Stem Cells in Autologous Microfragmented Adipose Tissue: Current Perspectives in Osteoarthritis Disease

Should I add Orthobiologics to my Knee Osteotomy Practice? A Systematic Review

IMPORTANCE

Orthobiologics has seen a renaissance over the last decade as an adjunct therapy during osteotomy due to the limited inherent regenerative potential of damaged intraarticular tissues.

AIM OR OBJECTIVE

This systematic review aims to present the latest evidence regarding using orthobiologics with simultaneous high tibial osteotomy (HTO) for knee osteoarthritis. The results of this study may guide surgeons to improve their clinical results and clear the air regarding confusion over whether or not to add orthobiologics to HTO in clinical practice backed by scientific evidence.

EVIDENCE REVIEW

According to PRISMA guidelines a systematic search for relevant literature was performed in the PubMed (MEDLINE), Scopus, EMBASE, and Cochrane Library databases of all studies published in English from January 1990 to May 2023. The following search terms were entered into the title, abstract, and keyword fields: "knee" or "osteotomy" AND "valgus" or "varus" AND "regenerative medicine" or "PRP" or "mesenchymal stem cells" or "stem cells" or "BMAC" or "bone marrow" or "growth factors" or "umbilical cord blood-derived mesenchymal stem cell" or "stromal vascular fraction". The AMSTAR-2 checklist was used to confirm the quality of the systematic review. Randomised controlled trials (RCTs), prospective and retrospective comparative cohort studies, case-control studies, and case series were included. Studies that reported clinical outcomes in patients treated with knee osteotomy for varus/valgus knee with concomitant adjunction of regenerative treatment [Platelet-rich plasma (PRP), Adipose-derived stem cells (ADSC), Human Umbilical Cord Blood-Derived (HUCBD), Mesenchymal Stem Cells (MSC), bone marrow aspirate concentrate (BMAC), stromal vascular fraction (SVF)] were included. The outcome measures extracted from the studies were the KOOS score, Lysholm score, Subjective IKDC, WOMAC Score, KSS, Tegner, HSS, radiographic tibiofemoral angle, posterior tibial slope and complications. The current systematic review is registered in the PROSPERO Registry (CRD42023439379).

FINDINGS

Osteotomy for unicompartmental arthritis with adjunction of orthobiologics such as PRP, ADSC, HUCBD, MSC, BMAC, and SVF presents a consistent statistically significant clinical improvement compared to preoperative scores regardless of the treatment modality used and there were no notable complications associated with the use of these novel agents.

CONCLUSIONS AND RELEVANCE

Orthobiologics and knee osteotomies could improve outcomes in patients with knee osteoarthritis desiring Knee preservation surgeries. However, only a few studies are available on the topic to conclude anything with certainty, the patients included in the studies could not be disintegrated based on the grade of osteoarthritis (OA), type, dosage and frequency of administration of orthobiologic and type of additional surgical procedures used. Therefore, better-structured RCTs are required to implement this finding into routine Orthopaedic practice.

LEVEL OF EVIDENCE

Level 4.

Pain Management Strategies in Osteoarthritis

Pain is the major symptom of osteoarthritis (OA) and is an important factor in strategies to manage this disease. However, the current standard of care does not provide satisfactory pain relief for many patients. The pathophysiology of OA is complex, and its presentation as a clinical syndrome is associated with the pathologies of multiple joint tissues. Treatment options are generally classified as pharmacologic, nonpharmacologic, surgical, and complementary and/or alternative, typically used in combination to achieve optimal results. The goals of treatment are the alleviation of symptoms and improvement in functional status. Several studies are exploring various directions for OA pain management, including tissue regeneration techniques, personalized medicine, and targeted drug therapies. The aim of the present narrative review is to extensively describe all the treatments available in the current practice, further describing the most important innovative therapies. Advancements in understanding the molecular and genetic aspects of osteoarthritis may lead to more effective and tailored treatment approaches in the future.

