Comparative analysis of mesenchymal stem cells from bone marrow, umbilical cord blood, or adipose tissue

Engineering functional electroconductive hydrogels for targeted therapy in myocardial infarction repair

Myocardial infarction (MI) is characterized by a paucity of cardiomyocyte regeneration, leading to significant morbidity and mortality. Contemporary therapeutic modalities, while mitigating ischemic effects, fail to reconstitute the impaired electromechanical coupling within the infracted myocardium. Emerging evidence supports the utility of electroconductive hydrogels (ECHs) in facilitating post-MI cardiac function recovery by restoring the conductive microenvironment of the infarcted tissue. This comprehensive review delineates the taxonomy of ECHs predicated on their constituent conductive materials. It also encapsulates prevailing research trends in ECH-mediated MI repair, encompassing innovative design paradigms and microenvironment-sensitive strategies. The review also provides a critical appraisal of various implantation techniques, underscored by a thorough examination of the attendant considerations. It elucidates the mechanistic underpinnings by which hydrogels exert salutary effects on myocardial repair, namely by augmenting mechanical and electrical integrity, exerting anti-inflammatory actions, fostering angiogenesis, and curtailing adverse remodeling processes. Furthermore, the review engages with the pressing challenge of optimizing ECH functionality to achieve superior reparative outcomes post-MI. The discourse concludes with an anticipatory perspective on the evolution of ECH scaffolds, advocating for a tailored approach that integrates multifaceted physicochemical properties to cater to the nuances of personalized medicine.

The revolutionary role of placental derivatives in biomedical research

The human placenta is a transient yet crucial organ that plays a key role in sustaining the relationship between the maternal and fetal organisms. Despite its historical classification as "biowaste," placental tissues have garnered increasing attention since the early 1900s for their significant medical potential, particularly in wound repair and surgical application. As ethical considerations regarding human placental derivatives have largely been assuaged in many countries, they have gained significant attention due to their versatile applications in various biomedical fields, such as biomedical engineering, regenerative medicine, and pharmacology. Moreover, there is a substantial trend toward various animal product substitutions in laboratory research with human placental derivatives, reflecting a broader commitment to advancing ethical and sustainable research methodologies. This review provides a comprehensive examination of the current applications of human placental derivatives, explores the mechanisms behind their therapeutic effects, and outlines the future potential and directions of this rapidly advancing field.

Umbilical cord-derived mesenchymal stem cells secretomes promote embryo development and implantation

AIMS

Successful implantation relies on high-quality blastocysts, uterine receptivity, and effective embryo-endometrium communication. This study investigated the effects of umbilical cord-derived mesenchymal stem cells (UC-MSC) secretomes on embryo development and implantation.

MAIN METHODS

Trophoblastic spheroids and murine embryos were used to evaluate the impact of UC-MSC secretomes. Embryos obtained through superovulation were cultured in vitro and divided into five groups: a control group and four experimental groups treated with varying concentrations of UC-MSC secretomes (2.5, 5, 10, and 50 μg/mL). Embryo development competence and implantation potential were assessed in each group, and the expression levels of related genes were analyzed.

KEY FINDINGS

Supplementation with UC-MSC secretomes significantly enhanced trophoblast cell migration. It also stimulated endometrial cell proliferation and upregulated key implantation-related genes (LIF, LIFR, VEGFA, ITGB3, and ITGAV), improving endometrial receptivity and adhesion in trophoblastic spheroid co-cultures. While morulation rates of murine embryos remained unchanged, UC-MSC secretomes supplement significantly increased blastulation, pluripotency gene expression, and hatching rates. Supplementation with 10 and 50 μg/mL significantly increased blastocyst diameter and blastomere number, as well as embryo adhesion, outgrowth areas, and implantation rates. Additionally, growth factor analysis showed elevated VEGF-A and PDGF-AA levels in the culture media.

SIGNIFICANCE

This study demonstrates that UC-MSC secretomes enhance both embryo development and endometrial cell function, facilitating implantation potential. These findings suggest their potential utility in supporting preimplantation embryos and improving maternal endometrial receptivity in ART.

Determination and validation of design space for mesenchymal stem cell cultivation processes using prediction intervals

In regenerative medicine, mesenchymal stem cells (MSCs) constitute a promising therapeutic route for many diseases. The current quality-by-design guidelines do not clearly define a framework for MSC production. Here, we suggest and experimentally validate a model-based method to determine design spaces (DSs) for MSC cultivation. A kinetic model used in previous work was employed; part of the experimental data was used to re-estimate the maximum specific growth rate in the kinetic model and then calculate the prediction intervals of this parameter. Subsequently, regions of seeding density and harvesting time where both the upper and lower limits of growth predictions met the acceptable number of cells and confluency with given risk levels were defined as DSs. Finally, the established DS was validated with the remaining data; it allowed better predictions of the cell numbers and confluency under specific cultivation conditions and improved the overall robustness of MSC cultivation processes.

Cell-based therapies have disease-modifying effects on osteoarthritis in animal models: A systematic review by the ESSKA Orthobiologic Initiative. Part 3: Umbilical cord, placenta, and other sources for cell-based injectable therapies

PURPOSE

This systematic review aimed to investigate in animal models the presence of disease-modifying effects driven by non-bone marrow-derived and non-adipose-derived products, with a particular focus on umbilical cord and placenta-derived cell-based therapies for the intra-articular injective treatment of osteoarthritis (OA).

METHODS

A systematic review was performed on three electronic databases (PubMed, Web of Science and Embase) according to PRISMA guidelines. The results were synthesised to investigate disease-modifying effects in preclinical animal studies comparing injectable umbilical cord, placenta, and other sources-derived products with OA controls. The risk of bias was assessed using the SYRCLE tool.

RESULTS

A total of 80 studies were included (2314 animals). Cell therapies were most commonly obtained from the umbilical cord in 33 studies and placenta/amniotic tissue in 18. Cell products were xenogeneic in 61 studies and allogeneic in the remaining 19 studies. Overall, 25/27 (92.6%) of studies on umbilical cord-derived products documented better results compared to OA controls in at least one of the following outcomes: macroscopic, histological and/or immunohistochemical findings, with 19/22 of studies (83.4%) show positive results at the cartilage level and 4/6 of studies (66.7%) at the synovial level. Placenta-derived injectable products documented positive results in 13/16 (81.3%) of the studies, 12/15 (80.0%) at the cartilage level, and 2/4 (50.0%) at the synovial level, but 2/16 studies (12.5%) found overall worse results than OA controls. Other sources (embryonic, synovial, peripheral blood, dental pulp, cartilage, meniscus and muscle-derived products) were investigated in fewer preclinical studies. The risk of bias was low in 42% of items, unclear in 49%, and high in 9% of items.

CONCLUSION

Interest in cell-based injectable therapies for OA treatment is soaring, particularly for alternatives to bone marrow and adipose tissue. While expanded umbilical cord mesenchymal stem cells reported auspicious disease-modifying effects in preventing OA progression in animal models, placenta/amniotic tissue also reported deleterious effects on OA joints. Lower evidence has been found for other cellular sources such as embryonic, synovial, peripheral blood, dental-pulp, cartilage, meniscus, and muscle-derived products.

LEVEL OF EVIDENCE

Level II.

Human stromal cell-based protocol to generate astrocytes: a straightforward in vitro predictive strategy in neurotoxicology

The inherent adaptability of human mesenchymal stromal cells (hMSCs) to differentiate into neural lineages provides a valuable resource for investigating potential neurotoxicity in humans. By harnessing the ability of hMSCs to transform into astrocytes, we can evaluate the effects of various agents on these vital cells. Our protocol employs hMSCs sourced from umbilical cord tissue, ensuring a readily available supply of high-quality cells. The hMSC-to-neural workflow encompasses six essential steps: hMSC culture, followed by the generation of embryoid bodies (EBs) from these cells on specialized surfaces. Next, EBs and cells are expanded in a growth-promoting medium, directing them toward neural lineages. Subsequent differentiation into immature astrocytes is achieved through the use of specific factors. The process continues with the maturation of EBs/cells into astrocyte-like cells (hALCs) under optimized conditions, culminating in the final development of hALCs in a specialized medium. This methodology yields cells that display astrocyte morphology and express characteristic markers such as GFAP and S100β. The protocol is efficient, requiring roughly 6 weeks to generate hALCs from primary hMSCs without genetic manipulation. The application of hMSCs in evaluating cell damage triggered by neurotoxicants like MeHg and MGO underscores their potential as a valuable component within a more extensive battery of neurotoxicity tests.

Treatment of osteoarthritic knee with high tibial osteotomy and allogeneic human umbilical cord blood-derived mesenchymal stem cells combined with hyaluronate hydrogel composite

BACKGROUND

Delaying total knee arthroplasty is crucial for middle-aged patients with severe osteoarthritis. The long-term outcomes of high tibial osteotomy (HTO) remain uncertain. Recently, mesenchymal stem cells (MSCs) have shown promising potential in enhancing cartilage regeneration. Therefore, this study aimed to assess cartilage regeneration following the implantation of allogeneic human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) with HTO.

