Search Results (544)

Cells of higher organisms express numerous cell surface proteins, and their spectrum and level of expression are directly related to cells’ functions. The technology of mass cell selection based on the surface protein expression levels may be highly important both for basic research and cell therapy applications. We have previously developed a method of magnetic selection of cells differing in surface marker expression levels, which we term here MACS-MEL (Magnetic-Assisted Cell Selection by Marker Expression Levels). The method demonstrated its effectiveness in the artificial model system, namely retrovirally transduced NIH 3T3 cells. However, whether it was also applicable to complex natural cell populations remained unclear. In the current study, we validated the MACS-MEL approach by separating mouse bone marrow (BM) cells into fractions according to the expression of pan-hematopoietic marker CD45. In the basic protocol, two-stage fractionation of CD45⁺ cells from BM was performed using selection of cells consecutively with 2 μL and 8 μL of anti-CD45 magnetic beads, resulting in isolation of CD45^high and CD45^int cell populations. To explore in full the potential of the method, the extended protocol was also tested, where a third selection stage with 30 μL of anti-CD45 beads was added. The isolated cell fractions were analyzed by flow cytometry for CD45 expression, as well for CD11b, Gr-1, CD117, CD115 and CD19 markers, while their in vitro progenitor function was assessed by quantitating colony-forming units (CFUs) in methyl cellulose. The results of analysis demonstrate that the isolated cell fractions significantly differed both in their surface phenotypes and CFU potential. In particular, cell fractions with progressively reduced CD45 expression were characterized by decreasing expression of myeloid differentiation markers CD11b and Gr-1, as well as B-lymphoid marker CD19. The expression of stem/progenitor cell marker CD117, on the contrary, significantly increased. The CFU frequency also strongly correlated with decrease in CD45 expression, while the differentiation potential of CFUs differed substantially in various cell fractions. In general, our results demonstrate that less differentiated hematopoietic cells in mouse BM studied using in vitro tests are characterized by lower CD45 expression levels, in full accordance with data obtained in human system. Successful validation of the MACS-MEL in a BM system, characterized by existence of multiple cell types and high phenotypic and functional heterogeneity, demonstrated the effectiveness, simplicity and affordability of this method. The MACS-MEL approach can be applied for mass selection of cells based on differential marker expression and may yield cell subsets suitable for advanced cell therapy applications. Full article

Background/Objectives: Osteoarthritis (OA) is a common degenerative joint disease associated with pain, functional limitation, and reduced quality of life. Interest in orthobiological treatments, including platelet-rich plasma (PRP), mesenchymal stem cells (MSCs), bone marrow aspirate concentrate (BMAC), exosomes, and biomaterial-based approaches has increased markedly in recent years. This study was aimed at investigating the bibliometric characteristics, research trends, and future directions of scientific literature on orthobiological treatments in OA. Methods: Publications indexed in the Web of Science Core Collection (WoSCC) between 2000 and 2026 were searched on 3 June 2026 using keywords related to OA and orthobiological therapies. The WoSCC was selected because it provides standardized citation data and comprehensive coverage of high-impact scientific journals for bibliometric analyses. In the study, 7875 publications were included. Bibliometric analyses were performed using the Bibliometrix package and Biblioshiny interface. Publication trends, country and institutional contributions, influential publications, keyword patterns, trending topics, and thematic structures were analyzed. Results: Scientific production on orthobiological treatments in OA increased substantially, particularly after 2015, with an annual growth rate of 22.8%. China was the most productive country, whereas the United States had the highest scientific impact. The most productive institutions were mainly universities in China. The most frequent keywords were “osteoarthritis,” “mesenchymal stem cells,” “platelet-rich plasma,” “knee osteoarthritis,” and “cartilage.” Trend analyses indicated a shift from PRP- and stem cell-based applications toward emerging regenerative strategies, including exosomes, extracellular vesicles, biomaterials, and controlled drug delivery systems. Thematic mapping demonstrated that MSCs and cartilage regeneration formed the central research axis. Conclusions: While MSCs and PRP remain key research topics in orthobiological treatments for OA, exosomes, biomaterials, and smart drug delivery systems are attracting increasing attention as crucial areas for future research. Full article