Autologous microfragmented adipose tissue treatment of knee osteoarthritis demonstrates effectiveness in 68% of patients at 4-year follow-up

BACKGROUND

Adipose tissue-derived stem cells are an interesting therapeutic option for early knee osteoarthritis (OA) treatment due to their high plasticity, easiness of harvesting and rapidity of administration. The aim of this study was to evaluate the medium-term effectiveness and safety of Microfragmented Autologous Fat Tissue (MFAT) injection treatment at 4-year follow-up and to investigate potential correlations among patients' pre-treatment clinical condition and clinical outcomes to identify possible predicting factors for procedure success or failure.

PATIENTS AND METHODS

This is a prospective trial enrolling 46 patients with diagnosis of symptomatic knee OA and failure of previous conservative measures who underwent diagnostic arthroscopy and single autologous MFAT injection between June 2017 and July 2018. Patients were assessed with repeated clinical scoring systems at baseline, 6 months, 1 and 4 years after surgery. The evaluation included demographic characteristics, arthroscopic findings, and stem cell number from injected tissue.

RESULTS

No major complications were reported during follow-up period and there was a significant increase of Lysholm knee score from baseline value of 61.7 ± 13.8 to 79.5 ± 16.9 at 4 years (p < 0.001). The WOMAC score increased from a baseline value of 66.5 ± 14.7 to 82.8 ± 15.7 at 4 years (p < 0.001) and there was a significant decrease of VAS pain score from baseline value of 6.3 ± 1.5 to 3.5 ± 2.6 at 4-year follow-up (p < 0.001). ROM improved significantly from 118.4 ± 2.6 to 122.5 ± 2.5 at 12 months (p < 0.001), but did not improve at 4 years (p > 0.05). 15 patients (32.6%) were considered treatment failures, because they required secondary surgery, further injection therapy or experienced symptoms persistence. Patient with synovitis had 75% failure rate, although synovitis did not result as a statistically significant factor influencing clinical outcome up to 4-year follow-up (p = 0.058). Age, cartilage defects severity, BMI, concomitant procedures, and stem cell number from injected MFAT did not show any significant correlation with the results.

CONCLUSIONS

MFAT intra-articular injection is a safe procedure with positive improvements up to 4-year follow-up in patients with early knee OA. These findings suggest MFAT could be a minimally invasive treatment of early knee OA with durable benefits at mid-term evaluation.

TRIAL REGISTRATION

IRB number ID-3522.

The Evolution of Current Concept of the Reconstructive Ladder in Plastic Surgery: The Emerging Role of Translational Medicine

Plastic surgeons have used the reconstructive ladder for many decades as a standard directory for complex trauma reconstruction with the goal of repairing body structures and restoring functionality. This consists of different surgical maneuvers, such as secondary intention and direct tissue closure, as well as more complex methods such as local tissue transfer and free flap. The reconstructive ladder represents widely known options achievable for tissue reconstruction and wound closure that puts at the bottom rung the simplest methods of reconstruction and strengthens the complexity by moving upward. Regenerative medicine and surgery constitute a quickly spreading area of translational research that can be employed by minimally invasive surgical strategies, with the aim of regenerating cells and tissues in vivo in order to reestablish normal function through the intrinsic potential of cells, in combination with biomaterials and appropriate biochemical stimuli. These translational procedures have the aim of creating an appropriate microenvironment capable of supporting the physiological cellular function to generate the desired cells or tissues and to generate parenchymal, stromal, and vascular components on demand, and above all to produce intelligent materials capable of determining the fate of cells. Smart technologies have been grown that give extra "rungs" on the classic reconstructive ladder to integrate a more holistic, patient-based approach with improved outcomes. This commentary presents the evolution of the traditional concept of the reconstructive ladder in the field of plastic surgery into a new course with the aim of achieving excellent results for soft tissue reconstruction by applying innovative technologies and biologically active molecules for a wide range of surgical diseases.

