Mesenchymal stem cells and macrophages and their interactions in tendon-bone healing

Highly sensitive electrochemical Osteoprotegerin (OPG) immunosensor for assessing fracture healing and evaluating drug efficacy

Tibial fractures are common long bone injuries requiring effective monitoring for optimal healing. Osteoprotegerin (OPG), as a key marker of bone formation, is closely related to the degree of fracture healing. However, existing detection methods have certain limitations in sensitivity and specificity. This study successfully crafted an exceptionally sensitive electrochemical immunosensor based on COOH-CNFs/Ti3C2Tx MXene/PANI-AgNPs nanocomposite material for the quantitative analysis of OPG in serum, providing a methodological basis for auxiliary diagnosis of fracture healing degree and evaluation of drug efficacy. A one-pot hydrothermal method was employed to synthesize and modify the nanocomposite material on gold electrode surfaces, which exhibit high electrochemical activity, low charge transfer resistance, and a large electroactive surface area, thereby enhancing the immunosensor's conductivity and stability, with a wide linear range (10-17 to 10-12 g/mL) and a low detection limit (1.94 × 10-18 g/mL). Methodological validation further confirmed the immunosensor's excellent performance in specificity, reproducibility, and stability. Moreover, the successful application of this immunosensor in detecting OPG in serum samples from actual tibial fracture patients before and after medication demonstrates significant potential for clinical application in assisting the assessment of fracture healing and evaluating the efficacy of orthopedic drugs.

Adipose derived stem cell activation by macrophages and tendon fibroblasts

AIMS

Tendon injuries are common, and healing often fails due to an over-exuberant inflammatory response and a lack of regeneration. Inflammatory cells play key roles in these processes, with a balance between classically activated pro-inflammatory M1 macrophages and alternatively activated inflammatory resolving M2 macrophages. Adipose-derived mesenchymal stem cells (ASCs) can dampen the pro-inflammatory effectsof macrophages, promote a regenerative environment, and enhance healing. Therefore, the goal of the study was to understand how ASCs are activated by macrophages in vitro.

METHODS

In vitro co-culture experiments were carried out with ASCs, macrophages, and tendon fibroblasts. RNA-seq and qRT-PCR were performed to determine expression patterns of activated ASCs.

RESULTS

M1 macrophages prompted ASCs to upregulate pro-inflammatory signaling, matrix remodeling, and cytokine production pathways, while downregulating those related to cell adhesion and cell cycle. Conversely, TFs prompted ASCs to upregulate pathways involved in cell cycle and cytoskeleton remodeling, and to downregulate pathways associated with immune cell adhesion, inflammatory mediator production, and protein metabolism.

CONCLUSIONS

The cell-specific activation profiles indicate a possible switch in ASC paracrine signaling depending on the context, from a pro-inflammatory pattern in response to M1 macrophages to a proliferative pattern in response to TFs. Understanding crosstalk between ASCs, TFs, and macrophages is essential for developing stem cell-based therapeutic strategies.

Tendon-Bone Healing: Synergistic Role of Platelets and Mesenchymal Stem Cells in Tissue Engineering

Repair of the tendon-bone interface (TBI) remains a significant clinical challenge due to its complex biomechanical environment and hierarchical structure. Conventional surgical approaches often fail to fully reestablish native tissue architecture and function. In recent years, tissue engineering strategies have increasingly emphasized the application of mesenchymal stem cells (MSCs) and platelet-derived products to promote regeneration. MSCs possess multilineage differentiation potential and immunomodulatory capabilities, making them attractive candidates for TBI repair. Platelets, through their rich secretome, orchestrate essential regenerative processes such as cell recruitment, angiogenesis, and immune modulation. This review explores the molecular crosstalk between MSCs and platelets, critically examines current approaches utilizing platelet-rich plasma (PRP)-MSC combinations and platelet-derived exosome therapies and underscores the urgent need for standardization to optimize therapeutic outcomes in PRP-MSC-based regenerative strategies.

Effects of a PDGF-stem cell-hydrogel compound on skin wound healing in mice

BACKGROUND AIMS

The treatment of chronic refractory skin wounds still remains a serious clinical challenge. Stem cells and hydrogels are widely used in healing of skin wound of various types due to their superior bioactivities and biocompatibility. This study aimed to demonstrate the wound healing effect of a hydrogel compound loaded with enucleated stem cells expressing the platelet-derived growth factor (PDGF).

METHODS

An injectable hydrogel was formulated using 22% poloxamer 407, 1% poloxamer 188, and 1% hyaluronic acid. A PDGF-B transgenic cell line of mouse bone marrow mesenchymal stem cells (BMSCs) was generated by lentiviral infection. Cells were enucleated and embedded in hydrogel. The healing effects of the compound was tested in a full-thickness skin wound model of Balb/c mice. The wound models were randomly divided into four groups: the control group applied with PBS buffer; the hydrogel group with hydrogel only; the BMSC group with hydrogel mixed with normal BMSCs; and the BMSC-PDGF group with hydrogel mixed with enucleated BMSCs expressing PDGF.

RESULTS

Overexpression of PDGF-B in transgenic cell line of BMSCs was verified by RT-PCR, immunofluorescence staining and western blot. When enucleated, the viability measured by Calcein-AM staining reduced to 54.29% at 48 h. Conditioned medium was collected with or without hydrogel layered over cells. PDGF concentration measured by ELISA reached 14.66 ng/μL and 257.89 ng/μL respectively after 48-h cultivation, suggesting a possible slow releasing effect in the presence of hydrogel. When applied to the skin wound, the healing rates of the BMSC-PDGF group was significantly higher than that of the control group on day 3. BMSC-PDGF group had significantly more neovascularization and cutaneous appendages from day 7. The proliferation of collagen fibers in BMSC-PDGF group was significantly higher than the control group on day 3 and day 7. Finally, BMSC-PDGF group had significantly lower amount of the inflammatory factors TNF-α, IL-1β, IL-6, MMP-3 and MMP-9 than that of the control group on day 7.

CONCLUSIONS

PDGF-stem cell-hydrogel compound significantly improved wound healing and reduced wound inflammatory factor expression in Balb/c mice. This biomaterial-based approach provides a new powerful reference for the treatment of chronically wounded skin.

Multilayer Film with Bioactive and Antiadhesive Layers for Accelerated Tendon Regeneration

Despite advances in surgical techniques for tendon injuries and improvements in rehabilitation, the challenge of achieving sufficient tendon regeneration and preventing postoperative tissue adhesions persists for orthopedic surgeons. In this study, we developed a multilayer film with a platelet-derived growth factor-BB (PDGF-BB)-immobilized leaf-stacked structure (LSS) layer (bioactive layer) and an alginate layer (antiadhesive layer) on both sides of a PCL film (PDGF/FLSS-Alg). The porous LSS layer on the PCL film was fabricated using a heating-cooling method with tetraglycol, where PDGF-BB was adsorbed onto the LSS layer. An alginate coating was applied on the opposite side to form the antiadhesion layer. The PDGF-BB loaded on the LSS layer provided a sustained release at effective concentrations for over 29 days. From in vitro cell culture and in vivo animal studies, the alginate layer proved effective in preventing cell/tissue adhesion; meanwhile, the bioactive layer facilitated tenogenic differentiation in hBMSCs and supported tendon regeneration. Accordingly, we propose that PDGF/FLSS-Alg offers a viable strategy for effective tendon regeneration in clinical practice.

