 reported functional parameter (pain level or Patient-Reported Outcome Measures) were included. Exclusion criteria encompassed focal chondral defects and techniques including additional arthroscopic bone marrow stimulation. In 28 of 29 studies, FDO showed a subjective improvement in symptoms (pain and Patient-Reported Outcome Measures) up to a maximum follow-up of 7.2 years. Radiographic cartilage regeneration up to 3 years postoperatively, as well as macroscopic cartilage regeneration investigated via second-look arthroscopy, may corroborate the favorable clinical findings in patients with knee osteoarthritis. The methodological heterogeneity in FDO treatments leads to variations in cell composition and represents a limitation in the current state of knowledge. However, this systematic review suggests that FDO injection leads to beneficial mid-term results including symptom reduction and preservation of the affected joint in knee osteoarthritis patients.

Adipose-derived stem cells applied to ankle pathologies: a systematic review

The purpose of this systematic review was to analyze the current use of adipose-derived mesenchymal stem cells (ADMSCs) and present the available evidence on their therapeutic potential in the treatment of ankle orthopedic issues, evaluating the applications and results. A literature search of PubMed, Google Scholar, EMBASE and Cochrane Library database was performed. The review was conducted following PRISMA guidelines. Risk of bias assessment was conducted through the Methodological Index for Non-Randomized Studies (MINORS) criteria. Initial search results yielded 4348 articles. A total of 8 articles were included in the review process. No clinical evidence has demonstrated the effectiveness of one isolation method over the other, but nonenzymatic mechanical method has more advantages. In all studies included significant clinical outcomes improvement were recorded in patients affected by osteochondral lesion and osteoarthritis of ankle. All studies performed a concomitant procedure. No serious complications were reported. ADMSC injection, especially through the nonenzymatic mechanical methods, looks to be simple and promising treatment for osteochondral lesions and osteoarthritis of the ankle, with no severe complications. The current scarcity of studies and their low-quality level preclude definitive conclusions presently. LEVEL OF EVIDENCE: III.

Exploring the Regenerative Potential of Stem Cells for Treating Eye Diseases: A Review of the New Findings

The escalating prevalence of vision loss due to eye diseases has instigated a quest for innovative therapies, given that conventional approaches often fall short in repairing and regenerating damaged eye tissues, particularly the retina. Stem cell-based interventions have emerged as a promising avenue, with numerous studies in animal models and human trials exploring their potential to enhance visual acuity. Beyond addressing conditions like age-related macular degeneration (AMD) and diabetic retinopathy (DR), stem cell therapies demonstrate efficacy in treating genetic disorders such as retinitis pigmentosa (RP). In severe eye damage necessitating regeneration, stem cells play a pivotal role, leveraging their regenerative capabilities. Noteworthy is the transplantation of retinal pigment epithelial (RPE) cells derived from embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), showcasing promising results in preclinical models and clinical studies, leading to improved retinal function without severe side effects. Mesenchymal stem cells (MSCs) have successfully treated optic neuropathy, RP, DR, and glaucoma, yielding positive clinical outcomes. The safety of adult stem cells, particularly MSCs derived from adipose tissue or bone marrow, has been firmly established. This review highlights significant advancements in utilizing human ESC-derived retinal pigmented epithelium and iPSCs for treating eye injuries. While cell-based therapy is relatively nascent, with numerous clinical trials pending review, stem cells' regenerative potential and clinical applications in addressing eye diseases offer substantial promise. This study aims to comprehensively examine the applications of stem cells in the context of eye diseases and their potential role in regenerative medicine.

Exploring Orthopedic Stem-Cell Approaches for Osteoarthritis Management: Current Trends and Future Horizons

PURPOSE OF REVIEW

Osteoarthritis (OA) is a prevalent and debilitating condition characterized by joint degeneration and pain. Current treatment options aim to alleviate symptoms and slow disease progression but lack curative potential. Stem cell therapies have emerged as a promising alternative. This article explores the epidemiology, pathophysiology, clinical manifestations of hip and knee OA, and the evolving role of stem cell therapies in their treatment.

RECENT FINDINGS

The global prevalence of OA, with knee OA being the most common form, has fueled the demand for stem cell therapies. Despite limited robust evidence supporting their efficacy, clinical trials investigating stem-cell treatments for OA have reported encouraging radiological and clinical improvements. Stem cell therapies offer potential disease-modifying benefits through immunomodulatory actions, growth factor secretion, and chondrogenic capabilities. Adipose-derived mesenchymal stem cells (ADMSCs) have shown promise in clinical trials for OA treatment, offering potential pain relief and functional improvement. ADMSCs possess advantages such as accessibility and a favorable safety profile, making them a viable option for OA management. Although other stem-cell types, including human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs), have been used in OA treatment, ADMSCs have demonstrated superior outcomes. By providing a comprehensive overview of the evolving landscape of stem cell therapies for hip and knee OA, this article highlights the potential of stem-cell treatments to address the limitations of current therapies. However, further research is required to establish their long-term efficacy, identify optimal stem-cell types, and develop standardized protocols.