Acute myeloid leukemia (AML) harboring KMT2A rearrangements (KMT2A-r) accounts for approximately 5–10% of newly diagnosed cases and represents a high-risk AML subtype associated with poor clinical outcomes despite intensive treatment strategies, including allogeneic hematopoietic stem cell transplantation (HSCT). KMT2A-r AML is also characterized by a higher incidence of extramedullary disease compared with other AML subtypes. Therapeutic options for patients with relapsed/refractory (R/R) disease, particularly after post-HSCT relapse, remain extremely limited. In recent years, menin inhibitors have emerged as a promising targeted therapeutic class for KMT2A-r and NPM1-mutated AML by disrupting the aberrant HOX/MEIS1 transcriptional program. Revumenib, a first-in-class menin inhibitor, has shown encouraging efficacy in early-phase clinical trials. Other menin inhibitors, including ziftomenib, bleximenib, and enzomenib, have also demonstrated clinical activity, with distinct pharmacokinetic, pharmacodynamic, and safety profiles. We report the case of a 36-year-old patient with KMT2A-r AML who relapsed after HSCT with both bone marrow and hepatic involvement. Compassionate-use treatment with revumenib (160 mg twice daily on days 1–28 of each 28-day cycle) induced, after two treatment cycles, complete hematologic remission with no detectable abnormal myeloid blast population by multiparameter flow cytometry (MFC) and complete radiological resolution of hepatic lesions. However, despite prior intrathecal CNS-directed therapy and sustained systemic disease control, the patient subsequently developed an isolated central nervous system (CNS) relapse. This case highlights a potential discordance between systemic and CNS disease control during menin inhibitor therapy and emphasizes the need for further investigation into CNS surveillance and disease management in patients achieving deep systemic responses. Full article

Genitourinary syndrome of menopause (GSM) is a common hypoestrogenic condition marked by vulvovaginal atrophy and lower urinary tract symptoms that significantly impair quality of life in peri- and postmenopausal women. Although local estrogen therapy remains the standard of care, its use is constrained by contraindications, adherence challenges, and concerns regarding long-term safety, particularly in women with estrogen-sensitive conditions. As a result, interest has grown in regenerative, non-hormonal alternatives. Stem cell-based therapy, particularly using mesenchymal stem cells (MSCs), has emerged as a potential therapeutic strategy for restoring urogenital tissue structure and function. The current body of evidence largely consists of preclinical studies, small clinical case series, and investigations in related but distinct conditions, which provide potential mechanistic insights. Preclinical studies suggest that MSCs from adipose tissue, bone marrow, and umbilical cord promote vaginal epithelial regeneration through paracrine mechanisms, including angiogenesis, immunomodulation, extracellular matrix remodeling, and restoration of local estrogen signaling and vaginal microbiota. To date, current clinical studies have not provided direct evidence on the efficacy of characterized MSC-based therapies specifically in GSM populations. Early clinical evidence, primarily involving adipose-derived tissue products such as micro-fragmented adipose tissue, reports improvements in symptoms overlapping with GSM, including vaginal dryness, dyspareunia, urinary symptoms, and sexual function, with benefits lasting up to two to three years after a single treatment and no serious adverse events reported. However, available data are limited by small cohorts, the absence of randomized trials, and regulatory variability. This review summarizes current evidence and outlines key scientific, ethical, and regulatory challenges that must be addressed to guide future research and clarify the therapeutic potential of MSC-based approaches in GSM, ultimately enabling translation. Full article