METHODS

In this case series, ten patients underwent hUCB-MSC implantation with HTO. The median age was 58.50 (range: 57.00-60.00) years, and the mean body mass index was 27.81 (range: 24.42-32.24) kg/m2. Clinical outcomes, including the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), visual analog scale (VAS), Physical Component Score (PCS) and Mental Component Score (MCS) from the 36-Item Short-Form Health Survey (SF-36), were evaluated 6 months, 1 year, and 2 years postoperatively. Cartilage status of the medial femoral condyle (MFC) was assessed during hardware removal surgery, at least 2 years after the initial procedure, and compared with preoperative MFC cartilage status regarding lesion size and International Cartilage Repair Society (ICRS) grade. Radiological assessments included the Kellgren-Lawrence (KL) grading system for medial compartment osteoarthritis and hip-knee-ankle (HKA) angle.

RESULTS

Significant improvements were observed in WOMAC scores (preoperative: 57.00 (range: 44.75-63.00), postoperative: 27.50 (range: 22.25-28.75)), VAS scores (preoperative: 66.25 (range: 48.00-74.25), postoperative: 26.25 (range: 14.50-31.13)), SF-36 PCS (preoperative: 27.97 (range: 26.64-31.25), postoperative: 55.31 (range: 51.64-62.50)), and SF-36 MCS (preoperative: 41.04 (range: 29.95-50.96), postoperative: 63.18 (range: 53.83-65.16)) 2 years postoperatively (p = 0.002, 0.002, 0.002, and 0.020, respectively). The MFC chondral lesion demonstrated significant improvement in both lesion size (preoperative: 7.00 cm² (range: 4.38-10.50 cm²), postoperative: 0.16 cm² (range: 0.00-1.75 cm²), p = 0.002) and ICRS grade (preoperative: 4 (range: 4-4), postoperative: 1 (range: 1-2.25), p = 0.002). Additionally, the KL grade significantly decreased from 3 (range: 3-3) preoperatively to 2 (range: 2-2) postoperatively, while the HKA angle was corrected from 7.50° (range: 7.00-10.25°) preoperatively to -1.00° (range: -3.5-0.00°) postoperatively.

CONCLUSIONS

hUCB-MSC implantation with HTO is an effective treatment for medial compartment osteoarthritis and varus deformities, resulting in significant improvements in cartilage regeneration and overall clinical outcomes.

TRIAL REGISTRATION

NCT04234412.

Different temporal dynamics of primary cilia formation and elongation during adipocyte differentiation in umbilical cord- and bone marrow-derived mesenchymal stem cells

Umbilical cord-derived mesenchymal stem cells (UC-MSCs) are considered a promising alternative to bone marrow-derived MSCs (BM-MSCs) due to their high proliferative capacity and non-invasive accessibility. While UC-MSCs exhibit osteogenic, chondrogenic, and myogenic differentiation potential comparable to BM-MSCs, their adipogenic differentiation is significantly delayed. To investigate the underlying mechanisms, we focused on primary cilia, sensory organelles that regulate key adipogenic signaling pathways, including the insulin-Akt axis. Under serum-starved, growth-arrest conditions, both UC-MSCs and BM-MSCs formed primary cilia at similar frequencies and lengths; however, under serum-fed, proliferative conditions, UC-MSCs showed a significantly lower frequency of ciliation. During adipogenesis, BM-MSCs exhibited early ciliogenesis and stable cilium length, whereas UC-MSCs displayed delayed ciliogenesis and developed significantly longer cilia after repeated induction cycles. Despite comparable ciliation frequency and longer cilia in UC-MSCs at later stages, insulin-induced Akt activation was reduced compared to BM-MSCs, suggesting that primary cilia in UC-MSCs may be less efficient in sensing insulin. These alterations in insulin signaling may contribute to the reduced adipogenic capacity observed in UC-MSCs.

Human umbilical cord mesenchymal stem cell-derived exosomal miR-199a-3p inhibits the MAPK4/NF-κB signaling pathway to relieve osteoarthritis

BACKGROUND

There is currently no effective treatment for osteoarthritis (OA), which is the most common joint disorder leading to disability. Although human umbilical cord mesenchymal stem cells (hUC-MSCs) are promising OA treatments, their use is limited by the condition itself, and understanding of the underlying mechanisms of OA is lacking.

AIM

To explore the specific molecular mechanism by which hUC-MSC-derived exosomal miR-199a-3p improves OA.

METHODS

Sodium iodoacetate was injected into rat articulations to construct an animal model of OA. Interleukin (IL)-1β was used to induce human chondrocytes (CHON-001) to construct an OA chondrocyte model. Exosomes in hUC-MSCs were isolated using Ribo™ Exosome Isolation Reagent. Real-time reverse transcriptase-polymerase chain reaction and western blotting were used to detect the expression of related genes and proteins, and damage to CHON-001 cells and rat articular cartilage tissue was evaluated by enzyme-linked immunosorbent assay, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-nick end labelling staining and hematoxylin and eosin staining.

RESULTS

hUC-MSC-derived exosomes (hUC-MSC-Exos) inhibited the expression of IL-1β-induced inflammatory cytokines, namely, IL-6, IL-8 and tumor necrosis factor-α. hUC-MSC-Exos also improved the viability but inhibited the apoptosis of CHON-001 cells, improved the pathological condition of articular cartilage tissue and alleviated the development of OA in vivo. Mechanistically, hUC-MSC-Exos downregulated the expression of mitogen-activated protein kinase 4 by delivering miR-199a-3p, thereby inhibiting the activation of the nuclear factor-kappaB signaling pathway, alleviating IL-1β-induced chondrocyte inflammation and apoptosis, and ultimately improving the development of OA.

CONCLUSION

hUC-MSC-derived exosomal miR-199a-3p alleviates OA by inhibiting the mitogen-activated protein kinase 4/nuclear factor-kappaB signaling pathway. The present findings suggest that miR-199a-3p delivery by hUC-MSC-Exos may be a novel strategy for the treatment of OA.

Puerarin raises exosomal miR- 342 - 3p by inhibiting lncRNA NEAT1 in umbilical cord mesenchymal stem cells to alleviate renal tubular epithelial cell pyroptosis in chronic renal failure

The therapeutic effect of exosomes (Exo) secreted by the Puerarin-treated umbilical cord mesenchymal stem cells (UC-MSC) on chronic renal failure (CRF) was explored. UC-MSC were treated by Puerarin, or transfected by lncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) overexpression vectors, or both. HK-2 cells were treated with LPS/H2O2 to establish the CRF cell model. The CRF rat model was constructed by adenine administration. Exo derived from UC-MSC were used to treat the CRF cell and rat models. The therapeutic effect of the Puerarin-treated UC-MSC-derived Exo on CRF was evaluated by a series of logical tests. NEAT1 had binding sites for miR-342-3p. miR-342-3p in the Puerarin-treated UC-MSC-derived Exo was increased. miR-342-3p in the NEAT1-overexpressed and Puerarin-treated UC-MSC-derived Exo was lower than that in the Puerarin-treated UC-MSC-derived Exo. The CRF cell model treated by the Puerarin-treated UC-MSC-derived Exo expressed higher miR-342-3p, and lower TGF-β1, SMAD2/3, Cleaved-caspase-1, GSDMD-N, IL-1β and IL-18. The relieved renal injury, up-regulated renal miR-342-3p, down-regulated renal TGF-β1, SMAD2/3, Cleaved-caspase-1 and GSDMD-N, and decreased serum creatinine and blood urea nitrogen were found in the CRF rat model treated by the Puerarin-treated UC-MSC-derived Exo. However, compared to the CRF cell and rat models treated by the Puerarin-treated UC-MSC-derived Exo, those treated by the NEAT1-overexpressed and Puerarin-treated UC-MSC-derived Exo showed the opposite results. Puerarin elevates exosomal miR-342-3p by suppressing NEAT1 in UC-MSC, thereby inactivating the TGF-β1/SMAD pathway in renal tubular epithelial cells to alleviate pyroptosis in CRF. The Puerarin-treated UC-MSC-derived Exo may be useful in treating CRF.

A Mathematical Model for Determining Probabilistic Design Space in Mesenchymal Stem Cell Passage Culture

With their many therapeutic functions, mesenchymal stem cells (MSCs) are promising sources for regenerative medicine. However, in the manufacture of MSCs, without a method for exploring the effects of long-term passage on cell proliferation potentials, the design of passage culture processes is challenging. Here, for the process design of the MSC passage culture, we propose a model for predicting the growth rate as a function of the cumulative population doubling level (cPDL) for each passage. Three steps were implemented: (1) passage culture experiments to correlate apparent growth rate with cPDL were conducted, (2) a model for predicting the growth rate as a function of cPDL was developed, and (3) a model to design the passage culture of MSCs from bone marrow (BM-MSCs) and umbilical cord (UC-MSCs) with stochastic simulation was applied. Two design variables (passage number and harvesting time) were investigated to define feasible operation regions as probabilistic design spaces to meet three quality indicators (senescence level, confluency level, and total number of cells) with given probabilities. Consequently, 10 and 62 conditions out of 165 were identified as feasible for BM- and UC-MSCs, respectively, which would contribute to the industrial MSC passage culture process design.