Management of chondral and osteochondral lesions of the hip : A comprehensive review

Chondral and osteochondral lesions encompass several acute or chronic defects of the articular cartilage and/or subchondral bone. These lesions can result from several different diseases and injuries, including osteochondritis dissecans, osteochondral defects, osteochondral fractures, subchondral bone osteonecrosis, and insufficiency fractures. As the cartilage has a low capacity for regeneration and self-repair, these lesions can progress to osteoarthritis. This study provides a comprehensive overview of the subject matter that it covers. PubMed, Scopus and Google Scholar were accessed using the following keywords: "chondral lesions/defects of the femoral head", "chondral/cartilage lesions/defects of the acetabulum", "chondral/cartilage lesions/defects of the hip", "osteochondral lesions of the femoral head", "osteochondral lesions of the acetabulum", "osteochondral lesions of the hip", "osteochondritis dissecans," "early osteoarthritis of the hip," and "early stage avascular necrosis". Hip osteochondral injuries can cause significant damage to the articular surface and diminish the quality of life. It can be difficult to treat such injuries, especially in patients who are young and active. Several methods are used to treat chondral and osteochondral injuries of the hip, such as mesenchymal stem cells and cell-based treatment, surgical repair, and microfractures. Realignment of bony anatomy may also be necessary for optimal outcomes. Despite several treatments being successful, there is a lack of head-to-head comparisons and large sample size studies in the current literature. Additional research will be required to provide appropriate clinical recommendations for treating chondral/osteochondral injuries of the hip joint.

The 50 Most Cited Publications in Adipose-Derived "Stem Cell Therapies" with Application in Orthopaedic Surgery

Stem cell therapies have become widely popular in orthopaedic surgery, with a recent interest in adipose-derived therapeutics. Adipose-derived mesenchymal signaling cells (ADSCs) and micronized adipose tissue (MAT) are unique therapies derived from different processing methods. Characterizing the most influential studies in lipoaspirate research can help clarify controversies in definitions, identify core literature, and further collective knowledge for educational purposes. The Science Citation Index Expanded subsection of the Web of Science Core Collection was systematically searched to identify the top 50 most cited publications (based on citation/year) on orthopaedic ADSCs or MAT research. Publication and study characteristics were extracted and reported using descriptive statistics. Level of evidence was assessed for applicable studies, and Spearman correlations were calculated to assess the relationship between citation data and level of evidence. The top 50 articles were published between the years 2003 and 2020, with 78% published in the year 2010 or later. The mean number of citations was 103.1 ± 81.1. The mean citation rate was 12.4 ± 6.0 citations per year. Of the 21 studies for which level of evidence was assessed, the majority were level III (10, 47.6%). The single study design most common among the top 50 cited articles was in vitro basic science studies (17 studies, 34%). Twenty-nine articles (58%) were classified as basic science or translational. Application to treat knee osteoarthritis was the most common focus of studies (14 studies, 28%), followed by in vitro analysis of growth factor and cell signaling markers (11 studies, 22%). No correlation was found between rank, citation rate, or year of publication and level of evidence. This study provides a current landscape on the most cited articles in lipoaspirates in orthopaedic surgery. With the expansion of ADSCs and MAT in the past two decades, this study provides the first historical landmark of the literature and a launching point for future research. Studies should explicitly state their processing methodology and whether their study investigates ADSCs or MAT to avoid misinformation.

The Effects of Tissue Healing Factors in Wound Repair Involving Absorbable Meshes: A Narrative Review

Wound healing is a complex and meticulously orchestrated process involving multiple phases and cellular interactions. This narrative review explores the intricate mechanisms behind wound healing, emphasizing the significance of cellular processes and molecular factors. The phases of wound healing are discussed, focusing on the roles of immune cells, growth factors, and extracellular matrix components. Cellular shape alterations driven by cytoskeletal modulation and the influence of the 'Formin' protein family are highlighted for their impact on wound healing processes. This review delves into the use of absorbable meshes in wound repair, discussing their categories and applications in different surgical scenarios. Interleukins (IL-2 and IL-6), CD31, CD34, platelet rich plasma (PRP), and adipose tissue-derived mesenchymal stem cells (ADSCs) are discussed in their respective roles in wound healing. The interactions between these factors and their potential synergies with absorbable meshes are explored, shedding light on how these combinations might enhance the healing process. Recent advances and challenges in the field are also presented, including insights into mesh integration, biocompatibility, infection prevention, and postoperative complications. This review underscores the importance of patient-specific factors and surgical techniques in optimizing mesh placement and healing outcomes. As wound healing remains a dynamic field, this narrative review provides a comprehensive overview of the current understanding and potential avenues for future research and clinical applications.