Cardiovascular diseases (CVDs) remain the foremost cause of death globally, responsible for 19.2 million deaths and 437 million disability-adjusted life years in 2023, with prevalent cases having more than doubled since 1990. No approved therapy restores myocardium lost to infarction. The adult heart replaces cardiomyocytes at approximately 1% per year in young adults, declining to about 0.45% per year with ageing, far below what is needed to recover the more than one billion cells destroyed by a large myocardial infarction. Cell-based regenerative strategies have been investigated for more than two decades, encompassing bone marrow mononuclear cells (BM-MNCs), mesenchymal stromal cells (MSCs), cardiac progenitor cells, cardiosphere-derived cells (CDCs), skeletal myoblasts, and induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs). Safety has been consistent. Efficacy has been modest and variable: the CADUCEUS trial demonstrated scar mass reduction with CDCs without proportionate ejection fraction improvement; the Phase 1/2 POSEIDON trial confirmed MSC safety in 30 patients; and the Phase 3 DREAM-HF trial, enrolling 537 patients, failed its primary endpoint (HR 1.2, p = 0.406). Mechanistic work has established that transplanted cells engraft poorly and exert their benefit principally through paracrine signalling mediated by secreted extracellular vesicles and exosomes carrying microRNAs, trophic factors, and immunomodulatory proteins. For iPSC-CMs, electrophysiological immaturity and arrhythmogenic risk in primate models remain unresolved barriers. Emerging strategies include CRISPR-engineered hypoimmune iPSC lines, bioengineered cardiac patches, injectable hydrogel scaffolds, and engineered exosome platforms. This review provides a comprehensive synthesis of preclinical and clinical evidence, examines translational barriers, and identifies the scientific and regulatory priorities required before these therapies can enter routine clinical practice. Full article

Acute myeloid leukemia (AML) develops within a bone marrow environment that influences leukemic stem cell behavior, residual disease, and response to therapy. This review examines evidence that the marrow microenvironment is not only a site of leukemic growth, but can actively shape AML initiation, maintenance, and treatment resistance. Clinical observations such as donor cell leukemia after allogeneic transplantation, together with experimental models in which stromal or osteolineage abnormalities induce myeloid disease, suggest that altered niches may contribute to leukemogenesis in selected settings. In established AML, vascular and endosteal compartments provide adhesive, chemokine, inflammatory, and metabolic signals that promote leukemic-cell retention, quiescence, survival, and chemotherapy tolerance. AML cells also remodel the surrounding marrow, suppressing normal hematopoiesis and generating stromal, endothelial, osteoblastic, adipocytic, and immune-cell programs that favor leukemic persistence. These interactions are especially relevant to drug resistance, including resistance to venetoclax-based therapy, where cytokine-mediated changes in apoptotic dependence, fatty-acid metabolism, mitochondrial adaptation, and stromal support may all contribute. Several therapeutic approaches have attempted to disrupt niche-mediated protection, including targeting CXCL12/CXCR4 signaling, adhesion pathways, inflammatory circuits, Hedgehog signaling, and metabolic dependencies. Although early-phase studies have shown activity in some AML subsets, randomized evidence remains limited and results have been inconsistent. We discuss how a better understanding of microenvironmental biology may help define when niche-directed therapy is most likely to complement conventional and molecularly targeted AML treatment. Full article

Background: Neuroblastoma is a common extracranial solid malignant tumor of early childhood; however, mandibular involvement is rare and may mimic odontogenic or inflammatory disease. Case Presentation: We report an 8-month-old girl with left paramandibular swelling initially suspected to represent parotitis or odontogenic inflammation. Imaging revealed a destructive mandibular lesion with sunburst periosteal reaction, and histology confirmed undifferentiated neuroblastoma. Staging identified a left primary adrenal tumor with extensive bone marrow infiltration and MYCN proto-oncogene amplification. The patient received multimodal high-risk neuroblastoma therapy, including chemotherapy, surgery, autologous stem cell transplantation, proton therapy, antibody therapy, and Lorlatinib. Despite radiological remission, she developed severe pulmonary complications and died shortly before the age of five years. Methods: A focused literature review was conducted to identify published pediatric cases of metastatic neuroblastoma involving the mandible. Results: Through our review, we identified 31 published pediatric cases of mandibular metastatic neuroblastoma. Reported cases most commonly described mandibular swelling, pain, tooth mobility, and facial asymmetry. Most mandibular lesions represented metastatic disease from an adrenal or abdominal primary tumor. Conclusions: Mandibular involvement of neuroblastoma is rare but clinically important. In infants and young children, persistent or atypical (para-/peri)mandibular swelling should not be assumed to be odontogenic or inflammatory. Early imaging, biopsy, and interdisciplinary referral are essential for timely diagnosis and treatment. Full article