Efficacy and Long-Term Outcomes of Intra-Articular Autologous Micro-Fragmented Adipose Tissue in Individuals with Glenohumeral Osteoarthritis: A 36-Month Follow-Up Study

BACKGROUND

Glenohumeral osteoarthritis (GOA) is associated with disabling shoulder pain that affects everyday life. Its management comprises various treatment approaches, both conservative and surgical. Regenerative medicine has gained a major role in the conservative treatment of osteoarthritis. Intra-articular injection of adipose-derived mesenchymal stem cells (ADMSCs) is a widely used regenerative medicine approach. The aim of this retrospective study was to report the safety and clinical outcomes of intra-articular injection of ADMSCs in patients with GOA over 36-months.

METHODS

This retrospective observational study involved patients with chronic shoulder pain resistant to standard conservative treatment and a diagnosis of concentric GOA, who received an intra-articular injection of autologous micro-fragmented adipose tissue (μFAT). The values of the Constant-Murley score (CMS), the visual analog scale (VAS), and the simple shoulder test (SST), collected at baseline and at 12, 24, and 36 months, were analyzed to assess treatment efficacy. The single assessment numeric evaluation (SANE) was used to rate patient satisfaction. The Friedman test was used to compare observations of CMS, VAS, and SST values repeated on the same subjects. The significance threshold was set at 0.05.

RESULTS

The participants were 65 patients with a mean age of 54.19 years and a nearly equal gender distribution. Most had mild concentric GOA classified as Samilson-Prieto grade 1. The mean follow-up duration was 44.25 months. The postoperative clinical scores showed significant improvement. At 36 months, the CMS was 84.60, the VAS score was 3.34, and the SST score was 10.15 (all p < 0.0001). The SANE score at 36 months indicated that 54 patients (83.08%) were completely satisfied with the treatment.

CONCLUSION

ADMSC treatment exerted favorable effects on the clinical outcomes of patients with GOA, providing pain relief and improving shoulder function. Our data support its use as a conservative treatment option for osteoarthritis.

In Vitro Study of a Novel Vibrio alginolyticus-Based Collagenase for Future Medical Application

Mesenchymal stem cells extracted from adipose tissue are particularly promising given the ease of harvest by standard liposuction and reduced donor site morbidity. This study proposes a novel enzymatic method for isolating stem cells using Vibrio alginolyticus collagenase, obtaining a high-quality product in a reduced time. Initially, the enzyme concentration and incubation time were studied by comparing cellular yield, proliferation, and clonogenic capacities. The optimized protocol was phenotypically characterized, and its ability to differentiate in the mesodermal lineages was evaluated. Subsequently, that protocol was compared with two Clostridium histolyticum-based collagenases, and other tests for cellular integrity were performed to evaluate the enzyme's effect on expanded cells. The best results showed that using a concentration of 3.6 mg/mL Vibrio alginolyticus collagenase allows extracting stem cells from adipose tissue after 20 min of enzymatic reaction like those obtained with Clostridium histolyticum-based collagenases after 45 min. Moreover, the extracted cells with Vibrio alginolyticus collagenase presented the phenotypic characteristics of stem cells that remain after culture conditions. Finally, it was seen that Vibrio alginolyticus collagenase does not reduce the vitality of expanded cells as Clostridium histolyticum-based collagenase does. These findings suggest that Vibrio alginolyticus collagenase has great potential in regenerative medicine, given its degradation selectivity by protecting vital structures for tissue restructuration.

An Innovative Surgical Technique to Obtain an Adipose-Derived Stromal Cell-Rich Graft for the Treatment of Osteoarthritis: Technical Note

Osteoarthritis (OA) is one of the main causes of disability worldwide and is caused by the progressive degeneration of joint tissues, ultimately leading to chronic pain and loss of function. Intraarticular delivery of mesenchymal stromal cells, such as adipose-derived stromal cells (ASCs), is being actively investigated due to their trophic properties observed in both preclinical and clinical studies. However, cell expansion and handling involve costly and time-consuming processes that limit their application. Recently, several devices and kits have been developed to isolate and process the stromal vascular fraction (SVF), a high biologically active compound of the adipose tissue, right at the patient’s bedside. In this study, we introduce a novel technique to obtain an SVF graft with a high content of ASCs for intraarticular injection directly from liposuction and with minimal equipment. In this technical note, we describe in detail the steps of the surgical technique as well as strategies to avoid common pitfalls and complications.