Beyond the Injury: How Does Smoking Impair Stem Cell-Mediated Repair Mechanisms? A Dual Review of Smoking-Induced Stem Cell Damage and Stem Cell-Based Therapeutic Applications

While the literature on molecular and clinical effects of smoking on the lungs and other organs has been expansively reviewed, there is no comprehensive compilation of the effects of smoking on stem cell (SC) populations. Recent research has shown that tobacco exposure severely compromises the function of SC populations, particularly those involved in tissue regeneration: mesenchymal SCs (MSCs), neural progenitors, and hematopoietic SCs. SC-based therapies have emerged as a promising approach to counteract smoking-related damage. In particular, MSCs have been extensively studied for their immunomodulatory properties, demonstrating the ability to repair damaged tissues, reduce inflammation, and slow disease progression in conditions such as chronic obstructive pulmonary disease. Combination therapies, which integrate pharmaceuticals with SC treatments, have shown potential in enhancing regenerative outcomes. This review examines the impact of smoking on SC biology, describes the processes impairing SC-mediated repair mechanisms and highlights recent advancements in SC-based therapies in the treatment of smoking-induced diseases. This review has two prongs: (1) it attempts to explain potential smoking-related disease etiology, and (2) it addresses a gap in the literature on SC-mediated repair mechanisms in chronic smokers.

New mesenchymal stem/stromal cell-based strategies for osteoarthritis treatment: targeting macrophage-mediated inflammation to restore joint homeostasis

Macrophages are pivotal in osteoarthritis (OA) pathogenesis, as their dysregulated polarization can contribute to chronic inflammatory processes. This review explores the molecular and metabolic mechanisms that influence macrophage polarization and identifies potential strategies for OA treatment. Currently, non-surgical treatments for OA focus only on symptom management, and their efficacy is limited; thus, mesenchymal stem/stromal cells (MSCs) have gained attention for their anti-inflammatory and immunomodulatory capabilities. Emerging evidence suggests that small extracellular vesicles (sEVs) derived from MSCs can modulate macrophage function, thus offering potential therapeutic benefits in OA. Additionally, the transfer of mitochondria from MSCs to macrophages has shown promise in enhancing mitochondrial functionality and steering macrophages toward an anti-inflammatory M2-like phenotype. While further research is needed to confirm these findings, MSC-based strategies, including the use of sEVs and mitochondrial transfer, hold great promise for the treatment of OA and other chronic inflammatory diseases.

Adipose-mesenchymal stem cells enhance the formation of auricular cartilage in vitro and in vivo

Patients suffering from microtia have limited treatment options for auricular reconstruction due to donor-site morbidity, complications, and unaesthetic outcome. Therefore, tissue engineering emerged as an alternative therapeutic option. Here, we generated and characterized human auricular cartilage using differentiated human adipose mesenchymal stem cells (hASCs) combined with human auricular chondrocytes. The differentiated hASCs were analysed for their morphology, phenotype, gene, and protein expression of chondrogenic markers, and biochemical composition at different time points in 2D and 3D in vitro. Importantly, we improved conditions for chondrogenic differentiation of hASCs in vitro to enhance their proliferation, survival, and deposition of cartilaginous-matrix proteins. In particular, gene expression analysis revealed an upregulation of cartilage oligomeric matrix protein (COMP) and aggrecan core protein (ACAN) in hASCs using the improved differentiation protocol in vitro. Additionally, we observed that co-seeding of hASCs with chondrocytes in a 1:5 ratio significantly enhanced the de novo auricular cartilage formation in a collagen-I bioink after 8 weeks on immunodeficient rat. In particular, the co-culture resulted in reduced shrinkage, and increased cartilage matrix production as confirmed by GAG deposition in vivo. Our results demonstrate that in co-cultures, hASCs stimulate cartilage formation due to a synergistic effect: hASCs' differentiation into chondrocytes and a trophic effect of hASCs on human auricular chondrocytes. Here we demonstrate the successful use of an hASC-chondrocyte co-culture technique for auricular cartilage tissue engineering in 3D collagen-I bioink. This co-culture approach omits the major drawbacks of traditional cartilage transplantation and thus, represents a fundamental step towards clinical translation.

The influence of cell source on the senescence of human mesenchymal stem/stromal cells

While mesenchymal stem/stromal cells (MSCs) exhibit the ability to self-renew, they are not immortal; they eventually reach a point of irreversible growth cessation and functional deterioration following a limited series of population doublings, referred to as replicative senescence. When evaluated according to the criteria set by the International Society for Cell Therapy (ISCT), MSCs show significant differences in their senescence patterns and other characteristics related to their phenotype and function. These differences are attributed to the source of the MSCs and the conditions in which they are grown. MSCs derived from fetal or adult sources have variations in their genome stability, as well as in the expression and epigenetic profile of the cells, which in turn affects their secretome. Understanding the key factors of MSC senescence based on cell source can help to develop effective strategies for regulating senescence and improving the therapeutic potential.

Coculture of mesenchymal stem cells and macrophage: A narrative review

Stem cell transplantation is a promising treatment for repairing damaged tissues, but challenges like immune rejection and ethical concerns remain. Mesenchymal stem cells (MSCs) offer high differentiation potential and immune regulatory activity, showing promise in treating diseases such as gynecological, neurological, and kidney disorders. With scientific progress, MSC applications are overcoming traditional treatment limitations. In MSCs-macrophage coculture, MSCs transform macrophages into anti-inflammatory M2 macrophages, reducing inflammation, whereas macrophages enhance MSCs osteogenic differentiation. This coculture is vital for immune modulation and tissue repair, with models varying by contact type and dimensional arrangements. Factors such as coculture techniques and cell ratios influence outcomes. Benefits include improved heart function, wound healing, reduced lung inflammation, and accelerated bone repair. Challenges include optimizing coculture conditions. This study reviews the methodologies, factors, and mechanisms of MSC-macrophage coculture, providing a foundation for tissue engineering applications. SIGNIFICANCE STATEMENT: This review underlines the significant role of mesenchymal stem cell-macrophage coculture, providing a foundation for tissue engineering application.

Application and Mechanism of Adipose Tissue-Derived Microvascular Fragments in Tissue Repair and Regeneration

One of the long-standing challenges in the field of tissue repair and regeneration is the rapid establishment of local microvascular circulation and restoration of perfusion at the site of defects or injuries. Recently, adipose tissue-derived microvascular fragments (ad-MVFs) have attracted increasing attention from researchers. Adipose tissue is rich in blood vessels, and significant progress has been made in the extraction and preservation techniques for microvascular fragments within it. Ad-MVFs promote tissue and organ repair and regeneration through three main mechanisms. First, they accelerate rapid and efficient vascularization at the injury site, enabling early vessel perfusion. Second, the stem cell components within ad-MVFs provide a rich source of cells for tissue and organ regeneration. Third, they play a role in immune regulation, facilitating integration with host tissues after implantation. The application methods of ad-MVFs are diverse. They can be directly implanted or pre-cultivated, facilitating their combination with various scaffolds and broadening their application scope. These properties have led to the wide use of ad-MVFs in tissue engineering, with promising prospects. This review demonstrates that ad-MVFs can serve as a reliable and highly feasible unit for tissue regeneration.

Epigenetic mechanisms in stem cell therapies for achilles tendinopathy

Achilles tendinopathy (AT) is a chronic degenerative tendinopathy that affects people's daily lives. Multiple clinical studies have found that current conservative treatments fail to promote quality tendon healing. Recent studies have found that stem cell therapy can target pathophysiological changes in the tendon by replenishing tendon-derived cells, promoting extracellular matrix (ECM) remodeling, and modulating the inflammatory response to improve the microenvironment of Achilles tendon regeneration. And epigenetic modifications play an important role in stem cell fate determination and function. In this review, we provided a brief overview of the biological properties of relevant stem cells. The influence of epigenetic modifications on stem cell proliferation, differentiation, and immune regulatory function in the treatment of AT was also explored. We focused on gene regulatory mechanisms controlled by DNA methylation, histones and non-coding RNAs including microRNAs, circRNAs and long non-coding RNAs. We also discuss the current challenges faced by stem cell therapies in treating AT and their potential solutions. Further research in this area will provide a more comprehensive epigenetic explanation for stem cell therapy for AT, leading to the development of stable, safe and effective stem cell therapies.

Differentiation of Wharton's jelly-derived mesenchymal stromal cells into hepatocyte-like cells using a refined method

BACKGROUND

The production of functional hepatocyte cells in enough quantities is of paramount importance for the replacement of lost hepatocytes. In this investigation, a series of 7-mimic microRNAs was harnessed to induce the differentiation of Wharton's jelly-derived mesenchymal stromal cells (WJ-MSCs) into hepatocyte-like cells (HLC) through the application of two distinct techniques: transfection agents and electroporation. The results were then compared with those of HLCs differentiated through the consumption of chemical compounds.

RESULTS

Different time points (48 h, 72 h, and 96 h), unlike concentrations of mimic miRNAs (100 pM, and 200 pM), and dissimilar combinations of mimic-miRNAs (4-mimic and 7-mimic miRNAs) were selected to assess the stage of differentiated cells through electroporation and lipofection methods. For chemical differentiation, a two-step chemical hepatic differentiation protocol was used (for 21 days). The expression level of eleven key genes that were selected to estimate the stage of produced HLCs by each method were tested at different time points, concentrations and combination of mimic-miRNA. Results demonstrated that the 7-miR-mimics/72 h culture method by electroporation, then the 7-miR-mimics/72 h culture method by lipofection, and finally the chemical differentiation (72 h culture) showed the best result for differentiation. Furthermore, the period in which HLCs are maintained under culture conditions is important, as prolonged culture (more than 72 h) leads to cell loss.