Size-Dependent Pulmonary Toxicity and Whole-Body Distribution of Inhaled Micro/Nanoplastic Particles in Male Mice from Chronic Exposure

The ubiquitous presence of micro/nanoplastics (MP/NP) in the atmosphere has raised significant concerns about their potential health risks through inhalation, yet the effects of natural respiratory exposure remain underexplored. This study addresses this critical knowledge void by utilizing a whole-body inhalation exposure system to investigate the distribution, accumulation, and pulmonary toxicity of polystyrene MP/NP (1.5 × 105 particles/m3) in male ICR mice (n = 16/group). Fluorescently labeled MP/NP revealed the highest particle accumulation in the lungs, followed by the bloodstream and spleen, with minimal detection in the brain. Unsurprisingly, 80 nm nanoplastics displayed greater intertissue transport efficiency than 1 μm microplastics. Chronic exposure to both microplastics and nanoplastics disrupted oxidative balance and exacerbated oxidative stress within the extracellular environment of the lungs. The impaired antioxidant defenses and disrupted intra- and extracellular metabolism led to inflammation, apoptosis, and fibrosis. Intriguingly, 1 μm microplastics induced more severe pulmonary toxicity than their smaller counterparts, promoting epithelial-mesenchymal transition and fibrosis. These findings underscore the need for a nuanced understanding of size-dependent toxicities of inhalable plastic particles and highlight the health risks posed by airborne MP/NP.

Hypoxia-regulated miR-103-3p/FGF2 axis in adipose-derived stem cells promotes angiogenesis by vascular endothelial cells during ischemic tissue repair

BACKGROUND

Identifying factors mediating adipose-derived stem cells (ADSCs)-induced endothelial cell angiogenesis in hypoxic skin flap tissue is critical for reconstruction. While the paracrine action of VEGF by adipose-derived stem cells (ADSCs) is established in promoting endothelial cell angiogenesis, the role of FGF2 and its regulatory mechanisms in ADSCs paracrine secretion remains unclear.

METHODS

We induced hypoxia and examined the expression level of FGF2 in ADSCs using ELISA, qRT-PCR, and western blotting. Proliferation of ADSCs under hypoxia was assessed using a CCK-8 assay. Co-culture experiments of hypoxia-induced ADSCs with vascular endothelial cells were conducted, and migration and tube formation abilities were evaluated through wound healing assays, transwell cell migration, and tube formation experiments.

RESULTS

Hypoxia treatment induced significant upregulation of FGF2 expression in ADSCs, along with enhanced cell proliferation. Co-culture of hypoxia-induced ADSCs with vascular endothelial cells showed increased migration and tube formation abilities of endothelial cells. Knockdown of FGF2 inhibited these processes, while overexpression of miR-103-3p mimics in ADSCs suppressed endothelial cell migration and tube formation. FGF2 is a direct target of miR-103-3p in ADSCs. miR-103-3p/FGF2 axis regulates ADSCs on the biological activity of co-cultured vascular endothelial cells. Moreover, in the ischemic skin flap nude mouse model, ADSCs injection showed increased blood vessel formation and reduced flap necrosis, with the most significant improvement observed with ADSCs of miR-103-3p inhibitor overexpressed.

CONCLUSION

Hypoxia induces paracrine secretion of FGF2 from ADSCs, which enhances endothelial cell angiogenesis. FGF2 expression is regulated by miR-103-3p in ADSCs. The miR-103-3p/FGF2 axis induces endothelial cell migration and angiogenesis and finally modulates ischemic skin flap repair in nude mice in vivo.

tsRNA-12391-Modified Adipose Mesenchymal Stem Cell-Derived Exosomes Mitigate Cartilage Degeneration in Osteoarthritis by Enhancing Mitophagy

Osteoarthritis (OA) is a cartilage-degenerative joint disease. Mitophagy impacts articular cartilage damage. tRNA-derived small RNAs (tsRNAs) are one of the contents of adipose mesenchymal stem cell (AMSC)-derived exosomes (AMSC-exos) and are involved in disease progression. However, whether tsRNAs regulate mitophagy and whether tsRNA-modified AMSC-exos improve OA via mitophagy remain unclear. We performed small RNA sequencing to identify OA-related tsRNAs, which were then loaded into AMSC-exos, exploring the function and mechanisms related to mitophagy in vitro and in vivo. Overall, 53 differentially expressed tsRNAs (DEtsRNAs) were identified between OA and normal cartilage tissues, among which 42 DEtsRNAs, including tsRNA-12391, were downregulated in the OA group. Target genes of tsRNA-12391 mainly participated in mitophagy-related pathways such as Rap1 signaling pathway. Compared to the control group, tsRNA-12391 mimics significantly promoted mitophagy, as shown by the upregulated expression of PINK1 and LC3 and the co-localization of Mito-Tracker Green and PINK1. Furthermore, tsRNA-12391 mimics effectively enhanced chondrogenesis in chondrocytes, as demonstrated by the elevated expression of collagen II and ACAN. AMSC-exos with tsRNA-12391 overexpression also facilitated mitophagy and chondrogenesis in vitro and in vivo. Mechanistically, tsRNA-12391 bound to ATAD3A restricted ATAD31 from degrading PINK1, leading to PINK1 accumulation. ATAD31 overexpression reversed the effects of tsRNA-12391 mimics on mitophagy and chondrogenesis. AMSC-exos loaded with tsRNA-12391 promoted mitophagy and chondrogenesis by interacting with ATAD31; this may be a novel therapeutic strategy for OA.

Procyanidin-crosslinked gradient silk fibroin composite nanofiber scaffold with sandwich structure for rotator cuff repair

Improving the regeneration of the tendon-bone interface (TBI) helps to decrease the risk of rotator cuff retears after repair surgeries. Unfortunately, the lack of inherent healing capacity of the TBI, insufficient mechanical properties, and abnormal and persistent inflammation during repair are the key factors leading to suboptimal healing of the rotator cuff. Therefore, a high-strength rotator cuff repair material capable of regulating the unbalanced immune response and enhancing the regeneration of the TBI is urgently needed. In this study, a novel sandwiched silk fibroin composite nanofiber scaffold with a biomimetic gradient structure was prepared through layer-by-layer continuous electrospinning, and then procyanidin was utilized to further enhance the mechanical properties and biological activities of the scaffold. The physicochemical characterization revealed that the procyanidin-crosslinked sandwiched gradient scaffold (GMPC) possessed an appropriate porosity and pore size and superior mechanical properties. Cytocompatibility assessment and immunofluorescence staining indicated that GMPC allowed rapid adhesion, proliferation, and infiltration of osteoblasts. ELISA and macrophage polarization experiments further confirmed that GMPC could effectively inhibit excessive inflammation in injured tissues and regulate the polarization of macrophages to the beneficial phenotype. Therefore, the procyanidin-crosslinked sandwiched gradient nanofiber scaffold might be a promising candidate for rotator cuff repair.

Improving the Wound Healing Process: Pivotal role of Mesenchymal stromal/stem Cells and Immune Cells

Wound healing, a physiological process, involves several different types of cells, from immune cells to non-immune cells, including mesenchymal stromal/stem cells (MSC), and their interactions. Immune cells including macrophages, neutrophils, dendritic cells (DC), innate lymphoid cells (ILC), natural killer (NK) cells, and B and T lymphocytes participate in wound healing by secreting various mediators and interacting with other cells. MSCs, as self-renewing, fast proliferating, and multipotent stromal/stem cells, are found in a wide variety of tissues and critically involved in different phases of wound healing by secreting various molecules that help to improve tissue healing and regeneration. In this review, first, we described the four main phases of wound healing, second, we reviewed the function of MSCs, MSC secretome and immune cells in improving the progress of wound repair (mainly focusing on skin wound healing), third, we explained the immune cells/MSCs interactions in the process of wound healing and regeneration, and finally, we introduce clinical applications of MSCs to improve the process of wound healing.

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.

Sustained slow-release TGF-β3 in a three-dimensional-printed titanium microporous scaffold composite system promotes ligament-to-bone healing

The treatment of tendon/ligament-to-bone injury is a long-standing research challenge in orthopedics and bone tissue engineering. Orderly healing of the fibrocartilage layer and mineralized bone layer is crucial for treating tendon-bone interface injuries. We designed a three-dimensional printed porous titanium scaffold composite system with thermosensitive collagen hydrogel loaded with transforming growth factor β3 (TGF-β3), formulated for the sustained slow release of TGF-β3 at a constant rate. In vitro, the composite system exhibited good biocompatibility and was beneficial for the adhesion and proliferation of bone marrow mesenchymal stem cells (BMSCs), which showed high growth activity. Moreover, the composite system promoted the differentiation of BMSCs via osteogenesis and chondrogenesis. In vivo, the composite system provided active substances at the injured site, promoting the repair of the fibrocartilage layer and of the mineralized bone layer at the interface between the ligament and bone. Micro-CT results demonstrated that the complex promotes the osseointegration of titanium scaffolds in bone defects. Hard tissue sections showed that the new bone, ligament, and the titanium alloy scaffold system formed a closely integrated whole; the composite system provided suitable attachment points for ligament growth. Additionally, the biomechanical strength of the tendon interface improved to some extent. Our results indicate that the composite system has potential as a bioactive implant interface for repairing ligament and bone injuries.