Cartilage lesion size and number of stromal vascular fraction (SVF) cells strongly influenced the SVF implantation outcomes in patients with knee osteoarthritis

PURPOSE

This study evaluated outcomes in patients with knee osteoarthritis following stromal vascular fraction implantation and assessed the associated prognostic factors.

METHODS

We retrospectively evaluated 43 patients who underwent follow-up magnetic resonance imaging 12 months after stromal vascular fraction implantation for knee osteoarthritis. Pain was assessed using the visual analogue scale and measured at baseline and 1-, 3-, 6-, and 12-month follow-up appointments. In addition, cartilage repair was evaluated based on the Magnetic Resonance Observation of Cartilage Repair Tissue scoring system using the magnetic resonance imaging from the 12-month follow-up. Finally, we evaluated the effects of various factors on outcomes following stromal vascular fraction implantation.

RESULTS

Compared to the baseline value, the mean visual analogue scale score significantly and progressively decreased until 12 months post-treatment (P < 0.05 for all, except n.s. between the 1 and 3-month follow-ups). The mean Magnetic Resonance Observation of Cartilage Repair Tissue score was 70.5 ± 11.1. Furthermore, the mean visual analogue scale and Magnetic Resonance Observation of Cartilage Repair Tissue scores significantly correlated 12 months postoperatively (P = 0.002). Additionally, the cartilage lesion size and the number of stromal vascular fraction cells significantly correlated with the 12-month visual analogue scale scores and the Magnetic Resonance Observation of Cartilage Repair Tissue score. Multivariate analyses determined that the cartilage lesion size and the number of stromal vascular fraction cells had a high prognostic significance for unsatisfactory outcomes.

CONCLUSION

Stromal vascular fraction implantation improved pain and cartilage regeneration for patients with knee osteoarthritis. The cartilage lesion size and the number of stromal vascular fraction cells significantly influenced the postoperative outcomes. Thus, these findings may serve as a basis for preoperative surgical decisions.

LEVEL OF EVIDENCE

IV.

Ginsenoside Rg1/ADSCs supplemented with hyaluronic acid as the matrix improves rabbit temporomandibular joint osteoarthrosis

OBJECTIVE

To investigate whether and how ginsenoside Rg1/ADSCs supplemented with hyaluronic acid as the matrix can improve rabbit temporomandibular joint osteoarthrosis.

METHOD

Isolate and culture adipose stem cells, measure the activity of differentiated chondrocytes by MTT assay and expression of type II collagen in these cells by immunohistochemistry, in order to evaluate the effect of ginsenoside Rg1 on adipose stem cell proliferation and differentiation into chondrocytes.32 New Zealand white rabbits were randomly divided into four groups: blank group, model group, control group and experimental group, 8 in each group. Osteoarthritis model was established by intra-articular injection of papain. Two weeks after successful model building, medication was given for the rabbits in control group and experimental group. 0.6 mL ginsenoside Rg1/ ADSCs suspension was injected into superior joint space for the rabbits in control group, once a week; 0.6 mL ginsenoside Rg1/ ADSCs complex was injected for the rabbits in experimental group, once a week.

RESULTS

Ginsenoside Rg1 can promote ADSCs-derived chondrocytes' activity and expression of type II collagen. Scanning electron microscopy histology images showed cartilage lesions of the experimental group was significantly improved in comparison with control group.

CONCLUSION

Ginsenoside Rg1 can promote ADSCs differentiate into chondrocytes, and Ginsenoside Rg1/ADSCs supplemented with hyaluronic acid as the matrix can significantly improve rabbit temporomandibular joint osteoarthrosis.