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

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

LNX2 involves in the role of ghrelin to promote the neuronal differentiation of adipose tissue-derived mesenchymal stem cells

Adipose tissue-derived mesenchymal stem cells (ADSCs) have promising effects on nerve repair due to the differentiation ability to neural cells. Ghrelin has been shown to promote the neural differentiation of ADSCs. This work was designed to explore its underlying mechanism. Herein, we found high expression of LNX2 in ADSCs after neuronal differentiation. Knockdown of LNX2 might block neuronal differentiation of ADSCs, as evidenced by the decreased number of neural-like cells and dendrites per cell, and the reduced expressions of neural markers (including β-Tubulin III, Nestin, and MAP2). We also demonstrated that LNX2 silencing suppressed the nuclear translocation of β-catenin in differentiated ADSCs. Luciferase reporter assay indicated that LNX2 inhibited wnt/β-catenin pathway by reducing its transcriptional activity. In addition, results showed that LNX2 expression was increased by ghrelin, and its inhibition diminished the effects of ghrelin on neuronal differentiation. Altogether, the results suggest that LNX2 is involved in the role of ghrelin to facilitate neuronal differentiation of ADSCs.

microRNA-449a reduces growth hormone-stimulated senescent cell burden through PI3K-mTOR signaling

Cellular senescence, a hallmark of aging, has been implicated in the pathogenesis of many major age-related disorders, including neurodegeneration, atherosclerosis, and metabolic disease. Therefore, investigating novel methods to reduce or delay the accumulation of senescent cells during aging may attenuate age-related pathologies. microRNA-449a-5p (miR-449a) is a small, noncoding RNA down-regulated with age in normal mice but maintained in long-living growth hormone (GH)-deficient Ames Dwarf (df/df) mice. We found increased fibroadipogenic precursor cells, adipose-derived stem cells, and miR-449a levels in visceral adipose tissue of long-living df/df mice. Gene target analysis and our functional study with miR-449a-5p have revealed its potential as a serotherapeutic. Here, we test the hypothesis that miR-449a reduces cellular senescence by targeting senescence-associated genes induced in response to strong mitogenic signals and other damaging stimuli. We demonstrated that GH downregulates miR-449a expression and accelerates senescence while miR-449a upregulation using mimetics reduces senescence, primarily through targeted reduction of p16Ink4a, p21Cip1, and the PI3K-mTOR signaling pathway. Our results demonstrate that miR-449a is important in modulating key signaling pathways that control cellular senescence and the progression of age-related pathologies.

Exosomes derived from human adipose-derived stem cells alleviate hepatic ischemia-reperfusion (I/R) injury through the miR-183/ALOX5 axis

Ischemia-reperfusion (I/R) injury is a crucial factor causing liver injury in the clinic. Recent research has confirmed that human adipose-derived stem cells (ADSCs) can differentiate into functional hepatocytes. However, the mechanism of the effects of ADSCs in the treatment of liver injury remains unclear. The characteristics of ADSCs were first identified, and exosome-derived ADSCs were isolated and characterized. The function and mechanism of action of miR-183 and arachidonate 5-lipoxygenase (ALOX5) were investigated by functional experiments in HL-7702 cells with I/R injury and in I/R rats. Our data disclosed that exosome release from ADSCs induced proliferation and inhibited apoptosis in HL-7702 cells with I/R injury. The effect of miR-183 was similar to that of exosomes derived from ADSCs. In addition, ALOX5, as a target gene of miR-183, was involved in the related functions of miR-183. Moreover, in vivo experiments confirmed that miR-183 and exosomes from ADSCs could improve liver injury in rats and inhibit the MAPK and NF-κB pathways. All of these findings demonstrate that exosomes derived from ADSCs have a significant protective effect on hepatic I/R injury by regulating the miR-183/ALOX5 axis, which might provide a therapeutic strategy for liver injury.