Mitochondrial Quality Control Systems in Septic AKI: Molecular Mechanisms and Therapeutic Implications

Objectives: Despite significant advancements in medical treatments, the creation of a successful treatment strategy for acute kidney injury (AKI) remains a pressing concern. Given the well-documented clinical benefits of canagliflozin in renal protection, our research focused on exploring the possible therapeutic benefits of canagliflozin in treating AKI, with a focus on its underlying mechanisms of action. Methods: To induce AKI, we utilized lipopolysaccharide (LPS) in the presence of canagliflozin, allowing us to assess the drug's effects on kidney function and structure. Results: Our results indicate that canagliflozin lowered blood urea nitrogen and serum creatinine concentrations while enhancing tubular architecture in rodents with LPS-triggered septic AKI. It additionally diminished inflammation, oxidative damage, and tubular cell apoptosis. In vitro, canagliflozin maintained mitochondrial functionality in LPS-exposed HK-2 cells by stabilizing membrane potential, reducing ROS generation, and normalizing respiratory chain activity. Its benefits were facilitated through the AMPKα1/PGC1α/NRF1 axis, promoting mitochondrial regeneration. Importantly, blocking this pathway or employing AMPKα1-deficient animals negated canagliflozin's protective effects, highlighting the essential role of AMPKα1 in its kidney-protective mechanisms. Conclusion: Our investigation implies that canagliflozin might represent a viable treatment strategy for septic AKI, operating through the stimulation of the AMPKα1/PGC1α/NRF1 axis to preserve kidney performance and structural integrity. These findings warrant further investigation into the clinical potential of canagliflozin in this context.

Targeting Caveolin-1 for enhanced rotator cuff repair: findings from single-cell RNA sequencing

Rotator cuff injury (RCI), a prevalent cause of shoulder pain and disability, often leads to significant functional impairments due to adipocyte infiltration into the damaged tissue. Caveolin-1 (Cav-1), a critical membrane protein, plays a significant role in adipocyte differentiation and lipid metabolism. This study utilized single-cell RNA sequencing (scRNA-seq) to investigate the heterogeneity of cell subpopulations in RCI tissues and assess the regulatory effects of Cav-1. The findings revealed that Cav-1 expression negatively correlates with adipogenic activity, and its modulation through exercise or targeted therapies can significantly reduce adipocyte infiltration and enhance tissue repair. Further, Cav-1 knockout and overexpression models demonstrated the protein's impact on key genes involved in adipocyte differentiation and lipid metabolism, such as Scd1, fatty acid synthase (FASN), and peroxisome proliferator-activated receptor gamma (Pparg). Animal studies corroborated these results, showing that exercise intervention increased Cav-1 expression, decreased adipocyte infiltration, and promoted structural repair. These insights suggest that targeting Cav-1 could offer a novel therapeutic strategy for improving RCI outcomes.

Exploring scanning electrochemical probe microscopy in single-entity analysis in biology: Past, present, and future

Scanning Electrochemical Probe Microscopy (SEPM) shows significant potential promise for analyzing localized electrochemical activity at biological interfaces of single entities. Utilizing various SEPM probe manipulations allows real-time monitoring of the morphology and physiological activities of single biological entities, offering vital electrochemical insights into biological processes. This review focuses on the application of five SEPM techniques in imaging single biological entities, highlighting their unique advantages in the observation and quantitative evaluation of biological morphology. Specifically, these techniques not only enable high-resolution imaging of single biological structures but also allow for quantitative analysis of their response behavior. Additionally, the integration of Artificial Intelligence (AI) is discussed to improve data processing and image analysis, potentially advancing SEPM technology towards automation. Although still in an early stage, AI integration opens new avenues for deeper single-entity analysis. This review aims to offer an interdisciplinary perspective and encourage advancements in SEPM-based imaging and analytical techniques, contributing to the bioanalytical field.

Tissue Mimetic Membranes for Healing Augmentation of Tendon-Bone Interface in Rotator Cuff Repair

The globally prevalent rotator cuff tear has a high re-rupture rate, attributing to the failure to reproduce the interfacial fibrocartilaginous enthesis. Herein, a hierarchically organized membrane is developed that mimics the heterogeneous anatomy and properties of the natural enthesis and finely facilitates the reconstruction of tendon-bone interface. A biphasic membrane consisting of a microporous layer and a mineralized fibrous layer is constructed through the non-solvent induced phase separation (NIPS) strategy followed by a co-axial electrospinning procedure. Cationic kartogenin (KGN)-conjugated nanogel (nGel-KGN) and osteo-promotive struvite are incorporated within the membranes in a region-specific manner. During in vivo repair, the nGel-KGN-functionalized microporous layer is adjacent to the tendon which intends to suppress scar tissue formation at the lesion and simultaneously heightens chondrogenesis. Meanwhile, the struvite-containing fibrous layer covers the tubercula minus to enhance stem cell aggregation and bony ingrowth. Such tissue-specific features and spatiotemporal release behaviors contribute to effective guidance of specific defect-healing events at the transitional region, further leading to the remarkably promoted regenerative outcome in terms of the fibrocartilaginous tissue formation, collagen fiber alignment, and optimized functional motion of rotator cuff. These findings render a novel biomimetic membrane as a promising material for clinical rotator cuff repair.

3D-Printed PCL Scaffolds Loaded with bFGF and BMSCs Enhance Tendon-Bone Healing in Rat Rotator Cuff Tears by Immunomodulation and Osteogenesis Promotion

Rotator cuff tears are the most common conditions in sports medicine and attract increasing attention. Scar tissue healing at the tendon-bone interface results in a high rate of retears, making it a major challenge to enhance the healing of the rotator cuff tendon-bone interface. Biomaterials currently employed for tendon-bone healing in rotator cuff tears still exhibit limited efficacy. As a promising technology, 3D printing enables the customization of scaffold shapes and properties. Bone marrow mesenchymal stem cells (BMSCs) have multidifferentiation potential and valuable immunomodulatory effects. The basic fibroblast growth factor (bFGF), known for its role in proliferation, has been reported to promote osteogenesis. These properties make them applicable in tissue engineering. In this study, we developed a 3D-printed polycaprolactone (PCL) scaffold loaded with bFGF and BMSCs (PCLMF) to restore the tendon-bone interface and regulate the local inflammatory microenvironment. The PCLMF scaffolds significantly improved the biomechanical strength, histological score, and local bone mineral density at regenerated entheses at 2 weeks postsurgery and achieved optimal performance at 8 weeks. Furthermore, PCLMF scaffolds facilitated BMSC osteogenic differentiation and suppressed adipogenic differentiation both in vivo and in vitro. In addition, RNA-seq showed that PCLMF scaffolds could regulate macrophage polarization and inflammation through the MAPK pathway. The implanted scaffold demonstrated excellent biocompatibility and biosafety. Therefore, this study proposes a promising and practical strategy for enhancing tendon-bone healing in rotator cuff tears.