Highly Pluripotent Adipose-Derived Stem Cell-Enriched Nanofat: A Novel Translational System in Stem Cell Therapy

Fat graft is widely used in plastic and reconstructive surgery. The size of the injectable product, the unpredictable fat resorption rates, and subsequent adverse effects make it tricky to inject untreated fat into the dermal layer. Mechanical emulsification of fat tissue, which Tonnard introduced, solves these problems, and the product obtained was called nanofat. Nanofat is widely used in clinical and aesthetic settings to treat facial compartments, hypertrophic and atrophic scars, wrinkle attenuation, skin rejuvenation, and alopecia. Several studies demonstrate that the tissue regeneration effects of nanofat are attributable to its rich content of adipose-derived stem cells. This study aimed to characterize Hy-Tissue Nanofat product by investigating morphology, cellular yield, adipose-derived stem cell (ASC) proliferation rate and clonogenic capability, immunophenotyping, and differential potential. The percentage of SEEA3 and CD105 expression was also analyzed to establish the presence of multilineage-differentiating stress-enduring (MUSE) cell. Our results showed that the Hy-Tissue Nanofat kit could isolate 3.74 × 10⁴ ± 1.31 × 10⁴ proliferative nucleated cells for milliliter of the treated fat. Nanofat-derived ASC can grow in colonies and show high differentiation capacity into adipocytes, osteocytes, and chondrocytes. Moreover, immunophenotyping analysis revealed the expression of MUSE cell antigen, making this nanofat enriched of pluripotent stem cell, increasing its potential in regenerative medicine. The unique characteristics of MUSE cells give a simple, feasible strategy for treating a variety of diseases.

LPS-pretreatment adipose-derived mesenchymal stromal cells promote wound healing in diabetic rats by improving angiogenesis

Mesenchymal stem cells (MSCs) play a key role in wound healing, and the advantages of pretreated MSCs in wound healing have previously been reported. In the present study, we investigated the impact of LPS pretreated human adipose-derived MSCs on skin wound healing in diabetic rats. We found that some improvements occurred through improving angiogenesis. Then, we scrutinized the impact of lipopolysaccharide (LPS) treatment on human adipose-derived MSCs in a high-glucose (HG) medium, as an in vitro diabetic model. In vivo findings revealed significant improvements in epithelialization and angiogenesis of diabetic wounds which received LPS pre-MSCs. Particularly, LPS pre-MSCs-treated diabetic wounds reached considerably higher percentages of wound closure. Also, the granulation tissue of these wounds had higher pronounced epithelialization and more vascularization compared with PBS-treated and MSCs-treated diabetic ones by CD31, VEGF, CD90, collagen 1, and collagen 3 immunostaining. Western-blots analyses indicated that LPS pre-MSCs led to the upregulation of vascular endothelial growth factor (VEGF) and DNMT1. In addition, significantly higher cell viability (proliferation/colonie), and elevated VEGF and DNMT1 protein expression were observed when MSCs were treated with LPS (10 ng/ml, 6 h) in HG culture media. Based on these findings, it is suggested that LPS pre-MSCs could promote wound repair and skin regeneration, in some major processes, via the improvement of cellular behaviors of MSCs in the diabetic microenvironment. The beneficial advantages of LPS treated with mesenchymal stem cells on wound healing may lead to establishing a novel approach as an alternative therapeutic procedure to cure chronic wounds in diabetic conditions.

Autologous micro-fragmented adipose tissue associated with arthroscopy in moderate–severe knee osteoarthritis: outcome at two year follow-up

Background

Adipose tissue has recently gained growing interest in the treatment of osteoarthritis (OA). The aim of the present study was to evaluate the efficacy of a single injection of autologous micro-fragmented adipose tissue (aMFAT) associated with arthroscopy (cartilage debridement/meniscal regularization or selective meniscectomy/micro-drilling) for symptomatic knee OA.

Methods

This retrospective, single-center study included 49 patients (50 knees) affected by knee OA (radiographic Kellgren-Lawrence III-IV) treated with a single injection of autologous micro-fragmented adipose tissue and knee arthroscopy. Knee Injury and Osteoarthritis Outcome Score (KOOS) and subjective International Knee Documentation Committee (IKDC) score were the primary outcome measures and were collected at one and 2 years post-operatively. Patients were divided into clusters based on age, complexity of arthroscopic procedures and chondral lesion grade.