Efficacy of Adipose-Derived Mesenchymal Stem Cells and Stromal Vascular Fraction Alone and Combined to Biomaterials in Tendinopathy or Tendon Injury: Systematic Review of Current Concepts

Background and Objectives: Tendon injury and tendinopathy are among the most frequent musculoskeletal diseases and represent a challenging issue for surgeons as well as a great socio-economic global burden. Despite the current treatments available, either surgical or conservative, the tendon healing process is often suboptimal and impaired. This is due to the inherent scarce ability of tendon tissue to repair and return itself to the original structure. Recently, Adipose-derived mesenchymal stem cells (ADSC) and stromal vascular fraction (SVF) have gained a central interest in the scientific community, demonstrating their effectiveness in treatments of acute and chronic tendon disorders in animals and humans. Either enzymatic or mechanical procedures to obtain ADSC and SVF have been described and used in current clinical practice. However, no unified protocols and processes have been established. Materials and Methods: This systematic review aims at providing a comprehensive update of the literature on the clinical application of ADSC enzymatically or mechanically processed to obtain SVF, alone and in association with biomaterials in the local treatment of tendinopathy and tendon injury in vivo, in animal models and humans. The study was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Results: Thirty-two articles met our inclusion criteria, with a total of 18 studies in animals, 10 studies in humans and 4 studies concerning the application of biomaterials in vivo in animals. The review of the literature suggests that ADSC/SVF therapy can represent a promising alternative in tendonregenerative medicine for the enhancement of tendon healing. Conclusions: Nevertheless, further investigations and randomized control trials are needed to improve the knowledge, standardize the procedures and extend the consensus on their use for such applications.

The role of adipose-derived mesenchymal stem cells in knee osteoarthritis: a meta-analysis of randomized controlled trials

Background

Adipose-derived mesenchymal stem cells (ADMSCs) have recently been studied for the treatment of knee osteoarthritis. The goal is pain reduction and improvement of joint function leading to superior health-related quality of life.

Objectives

The aim of this study was to provide a comprehensive meta-analysis assessing the evidence on the use of ADMSCs in knee osteoarthritis.

Design

This is a Meta-analysis of randomised controlled trials.

Data Sources and Methods

PubMed/MEDLINE, Embase, and Cochrane Databases were searched for randomized controlled trials using ADMSCs to treat patients with knee osteoarthritis. Only trials comparing ADMSCs to placebo or conservative treatment were included. The outcomes studied were improvement in functional, pain, and quality of life scores along with radiographic findings.

Results

A total of four trials were included, representing 138 patients with knee osteoarthritis. WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) scores favored ADMSCs with a statistically and clinically significant difference over controls at 6- and 12-month follow-ups (p value < 0.0001). Pain, functional, and quality of life scores also favored ADMSCs at 12-month follow-up (p value < 0.0001).

Conclusion

ADMSCs are effective in treating knee osteoarthritis symptoms as observed by functional and pain improvements. Furthermore, ADMSCs injection showed improvement of cartilage integrity, which indicates the potential for regenerating the knee cartilage. Future trials with larger number of patients and longer follow-up periods would help to elaborate further the therapeutic potential of ADMSCs.

Plain Language Summary

Adipose-derived mesenchymal stem cells use in knee osteoarthritis Knee osteoarthritis is an extremely common disease that causes damage of the lining of the knee joint.This will lead to pain and limited range of motion of the knee hence limited functionality.Multiple treatments are used currently for knee osteoarthritis which all aim at slowing down the progression and limiting the need for knee replacement surgery.Adipose-derived mesenchymal stem cells (ADMSCs) are stem cells harvested from the fat around the belly. These stem cells have the potential to be converted into cells of a certain origin (cartilage, muscle, fat).Many studies are being performed to see whether these cells can transform to cartilage and repair the damaged knee joint.In this study, we tried to find how the results of different studies comparing the usual treatments for knee osteoarthritis with that of ADMSCs compared.We were mostly interested in the pain, functional, stiffness, and quality of life scores.We also reviewed the MRI findings to find out whether the lining of the knee joint improved.Four studies were included with 138 patients having knee osteoarthritis.WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) score which is a self-administered questionnaire evaluating hip and knee osteoarthritis, showed better results in patients receiving ADMSC injections compared with other usual treatments at 12-month follow-up.Pain, functional, stiffness, and quality of life scores also showed better results in ADMSCs at 12-month follow-up.MRI images also showed better cartilage lining in the patients treated with ADMSCs.We concluded that ADMSCs are both effective and safe to be used in treating knee osteoarthritis symptoms. However, studies with longer follow-up periods are needed to better assess the regenerative potential of ADMSCs.