Identifying Water-Salt Homeostasis and Inflammatory Response in Pathological Cardiac Surgery-Associated Acute Kidney Injury: NT-proBNP-related lncRNAs and miRNAs as Novel Diagnostic Biomarkers and Therapeutic Targets

Acute kidney injury related to cardiac surgery (CS-AKI) is a serious medical issue that creates significant social and economic challenges globally. Inflammatory responses and disruptions in water and salt balance are important contributors to CS-AKI. Earlier studies indicated that pre-surgery levels of NT-proBNP were a dependable indicator of CS-AKI. Emerging evidence indicates that the abnormal expression of microRNA (miRNA) and long non-coding RNA (lncRNA) plays a role in the occurrence of CS-AKI. However, the important roles and mechanisms by which NT-proBNP affects lncRNA and miRNA in CS-AKI are still unclear. Here, we investigated lncRNA and miRNA expression patterns in BNP-high, BNP-stable, AKI, and non-AKI groups through whole transcriptome sequencing analysis. The BNP group exhibited differential expressions of 105 miRNAs and 138 lncRNAs. We identified 7 common miRNAs and lncRNAs in both the BNP and AKI groups. A functional and pathway enrichment analysis of the target genes associated with these miRNAs and lncRNAs was conducted, indicating that miR-135a-5p, miR-138-5p, miR-143-3p, and miR-206 are key factors in CS-AKI, particularly in regulating inflammatory responses and water-salt balance. These results provide fresh perspectives on research directions and possible treatment approaches for CS-AKI.

Spinal Metastasis Pain Surveillance: A Comprehensive Imaging-Based Tool Design for Evaluating Metastatic Burden and Guiding Therapeutic Strategies

Background: The current research aims to elucidate the interplay between the anatomical distribution of spinal metastases, MRI features, and the intensity of bone pain in patients with breast cancer. Methods: A retrospective analysis was used on a cohort of 45 breast cancer patients with verified spinal metastases, examining the relationship between metastatic locations, MRI-derived metrics, and bone pain scores. The Visual Analogue Scale (VAS) was conducted to measure the severity of bone pain. Results: The results revealed a significant association between lumbar spine metastases and elevated pain scores, outpacing those observed in thoracic and cervical regions. Furthermore, a strong correlation was found between the multiplicity of metastatic sites and the ratio of high-intensity areas on MRI, both of which were predictive of increased pain severity. Conclusions: The study's outcomes indicate that distinct MRI profiles, including the number and location of spinal metastases, can serve as prognostic indicators of bone pain intensity in breast cancer patients. Our data highlighted the need for personalized pain management strategies and targeted interventions tailored to specific imaging characteristics. Ultimately, this research underscores the dual role of MRI in both detecting spinal metastases and informing symptom management, with the potential to augment the overall well-being of breast cancer patients with spinal involvement.

Unveiling the role of risk factors and predictive models in acute type-a aortic dissection surgery: OI downregulation and its association with immune disorders

Background and Objective: Acute type A aortic dissection (ATAAD) represents a critical and life-threatening condition requiring urgent surgical intervention, which is often life-saving. However, postoperative acute lung injury (ALI) has emerged as a prominent complication that significantly impacts patient outcomes and prognosis. This study aims to systematically analyze the risk factors associated with the development of severe ALI following ATAAD surgery, providing insights to improve postoperative management strategies. Methods: A retrospective analysis was conducted using a comprehensive database comprising 483 patients diagnosed with ATAAD. Patients were stratified into two groups based on the severity of postoperative ALI: severe ALI group (n = 182) and non-severe ALI group (n = 301). Clinical data were systematically collected and compared between the two cohorts. Binary logistic regression analysis was employed to identify independent predictors of severe ALI following ATAAD surgery. The diagnostic accuracy of these risk factors was assessed using receiver operating characteristic (ROC) curve analysis, with the area under the curve (AUC) serving as the metric for prognostic performance. Results: The severe ALI group exhibited a higher prevalence of preoperative oxygenation index (OI) ≤ 200 mmHg, smoking history, and coronary artery disease compared to the non-severe ALI group (P < 0.001, P = 0.032, and P = 0.039, respectively), while the prevalence of Marfan syndrome was lower (P = 0.033). Moreover, significant differences were observed in several clinical and intraoperative parameters, including body mass index (BMI), C-reactive protein (CRP), procalcitonin (PCT), D-dimer, white blood cell count (WBC), aortic cross-clamp time, moderate hypothermic circulatory arrest (MHCA) time, cardiopulmonary bypass (CPB) duration, and ICU length of stay (all P < 0.05). Multivariate logistic regression identified preoperative OI [P = 0.008, OR (95% CI): 0.002 (0.000-0.183)], BMI [P = 0.037, OR (95% CI): 1.569 (1.027-2.397)], CRP [P = 0.022, OR (95% CI): 1.292 (1.037-1.609)], D-dimer [P < 0.001, OR (95% CI): 3.841 (1.820-8.108)], MHCA time [P = 0.001, OR (95% CI): 3.306 (1.670-6.544)], and CPB duration [P = 0.017, OR (95% CI): 1.117 (1.020-1.223)] as independent predictors of severe ALI. ROC curve analysis revealed the diagnostic performance of preoperative OI, BMI, CRP, D-dimer, MHCA time, and CPB duration, with AUC values of 0.715, 0.844, 0.871, 0.955, 0.944, and 0.833, respectively (all P < 0.001). Conclusion: Preoperative oxygenation index, BMI, CRP, D-dimer levels, MHCA time, and CPB duration are independent risk factors for the development of severe ALI following ATAAD surgery. These findings underscore the importance of preoperative risk assessment and perioperative optimization to mitigate the risk of severe ALI and improve patient outcomes.

Glycosphingolipids-Dependent Phospholipid Metabolism Enhances Cancer Initiation and Progression through SMPD1/GLTP/B3GALT4/ST8SIA6 Signaling Axis: A Novel Therapeutic Target

Colorectal cancer (CRC) is a prevalent malignancy with high morbidity and mortality rates globally. Advances in single-cell sequencing technology have enabled comprehensive analyses of tumor cells at single-cell resolution, providing valuable insights into the molecular mechanisms underlying CRC initiation and progression. In this study, we integrated single-cell sequencing data with the TCGA database to identify key molecular pathways involved in CRC pathogenesis. Our analysis revealed that dysregulation of phospholipid metabolism, particularly sphingolipid metabolism, plays a crucial role in CRC development. Specifically, we observed aberrant expression of genes involved in sphingolipid biosynthesis and degradation, as well as altered levels of various sphingolipid metabolites in CRC cells. Furthermore, we identified several potential therapeutic targets, including SMPD1, GLTP, B3GALT4, and ST8SIA6, within the sphingolipid metabolism pathway that could be exploited for the development of novel CRC treatments. Overall, our findings provide novel insights into the molecular mechanisms underlying CRC and highlight the importance of targeting phospholipid metabolism, specifically sphingolipid metabolism, as a potential therapeutic strategy for CRC.

Inflammation-Responsive Functional Core-Shell Micro-Hydrogels Promote Rotator Cuff Tendon-To-Bone Healing by Recruiting MSCs and Immuno-Modulating Macrophages in Rats

Rotator cuff injuries often necessitate surgical intervention, but the outcomes are often unsatisfactory. The underlying reasons can be attributed to multiple factors, with the intricate inflammatory activities and insufficient presence of stem cells being particularly significant. In this study, an innovative inflammation-responsive core-shell micro-hydrogel is designed for independent release of SDF-1 and IL-4 within a single delivery system to promote tendon-to-bone healing by recruiting MSCs and modulating M2 macrophages polarization. First, a MMP-2 responsive hydrogel loaded with IL-4 (GelMA-MMP/IL-4) is synthesized by cross-linking gelatin methacrylate (GelMA) with MMP-2 substrate peptide. Then, the resulting core particles are coated with a shell of chitosan /SDF-1/hyaluronic acid (CS/HA/SDF-1) using the layer-by-layer electrostatic deposition method to form a core-shell micro-hydrogel composite. The core-shell micro-hydrogel shows sustained release of SDF-1 and MMP-2-responsive release of IL-4 associated in situ MSCs homing and smart inflammation regulation by promoting M2 macrophages polarization. Additionally, by injecting these micro-hydrogels into a rat rotator cuff tear and repair model, notable improvements of fibrocartilage layer are observed between tendon and bone. Notably, this study presents a new and potentially powerful environment-responsive drug delivery strategy that offers valuable insights for regulating the intricate micro-environment associated with tissue regeneration.