Background/Objectives: Modern approaches for post-stroke rehabilitation cover mechanistically different ways—from physiotherapy to digital technologies. Among these approaches, stem cell-based therapy represents probably the most complex but promising strategy. Methods: We discuss the current state-of-the-art of using mesenchymal stem cells (MSCs) in post-stroke regenerative therapy. Despite relatively wide use of bone marrow and adipose tissue MSCs, these cells represent a more mature (“adult”) state, which limits their proliferative and regenerative potentials. Compared to the “adult” MSCs, less “mature” MSCs obtained from umbilical cord, specifically Wharton’s jelly MSCs (WJ-MSCs), demonstrate unique functional capabilities and are free from certain technical and ethical issues. Results: The molecular and cellular mechanisms of action of WJ-MSCs are thoroughly discussed in comparison with abundantly used “adult” types of MSCs. We also comparatively evaluate their preclinical and clinical application for treating post-stroke patients. Recent findings indicate that not only MSCs but also their secretome/exosomes (cell-free product) represent a therapeutically beneficial cellular drug in post-stroke recovery. Specially designed and carefully evaluated protocols, which preserve the bioactivity of the cell-free product intact, are mentioned. Neuroprotective and neuroreparative properties of cell-free products—secretome and exosomes—derived from Wharton’s jelly MSCs are summarized. Conclusions: Cell-free products obtained from WJ-MSCs are an innovative adjunct therapy for post-stroke disorders, despite certain challenges and limitations of this type of therapy still present. By further investigation of the molecular composition and biological mechanisms of the WJ-MSC secretome and exosomes, their clinical applicability in neuroinflammatory and neurodegenerative pathologies will be promoted. Full article

Restoration of the osteochondral unit remains a major challenge in regenerative orthopaedics, largely due to the limited intrinsic healing capacity of articular cartilage and the complex, multilayered nature of the cartilage–bone interface. Osteochondral regeneration must accommodate differences in cellular composition, vascularization, metabolic demand, and mechanical properties between cartilage and bone, while simultaneously recreating a stable, functional interface. While exogenous mesenchymal stem cell (MSC) therapies have dominated the field, their clinical translation has been hindered by donor variability, phenotypic instability, logistical complexity, and inconsistent long-term outcomes. Resident stem cells from sources such as articular cartilage, bone marrow, periosteum, synovium, synovial fluid, and adipose tissue (infrapatellar fat pad) can act as potential targets for in situ osteochondral regenerative therapies. Joint-resident MSCs are adapted to the biomechanical and biochemical environment of the joint and may therefore represent a promising cell source for osteochondral regeneration; however, much of the supporting evidence remains preclinical. Effective osteochondral repair depends on the precise orchestration of stem cell recruitment, maintenance of chondrogenic phenotypes, induction of osteogenic differentiation in the subchondral compartment, and modulation of local immune responses. Patient-specific factors, including age, inflammatory status, and the severity of osteoarthritis, can significantly influence the regenerative potential of resident MSC populations and should therefore guide biomaterial design strategies. The proposed niche-by-design framework integrates stem cell biology with advanced biomaterial engineering, offering a rational roadmap for developing next-generation therapies that promote endogenous osteochondral regeneration through targeted activation of joint-resident progenitor cells. Full article

Stage-specific embryonic antigen-3-positive pluripotent-like/macrophage-like multilineage-differentiating stress-enduring (Muse) cells are a distinct subpopulation of mesenchymal stromal cells (MSCs), accounting for 1% to several percent of MSCs. Although stem cell therapy for spinal cord injury (SCI) typically targets the subacute phase to avoid the hostile acute environment, the therapeutic window for Muse cells remains unclear. C57BL/6J mice with severe T9 contusion SCI received a single tail vein injection of human bone marrow-derived (BM) Muse cells, BM-MSCs (both 5 × 10⁴ cells), or vehicle at 2, 8, 14, or 28 days post-injury (DPI) without immunosuppressants. Among the different administration time points, the 2-DPI Muse cell group exhibited significantly higher Basso Mouse Scale scores than the BM-MSC and vehicle groups from 14 days after injection, while no significant differences were observed at the other administration time points. The 2-DPI Muse cell group showed significantly greater homing to the injured spinal cord than the BM-MSC group, with persistent engraftment and neural-lineage marker expression at day 42. Ablation of engrafted Muse cells at day 42 partially reversed locomotor recovery, suggesting that engrafted Muse cells contributed to functional recovery. These findings suggest that intravenous Muse cell therapy exerts timing-dependent therapeutic effects after SCI, with greater efficacy during the early post-injury phase. Full article