Autologous Adipose-Derived Tissue Stromal Vascular Fraction (AD-tSVF) for Knee Osteoarthritis

Adipose tissue contains adult mesenchymal stem cells that may modulate the metabolism when applied to other tissues. Stromal vascular fraction (SVF) can be isolated from adipose tissue mechanically and/or enzymatically. SVF was recently used to decrease the pain and improve the function of knee osteoarthritis (OA) patients. Primary and/or secondary OA causes inflammation and degeneration in joints, and regenerative approaches that may modify the natural course of the disease are limited. SVF may modulate inflammation and initiate regeneration in joint tissues by initiating a paracrine effect. Chemokines released from SVF may slow down degeneration and stimulate regeneration in joints. In this review, we overviewed articular joint cartilage structures and functions, OA, and macro-, micro-, and nano-fat isolation techniques. Mechanic and enzymatic SVF processing techniques were summarized. Clinical outcomes of adipose tissue derived tissue SVF (AD-tSVF) were evaluated. Medical devices that can mechanically isolate AD-tSVF were listed, and publications referring to such devices were summarized. Recent review manuscripts were also systematically evaluated and included. Transferring adipose tissues and cells has its roots in plastic, reconstructive, and aesthetic surgery. Micro- and nano-fat is also transferred to other organs and tissues to stimulate regeneration as it contains regenerative cells. Minimal manipulation of the adipose tissue is recently preferred to isolate the regenerative cells without disrupting them from their natural environment. The number of patients in the follow-up studies are recently increasing. The duration of follow up is also increasing with favorable outcomes from the short- to mid-term. There are however variations for mean age and the severity of knee OA patients between studies. Positive outcomes are related to the higher number of cells in the AD-tSVF. Repetition of injections and concomitant treatments such as combining the AD-tSVF with platelet rich plasma or hyaluronan are not solidified. Good results were obtained when combined with arthroscopic debridement and micro- or nano-fracture techniques for small-sized cartilage defects. The optimum pressure applied to the tissues and cells during filtration and purification of the AD-tSVF is not specified yet. Quantitative monitoring of articular joint cartilage regeneration by ultrasound, MR, and synovial fluid analysis as well as with second-look arthroscopy could improve our current knowledge on AD-tSVF treatment in knee OA. AD-tSVF isolation techniques and technologies have the potential to improve knee OA treatment. The duration of centrifugation, filtration, washing, and purification should however be standardized. Using gravity-only for isolation and filtration could be a reasonable approach to avoid possible complications of other methodologies.

Why Use Adipose-Derived Mesenchymal Stem Cells in Tendinopathic Patients: A Systematic Review

The aim of the present systematic review was to provide a clear overview of the clinical current research progress in the use of adipose-derived mesenchymal stem cells (ASCs) as an effective therapeutic option for the management of tendinopathies, pathologies clinically characterized by persistent mechanical pain and structural alteration of the tendons. The review was carried out using three databases (Scopus, ISI Web of Science and PubMed) and analyzed records from 2013 to 2021. Only English-language papers describing the isolation and manipulation of adipose tissue as source of ASCs and presenting ASCs as treatment for clinical tendinopathies were included. Overall, seven clinical studies met the inclusion criteria and met the minimum quality inclusion threshold. Data extraction and quality assessment were performed by groups of three reviewers. The available evidence showed the efficacy and safety of ASCs treatment for tendinopathies, although it lacked a clear description of the biomolecular mechanisms underlying the beneficial properties of ASCs.

One of the Primary Functions of Tissue-Resident Pluripotent Pericytes Cells May Be to Regulate Normal Organ Growth and Maturation: Implications for Attempts to Repair Tissues Later in Life

Adult mesenchymal stem cells were reported more than 30 years ago. Since then, their potential to repair and regenerate damaged or diseased tissues has been studied intensively in both preclinical models and human trials. Most of the need for such tissue repair/regeneration is in older populations, so much of the effort has been performed with autologous cells in older patients. However, success has been difficult to achieve. In the literature, it has been noted that such progenitor cells from younger individuals often behave with more vigorous activity and are functionally enhanced compared to those from older individuals or animals. In addition, cells with the characteristics of mesenchymal stem cells or pluripotent mesenchymal regulatory cells exist in nearly all tissues and organs as pericytes since fetal life. Such evidence raises the possibility that one of the primary roles of these organ-specific cells is to regulate organ growth and maturation, and then subsequently play a role in the maintenance of organ integrity. This review will discuss the evidence to support this concept and the implications of such a concept regarding the use of these progenitor cells for the repair and regeneration of tissues damaged by injury or disease later in life. For the latter, it may be necessary to return the organ-specific progenitor cells to the functional state that contributed to their effectiveness during growth and maturation rather than attempting to use them after alterations imposed during the aging process have been established and their function compromised.