CONCLUSION

In conclusion, the results demonstrated that the 7-miR cocktail delivered by electroporation after 72 h effectively promoted the acquisition of hepatocyte-like characteristics which was evidenced by a significant decrease in the Oct4 stemness factor and an increase in the expression of ALB, TAT, AAT, CYP, G6P and HNF4A.

Isolation and Analysis of Matched Osteoarthritic Cartilage Progenitor Cells and Bone Marrow Mesenchymal Stem Cells

INTRODUCTION

Osteoarthritis (OA) is a chronic degenerative disorder that impacts synovial joints, leading to the degradation of articular cartilage and alterations in bone structure. As the most prevalent type of polyarthritis, its occurrence is increasing, particularly in Western countries. Current treatment options for OA involve various pharmacological therapies and prosthetic devices, which come with numerous limitations. Consequently, there is a growing interest among both patients and health care professionals in biological therapies, particularly the use of stem and progenitor cells for cartilage regeneration.

METHODS

We extract articular cartilage progenitor cells (CPCs) and bone marrow mesenchymal stem cells (MSCs) from the femoral side of the knee joint of OA patients undergoing total knee arthroplasty. To isolate CPCs, digested full-depth chondrocytes from the femoral condyle undergo a fibronectin adhesion assay, while we separate bone marrow MSCs using the Ficoll™ density gradient centrifugation method. We expand both cell types in culture and measure their growth kinetics over 80 days. Additionally, we evaluate proliferation potential and senescence through bromodeoxyuridine incorporation and the senescence-associated β-galactosidase assay, respectively. Further, we analyze the expression of specific MSC markers in articular CPCs and bone marrow MSCs using flow cytometry.  Results: We successfully isolated CPCs and bone marrow MSCs from matched osteoarthritic donors. The isolated CPCs and MSCs exhibit similar morphology and proliferation ability. Moreover, both cell types show positive expression for MSC markers CD-90, CD-105, and CD-166, while expressing low or no levels of CD-34 (a marker for hematopoietic stem cells) and exhibiting tri-lineage differentiation potential.  Conclusion: We successfully isolate CPCs and bone marrow MSCs from the knee joints of osteoarthritic donors. Our findings indicate that both cell types demonstrate comparable morphology and growth kinetics, concurrently marking for classical MSC markers and exhibiting differentiation potential. These results are promising for the field of regenerative medicine. In this study, we outline the isolation of a rare group of matching mesenchymal stem/progenitor cells collected from the articular cartilage and bone marrow of patients undergoing total knee arthroplasty. This discovery lays the groundwork for comparative analyses, in that these cell types are primary candidates for cartilage-based regenerative therapies.

Healing the cornea: Exploring the therapeutic solutions offered by MSCs and MSC-derived EVs

Affecting a large proportion of the population worldwide, corneal disorders constitute a concerning health hazard associated to compromised eyesight or blindness for most severe cases. In the last decades, mesenchymal stem/stromal cells (MSCs) demonstrated promising abilities in improving symptoms associated to corneal diseases or alleviating these affections, especially through their anti-inflammatory, immunomodulatory and pro-regenerative properties. More recently, MSC therapeutic potential was shown to be mediated by the molecules they release, and particularly by their extracellular vesicles (EVs; MSC-EVs). Consequently, using MSC-EVs emerged as a pioneering strategy to mitigate the risks related to cell therapy while providing MSC therapeutic benefits. Despite the promises given by MSC- and MSC-EV-based approaches, many improvements are considered to optimize the therapeutic significance of these therapies. This review aspires to provide a comprehensive and detailed overview of current knowledge on corneal therapies involving MSCs and MSC-EVs, the strategies currently under evaluation, and the gaps remaining to be addressed for clinical implementation. From encapsulating MSCs or their EVs into biomaterials to enhance the ocular retention time to loading MSC-EVs with therapeutic drugs, a wide range of ground-breaking strategies are currently contemplated to lead to the safest and most effective treatments. Promising research initiatives also include diverse gene therapies and the targeting of specific cell types through the modification of the EV surface, paving the way for future therapeutic innovations. As one of the most important challenges, MSC-EV large-scale production strategies are extensively investigated and offer a wide array of possibilities to meet the needs of clinical applications.

Mesenchymal stem cells in hematology: Therapeutic initiatives and future directions

In recent years, the landscape of hematology has undergone rapid transformation, driven by innovative therapeutic strategies harnessing the properties of novel cellular therapies. Mesenchymal stem cells (MSCs) represent one of these promising therapies, with potential applications across a range of hematologic conditions. These cells are notable for their immunomodulatory properties, key role in supporting the hematopoietic micro-environment and capacity for multi-directional differentiation. This review will focus on the biologic mechanisms underlying MSC therapeutic use, current avenues of clinical investigation, and potential challenges and future directions for MSC derived therapies.

State-of the-art and future perspective in co-culture systems for tendon engineering

Tendon is a connective tissue that links bone to muscle, allowing for maintenance of skeleton posture, joint movement, energy storage and transmission of muscle force to bone. Tendon is a hypocellular and hypovascular tissue of poor self-regeneration capacity. Current surgical treatments are of limited success, frequently resulting in reinjury. Upcoming cell therapies are primarily based on tenocytes, a cell population of limited self-renewal capacity in vitro or mesenchymal stromal cells, a cell population prone to ectopic bone formation in vivo. Over the years mono- or multi- factorial cell culture technologies have failed to effectively maintain tenocyte phenotype in culture during expansion or to prime mesenchymal stromal cells towards tenogenic lineage prior to implantation. Upon these limitations the concept of co-culture was conceived. Here, we comprehensively review and discuss tenogenic differentiation of mesenchymal stromal cells through direct or indirect culture with tenocytes in an attempt to generate a tenocyte or a tendon-like cell population for regenerative medicine purposes.

The promise of mesenchymal stromal/stem cells in erectile dysfunction treatment: a review of current insights and future directions

Erectile dysfunction is a common and multifactorial condition that significantly impacts men's quality of life. Traditional treatments, such as phosphodiesterase type 5 inhibitors (PDE5i), often fail to provide lasting benefits, particularly in patients with underlying health conditions. In recent years, regenerative medicine, particularly stem cell therapies, has emerged as a promising alternative for managing erectile dysfunction. This review explores the potential of mesenchymal stromal/stem cells (MSCs) and their paracrine effects, including extracellular vesicles (EVs), in the treatment of erectile dysfunction. MSCs have shown remarkable potential in promoting tissue repair, reducing inflammation, and regenerating smooth muscle cells, offering therapeutic benefits in models of erectile dysfunction. Clinical trials have demonstrated positive outcomes in improving erectile function and other clinical parameters. This review highlights the promise of MSC therapy for erectile dysfunction, discusses existing challenges, and emphasizes the need for continued research to refine these therapies and improve long-term patient outcomes.

Clinical research progress of umbilical cord blood mesenchymal stem cells in Knee articular cartilage repair: A review

Umbilical cord blood mesenchymal stem cells (UCB-MSCs) are a type of adult stem cell with multipotent differentiation potential and immunoregulatory functions, primarily found in neonatal cord blood. Due to their noninvasive collection method, abundance, and ease of preservation, UCB-MSCs represent a promising biological material. This review examines the clinical research on UCB-MSCs in knee articular cartilage repair, highlighting their regenerative potential for treating knee joint cartilage defects. Our aim is to provide insights into current applications and propose directions for future research, focusing on optimizing clinical use and enhancing patient outcomes.

Immune Evasion in Stem Cell-Based Diabetes Therapy-Current Strategies and Their Application in Clinical Trials

Background/Objectives: Human pancreatic islet transplantation shows promise for long-term glycemic control in diabetes patients. A shortage of healthy donors and the need for continuous immunosuppressive therapy complicates this. Enhancing our understanding of the immune tolerance mechanisms related to graft rejection is crucial to generate safer transplantation strategies. This review will examine advancements in immune protection strategies for stem cell-derived islet therapy and discuss key clinical trials involving stem cell-derived β-cells and their protective strategies against the host immune system. Methods: A comprehensive literature search was performed on peer-reviewed publications on Google Scholar, Pubmed, and Scopus up to September 2024 to extract relevant studies on the various strategies of immune evasion of stem cell-derived β-cells in humans. The literature search was extended to assimilate all relevant clinical studies wherein stem cell-derived β-cells are transplanted to treat diabetes. Results: Our analysis highlighted the importance of human pluripotent stem cells (hPSCs) as a potentially unlimited source of insulin-producing β-cells. These cells can be transplanted as an effective source of insulin in diabetes patients if they can be protected against the host immune system. Various strategies of immune protection, such as encapsulation and genetic manipulation, are currently being studied and clinically tested. Conclusions: Investigating immune tolerance in hPSC-derived islets may help achieve a cure for diabetes without relying on exogenous insulin. Although reports of clinical trials show promise in reducing insulin dependency in patients, their safety and efficacy needs to be further studied to promote their use as a long-term solution to cure diabetes.