Bone marrow aspirate concentrate (BMAC) is widely used as a source of mesenchymal stromal/stem cells (MSCs) for musculoskeletal regeneration; however, BMAC lacks essential bone marrow extracellular matrix (ECM) components, a critical component of the stem cell niche that regulates MSC survival, paracrine signaling, and regenerative capacity. We previously demonstrated that an ECM-retaining micronized bone marrow product (BMAX™) preserves pro-regenerative MSC phenotypes in vitro. Human bone marrow from a single donor was processed into conventional BMAC or BMAX™. Post-traumatic osteoarthritis was induced in immunodeficient rats using destabilization of the medial meniscus (DMM). Four weeks after surgery, animals were randomly assigned to receive intra-articular injections of BMAX™, BMAC, or phosphate-buffered saline (n = 10–12 in each group). Pain-related behavior (n = 5–6/group), histological assessment (n = 3–6/group), and micro-computed tomography (n = 4–6/group) were evaluated for up to 8 weeks after treatment. At 4 weeks after treatment, BMAC significantly increased the paw withdrawal threshold compared with PBS (p = 0.0068), whereas BMAX™ significantly reduced knee joint swelling compared with both PBS (p = 0.0235) and BMAC (p = 0.0039), and BMAX™ significantly improved knee bend scores compared with PBS (p = 0.0011). Neither treatment significantly improved OARSI histological scores at this time point. At 8 weeks after treatment, BMAX™ significantly increased the paw withdrawal threshold compared with PBS (p = 0.0305), whereas BMAC showed a non-significant trend (p = 0.0517); both treatments significantly reduced knee bend scores compared with PBS (p = 0.0027 and p = 0.0255), and BMAX™ demonstrated significantly lower knee bend scores than BMAC (p = 0.0090). BMAX™ significantly reduced knee swelling compared with PBS (p = 0.0196). Histologically, BMAX™ significantly improved OARSI scores in both the femoral condyle and tibial plateau compared with PBS (p = 0.0020 and p = 0.0003, respectively), whereas BMAC significantly improved only tibial plateau OARSI scores (p = 0.0014). Furthermore, BMAX™ demonstrated significantly lower femoral condyle OARSI scores than BMAC (p = 0.0243). Micro-computed tomography revealed that both BMAX™ and BMAC significantly reduced medial subchondral trabecular separation compared with PBS (p = 0.0340 and p = 0.0426, respectively), whereas no significant differences were observed between the two treatment groups for other bone structural parameters. In conclusion, preservation of the native bone marrow ECM was associated with improved functional outcomes and greater cartilage regeneration compared with conventional BMAC in this preclinical rat model of post-traumatic osteoarthritis. These findings support the concept that maintaining the native stem cell niche may enhance the therapeutic potential of bone marrow-derived cell therapies for osteoarthritis. Full article

Acute myeloid leukemia (AML) is a genetically and biologically heterogeneous hematologic neoplasm that arises from the clonal transformation of hematopoietic progenitor cells. AML cells undergo extensive metabolic reprogramming to sustain proliferation, survival, and adaptation to therapeutic stress. Among these alterations, cholesterol metabolism has emerged as a critical determinant of leukemic cell fitness. AML cells enhance cholesterol biosynthesis, uptake, trafficking, and storage, generating a dynamic network that supports membrane organization, mitochondrial function, oncogenic signaling, and resistance to therapy. Beyond these tumor-intrinsic roles, accumulating evidence indicates that cholesterol and its metabolites actively shape communication between leukemic and immune cells, influencing immune checkpoint expression, inflammatory signaling, and antitumor immune responses within the bone marrow microenvironment. This narrative review examines the mechanisms underlying cholesterol reprogramming in AML and discusses how alterations in cholesterol homeostasis integrate metabolic adaptation with immune regulation. Particular emphasis is placed on the interplay between cholesterol metabolism, leukemic stem cell persistence, therapeutic resistance, and immune dysfunction. Emerging therapeutic strategies targeting cholesterol-related pathways are also considered. Collectively, these findings position cholesterol metabolism as a central interface between tumor-intrinsic biology and immune crosstalk, highlighting its potential as a therapeutic vulnerability in AML. Full article