Mapping global trends in adipose-derived mesenchymal stem cell research: A bibliometric analysis using scopus database

Background and objective

Adipose-derived mesenchymal stem cells (AdMSC) are multipotent adult mesenchymal cells isolated and cultured from the stromal vascular fraction derived from adipose tissue. The present study was conducted to analyze the global trends in AdMSC research using bibliometric and visual analysis tools.

Methods

The literature search was done on February 13, 2022, using appropriate keywords and inclusion-exclusion criteria from the Scopus database. The extracted data were retrospectively analyzed and visualized using Bibliometrics and R packages and VOSviewer.

Results

Preliminary analysis identified 1569 documents from the Scopus database published between 2005 and 2021. The average citations received per document was 26.51, whereas the average citations per year per document was 3.347. In addition, the selected documents had an h-index value of 90. China was the most productive country, whereas Seoul National University (South Korea) was identified as the most productive institute/university in AdMSC research. In addition, the National Natural Science Foundation of China funded the most research studies in AdMSC research.

Conclusion

The findings from this study indicate a progressive increase in interest among the research community towards AdMSC, suggesting promising prospects in the coming years.

Ultra-Low Electromagnetic Fields Application on In Vitro Cartilage Regeneration: A Pilot Study to Improve Treatment of Osteoarticular Diseases

Extremely low-frequency and low-intensity electromagnetic fields show positive effects on the treatment of several osteoarticular diseases, such as osteoarthritis, and are currently applied in the clinical setting with promising results on tissue regeneration. However, the biological mechanisms underlying the beneficial effects triggered by this type of physical stimulation still need to be deciphered. We tested the hypothesis that ultra-low complex electromagnetic fields stimulation using an innovative medical device could enhance chondrogenesis in human adipose-derived stem cells (ADSCs), and analyzed its biological effects. Chondrogenic lineage markers, like ACAN, SOX9, RUNX2, COL2A1, and COL10A1, were evaluated after 21 days of treatment. Thus far, we have provided preliminary evidence that a dedicated pattern of ultra-weak complex electromagnetic sequences emitted by a cutting-edge technology can promote cartilage regeneration, inducing the chondrogenic differentiation and maturity of ADSCs.

The Role of Mesenchymal Stromal Cells in the Management of Knee Chondral Defects

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Mesenchymal stromal cells (MSCs) are a subset of progenitor cells that help to promote tissue healing and regeneration through the secretion of various cytokines and growth factors. Although technically pluripotent, MSCs in vivo rarely repair damaged tissue through direct differentiation and engraftment.

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Augmentation of traditional marrow stimulation techniques with MSCs has been theorized to improve repair tissue quality and defect fill. Clinical trials evaluating this technique are limited but have shown modest improvements compared with isolated marrow stimulation.

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Various scaffolds also have been utilized in combination with MSCs to treat focal chondral defects. Although the techniques described are heterogeneous, many have shown promising early clinical outcomes.

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Newer techniques involving 3-dimensional bioprinted scaffolds seeded with MSCs allow for the recreation of complex architecture, more closely resembling articular cartilage. These techniques are evolving and have not yet been studied in human clinical trials.

Biological Augments for Acetabular Chondral Defects in Hip Arthroscopy-A Scoping Review of the Current Clinical Evidence

PURPOSE OF REVIEW

A wide array of joint-preserving surgical techniques exists in the management of acetabular chondral defects (ACDs). The purpose of this review is to summarize the clinical outcomes of the recent biologics used to treat ACDs during hip arthroscopy.

RECENT FINDINGS

Increasing evidence is available for different biological solutions used in the hip. Studies have shown promising outcomes with minimal complications when using biologics as augmentation to microfracture (MF), including different scaffolds or stem cells, or to enhance autologous chondrocyte implantation (ACI). However, data so far is scarce, and more trials and longer follow-ups are needed to better delineate the appropriate indications and benefits for each technique. Presently, the level of evidence is low, but in general, biologics appear safe and trend toward beneficial compared to standard surgical techniques. Augmented MF is recommended for small to medium ACDs, and matrix-assisted ACI or three-dimensional ACI is recommended for medium to large defects.

Public Opinion and Expectations of Stem Cell Therapies in Orthopaedics

PURPOSE

To explore public opinion, understanding, and preferences regarding the use of stem cell therapies for the treatment of joint and tendon pathologies using online crowdsourcing.