Results

Four patients underwent knee replacement (8%). No major adverse events were reported. Minimal Clinically Important Difference (MCID) for KOOS and IKDC was reached by 84 and 74% of all cases at 1 year and by 80 and 76% at 2 years, respectively. High grade chondral lesions negatively affected the outcome at 2 years follow-up (p < 0.05 for IKDC, KOOS overall and 3 out of 5 subscales).

Conclusion

The injection of micro-fragmented adipose tissue associated with arthroscopy demonstrated to be a safe and effective procedure for the treatment of knee OA, with a substantial improvement in IKDC and KOOS scores and without major complications.

Is intra-articular injection of autologous micro-fragmented adipose tissue effective in hip osteoarthritis? A three year follow-up

Background

Recently, increased attention on regenerative medicine and biological injective treatments have been proposed to restore native cartilage. Micro-fragmented adipose tissue (MFAT) has been studied for its anti-inflammatory, paracrine, and immunomodulatory effects. The long-term effects of MFAT are still poorly understood: the aim of the present study is to demonstrate how hip articular injections with autologous MFAT can have an impact on clinical outcomes.

Methods

Seventy-one consecutive patients affected by early hip osteoarthritis underwent an ultrasound-guided hip injection of autologous MFAT between June 2017 and December 2018. Patients were divided into four groups according to the Oxford Hip Score. All patients received 4 mL of autologous micro-fragmented adipose tissue under an ultrasound guide. A clinical evaluation was done between 29 and 41 months after the initial treatment. During this follow-up period, we recorded any new treatment the patients had done, whether that be injection or arthroplasty surgery.

Results

The study included 55 patients. Out of 55 patients, 28 saw benefits and were in no need of further treatment. Moreover, the score between the beginning and control increased by 6.9 points. Ten patients underwent a new articular injection: the mean time between the two injections was 635.7 ± 180 days. Seventeen patients underwent total hip replacement: the mean period between the autologous MFAT injection and the surgery was 495 days.

Conclusion

This study found that intra-articular injections with autologous MFAT achieve beneficial clinical results in patients affected by early to moderate hip osteoarthritis, with an OHS between 48 and 30. Furthermore, these subjects are the ideal patients for whom this treatment obtains good clinical results.

NR4A1-3 nuclear receptor activity and immune cell dysregulation in rheumatic diseases

The development and progression of immune-mediated rheumatic disease (IMRD) involves dysfunction of innate and adaptive immune cell populations leading to altered responses including inflammasome activation, dysregulated cytokine networks, increased immune cell numbers and multifaceted cell-cell communication. Several rheumatic diseases are further characterized by the presence of autoantibodies, immune complex mediated complement activation and the deficit of peripheral immune tolerance due to reduced regulatory T-lymphocyte cell function. Ultimately, in rheumatic disease the loss in cellular and tissue homeostasis culminates in the advancement of chronic inflammation. The three members of the NR4A subfamily of nuclear receptors are immediate early genes, and act as potent transcriptional responders to changes in the cellular and tissue microenvironment. Subfamily members are rapidly expressed in diseases characterized by inflammation and function to control the differentiation and activity of innate and adaptive immune cells in a cell-type and cell-context specific manner. Rheumatic disease including rheumatoid-, psoriatic-, osteo-arthritis and systemic sclerosis display altered NR4A1-3 activity in controlling immune cell migration and function, production of paracrine signaling molecules, synovial tissue hyperplasia, and regulating cartilage turn-over in vivo. Additionally, NR4A1-3 activities mediate cytokine, prostanoid and growth factor signaling to control angiogenesis, modulate the regulatory functions of mesenchymal stromal cells, alter the activation status of dendritic cells, influence the generation of peripheral myeloid and T-lymphocyte lineages and promote the maintenance of functional regulatory T-cells. Further reports uncover the potential of moderating NR4A 1-3 receptors as therapeutic targets in altering immune tolerance, pathological angiogenesis and controlling inflammation in several models of disease.