Mesenchymal stem cells and their extracellular vesicle therapy for neurological disorders: traumatic brain injury and beyond

Traumatic brain injury (TBI) is a complex condition involving mechanisms that lead to brain dysfunction and nerve damage, resulting in significant morbidity and mortality globally. Affecting ~50 million people annually, TBI's impact includes a high death rate, exceeding that of heart disease and cancer. Complications arising from TBI encompass concussion, cerebral hemorrhage, tumors, encephalitis, delayed apoptosis, and necrosis. Current treatment methods, such as pharmacotherapy with dihydropyridines, high-pressure oxygen therapy, behavioral therapy, and non-invasive brain stimulation, have shown limited efficacy. A comprehensive understanding of vascular components is essential for developing new treatments to improve blood vessel-related brain damage. Recently, mesenchymal stem cells (MSCs) have shown promising results in repairing and mitigating brain damage. Studies indicate that MSCs can promote neurogenesis and angiogenesis through various mechanisms, including releasing bioactive molecules and extracellular vesicles (EVs), which help reduce neuroinflammation. In research, the distinctive characteristics of MSCs have positioned them as highly desirable cell sources. Extensive investigations have been conducted on the regulatory properties of MSCs and their manipulation, tagging, and transportation techniques for brain-related applications. This review explores the progress and prospects of MSC therapy in TBI, focusing on mechanisms of action, therapeutic benefits, and the challenges and potential limitations of using MSCs in treating neurological disorders.

Harnessing the Anti-Inflammatory Effects of Perinatal Tissue Derived Therapies for the Treatment of Inflammatory Skin Diseases: A Comprehensive Review

Dealing with chronic inflammatory skin conditions like atopic dermatitis and psoriasis can be extremely difficult. Current treatments, such as topical corticosteroids, often have limitations and side effects. However, researchers have discovered that the placenta's remarkable properties may provide a breakthrough in effectively addressing these skin conditions. The placenta comprises three essential tissues: decidua, placental membrane, and umbilical cord. Placental derivatives have shown significant potential in treating psoriasis by reducing inflammatory cytokines and inhibiting keratinocyte proliferation. In the case of atopic dermatitis, umbilical cord stem cells have demonstrated anti-inflammatory effects by targeting critical factors and promoting anti-inflammatory cytokines. The scope of benefits associated with placental derivatives transcends these specific applications. They also potentially address other inflammatory skin diseases, such as vitiligo, by stimulating melanin production. Moreover, these derivatives have been leveraged in the treatment of pemphigus and epidermolysis bullosa (EB), showcasing potential as a wound dressing that could eliminate the necessity for painful dressing changes in EB patients. In summary, the integration of placental derivatives stands to revolutionize our approach to inflammatory skin conditions owing to their distinct properties and the prospective benefits they offer. This comprehensive review delves into the current applications of placental derivatives in addressing inflammatory skin diseases, presenting a novel treatment approach.

Adipose Tissue and Bone Marrow-Derived Mesenchymal Stem Cells are not Really the Same: Investigating the Differences in Their Immunomodulatory, Migratory, and Adhesive Profile

Mesenchymal stem cells (MSCs) are the most widely used stem cells in regenerative medicine. They can be isolated from multiple sources, most commonly bone marrow and adipose tissue. MSCs derived from different sources show similar molecular and biological characteristics, but there is ongoing debate regarding the best source of MSCs and the potential biological differences between MSCs from different origins. Bone marrow derived-MSCs (BM-MSCs) and adipose tissue-derived MSCs (AD-MSCs) share many molecular and immunomodulatory properties. In this study, we compared the levels of major immunomodulatory, adhesive, and migratory factors in human BM-MSCs and AD-MSCs under normal conditions, which will help determine the suitability and specificity of each type for certain therapeutic applications. WST1 assay and fluorescent assay SUC-LLVY-AMC were used to measure MSC proliferation and 26S proteasome activity, respectively. Western blotting, ELISA Assays, and bright field live imaging were also used. AD-MSCs and BM-MSCs exhibited similar morphology and proliferation rate. A significantly higher 26S proteasome activity was detected in AD-MSCs than in BM-MSCs. Levels of ICAM-1, integrin α5 and integrin α6 were significantly higher in AD-MSCs compared to BM-MSCs, while no significant difference in CXCR4 levels was observed. Expression of IDO and factor H was significantly higher in AD-MSCs, while CTLA-4 and IL-10 levels were higher in BM-MSCs. This indicates that AD-MSCs and BM-MSCs have different immunomodulatory and adhesion profiles. MSCs isolated from different sources may show differences in their biological and immunomodulatory properties, suggesting a potential suitability of certain MSCs type for specific conditions. Also, combination of different MSCs types could help optimize therapeutic outcomes.

CRISPR-dCas9 Activation of TSG-6 in MSCs Modulates the Cargo of MSC-Derived Extracellular Vesicles and Attenuates Inflammatory Responses in Human Intervertebral Disc Cells In Vitro

Purpose

The purpose of this study was to boost the therapeutic effect of mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs) by overexpressing the gene TSG-6 through CRISPR activation, and assess the biological activity of EVs from these modified MSCs in vitro on human intervertebral disc (IVD) cells.

Methods

An immortalized human MSC line was transduced with a CRISPR activation lentivirus system targeting TSG-6. MSC-EVs were harvested by ultracentrifugation and particle number/size distribution was determined by nanoparticle tracking analysis. The efficiency of transduction activation was assessed by analyzing gene and protein expression. EV proteomic contents were analyzed by mass spectrometry. Human IVD cells from patients undergoing spinal surgery were isolated, expanded, exposed to IL-1β pre-stimulation and co-treated with MSC-EVs.

Results

MSC-EVs presented size distribution, morphology, and molecular markers consistent with common EV characteristics. The expression level of TSG-6 was significantly higher (> 800 fold) in transduced MSCs relative to controls. Protein analysis of MSCs and EVs showed higher protein expression of TSG-6 in CRISPR activated samples than controls. Proteomics of EVs identified 35 proteins (including TSG-6) that were differentially expressed in TSG-6 activated EVs vs control EVs. EV co-Treatment of IL-1β pre-Stimulated IVD cells resulted in a significant downregulation of IL-8 and COX-2.

Conclusions

We successfully generated an MSC line overexpressing TSG-6. Furthermore, we show that EVs isolated from these modified MSCs have the potential to attenuate the pro-inflammatory gene expression in IVD cells. This genomic engineering approach hence holds promise for boosting the therapeutic effects of EVs.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12195-025-00843-4.

Automated Manufacturing Processes and Platforms for Large-scale Production of Clinical-grade Mesenchymal Stem/ Stromal Cells

Mesenchymal stem/stromal cells (MSCs) hold immense potential for regenerative medicine due to their remarkable regenerative and immunomodulatory properties. However, their therapeutic application requires large-scale production under stringent regulatory standards and Good Manufacturing Practice (GMP) guidelines, presenting significant challenges. This review comprehensively evaluates automated manufacturing processes and platforms for the scalable production of clinical-grade MSCs. Various large-scale culture vessels, including multilayer flasks and bioreactors, are analyzed for their efficacy in MSCs expansion. Furthermore, automated MSCs production platforms, such as Quantum® Cell Expansion System, CliniMACS Prodigy®, NANT001/ XL, CellQualia™, Cocoon® Platform, and Xuri™ Cell Expansion System W25 are reviewed and compared as well. We also underscore the importance of optimizing culture media specifically emphasizing the shift from fetal bovine serum to humanized or serum-free alternatives to meet GMP standards. Moreover, advances in alternative cryopreservation methods and controlled-rate freezing systems, that offer promising improvements in MSCs preservation, are discussed as well. In conclusion, advancing automated manufacturing processes and platforms is essential for realizing the full potential of MSCs-based regenerative medicine and accomplishing the increasing demand for cell-based therapies. Collaborative initiatives involving industry, academia, and regulatory bodies are emphasized to accelerate the translation of MSCs-based therapies into clinical practice.

Cell therapy: A beacon of hope in the battle against pulmonary fibrosis

Pulmonary fibrosis (PF) is a chronic and progressive interstitial lung disease characterized by abnormal activation of myofibroblasts and pathological remodeling of the extracellular matrix, with a poor prognosis and limited treatment options. Lung transplantation is currently the only approach that can extend the life expectancy of patients; however, its applicability is severely restricted due to donor shortages and patient-specific limitations. Therefore, the search for novel therapeutic strategies is imperative. In recent years, stem cells have shown great promise in the field of regenerative medicine due to their self-renewal capacity and multidirectional differentiation potential, and a growing body of literature supports the efficacy of stem cell therapy in PF treatment. This paper systematically summarizes the research progress of various stem cell types in the treatment of PF. Furthermore, it discusses the primary methods and clinical outcomes of stem cell therapy in PF, based on both preclinical and clinical data. Finally, the current challenges and key factors to consider in stem cell therapy for PF are objectively analyzed, and future directions for improving this therapy are proposed, providing new insights and references for the clinical treatment of PF patients.

hUC-MSC preserves erectile function by restoring mitochondrial mass of penile smooth muscle cells in a rat model of cavernous nerve injury via SIRT1/PGC-1a/TFAM signaling

BACKGROUND

Cavernous nerve injury-induced erectile dysfunction (CNI-ED) is a common complication following radical prostatectomy and severely affects patients' quality of life. The mitochondrial impairment in corpus cavernosum smooth muscle cells (CCSMCs) may be an important pathological mechanism of CNI-ED. Previous studies have shown that transplantation of human adipose derived stem cells (ADSC) can alleviate CNI-ED in a rat model. However, little is known about the effect of human umbilical cord mesenchymal stem cells (hUC-MSC) on CNI-ED. It remains unclear whether hUC-MSC can ameliorate mitochondrial damage in CCSMCs. In this study, we aimed to investigate the impacts of hUC-MSC on the mitochondrial mass and function of CCSMCs, as well as elucidate its underlying molecular mechanism.