Effects of a 12-week Baduanjin regimen on biomechanical properties of axial muscle fascia in ankylosing spondylitis

BACKGROUND

This study aims to evaluate the effects of a 12-week Baduanjin regimen on the biomechanical properties of axial muscle fascia in patients with ankylosing spondylitis (AS) through a randomized controlled trial, and to explore the underlying mechanisms of Baduanjin in AS treatment.

METHODS

Thirty patients with AS were randomly assigned to either the Baduanjin intervention group or the nonintervention group, with 15 patients in each group. The intervention group underwent a 12-week Baduanjin fitness program, while the nonintervention group continued their usual lifestyle and medication. Biomechanical parameters of muscle fascia, including muscle stiffness (N/m), muscle tension (frequency, Hz), and muscle elasticity (logarithmic decrement of oscillation amplitude), were measured at specified spinal locations using the MyotonPRO® soft tissue tester at baseline (week 0) and after 12 weeks (week 12).

RESULTS

The Baduanjin group exhibited significant improvements in muscle fascia stiffness, tension, and elasticity in the lumbar and cervical spine compared to the nonintervention group, with notable differences in lumbar stiffness and tension (P < .05). Postintervention, lumbar stiffness and tension were significantly reduced, and elasticity increased in the Baduanjin group, indicating beneficial effects on the biomechanical properties of axial muscle fascia in AS patients. No significant changes were observed in the nonintervention group. The Baduanjin group reported only mild muscle pain initially, which resolved with appropriate management, with no serious adverse effects noted.

CONCLUSION

The findings suggest that Baduanjin significantly enhances the biomechanical properties of axial muscle fascia in AS patients. By improving these properties, Baduanjin may reduce mechanical stress, alleviate micro-damage and inflammation at attachment points, regulate downstream signaling pathways, and potentially limit new bone formation. This study provides scientific support for the use of Baduanjin in managing AS and offers a foundation for future research.

Ultrasmall Antioxidant Copper Nanozyme to Enhance Stem Cell Microenvironment for Promoting Diabetic Wound Healing

Purpose

Stem cell therapy is a promising approach for treating chronic diabetic wounds. However, its effectiveness is significantly limited by the high oxidative stress environment and persistent inflammation induced by diabetes. Strategies to overcome these challenges are essential to enhance the therapeutic potential of stem cell therapy.

Methods

Cu5.4O ultrasmall nanoparticles (Cu5.4O-USNPs), known for their excellent reactive oxygen species (ROS) scavenging properties, were utilized to protect adipose-derived stem cells (ADSCs) from oxidative stress injury. In vitro experiments were conducted to evaluate the viability, paracrine activity, and anti-inflammatory capabilities of ADSCs loaded with Cu5.4O-USNPs under oxidative stress conditions. In vivo experiments in diabetic mice were performed to assess the therapeutic effects of Cu5.4O-USNP-loaded ADSCs on wound healing, including their impact on inflammation, collagen synthesis, angiogenesis, and wound closure.

Results

ADSCs treated with Cu5.4O-USNPs showed significantly enhanced viability, paracrine activity, and anti-inflammatory properties under oxidative stress conditions in vitro. In diabetic mice, Cu5.4O-USNP-loaded ADSCs reduced inflammatory responses in wound tissues, promoted collagen synthesis and angiogenesis, and accelerated diabetic wound healing. These findings suggest that Cu5.4O-USNPs effectively mitigate the adverse effects of oxidative stress and inflammation, enhancing the therapeutic efficacy of ADSCs.

Conclusion

This study presents a simple and effective approach to improve the therapeutic potential of stem cell therapy for diabetic wounds. By incorporating Cu5.4O-USNPs, the antioxidative and anti-inflammatory capabilities of ADSCs are significantly enhanced, offering a promising strategy for ROS-related tissue repair and chronic wound healing.

Engineering exosomes from fibroblast growth factor 1 pre-conditioned adipose-derived stem cells promote ischemic skin flaps survival by activating autophagy

Background

The recovery of ischemic skin flaps is a major concern in clinical settings. The purpose of this study is to evaluate the effects of engineered exosomes derived from FGF1 pre-conditioned adipose-derived stem cells (FEXO) on ischemic skin flaps.

Method

6 patients who suffered from pressure ulcer at stage 4 and underwent skin flaps surgery were recruited in this study to screen the potential targets of ischemic skin flaps in FGF family. FGF1 was co-incubated with adipose stem cells, and ultracentrifugation was applied to extract FEXO. Transcriptome sequencing analysis was used to determine the most effective microRNA in FEXO. Animal skin flaps models were established in our study to verify the effects of FEXO. Immunofluorescence (IF), western blotting (WB) and other molecular strategy were used to evaluate the effects and mechanism of FEXO.

Results

FGF1 was expected to be the therapeutic and diagnostic target of ischemic skin flaps, but there is still some deficiency in rescuing skin flaps. FEXO significantly improved the viability of RPSFs and endothelial cells by inhibiting oxidative stress and alleviating apoptosis and pyroptosis through augmenting autophagy flux. In addition, FEXO inhibited the over-activated inflammation responses. Transcriptome sequencing analysis showed that miR-183-5p was significantly elevated in FEXO, and inhibiting miR-183-5p resulted in impaired protective effects of autophagy in skin flaps. The exosomal miR-183-5p markedly enhanced cell viability, inhibited oxidative stress and alleviated apoptosis and pyroptosis in endothelial cells by targeting GPR137 through Pi3k/Akt/mTOR pathway, indicating that GPR137 could also be a therapeutic target of ischemic skin flap. It was also notabale that FGF1 increased the number of exosomes by upregulating VAMP3, which may be a promising strategy for clinical translation.

Conclusion

FEXO markedly improved the survivial rate of ischemic skin flaps through miR-183-5p/GPR137/Pi3k/Akt/mTOR axis, which would be a promising strategy to rescue ischemic skin flaps.

Skin Stretching Techniques: A Review of Clinical Application in Wound Repair

Background

The repair of skin defect wounds is a long-term goal of clinical pursuit. Currently, free or pedicled skin flap transplantation is commonly used to repair skin defects. However, these methods may lead to complications such as flap necrosis, thrombosis, scarring, diminished sensation, and pigmentation in both the donor and recipient areas. Since its introduction in 1976, skin stretching techniques were widely used for minor skin and soft-tissue defects in the surgical field.

Methods

A narrative review was conducted to identify relevant articles about the skin stretching techniques for promoting wound healing. We searched the Web of Science and PubMed databases for all articles containing different combinations of "skin stretch techniques" and "wound repair," "skin defects," and "tissue expansion."

Results

Through the screening of 500 articles, 84 representative and persuasive articles were selected in this review. These studies collectively demonstrate the technique's effectiveness in reducing wound size, facilitating primary closure, and improving cosmetic outcomes. Reported complications were generally minor, including transient erythema and mild discomfort, with rare instances of skin necrosis.

Conclusions

Skin stretch techniques emerge as a promising approach for managing large-area wounds, offering the advantage of achieving primary healing without compromising surrounding healthy tissue. However, to optimize its clinical application, further research is warranted, particularly in addressing challenges related to precise stretching and infection management.

ACL injury management: a comprehensive review of novel biotherapeutics

The anterior cruciate ligament (ACL) is integral to the stability of the knee joint, serving to limit anterior tibial translation and regulate rotational movements. ACL injuries are among the most common and debilitating forms of knee trauma, often resulting in joint effusion, muscular atrophy, and diminished athletic capabilities. Despite the established efficacy of ACL reconstruction as the standard treatment, it is not uniformly successful. Consequently, there is a growing interest in novel biotherapeutic interventions as potential alternatives. This comprehensive review examines the latest advancements in ACL biotherapy, encompassing the application of hyaluronic acid, self-assembled short peptides, growth factors, stem cell therapy, gene therapy, platelet-rich plasma therapy, bone marrow aspirate concentrate cells, extracorporeal shock wave, electrical stimulation and cross bracing protocol. The collective aim of these innovative treatments is to facilitate the restoration of the ACL's native biological and biomechanical integrity, with the ultimate goal of enhancing clinical outcomes and the functional recovery of affected individuals.