METHODS

A 30-question survey was completed by 931 members of the public using Amazon Mechanical Turk, a validated crowdsourcing method. Outcomes included perceptions and preferences regarding the use of stem cells therapies for the nonsurgical treatment of orthopaedic conditions. Sociodemographic factors and a validated assessment of health literacy were collected. Inclusion criteria were adult participants 18 years or older, residence within the United States, and a valid Social Security number. Multivariable logistic regression modeling was used to determine population characteristics associated with the belief that stem cells represent the most effective treatment for long-standing joint or tendon disorders.

RESULTS

Most respondents reported that stem cell therapies have convincing evidence to support their use for orthopaedic conditions (84.5%) and are approved and regulated by the Food and Drug Administration (65%). About three-quarters of respondents reported that stem cells can stop the progression of and alleviate pain from arthritis or damaged tendons, and over half (53.5%) reported that stem cells can cure arthritis. Factors with the greatest influence on respondents' decision to receive stem cell therapies are research supporting their safety and effectiveness and doctor recommendation. However, 63.3% of respondents stated that they would consider stem cells if their doctor recommended it, regardless of evidence supporting their effectiveness, and over half would seek another doctor if their orthopaedic surgeon did not offer this treatment option.

CONCLUSIONS

The public's limited understanding regarding the current evidence associated with stem cell therapies for osteoarthritis and tendinous pathologies may contribute to unrealistic expectations and misinformed decisions. This study highlights the importance of patient education and expectation setting, as well as evidence transparency, as stem cell therapies become increasingly accessible.

LEVEL OF EVIDENCE

Level IV, case series.

Adipose-Derived Mesenchymal Stem Cells-Conditioned Medium Modulates the Expression of Inflammation Induced Bone Morphogenetic Protein-2, -5 and -6 as Well as Compared with Shockwave Therapy on Rat Knee Osteoarthritis

The dose-dependent effects of adipose-derived mesenchymal stem cell-conditioned medium (ADSC-CM) were compared with those of shockwave (SW) therapy in the treatment of early osteoarthritis (OA). Anterior cruciate ligament transaction (ACLT) with medial meniscectomy (MMx) was performed in rats divided into sham, OA, SW, CM1 (intra-articular injection of 100 μL ADSC-CM into knee OA), and CM2 (intra-articular injection of 200 μL ADSC-CM) groups. Cartilage grading, grading of synovium changes, and specific molecular analysis by immunohistochemistry staining were performed. The OARSI and synovitis scores of CM2 and SW group were significantly decreased compared with those of the OA group (p < 0.05). The inflammatory markers interleukin 1β, terminal deoxynucleotidyl transferase dUTP nick end labeling and matrix metalloproteinase 13 were significantly reduced in the CM2 group compared to those in the SW and CM1 groups (p < 0.001). Cartilage repair markers (type II collagen and SRY-box transcription factor 9, SOX9) expression were significantly higher in the CM2 group than in the other treatment groups (p < 0.001; p < 0.05). Furthermore, inflammation-induced growth factors such as bone morphogenetic protein 2 (BMP2), BMP5, and BMP6 were significantly reduced in the treatment groups, and the CM2 group showed the best results among the treatments (p < 0.05). In conclusion, ADSC-CM and SW ameliorated the expression of inflammatory cytokines and inflammation-induced BMPs to protect the articular cartilage of the OA joint.

Accentuating the sources of mesenchymal stem cells as cellular therapy for osteoarthritis knees-a panoramic review

The large economic burden on the global health care systems is due to the increasing number of symptomatic osteoarthritis (OA) knee patients whereby accounting for greater morbidity and impaired functional quality of life. The recent developments and impulses in molecular and regenerative medicine have paved the way for inducing the biological active cells such as stem cells, bioactive materials, and growth factors towards the healing and tissue regenerative process. Mesenchymal stem cells (MSCs) act as a minimally invasive procedure that bridges the gap between pharmacological treatment and surgical treatment for OA. MSCs are the ideal cell-based therapy for treating disorders under a minimally invasive environment in conjunction with cartilage regeneration. Due to the worldwide recognized animal model for such cell-based therapies, global researchers have started using the various sources of MSCs towards cartilage regeneration. However, there is a lacuna in literature on the comparative efficacy and safety of various sources of MSCs in OA of the knee. Hence, the identification of a potential source for therapeutic use in this clinical scenario remains unclear. In this article, we compared the therapeutic effects of various sources of MSCs in terms of efficacy, safety, differentiation potential, durability, accessibility, allogenic preparation and culture expandability to decide the optimal source of MSCs for OA knee.