METHODS

The CNI-ED rat model was established by bilaterally crushing cavernous nerves. Subsequently, hUC-MSC were transplanted into the cavernosum and ADSC were injected as a positive control group. Erectile function evaluation and histological detection were performed 4 weeks after cell transplantation. In vitro, CCSMCs underwent hypoxia and were then co-cultured with ADSC or hUC-MSC using a transwell system. The mitochondrial mass and function, as well as signaling pathways, were investigated. To explore the role of the SIRT1/PGC-1α/TFAM pathway in regulating mitochondrial biogenesis of CCSMCs, we knocked down SIRT1 by siRNA.

RESULTS

The administration of hUC-MSC significantly improved erectile function of CNI-ED rats and reduced the ratio of collagen to smooth muscle. Specifically, hUC-MSC treatment restored mitochondrial mass and function in CCSMCs injured by CNI or hypoxia, and inhibited the apoptosis of CCSMCs. Mechanistically, the application of hUC-MSC activated SIRT1/PGC-1α/TFAM pathway both in rat penile tissues and CCSMCs. In addition, knockdown of SIRT1 in CCSMCs abolished the protective effects of hUC-MSC on mitochondrial mass and function, while leading to an increase in cellular apoptosis.

CONCLUSIONS

hUC-MSC contribute to the recovery of erectile function in CNI-ED rats by restoring mitochondrial mass and function of CCSMCs through the SIRT1/PGC-1α/TFAM pathway. Our present study offers new insights into the role and molecular mechanisms of hUC-MSC in regulating mitochondrial homeostasis, thereby facilitating the restoration of the erectile function in CNI-ED.

Regional Gene Therapy for Bone Tissue Engineering: A Current Concepts Review

The management of segmental bone defects presents a complex reconstruction challenge for orthopedic surgeons. Current treatment options are limited by efficacy across the spectrum of injury, morbidity, and cost. Regional gene therapy is a promising tissue engineering strategy for bone repair, as it allows for local implantation of nucleic acids or genetically modified cells to direct specific protein expression. In cell-based gene therapy approaches, a variety of different cell types have been described including mesenchymal stem cells (MSCs) derived from multiple sources-bone marrow, adipose, skeletal muscle, and umbilical cord tissue, among others. MSCs, in particular, have been well studied, as they serve as a source of osteoprogenitor cells in addition to providing a vehicle for transgene delivery. Furthermore, MSCs possess immunomodulatory properties, which may support the development of an allogeneic "off-the-shelf" gene therapy product. Identifying an optimal cell type is paramount to the successful clinical translation of cell-based gene therapy approaches. Here, we review current strategies for the management of segmental bone loss in orthopedic surgery, including bone grafting, bone graft substitutes, and operative techniques. We also highlight regional gene therapy as a tissue engineering strategy for bone repair, with a focus on cell types and cell sources suitable for this application.

Stromal vascular fraction: Mechanisms and application in reproductive disorders

Stromal vascular fraction (SVF) is a complex mixture derived from adipose tissue, consisting of a variety of cells. Due to its potential for tissue repair, immunomodulation, and support of angiogenesis, SVF represents a promising frontier in regenerative medicine and offers potential therapy for a range of disease conditions. In this article, we delve into the mechanisms through which SVF exerts its effects and explore its potential applications in treating both male and female reproductive disorders, including erectile dysfunction, testicular injury, stress urinary incontinence and intrauterine adhesion.

Management of knee osteoarthritis using bone marrow aspirate concentrate: a systematic review

INTRODUCTION

Knee osteoarthritis (OA) is a common degenerative joint condition and a major cause of disability in the general population.

SOURCE OF DATA

Recent published literature identified from PubMed, EMBASE, Google Scholar, and Scopus.

AREAS OF AGREEMENT

Orthobiological therapies try to regenerate articular cartilage and stop the progression of the degenerative lesion. Intra-articular injections of biological derivates have been increasingly used in the last decade.

AREAS OF CONTROVERSY

The indications for the use of bone marrow aspirate concentrate (BMAC) are still unclear.

GROWING POINTS

We systematically reviewed the current literature on BMAC in the management of knee OA, giving an update on the current indications for the selection of the ideal patient and the preparations and efficacy of BMAC compared to other biological alternatives.

AREAS TIMELY FOR DEVELOPING RESEARCH

BMAC is a valuable source of mesenchymal stem cells, offering potential benefits in attenuating the inflammatory pathway associated with knee OA. Intra-articular injection of BMAC has shown effectiveness in clinical trials improving functional outcomes of knee OA patients. The superiority of BMAC over other orthobiological treatments cannot be assessed because of conflicting results.

Assessment of Umbilical Cord Mesenchymal Stem Cell Cultivation Using Fetal Bovine Serum or Platelet Lysate

BACKGROUND

Wharton's jelly (WJ) and umbilical cord blood (UCB) are considered marvelous sources of mesenchymal stem cells (MSCs) due to their availability, simply isolated without pain and ethical issues. Additionally, UC-MSCs are more primitive than MSCs isolated from adult sources, thus opening new possibilities for cell therapies.

OBJECTIVE

In this study, we aimed to develop a simple, economical, and efficient xenogenic-free protocol for the isolation and expansion of UC-MSCs to be compliant with good manufacturing practice (GMP) guidelines.

METHODS/DESIGN

In this work, we used the explant-partial enzymatic digestion technique for WJ-MSCs and Ficoll-Paque density centrifugation for CB-MSC isolation. Human platelet lysate (HPL) was used as a replacement for fetal bovine serum (FBS), which is used in most protocols.

RESULTS

We observed that the explants-partial enzymatic digestion technique is an effective protocol for MSC isolation from WJ, and HPL is a safe, powerful, and cost-effective substitute for FBS in the MSC propagation. Among all tested conditions, 10% HPL demonstrated the best growth rate, highest viability count, and highest expression level of a cluster of differentiation markers (CD).

CONCLUSION

We concluded that WJ-MSCs are superior to UCB-MSCs in the matter of rapidity and homogeneity, and both of them expressed MSC-positive markers CD44 and CD73, suggesting that WJ is a source with greater potential for MSC isolation for clinical application.

Advances in tissue engineering of peripheral nerve and tissue innervation - a systematic review

Although various options are available to treat injured organs and peripheral nerves, none is without limitations. Auto- and allografts are the first choice of treatment, but tissue survival or functionality is not guaranteed due to often limited vascular and neural networks. In response, tissue-engineered solutions have been developed, yet clinical translations is rare. In this study, a systematic review was performed on tissue-engineered advancements for peripheral nerves and tissues, to aid future developments in bridging the gap toward the clinic by identifying high-potential solutions and unexplored areas. A systematic search was performed in PubMed, Embase, Web of Science, and Scopus until November 9, 2023. Search terms involved "tissue engineering," "guided," "tissue scaffold," and "tissue graft," together with "innervation" and "reinnervation." Original in vivo or in vitro studies meeting the inclusion criteria (tissue-engineered peripheral nerve/innervation of tissue) and no exclusion criteria (no full text available; written in foreign language; nonoriginal article; tissue-engineering of central nervous system; publication before 2012; insufficient study quality or reproducibility) were assessed. A total of 68 out of 3626 original studies were included. Data extraction was based on disease model, cell origin and host species, biomaterial nature and composition, and external stimuli of biological, chemical or physical origin. Although tissue engineering is still in its infancy, explored innervation strategies of today were highlighted with respect to biomaterials, cell types, and external stimuli. The findings emphasize that natural biomaterials, pre-seeding with autologous cell sources, and solutions for reproductive organs are beneficial for future research. Natural biomaterials possess important cues required for cell-material interaction and closely resemble native tissue in terms of biomechanical, geometrical and chemical composition. Autologous cells induce biomaterial functionalization. As these solutions pose no risk of immunorejection and have demonstrated good outcomes, they are most likely to fulfill the clinical demands.

Harnessing the ubiquitin proteasome system as a key player in stem cell biology

Intracellular proteins take part in almost every body function; thus, protein homeostasis is of utmost importance. The ubiquitin proteasome system (UPS) has a fundamental role in protein homeostasis. Its main role is to selectively eradicate impaired or misfolded proteins, thus halting any damage that could arise from the accumulation of these malfunctioning proteins. Proteasomes have a critical role in controlling protein homeostasis in all cell types, including stem cells. We will discuss the role of UPS enzymes as well as the 26S proteasome complex in stem cell biology from several angles. First, we shall overview common trends of proteasomal activity and gene expression of different proteasomal subunits and UPS enzymes upon passaging and differentiation of stem cells toward various cell lineages. Second, we shall explore the effect of modulating proteasomal activity in stem cells and navigate through the interrelation between proteasomes' activity and various proteasome-related transcription factors. Third, we will shed light on curated microRNAs and long non-coding RNAs using various bioinformatics tools that might have a possible role in regulating UPS in stem cells and possibly, upon manipulation, can enhance the differentiation process into different lineages and/or delay senescence upon cell passaging. This will help to decipher the role played by individual UPS enzymes and subunits as well as various interrelated molecular mediators in stem cells' maintenance and/or differentiation and open new avenues in stem cell research. This can ultimately provide a leap toward developing novel therapeutic interventions related to proteasome dysregulation.