Exosomes from mesenchymal stem cells: Potential applications in wound healing

Wound healing is a continuous and complex process regulated by multiple factors, which has become an intractable clinical burden. Mesenchymal stem cell-derived exosomes (MSC-exos) possess low immunogenicity, easy preservation, and potent bioactivity, which is a mirror to their parental cells MSC-exos are important tools for regulating the biological behaviors of wound healing-associated cells, including fibroblasts, keratinocytes, immune cells, and endothelial cells. MSC-exos accelerate the wound healing process at cellular and animal levels by modulating inflammatory responses, promoting collagen deposition and vascularization. MSC-exos accelerate wound healing at the cellular and animal levels by modulating inflammatory responses and promoting collagen deposition and vascularization. This review summarizes the roles and mechanisms of MSC-exos originating from various sources in promoting the healing efficacy of general wounds, diabetic wounds, burn wounds, and healing-related scars. It also discusses the limitations and perspectives of MSC-exos in wound healing, in terms of exosome acquisition, mechanistic complexity, and exosome potentiation modalities. A deeper understanding of the properties and functions of MSC-exos is beneficial to advance the therapeutic approaches for achieving optimal wound healing.

Exosomes Derived from Antler Mesenchymal Stem Cells Promote Wound Healing by miR-21-5p/STAT3 Axis

Background

Deer antlers, unique among mammalian organs for their ability to regenerate annually without scar formation, provide an innovative model for regenerative medicine. This study explored the potential of exosomes derived from antler mesenchymal stem cells (AMSC-Exo) to enhance skin wound healing.

Methods

We explored the proliferation, migration and angiogenesis effects of AMSC-Exo on HaCaT cells and HUVEC cells. To investigate the skin repairing effect of AMSC-Exo, we established a full-thickness skin injury mouse model. Then the skin thickness, the epidermis, collagen fibers, CD31 and collagen expressions were tested by H&E staining, Masson's trichrome staining and immunofluorescence experiments. MiRNA omics analysis was conducted to explore the mechanism of AMSC-Exo in skin repairing.

Results

AMSC-Exo stimulated the proliferation and migration of HaCaT cells, accelerated the migration and angiogenesis of HUVEC cells. In the mouse skin injury model, AMSC-Exo stimulated angiogenesis and regulated the extracellular matrix by facilitating the conversion of collagen type III to collagen type I, restoring epidermal thickness to normal state without aberrant hyperplasia. Notably, AMSC-Exo enhanced the quality of wound healing with increased vascularization and reduced scar formation. MiRNAs in AMSC-Exo, especially through the miR-21-5p/STAT3 signaling pathway, played a crucial role in these processes.

Conclusion

This study underscores the efficacy of AMSC-Exo in treating skin wounds, suggesting a new approach for enhancing skin repair and regeneration.

Global trends in the clinical utilization of exosomes in dermatology: a bibliometric analysis

The arena of exosomal research presents substantial emerging prospects for clinical dermatology applications. This investigation conducts a thorough analysis of the contemporary global research landscape regarding exosomes and their implications for dermatological applications over the preceding decade. Employing bibliometric methodologies, this study meticulously dissects the knowledge framework and identifies dynamic trends within this specialized field. Contemporary scholarly literature spanning the last decade was sourced from the Web of Science Core Collection (WoSCC) database. Subsequent to retrieval, both quantitative and visual analyses of the pertinent publications were performed utilizing the analytical software tools VOSviewer and Citespace. A comprehensive retrieval yielded 545 scholarly articles dated from January 1, 2014, to December 31, 2023. Leading the research forefront are institutions such as Shanghai Jiao Tong University, The Fourth Military Medical University, and Sun Yat-sen University. The most prolific contributors on a national scale are China, the United States, and South Korea. Among the authors, Zhang Bin, Zhang Wei, and Zhang Yan emerge as the most published, with Zhang Bin also achieving the distinction of being the most cited. The International Journal of Molecular Sciences leads in article publications, whereas Stem Cell Research & Therapy holds the pinnacle in citation rankings. Theranostics boasts the highest impact factor among the periodicals. Current research hotspots in this area include Adipose mesenchymal stem cell-derived exosomes(ADSC-Exos), diabetic skin wounds, cutaneous angiogenesis, and the combination of biomaterials and exosomes. This manuscript constitutes the inaugural comprehensive bibliometric analysis that delineates the prevailing research trends and advancements in the clinical application of exosomes in dermatology. These analyses illuminate the contemporary research focal points and trajectories, providing invaluable insights that will inform further exploration within this domain.

Exosomes derived from tendon stem/progenitor cells enhance tendon-bone interface healing after rotator cuff repair in a rat model

The rate of retear after surgical repair remains high. Mesenchymal stem cells (MSCs) have been extensively employed in regenerative medicine for several decades. However, safety and ethical concerns constrain their clinical application. Tendon Stem/Progenitor Cells (TSPCs)-derived exosomes have emerged as promising cell-free therapeutic agents. Therefore, urgent studies are needed to investigate whether TSPC-Exos could enhance tendon-bone healing and elucidate the underlying mechanisms. In this study, TSPC-Exos were found to promote the proliferation, migration, and expression of fibrogenesis markers in BMSCs. Furthermore, TSPC-Exos demonstrated an ability to suppress the polarization of M1 macrophages while promoting M2 macrophage polarization. In a rat model of rotator cuff repair, TSPC-Exos modulated inflammation and improved the histological structure of the tendon-bone interface, the biomechanical properties of the repaired tendon, and the function of the joint. Mechanistically, TSPC-Exos exhibited high expression of miR-21a-5p, which regulated the expression of PDCD4. The PDCD4/AKT/mTOR axis was implicated in the therapeutic effects of TSPC-Exos on proliferation, migration, and fibrogenesis in BMSCs. This study introduces a novel approach utilizing TSPC-Exos therapy as a promising strategy for cell-free therapies, potentially benefiting patients with rotator cuff tear in the future.

Vitamin B-6 Prevents Heart Failure with Preserved Ejection Fraction Through Downstream of Kinase 3 in a Mouse Model

BACKGROUND

There is an urgent need to develop an efficient therapeutic strategy for heart failure with preserved ejection fraction (HFpEF), which is mediated by phenotypic changes in cardiac macrophages. We previously reported that vitamin B-6 inhibits macrophage-mediated inflammasome activation.

OBJECTIVES

We sought to examine whether the prophylactic use of vitamin B-6 prevents HFpEF.

METHODS

HFpEF model was elicited by a combination of high-fat diet and Nω-nitro-l-arginine methyl ester supplement in mice. Cardiac function was assessed using conventional echocardiography and Doppler imaging. Immunohistochemistry and immunoblotting were used to detect changes in the macrophage phenotype and myocardial remodeling-related molecules.

RESULTS

Co-administration of vitamin B-6 with HFpEF mice mitigated HFpEF phenotypes, including diastolic dysfunction, cardiac macrophage phenotypic shifts, fibrosis, and hypertrophy. Echocardiographic improvements were observed, with the E/E' ratio decreasing from 42.0 to 21.6 and the E/A ratio improving from 2.13 to 1.17. The exercise capacity also increased from 295.3 to 657.7 min. However, these beneficial effects were negated in downstream of kinase (DOK) 3-deficient mice. Mechanistically, vitamin B-6 increased DOK3 protein concentrations and inhibited macrophage phenotypic changes, which were abrogated by an AMP-activated protein kinase inhibitor.

CONCLUSIONS

Vitamin B-6 increases DOK3 signaling to lower risk of HFpEF by inhibiting phenotypic changes in cardiac macrophages.