Effects of Intra-Articular Autologous Adipose Micrograft for the Treatment of Osteoarthritis in Dogs: A Prospective, Randomized, Controlled Study

The purpose of this study was to estimate the safety, feasibility, and efficacy of the intra-articular treatment of autologous microfragmented adipose tissue in dogs with spontaneous osteoarthritis (OA) in comparison with hyaluronic acid (HA), the standard intra-articular treatment. Specifically, it clinically evaluated pain and lameness, the radiographic progression of osteoarthritis, and synovial fluid inflammation. This was a prospective, single-center, parallel-group, randomized, controlled, in vivo clinical study. Participants (n = 40) received either a single intra-articular injection of microfragmented adipose tissue or a single intra-articular injection of HA (1:1). Clinical outcomes were determined using a specialistic clinician assessment obtained by the completion of a specific clinical form based on the Vesseur modified lameness classification system, a pain evaluation using the Visual Analogue Scale (VAS), the measurement of the range of motion (ROM) of the affected joint, limb circumference, and the owners' score evaluation using the Canine Brief Pain Inventory (CBPI) for up to 6 months after the time of injection. Patients underwent a radiographic examination to establish the degree of OA in the affected joint, and synovial fluid samples were collected to assess the biochemical environment of the joint and evaluate and quantify the cellular population and the presence of three specific inflammation biomarkers for up to 60 days. The results of this study suggest that microfragmented autologous adipose tissue is safe and can effectively relieve pain and improve function in dogs with spontaneous articular OA. This one-step procedure is simple, timesaving, cost-effective, minimally invasive, and eliminates the need for complex and time-intensive cell culture processing. Furthermore, the clinical evidence and cytological results suggest better long-term pain control, resulting in an improvement in joint function, compared to HA treatment. The canine spontaneous OA model could play a key role in developing successful treatments for human medicine.

Non-homologous use of adipose-derived cell and tissue therapies: Osteoarthritis as a case study

Adipose tissue is widely recognized as an abundant and accessible human tissue that serves as a source of cells and extracellular matrix scaffolds for regenerative surgical applications. Increasingly, orthopedic surgeons are turning to adipose tissue as a resource in their treatment of osteoarthritis and related conditions. In the U.S., the regulatory landscape governing the orthopedic surgical utilization of autologous and allogeneic adipose tissue remains complex. This manuscript reviews the Food and Drug Administration's nomenclature and guidance regarding adipose tissue products. Additionally, it surveys recent pre-clinical and clinical trial literature relating to the application of adipose-derived cells and tissues in the treatment of osteoarthritis.

Human Amniotic Suspension Allograft Improves Pain and Function in Knee Osteoarthritis: A Prospective Not Randomized Clinical Pilot Study

Osteoarthritis (OA) is a chronic debilitating disorder causing pain and gradual degeneration of joints. Among various cell therapies, mesenchymal stem cell (MSC) therapy appears to provide encouraging results. Human amniotic suspension allografts (HASA) have anti-inflammatory and chondroregenerative potential and represent a promising treatment strategy. The purpose of the present study was to prospectively assess the safety, clinical effectiveness, and feasibility of intra-articular injections of human amniotic suspension allograft (HASA) in unilateral knee OA in order to assess the improvement of symptoms and delay the necessity for invasive surgical procedures. A total of 25 symptomatic patients, affected by knee OA were treated with 3 mL of HASA. Clinical evaluations before the treatment and after 3, 6, and 12 months were performed through International Knee Documentation Committee (IKDC) score and Visual Analogue Scale (VAS) scores. Adverse events were recorded. No severe complications were noted during the treatment and the follow-up period. A statistically significant improvement from basal evaluation to the 3-, 6-, and 12-month follow-up visits was observed. The present pilot study indicates that a single intra-articular injection of HASA seems safe and able to provide positive clinical outcomes, potentially offering a new minimally invasive therapeutic option for patients with knee OA.