Trehalose Cryopreservation of Human Mesenchymal Stem Cells from Cord Tissue

Adequate hypothermic storage of human mesenchymal stem cells (hMSCs) is of fundamental importance since they have been explored in several regenerative medicine initiatives. However, the actual clinical application of hMSCs necessitates hypothermic storage for long periods, a process that requires the use of non-toxic and efficient cryo-reagents capable of maintaining high viability and differentiating properties after thawing. Current cryopreservation methods are based on cryoprotectant agents (CPAs) containing dimethylsulphoxide (DMSO), which have been shown to be toxic for clinical applications. In this study, we describe a simple and effective trehalose (TRE)-based solution to cryo-store human umbilical cord-derived MSCs (UC-MSCs) in liquid nitrogen. Cells viability, identity, chromosomal stability, proliferative and migration capacity, and stress response were assessed after cryopreservation in TRE as CPA, testing different concentrations by itself or in combination with ethylene glycol (EG). Here we show that TRE-stored UC-MSCs provided lower cell recovery rates compared with DMSO-based solution, but maintained good functional properties, stability, and differentiating potential. The best cell recovery was obtained using 0.5 M TRE with 10% EG showing no differences in the osteogenic, adipogenic, and chondrogenic differentiation capacity. A second cycle of cryopreservation in this TRE-based solution had no additional impact on the viability and morphology, although slightly affected cell migration. Furthermore, the expression of the stress-related genes, HSPA1A, SOD2, TP53, BCL-2, and BAX, did not show a higher response in UC-MSCs cryopreserved in 0.5 M TRE + 10% EG compared with DMSO. Together these results, in addition to ascertained therapeutic properties of TRE, provide sufficient evidence to consider TRE-based medium as a low-cost and efficient solution for the storage of human UC-MSCs cells and potentially substitute DMSO-based cryo-reagents.

Adipose-Derived Mesenchymal Stem Cells (ADSCs) Have Anti-Fibrotic Effects on Lung Fibroblasts from Idiopathic Pulmonary Fibrosis (IPF) Patients

Idiopathic pulmonary fibrosis (IPF) is the most common type of fibrosis in lungs, characterized as a chronic and progressive interstitial lung disease involving pathological findings of fibrosis with a median survival of 3 years. Despite the knowledge accumulated regarding IPF from basic and clinical research, an effective medical therapy for the condition remains to be established. Thus, it is necessary for further research, including stem cell therapy, which will provide new insights into and expectations for IPF treatment. Recently, it has been reported that one of the new therapeutic candidates for IPF is adipose-derived mesenchymal stem cells (ADSCs), which have several benefits, such as easy accessibility and minimal morbidity compared to bone marrow-derived mesenchymal stem cells. Therefore, we investigated the possibility of ADSCs as a therapeutic candidate for IPF. Using human lung fibroblasts (LFs) from IPF patients, we demonstrated that human IPF LFs cocultured with ADSCs led to reduced fibrosis-related genes. Further analysis revealed that ADSCs prevented the activation of the ERK signaling pathway in IPF LFs via the upregulation of protein tyrosine phosphatase receptor-type R (PTPRR), which negatively regulates the ERK signaling pathway. Moreover, we demonstrated that intravascular administration of ADSCs improved the pathogenesis of bleomycin-induced pulmonary fibrosis with reduced collagen deposition in histology and hydroxyproline quantification and collagen markers such as the gene expression of types I and III collagen and α-smooth muscle actin (α-SMA) in a murine model. ADSC transfer was also investigated in a humanized mouse model of lung fibrosis induced via the infusion of human IPF LFs, because the bleomycin installation model does not fully recapitulate the pathogenesis of IPF. Using the humanized mouse model, we found that intravascular administration of ADSCs also improved fibrotic changes in the lungs. These findings suggest that ADSCs are a promising therapeutic candidate for IPF.

Prognostic Factors for Clinical Outcome and Cartilage Regeneration after Implantation of Allogeneic Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells in Large-Sized Cartilage Defects with Osteoarthritis

OBJECTIVE

To analyze the prognostic factors for clinical outcomes and cartilage regeneration after the implantation of allogeneic human umbilical cord blood mesenchymal stem cell (hUCB-MSC) for treating large-sized cartilage defects with osteoarthritis.

DESIGN

This study is a case-series with multiple subgroup analyses that divides the included patients into multiple subgroups based on various factors. Overall, 47 patients who underwent hUCB-MSC implantation were included. The patient-reported outcomes, magnetic resonance imaging (MRI), and second-look arthroscopy were used to assess the outcomes.

RESULTS

Combined realignment surgery significantly correlated with clinical outcomes, particularly pain. No other factors significantly influenced the clinical outcomes in short-term period. Subgroups with large defect sizes or meniscal insufficiency showed significantly poor MRI and arthroscopy outcomes (MRI, P = 0.001, P = 0.001; arthroscopy, P = 0.032, P = 0.042). The logistic regression showed that patients with a 1 cm2 larger defect size were 1.91 times less likely to achieve favorable MRI outcomes (P = 0.017; odds ratio [OR], 1.91). Cut-off value to predict the poor outcome was >5.7 cm2 (area under the curve, 0.756). A cartilage defect size >5.7 cm2 was the major poor prognostic factor for cartilage regeneration on MRI (P = 0.010; OR, 17.46). If the postoperative alignment shifted by 1° opposite to the cartilage defect, it was 1.4 times more likely to achieve favorable MRI outcomes (P = 0.028; OR, 1.4).

CONCLUSION

Combining realignment surgery showed a better prognosis for pain improvement. Cartilage defect size, meniscal function, and postoperative alignment are significant prognostic factors for cartilage regeneration. A cartilage defect size >5.7 cm2 was significantly related to poor cartilage regeneration.

Mesenchymal stem cells-derived exosomes alleviate liver fibrosis by targeting Hedgehog/SMO signaling

BACKGROUND & AIMS

Despite increasing knowledge regarding the cellular and molecular mechanisms of liver fibrogenesis, there is currently no approved drug for the treatment of liver fibrosis. Mesenchymal stem cells (MSCs) are multipotent progenitor cells representing an attractive therapeutic tool for tissue damage and inflammation. This study was designed to determine the protective effect and underlying mechanism of human umbilical cord-derived MSCs (UC-MSCs) on thioacetamide-induced liver fibrosis.

METHODS

Liver fibrosis was induced in mice by intraperitoneal injection of thioacetamide (TAA). Some mice were then given injection of UC-MSCs or UC-MSCs-derived exosomes (UC-MSCs-Exo) via the tail vein. Liver tissues were collected for histologic analysis.

RESULTS

We found that administration of UC-MSCs significantly reduced serum alanine aminotransferase and aspartate aminotransferase levels, and attenuated hepatic inflammation and fibrosis. Moreover, the therapeutic effect of UC-MSCs-derived exosomes was similar to that of UC-MSCs. Intriguingly, UC-MSCs-Exo treatment downregulated the expression of smoothened (SMO), a fundamental component of Hedgehog signaling which plays a critical role in fibrogenesis, and subsequently inhibited the activation of hepatic stellate cells, a central driver of fibrosis in experimental and human liver injury. Furthermore, the anti-inflammatory and anti-fibrotic effects of UCMSCs- Exo was reversed by the SMO agonist SAG treatment in mice.

CONCLUSION

Our findings suggest that UC-MSCs-Exo exert therapeutic effects on liver fibrosis, at least in part, through inhibiting the Hedgehog/SMO signaling pathway.

Amniotic fluid-derived mesenchymal stem cells reduce inflammation and improve lung function following transplantation in a porcine model

BACKGROUND

Lung transplantation is hindered by low donor lung utilization rates. Infectious complications are reasons to decline donor grafts due to fear of post-transplant primary graft dysfunction. Mesenchymal stem cells are a promising therapy currently investigated in treating lung injury. Full-term amniotic fluid-derived lung-specific mesenchymal stem cell treatment may regenerate damaged lungs. These cells have previously demonstrated inflammatory mediation in other respiratory diseases, and we hypothesized that treatment would improve donor lung quality and postoperative outcomes.

METHODS

In a transplantation model, donor pigs were stratified to either the treated or the nontreated group. Acute respiratory distress syndrome was induced in donor pigs and harvested lungs were placed on ex vivo lung perfusion (EVLP) before transplantation. Treatment consisted of 3 doses of 2 × 106 cells/kg: one during EVLP and 2 after transplantation. Donors and recipients were assessed on clinically relevant parameters and recipients were followed for 3 days before evaluation for primary graft dysfunction (PGD).

RESULTS

Repeated injection of the cell treatment showed reductions in inflammation seen through lowered immune cell counts, reduced histology signs of inflammation, and decreased cytokines in the plasma and bronchoalveolar lavage fluid. Treated recipients showed improved pulmonary function, including increased PaO2/FiO2 ratios and reduced incidence of PGD.