Optimizing Tissue Engineering for Clinical Relevance in Rotator Cuff Repair

Rotator cuff tear (RCT) is the most common cause of disability in the upper extremity. It results in 4.5 million physician visits in the United States every year and is the most common etiology of shoulder conditions evaluated by orthopedic surgeons. Over 460,000 RCT repair surgeries are performed in the United States annually. Rotator cuff (RC) retear and failure to heal remain significant postoperative complications. Literature suggests that the retear rates can range from 29.5% to as high as 94%. Weakened and irregular enthesis regeneration is a crucial factor in postsurgical failure. Although commercially available RC repair grafts have been introduced to augment RC enthesis repair, they have been associated with mixed clinical outcomes. These grafts lack appropriate biological cues such as stem cells and signaling molecules at the bone-tendon interface. In addition, they do little to prevent fibrovascular scar tissue formation, which causes the RC to be susceptible to retear. Advances in tissue engineering have demonstrated that mesenchymal stem cells (MSCs) and growth factors (GFs) enhance RC enthesis regeneration in animal models. These models show that delivering MSCs and GFs to the site of RCT enhances native enthesis repair and leads to greater mechanical strength. In addition, these models demonstrate that MSCs and GFs may be delivered through a variety of methods including direct injection, saturation of repair materials, and loaded microspheres. Grafts that incorporate MSCs and GFs enhance anti-inflammation, osteogenesis, angiogenesis, and chondrogenesis in the RC repair process. It is crucial that the techniques that have shown success in animal models are incorporated into the clinical setting. A gap currently exists between the promising biological factors that have been investigated in animal models and the RC repair grafts that can be used in the clinical setting. Future RC repair grafts must allow for stable implantation and fixation, be compatible with current arthroscopic techniques, and have the capability to deliver MSCs and/or GFs.

A Comprehensive Review of Stem Cell Conditioned Media Role for Anti-Aging on Skin

Various studies have been widely conducted on conditioned medium for the development of anti-aging preparations, including the utilization of stem cells, which present a promising alternative solution. This narrative review aims to understand the latest developments in various conditioned medium stem cell applications for anti-aging on the skin. A search of the Scopus database yielded publications of interest. The research focused on articles published without restrictions on the year. After finding 68 articles in the search results, they moved on to the checking phase. Upon comprehensive literature review, 23 articles met the inclusion criteria, while 45 articles were deemed ineligible for participation in this research. The results of the review indicate that conditioned medium from various stem cells has demonstrated success in reducing risk factors for skin aging, as proven in various tests. The successful reduction of the risk of skin aging has been established in vitro, in vivo, and in clinical trials. Given the numerous studies on the progress of exploring and utilizing conditioned medium, it is expected to provide a solution to the problem of skin aging.

Modulating mitochondrial dynamics ameliorates left ventricular dysfunction by suppressing diverse cell death pathways after diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) triggers a detrimental shift in mitochondrial dynamics, characterized by increased fission and decreased fusion, contributing to cardiomyocyte apoptosis and cardiac dysfunction. This study investigated the impact of modulating mitochondrial dynamics on DCM outcomes and underlying mechanisms in a mouse model. DCM induction led to upregulation of fission genes (Drp1, Mff, Fis1) and downregulation of fusion genes (Mfn1, Mfn2, Opa1). Inhibiting fission with Mdivi-1 or promoting fusion with Ginsenoside Rg1 preserved cardiac function, as evidenced by improved left ventricular ejection fraction (LVEF), fractional shortening (FS), and E/A ratio. Both treatments also reduced infarct size and attenuated cardiomyocyte apoptosis, indicated by decreased caspase-3 activity. Mechanistically, Mdivi-1 enhanced mitochondrial function by improving mitochondrial membrane potential, reducing reactive oxygen species (ROS) production, and increasing ATP generation. Ginsenoside Rg1 also preserved mitochondrial integrity and function under hypoxic conditions in HL-1 cardiomyocytes. These findings suggest that restoring the balance of mitochondrial dynamics through pharmacological interventions targeting either fission or fusion may offer a promising therapeutic strategy for mitigating MI-induced cardiac injury and improving patient outcomes.

Biologics in rotator cuff repair

Rotator cuff tears are common in middle-aged and elderly patients. Despite advances in the surgical repair of rotator cuff tears, the rates of recurrent tear remain high. This may be due to the complexity of the tendons of the rotator cuff, which contributes to an inherently hostile healing environment. During the past 20 years, there has been an increased interest in the use of biologics to complement the healing environment in the shoulder, in order to improve rotator cuff healing and reduce the rate of recurrent tears. The aim of this review is to provide a summary of the current evidence for the use of forms of biological augmentation when repairing rotator cuff tears.

Boosting antitumor efficacy of nanoparticles by modulating tumor mechanical microenvironment

Nanoparticles have shown great potential for tumor targeting delivery via enhanced permeability and retention effect. However, the tumor mechanical microenvironment, characterized by dense extracellular matrix (ECM), high tumor stiffness and solid stress, leads to only 0.7% of administered dose accumulating in solid tumors and even fewer (∼0.0014%) reaching tumor cells, limiting the therapeutic efficacy of nanoparticles. Furthermore, the tumor mechanical microenvironment can regulate tumor cell stemness, promote tumor invasion, metastasis and reduce treatment efficacy. In this review, methods detecting the mechanical are introduced. Strategies for modulating the mechanical microenvironment including elimination of dense ECM by physical, chemical and biological methods, disruption of ECM formation, depletion or inhibition of cancer-associated fibroblasts, are then summarized. Finally, prospects and challenges for further clinical applications of mechano-modulating strategies to enhance the therapeutic efficacy of nanomedicines are discussed. This review may provide guidance for the rational design and application of nanoparticles in clinical settings.

Adipose-Derived Stem Cell Exosomes Facilitate Diabetic Wound Healing: Mechanisms and Potential Applications

Wound healing in diabetic patients is frequently hampered. Adipose-derived stem cell exosomes (ADSC-eoxs), serving as a crucial mode of intercellular communication, exhibit promising therapeutic roles in facilitating wound healing. This review aims to comprehensively outline the molecular mechanisms through which ADSC-eoxs enhance diabetic wound healing. We emphasize the biologically active molecules released by these exosomes and their involvement in signaling pathways associated with inflammation modulation, cellular proliferation, vascular neogenesis, and other pertinent processes. Additionally, the clinical application prospects of the reported ADSC-eoxs are also deliberated. A thorough understanding of these molecular mechanisms and potential applications is anticipated to furnish a theoretical groundwork for combating diabetic wound healing.

Human umbilical cord mesenchymal stem cells overexpressing RUNX1 promote tendon-bone healing by inhibiting osteolysis, enhancing osteogenesis and promoting angiogenesis

BACKGROUND

Rotator cuff injury (RCI) is a common shoulder injury, which is difficult to be completely repaired by surgery. Hence, new strategies are needed to promote the healing of tendon-bone.

OBJECTIVE

We aimed to investigate the effect of human umbilical cord mesenchymal stem cells (hUC-MSCs) overexpressing RUNX1 on the tendon-bone healing after RCI, and to further explore its mechanism.

METHODS

Lentiviral vector was used to mediate the overexpression of RUNX1. RUNX1-overexpressed UCB-MSCs (referred to as MSC-RUNX1) were co-cultured with osteoclasts, and TRAP staining was performed to observe the formation of osteoclasts. Then MSC-RUNX1 was cultured in osteogenic differentiation medium, Alizarin red staining was conducted to detect osteogenic differentiation. The expression of markers of osteogenesis and osteoclast was detected by RT-qPCR. EA. hy926 cells were co-cultured with MSC-RUNX1. Transwell assay was used to detect the migration, and the expression of angiogenesis related-genes VEGF and TGF-β was detected by RT-qPCR. The rat rotator cuff reconstruction model was established and MSCs were injected at the tendon-bone junction. Biomechanical test and micro-CT scanning were performed, and HE, Masson and Alcian Blue staining were used for histological evaluation of tendon-bone healing. TUNEL and PCNA immunofluorescence (IF) staining were performed to evaluate apoptosis and proliferation at the tendon-bone healing site. The levels of TNF-α, IL-6 and IL-8 in serum were detected by ELISA. The expression of CD31 and Endomucin that related to angiogenesis was detected by IF. Safranin O-fast and TRAP/CD40L immunohistochemical staining were used to assess the levels of osteoclasts and osteoblasts at the tendon-bone healing site.