Mesenchymal Stem Cell Mechanisms of Action and Clinical Effects in Osteoarthritis: A Narrative Review

With the insufficient satisfaction rates and high cost of operative treatment for osteoarthritis (OA), alternatives have been sought. Furthermore, the inability of current medications to arrest disease progression has led to rapidly growing clinical research relating to mesenchymal stem cells (MSCs). The availability and function of MSCs vary according to tissue source. The three primary sources include the placenta, bone marrow, and adipose tissue, all of which offer excellent safety profiles. The primary mechanisms of action are trophic and immunomodulatory effects, which prevent the further degradation of joints. However, the function and degree to which benefits are observed vary significantly based on the exosomes secreted by MSCs. Paracrine and autocrine mechanisms prevent cell apoptosis and tissue fibrosis, initiate angiogenesis, and stimulate mitosis via growth factors. MSCs have even been shown to exhibit antimicrobial effects. Clinical results incorporating clinical scores and objective radiological imaging have been promising, but a lack of standardization in isolating MSCs prevents their incorporation in current guidelines.

Autologous Microfragmented Adipose Tissue for the Treatment of Knee Osteoarthritis: Real-World Data at Two Years Follow-Up

The purpose of the present study was to assess, prospectively, the safety, clinical effectiveness, and feasibility of a single intra-articular injection of microfragmented adipose tissue in different stages of knee osteoarthritis (OA). The study included patients (aged 18−70 years), affected by OA (Kellgren−Lawrence I-IV). Unselected patients were evaluated before and prospectively after 6, 12, and 24 months from the injection. Visual analog scale (VAS) and knee injury and osteoarthritis outcome score (KOOS) were used for clinical evaluations. A total of 202 patients were eligible. The mean follow-up time in the cohort of patients was 24.5 ± 9.6 months. Total KOOS significantly improved from pre-operative baseline levels to 6-month follow-up (p < 0.001), and again between 6- and 12-month follow-ups (p < 0.001). The VAS showed a prompt reduction at 6 months (p < 0.001 vs. baseline), but then it increased again at 12 months compared to the 6-month assessment (p < 0.001), even though it remained lower than baseline (p < 0.001). At 24 months, patients with KL-IV demonstrated a lower improvement compared to baseline; patients that had undergone previous corticosteroid injections had a greater risk to further injection treatment. The collected clinical results suggest that MFAT may represent a safe and effective treatment for OA symptoms, offering a low-demanding and minimally invasive treatment.

In Vitro Characterization of Canine Microfragmented Adipose Tissue Non-Enzymatically Extracted from the Thigh and Lumbar Regions

Simple Summary

Mesenchymal stem cells are located in bone marrow, adipose tissue, synovial membrane, and muscular tissue. They have an immunosuppressive, anti-inflammatory, and antifibrotic effect. Tissue engineering considers the usage of mesenchymal stem cells as a possible option for regenerating tissues, with respect to bone and cartilage, due to their ability to differentiate into multiple cytotypes (including chondrocytes and osteoblasts). Herein, we characterize a non-invasive solution based on Rigenera^® technology, a mechanical disaggregation method able to produce autologous adipose tissue-derived micrografts which are analogous to adipose-derived stem cells.

Abstract

Within the adult canine population, disabilities and symptoms including joint pain and functional impairment are commonly observed in articular cartilage lesions and present a challenging feat in the operating room. Clinical settings require less invasive and more minimally manipulated measures facilitated by innovative and advanced technology. Mesenchymal stem cells have recently been proposed and, furthermore, autologous adipose tissue administration via injection has emerged as a new albeit somewhat controversial therapeutic tool. The purpose of this study is to characterize canine autologous micro-fragmented adipose tissue (micrografts) by mechanical approach without substantial manipulations. Adipose tissue samples collected from six dogs were processed by a Rigenera device and by enzymatic digestion from two different body regions (lumbar and thigh region). Interestingly, the immunophenotypic analysis attested that cells from Rigenera^® were highly positive for the mesenchymal stem cells markers CD73 and CD90, less positive for hematopoietic CD45 and CD34, and negative for MHC class II antibodies (which play a role in immune responses). Finally, the Rigenera^® technology obtained micrografts with a 35% higher expression of the IL10 gene with relevant anti-inflammatory activities compared to the enzymatic digestion protocol. This evidence suggests a potential improved clinical outcome capable of modulating inflammation and immune responses.