Co-transfection with BMP2 and FGF2 via chitosan nanoparticles potentiates osteogenesis in human adipose-derived stromal cells in vitro

OBJECTIVE

To investigate if co-transfection of human bone morphogenetic protein 2 (BMP-2, BMP2) and human fibroblast growth factor 2 (FGF2, FGF2) via chitosan nanoparticles promotes osteogenesis in human adipose tissue-derived stem cells (ADSCs) in vitro.

MATERIALS AND METHODS

Recombinant BMP2 and/or FGF2 expression vectors were constructed and packaged into chitosan nanoparticles. The chitosan nanoparticles were characterized by atomic force microscopy. Gene and protein expression levels of BMP-2 and FGF2 in ADSCs in vitro were evaluated by real-time polymerase chain reaction (PCR), western blot, and enzyme-linked immunosorbent assay. Osteocalcin (OCN) and bone sialoprotein (BSP) gene expression were also evaluated by real-time PCR to assess osteogenesis.

RESULTS

The prepared chitosan nanoparticles were spherical with a relatively homogenous size distribution. The BMP2 and FGF2 vectors were successfully transfected into ADSCs. BMP-2 and FGF2 mRNA and protein levels were significantly up-regulated in the co-transfection group compared with the control group. OCN and BSP mRNA levels were also significantly increased in the co-transfection group compared with cells transfected with BMP2 or FGF2 alone, suggesting that co-transfection significantly enhanced osteogenesis.

CONCLUSIONS

Co-transfection of human ADSCs with BMP2/FGF2 via chitosan nanoparticles efficiently promotes the osteogenic properties of ADSCs in vitro.

Adipose-Derived Stem Cells: Current Applications and Future Directions in the Regeneration of Multiple Tissues

Adipose-derived stem cells (ADSCs) can maintain self-renewal and enhanced multidifferentiation potential through the release of a variety of paracrine factors and extracellular vesicles, allowing them to repair damaged organs and tissues. Consequently, considerable attention has increasingly been paid to their application in tissue engineering and organ regeneration. Here, we provide a comprehensive overview of the current status of ADSC preparation, including harvesting, isolation, and identification. The advances in preclinical and clinical evidence-based ADSC therapy for bone, cartilage, myocardium, liver, and nervous system regeneration as well as skin wound healing are also summarized. Notably, the perspectives, potential challenges, and future directions for ADSC-related researches are discussed. We hope that this review can provide comprehensive and standardized guidelines for the safe and effective application of ADSCs to achieve predictable and desired therapeutic effects.

Differentiation potential and mRNA profiles of human dedifferentiated adipose cells and&nbsp;adipose‑derived stem cells from young donors

Dedifferentiated adipose cells (DAs) and adipose-derived stem cells (ADSCs) are two of the primary types of stem cells derived from adipose tissue, which have been reported to possess similar characteristics, but also exhibit unique phenotypic and functional advantages. However, several reports have described inconsistent results regarding their differences in multilineage differentiation function. Moreover, to the best of our knowledge, there are no studies assessing their myogenic ability, or the differences in the transcriptome between the two cell types derived from lipoaspirates via tumescent liposuction from the same donors. The aim of the present study was to compare the properties and expression profiles of these cell types. Subcutaneous adipose tissue of three female patients (aged 23–30 years) with a physiological BMI (19.1–23.9 kg/m²) were obtained during tumescent liposuction of the abdomen or the thigh. The stromal vascular fraction and mature adipocytes were obtained via collagenase digestion, and ADSCs and DAs were cultured successively. To determine the differences between DAs and ADSCs after 6–7 passages, cell proliferation assays, phenotypic assessment, differentiation assays and high-throughput RNA sequencing (seq) were used. Similar cell morphologies, proliferation dynamics, surface markers and transcriptome expression profiles were observed between the DAs and ADSCs. Whilst there were notable individual differences in the osteogenic, lipogenic, chondrogenic and myogenic abilities of the DAs and ADSCs, it was difficult to determine their differentiation potential based only on the cell source. Interestingly, the myogenic ability was relatively stronger in cells with relatively weaker lipogenic ability. Only 186 differentially expressed genes between the two groups were identified using RNAseq. Several of these genes were involved in biological functions such as transcription regulation, protein translation regulation, cytokine interactions and energy metabolism regulation. The results of the present study suggested a similar functional potential of DAs and ADSCs from young donors undergoing tumescent liposuction operation in regeneration areas and the balance of the differentiative ability of the same cell populations. These data may provide a foundation for further clinical administration of stem cells derived from adipose tissues in therapy.