RESULTS

hUC-MSCs overexpressing RUNX1 inhibited osteoclast formation and promoted osteogenic differentiation. MSC-RUNX1 could promote the migration and tube formation of EA. hy926 cells, and up-regulate the levels of VEGF and TGF-β. Model mice treated with MSC-RUNX1 partially restored the biomechanical indexes. Treatment of MSC-RUNX1 obviously increased the bone density, accompanied by the formation of new bone. In vivo experiments showed that MSC-RUNX1 treatment could promote tendon-bone healing and inhibit inflammatory response in rats. MSC-RUNX1 treatment also promoted angiogenesis at the tendon-bone healing site, while inhibiting osteoclast formation and promoting osteogenic differentiation.

CONCLUSION

hUC-MSCs overexpressing RUNX1 can inhibit the formation of osteoclasts and differentiation of osteoblasts, promote angiogenesis and inhibit inflammation, thereby promoting tendon-bone healing after RCI.

Early delivery of human umbilical cord mesenchymal stem cells improves healing in a rat model of Achilles tendinopathy

Objective: This study aimed to explore the efficacy and optimal delivery time of human umbilical cord mesenchymal stem cells (hUC-MSCs) in treating collagenase-induced Achilles tendinopathy. Methods: Achilles tendinopathy in rats at early or advanced stages was induced by injecting collagenase I into bilateral Achilles tendons. A total of 28 injured rats were injected with a hUC-MSC solution or normal saline into bilateral tendons twice and sampled after 4 weeks for histological staining, gene expression analysis, transmission electron microscope assay and biomechanical testing analysis. Results: The results revealed better histological performance and a larger collagen fiber diameter in the MSC group. mRNA expression of TNF-α, IL-1β and MMP-3 was lower after MSC transplantation. Early MSC delivery promoted collagen I and TIMP-3 synthesis, and strengthened tendon toughness. Conclusion: hUC-MSCs demonstrated a therapeutic effect in treating collagenase-induced Achilles tendinopathy, particularly in the early stage of tendinopathy.

Hot spots and frontiers in bone-tendon interface research: a bibliometric analysis and visualization from 2000 to 2023

Objective

In this research, we investigated the current status, hotspots, frontiers, and trends of research in the field of bone-tendon interface (BTI) from 2000 to 2023, based on bibliometrics and visualization and analysis in CiteSpace, VOSviewer, and a bibliometric package in R software.

Methods

We collected and organized the papers in the Web of Science core collection (WoSCC) for the past 23 years (2000-2023), and extracted and analyzed the papers related to BTI. The extracted papers were bibliometrically analyzed using CiteSpace for overall publication trends, authors, countries/regions, journals, keywords, research hotspots, and frontiers.

Results

A total of 1,995 papers met the inclusion criteria. The number of papers published and the number of citations in the field of BTI have continued to grow steadily over the past 23 years. In terms of research contribution, the United States leads in terms of the number and quality of publications, number of citations, and collaborations with other countries, while the United Kingdom and the Netherlands lead in terms of the average number of citations. The University of Leeds publishes the largest number of papers, and among the institutions hosting the 100 most cited papers Hospital for Special Surgery takes the top spot. MCGONAGLE D has published the highest number of papers (73) in the last 10 years. The top three clusters include #0 "psoriatic arthritis", #1 "rotator cuff repair", and #2 "tissue engineering". The structure and function of the BTI and its key mechanisms in the healing process are the key to research, while new therapies such as mechanical stimulation, platelet-rich plasma, mesenchymal stem cells, and biological scaffolds are hot topics and trends in research.

Conclusion

Over the past 23 years, global research on the BTI has expanded in both breadth and depth. The focus of research has shifted from studies concentrating on the structure of the BTI and the disease itself to new therapies such as biomaterial-based alternative treatments, mechanical stimulation, platelet-rich plasma, etc.

Bone marrow mesenchymal stem cell‑derived exosomes: A novel therapeutic agent for tendon‑bone healing (Review)

In sports medicine, injuries related to the insertion of tendons into bones, including rotator cuff injuries, anterior cruciate ligament injuries and Achilles tendon ruptures, are commonly observed. However, traditional therapies have proven to be insufficient in achieving satisfactory outcomes due to the intricate anatomical structure associated with these injuries. Adult bone marrow mesenchymal stem cells possess self‑renewal and multi‑directional differentiation potential and can generate various mesenchymal tissues to aid in the recovery of bone, cartilage, adipose tissue and bone marrow hematopoietic tissue. In addition, extracellular vesicles derived from bone marrow mesenchymal stem cells known as exosomes, contain lipids, proteins and nucleic acids that govern the tissue microenvironment, facilitate tissue repair and perform various biological functions. Studies have demonstrated that bone marrow mesenchymal stem cell‑derived exosomes can function as natural nanocapsules for drug delivery and can enhance tendon‑bone healing strength. The present review discusses the latest research results on the role of exosomes released by bone marrow mesenchymal stem cells in tendon‑bone healing and provides valuable information for implementing these techniques in regenerative medicine and sports health.

Bi-lineage inducible and immunoregulatory electrospun fibers scaffolds for synchronous regeneration of tendon-to-bone interface

Facilitating regeneration of the tendon-to-bone interface can reduce the risk of postoperative retear after rotator cuff repair. Unfortunately, undesirable inflammatory responses following injury, difficulties in fibrocartilage regeneration, and bone loss in the surrounding area are major contributors to suboptimal tendon-bone healing. Thus, the development of biomaterials capable of regulating macrophage polarization to a favorable phenotype and promoting the synchronous regeneration of the tendon-to-bone interface is currently a top priority. Here, strontium-doped mesoporous bioglass nanoparticles (Sr-MBG) were synthesized through a modulated sol-gel method and Bi-lineage Inducible and Immunoregulatory Electrospun Fibers Scaffolds (BIIEFS) containing Sr-MBG were fabricated. The BIIEFS were biocompatible, showed sustained release of multiple types of bioactive ions, enhanced osteogenic and chondrogenic differentiation of mesenchymal stem cells (MSCs), and facilitated macrophage polarization towards the M2 phenotype in vitro. The implantation of BIIEFS at the torn rotator cuff resulted in greater numbers of M2 macrophages and the synchronous regeneration of tendon, fibrocartilage, and bone at the tendon-to-bone interface, leading to a significant improvement in the biomechanical strength of the supraspinatus tendon-humerus complexes. Our research offers a feasible strategy to fabricate immunoregulatory and multi-lineage inducible electrospun fibers scaffolds incorporating bioglass nanoparticles for the regeneration of soft-to-hard tissue interfaces.

Therapeutic Potential of Exosomes in Tendon and Tendon-Bone Healing: A Systematic Review of Preclinical Studies

Exosomes have been proven to play a positive role in tendon and tendon-bone healing. Here, we systematically review the literature to evaluate the efficacy of exosomes in tendon and tendon-bone healing. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic and comprehensive review of the literature was performed on 21 January 2023. The electronic databases searched included Medline (through PubMed), Web of Science, Embase, Scopus, Cochrane Library and Ovid. In the end, a total of 1794 articles were systematically reviewed. Furthermore, a "snowball" search was also carried out. Finally, forty-six studies were included for analysis, with the total sample size being 1481 rats, 416 mice, 330 rabbits, 48 dogs, and 12 sheep. In these studies, exosomes promoted tendon and tendon-bone healing and displayed improved histological, biomechanical and morphological outcomes. Some studies also suggested the mechanism of exosomes in promoting tendon and tendon-bone healing, mainly through the following aspects: (1) suppressing inflammatory response and regulating macrophage polarization; (2) regulating gene expression, reshaping cell microenvironment and reconstructing extracellular matrix; (3) promoting angiogenesis. The risk of bias in the included studies was low on the whole. This systematic review provides evidence of the positive effect of exosomes on tendon and tendon-bone healing in preclinical studies. The unclear-to-low risk of bias highlights the significance of standardization of outcome reporting. It should be noted that the most suitable source, isolation methods, concentration and administration frequency of exosomes are still unknown. Additionally, few studies have used large animals as subjects. Further studies may be required on comparing the safety and efficacy of different treatment parameters in large animal models, which would be conducive to the design of clinical trials.