Repairing large bone defects remains a clinical challenge in orthopedics. Near-infrared (NIR) photothermal therapy (PTT) has recently expanded from high-temperature tumor ablation to the field of mild bone regeneration. Maintaining temperatures within a mild window of 40–42 °C accelerates bone healing by activating osteogenic signals, modulating the immune microenvironment, and providing antibacterial effects. It is important to note that the therapeutic efficacy is highly dependent on the precise control of both temperature and exposure duration: temperatures exceeding 42–43 °C can induce cell apoptosis, while temperatures above 45 °C typically cause necrosis. The reviewed studies employed controlled exposure times (typically 5–15 min per session) to maintain cell viability above 85%, with functional assessments confirming preserved osteogenic differentiation capacity of bone marrow-derived mesenchymal stem cells (BMSCs) and maintained macrophage plasticity after mild photothermal treatment. This performance depends on photothermal conversion materials. This paper reviews the applications of MXene, black phosphorus (BP), polydopamine/graphene oxide (PDA/GO), and metal-based nanomaterials in bone repair. We also analyze photothermal-based immune regulation, sequential repair strategies, and tumor theranostics. Finally, we discuss current challenges and future trends to guide the design of next-generation smart bone repair materials. Full article

Mesenchymal stem cells (MSCs) are capable of self-renewal and differentiation into different cellular lineages, including adipocytes, chondrocytes, and osteocytes. This makes them strong candidates for repairing degenerative joint conditions such as osteoarthritis, in which native cartilage lacks repair capacity. The synovium is an attractive MSC source, with synovial MSCs demonstrating superior chondrogenic and proliferative potential compared to those from bone marrow or adipose tissue. The synovial joint is a heterogeneous environment, and MSCs can be isolated from the membrane, fluid, different histological subtypes of fibrous and adipose synovium, and different anatomical regions of synovium. This systematic review assesses whether MSCs from different synovial sources possess distinct properties. 2312 papers were identified, of which 10 met the inclusion and exclusion criteria and were included in the final review. Significant differences were identified in proliferation characteristics, immunophenotype and differentiation potential. Proximity to vasculature appeared to correlate with proliferation and differentiation potential, and MSCs from the synovial membrane may have superior proliferative characteristics compared to those from synovial fluid. More work is required to fully characterise these differences and understand their underlying molecular bases, but these findings may help inform the choice of MSC source for regenerative therapies. Full article

Cutaneous leishmaniasis (CL) is the most common clinical form of leishmaniasis, characterized by persistent skin ulcers and nodules. Standard chemotherapeutic agents have substantial toxicity and do nothing to repair the damaged tissue, an unmet need that motivates the search for adjunctive strategies. Mesenchymal stem cells (MSCs) can modulate macrophage activity and support tissue regeneration, yet their role in CL has received limited attention. In this study, we tested whether bone marrow-derived MSCs (BM-MSCs) could attenuate Leishmania mexicana-induced inflammation and facilitate skin repair. Indirect co-culture of BM-MSCs with infected RAW264.7 macrophages shifted the macrophage phenotype from M1 toward M2, with higher IL-10 and Arg-1 expression and lower iNOS and IL-1β. In BALB/c mice with established CL, three weekly intravenous injections of BM-MSCs reduced paw swelling, improved skin histology, decreased type I collagen deposition, lowered Integrin β1 and Cytokeratin 17 expression, and reduced tissue parasite load. Immunofluorescence confirmed a predominantly M2 macrophage distribution in treated lesions. We inferred that BM-MSCs acted on both the immune and reparative aspects of the disease process, supporting their potential as an adjunct to conventional anti-leishmanial therapy. Full article