CONCLUSIONS

Repeated injection of lung-specific cell treatment during EVLP and post transplant was associated with improved function of previously damaged lungs. Cell treatment may be considered as a potential therapy to increase the number of lungs available for transplantation and the improvement of postoperative outcomes.

Recent Strategies and Advances in Hydrogel-Based Delivery Platforms for Bone Regeneration

Bioactive molecules have shown great promise for effectively regulating various bone formation processes, rendering them attractive therapeutics for bone regeneration. However, the widespread application of bioactive molecules is limited by their low accumulation and short half-lives in vivo. Hydrogels have emerged as ideal carriers to address these challenges, offering the potential to prolong retention times at lesion sites, extend half-lives in vivo and mitigate side effects, avoid burst release, and promote adsorption under physiological conditions. This review systematically summarizes the recent advances in the development of bioactive molecule-loaded hydrogels for bone regeneration, encompassing applications in cranial defect repair, femoral defect repair, periodontal bone regeneration, and bone regeneration with underlying diseases. Additionally, this review discusses the current strategies aimed at improving the release profiles of bioactive molecules through stimuli-responsive delivery, carrier-assisted delivery, and sequential delivery. Finally, this review elucidates the existing challenges and future directions of hydrogel encapsulated bioactive molecules in the field of bone regeneration.

Strategies to engineer articular cartilage with biomimetic zonal features: a review

Articular cartilage (AC) is a highly specialized tissue with restricted ability for self-regeneration, given its avascular and acellular nature. Although a considerable number of surgical treatments is available for the repair, reconstruction, and regeneration of AC defects, most of them do not prioritize the development of engineered cartilage with zonal stratification derived from biomimetic biochemical, biomechanical and topographic cues. In the absence of these zonal elements, engineered cartilage will exhibit increased susceptibility to failure and will neither be able to withstand the mechanical loading to which AC is subjected nor will it integrate well with the surrounding tissue. In this regard, new breakthroughs in the development of hierarchical stratified engineered cartilage are highly sought after. Initially, this review provides a comprehensive analysis of the composition and zonal organization of AC, aiming to enhance our understanding of the significance of the structure of AC for its function. Next, we direct our attention towards the existing in vitro and in vivo studies that introduce zonal elements in engineered cartilage to elicit appropriate AC regeneration by employing tissue engineering strategies. Finally, the advantages, challenges, and future perspectives of these approaches are presented.

Hypoxia-Treated Adipose Mesenchymal Stem Cells Derived Exosomes Enhance the Therapeutic Effects on Unilateral Ureteral Obstruction Mice

INTRODUCTION

The exosomes from adipose-derived mesenchymal stem cells (AMSCs) had therapeutic effects. However, whether the exosomes derived from hypoxia-treated AMSCs could improve renal functions in unilateral ureteral obstruction (UUO) mice remains unclear.

METHODS

The exosomes were characterized using a transmission electron microscope and Western blot. Its size distribution was determined using the Zetasizer Nano ZS analysis system. The differentiation ability was assessed by alkaline phosphatase and oil red staining. Consequently, the function of exosomes in inhibiting inflammatory factors was evaluated using an enzyme-linked immunosorbent assay, and apoptosis inhibition was evaluated by Western blot. Finally, the function of exosomes to ameliorate kidney fibrosis was evaluated using quantitative reverse transcription polymerase chain reaction, Western blot, hematoxylin-eosin staining, and Masson staining.

RESULTS

The cultured AMSCs could differentiate into osteoblast and adipocyte. Meanwhile, the cultured AMSCs could effectively secrete the exosomes, which were characterized by around 110 nm diameter and surface marker expression. Exosomes derived from hypoxia-treated AMSCs improved renal functions in UUO mice. The mechanism exploration revealed that exosomes could decrease the TNF-α and IL-6 and inhibit cell apoptosis. Finally, the fibrosis-associated protein was reversed, and the renal dysfunctions were ameliorated in UUO mice.

CONCLUSION

The exosomes derived from the hypoxia-treated AMSCs have a better effect than those from normal AMSCs in ameliorating renal dysfunctions in UUO mice.

Prolonged cultivation enhances the stimulatory activity of hiPSC mesenchymal progenitor-derived conditioned medium

BACKGROUND

Human induced pluripotent stem cells represent a scalable source of youthful tissue progenitors and secretomes for regenerative therapies. The aim of our study was to investigate the potential of conditioned medium (CM) from hiPSC-mesenchymal progenitors (hiPSC-MPs) to stimulate osteogenic differentiation of human bone marrow-derived mesenchymal stromal cells (MSCs). We also investigated whether prolonged cultivation or osteogenic pre-differentiation of hiPSC-MPs could enhance the stimulatory activity of CM.

METHODS

MSCs were isolated from 13 donors (age 20-90 years). CM derived from hiPSC-MPs was added to the MSC cultures and the effects on proliferation and osteogenic differentiation were examined after 14 days and 6 weeks. The stimulatory activity of hiPSC-MP-CM was compared with the activity of MSC-derived CM and with the activity of CM prepared from hiPSC-MPs pre-cultured in growth or osteogenic medium for 14 days. Comparative proteomic analysis of CM was performed to gain insight into the molecular components responsible for the stimulatory activity.

RESULTS

Primary bone marrow-derived MSC exhibited variability, with a tendency towards lower proliferation and tri-lineage differentiation in older donors. hiPSC-MP-CM increased the proliferation and alkaline phosphatase activity of MSC from several adult/aged donors after 14 days of continuous supplementation under osteogenic conditions. However, CM supplementation failed to improve the mineralization of MSC pellets after 6 weeks under osteogenic conditions. hiPSC-MP-CM showed greater enhancement of proliferation and ALP activity than CM derived from bone marrow-derived MSCs. Moreover, 14-day cultivation but not osteogenic pre-differentiation of hiPSC-MPs strongly enhanced CM stimulatory activity. Quantitative proteomic analysis of d14-CM revealed a distinct profile of components that formed a highly interconnected associations network with two clusters, one functionally associated with binding and organization of actin/cytoskeletal components and the other with structural constituents of the extracellular matrix, collagen, and growth factor binding. Several hub proteins were identified that were reported to have functions in cell-extracellular matrix interaction, osteogenic differentiation and development.

CONCLUSIONS

Our data show that hiPSC-MP-CM enhances early osteogenic differentiation of human bone marrow-derived MSCs and that prolonged cultivation of hiPSC-MPs enhances CM-stimulatory activity. Proteomic analysis of the upregulated protein components provides the basis for further optimization of hiPSC-MP-CM for bone regenerative therapies.

Bioinspired injectable hydrogels for bone regeneration

The effective regeneration of bone/cartilage defects remains a significant clinical challenge, causing irreversible damage to millions annually.Conventional therapies such as autologous or artificial bone grafting often yield unsatisfactory outcomes, emphasizing the urgent need for innovative treatment methods. Biomaterial-based strategies, including hydrogels and active scaffolds, have shown potential in promoting bone/cartilage regeneration. Among them, injectable hydrogels have garnered substantial attention in recent years on account of their minimal invasiveness, shape adaptation, and controlled spatiotemporal release. This review systematically discusses the synthesis of injectable hydrogels, bioinspired approaches-covering microenvironment, structural, compositional, and bioactive component-inspired strategies-and their applications in various bone/cartilage disease models, highlighting bone/cartilage regeneration from an innovative perspective of bioinspired design. Taken together, bioinspired injectable hydrogels offer promising and feasible solutions for promoting bone/cartilage regeneration, ultimately laying the foundations for clinical applications. Furthermore, insights into further prospective directions for AI in injectable hydrogels screening and organoid construction are provided.

Enhancing osteoblast differentiation and bone repair: The priming effect of photobiomodulation on adipose stromal cells

Cellular therapy using adipose tissue-derived mesenchymal stromal cells (at-MSCs) has garnered attention for the treatment of bone defects. Therefore, preconditioning strategies to enhance the osteogenic potential of at-MSCs could optimize cell therapy outcomes, and photobiomodulation (PBM) therapy has emerged as an effective, noninvasive, and low-cost alternative. This study explored the impacts of PBM on at-MSCs differentiation and the subsequent repair of bone defects treated with cell injection. Rat at-MSCs were cultured and irradiated (at-MSCsPBM) following the PBM protocol (660 nm; 20 mW; 0.714 W/cm2; 0.14 J; 5 J/cm2). Cellular differentiation was assessed based on the expression of gene and protein markers. Reactive oxygen species (ROS) were detected using fluorescence. At-MSCsPBM were injected into 5-mm calvarial lesions, and bone formation was analyzed using micro-CT and histological evaluations. At-MSCs were used as control. Data were analyzed using the ANOVA or t-test. At-MSCsPBM exhibited high levels of gene and protein runt-related transcription factor-2 (Runx2) and alkaline phosphatase (Alp) expression. PBM increased ALP activity and significantly reduced ROS levels. In addition, PBM increased the expression of Wnt pathway-associated genes. In vivo, there was an increase in the morphometric parameters, including bone volume, percentage of bone volume, bone surface area, and trabecular number, in at-MSCsPBM-treated defects compared with those in the control. These findings suggest that PBM enhances the osteogenic potential of at-MSCs, thereby supporting the advancement of improved cellular therapies for bone regeneration.