Chondrogenic Lineages Research Articles

Robust differentiation and potent immunomodulation of human mesenchymal stromal cells cultured with a xeno-free GMP protein supplement.

Human mesenchymal stromal cells (hMSC) are multipotent adult cells commonly used in regenerative medicine as advanced therapy medicinal products. The expansion of these cells in xeno-free supplements is highly encouraged by regulatory agencies due to safety concerns. However, the number of supplements with robust performance and consistency for hMSC expansion are limited. Here, we evaluate a xeno-free human plasma-derived protein supplement (Plastem, Grifols) for the expansion and functional evaluation of hMSCs. hMSC from bone marrow, adipose tissue and umbilical cord were obtained from two suppliers and cultured in Dulbecco's modified Eagle's medium (DMEM/F-12) supplemented with fetal bovine serum 10% (FBS), human platelet lysate 5% (hPL) or Plastem 10%+ hPL0.5%. Cell proliferation was evaluated after culturing hMSC for 13 days with trypan blue exclusion. hMSC immunophenotype was assessed by flow cytometry of surface markers expression. Multipotentiality assay determined the ability of hMSC to differentiate into osteogenic, chondrogenic and adipogenic lineages after 21 days, by using specific staining. Immunomodulatory properties of hMSC were analyzed by measuring suppression of human peripheral blood mononuclear cell (PBMC) proliferation in co-culture with hMSC. Plastem 10% + hPL 0.5% supported robust and sustained hMSC growth with a similar efficiency to the reference supplement FBS 10%. hMSC cultured with the xeno-free supplement presented a similar morphology comparable to FBS-supplemented cells and maintained typical expression of markers: positive (>95%) for CD90, CD73 and CD105; and negative (<5%) for CD45, CD14, CD19, CD34 and HLA-DR. Likewise, hMSC showed potent, in vitro differentiation potential into osteogenic, chondrogenic and adipogenic lineages, outperforming the results obtained with traditional reference supplements in several instances. They retained their immunomodulatory properties, inhibiting the proliferation of phytohemagglutinin (PHA)-stimulated PBMCs with a notable enhancement of the immunomodulatory capacity of hMSCs compared to conventional reference supplements. Plastem allowed hMSC expansion while preserving phenotype and showed remarkable differentiation and immunomodulatory properties, supporting its use for cell therapy manufacturing processes as a robust, xeno-free alternative to FBS and hPL. Moreover, Plastem can be manufactured at an industrial level, making it a scalable solution for widespread application.

A Safe and Convenient Method to Isolate Bone Marrow Mononuclear Cells in Clinical Practice.

Bone marrow mononuclear cells (BMMNCs) are becoming a promising cell therapy in regeneration medicine. BMMNCs are now obtained by density gradient centrifugation (DGC) in clinical practice, which is complicated and greatly influenced by human manipulation. Our objective is to develop a simple and safe method to isolate BMMNCs. Bone marrow was aspirated from nine minipigs. The optimal hypotonic sodium chloride (NaCl) concentration was first investigated based on the BMMNCs viability and lysis efficiency tests. Afterward, three different methods (ammonium chloride (NH4Cl) lysis, hypotonic NaCl lysis, and DGC) were used for BMMNCs isolation. Nucleated cell yield, residual red blood cells (RBCs) level, BMMNCs viability, apoptotic cell percentage, and colony-forming ability were measured in three groups. Cell morphology, cell phenotype, proliferative capacity, and osteogenic, adipogenic, and chondrogenic lineage differentiation potential of the bone marrow mesenchymal stem cells (BMSCs) were compared in three groups. 0.3% NaCl lysis group had optimal cell viability and lysis efficiency and the 0.3% NaCl lysis group had higher cell yield and lower RBCs remaining in BMMNCs compared to the DGC group. The BMSCs harvested from the NH4Cl lysis group had the worst proliferation ability. The NaCl lysis group was not inferior to the other two groups in terms of other biological characteristics of BMMNCs/BMSCs. The optimal concentration for hypotonic NaCl lysis to obtain BMMNCs is 0.3%. Compared with NH4Cl lysis and DGC, the 0.3% NaCl lysis may be a safe, appropriate, and low-cost method for BMMNCs isolation. This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Antineoplastic therapy affects the in vitro phenotype and functionality of healthy human bone marrow-derived mesenchymal stromal cells

While antineoplastic therapies aim to specifically target cancer cells, they may also exert adverse effects on healthy tissues, like healthy hematopoietic stem and progenitor cells (HSPC), leading to hematotoxicity as a common side effect. Mesenchymal stromal cells (MSC) are a major component of the bone marrow (BM) microenvironment, regulating normal hematopoiesis, while their susceptibility to anticancer therapies and contribution to therapy-related hematotoxicity remains largely unexplored. To address this, we investigated the effects of etoposide, temozolomide, 5-azacitidine, and venetoclax on healthy BM-derived MSC functionality. Doses below therapeutic effects of etoposide (0.1–0.25 µM) inhibited cellular growth and induced cellular senescence in healthy MSC, accompanied by an increased mRNA expression of CDKN1A, decreased trilineage differentiation capacity, and insufficient hematopoietic support. Pharmacological doses of 5-azacitidine (2.5 µM) shifted MSC differentiation capacity by inhibiting osteogenic capacity but enhancing the chondrogenic lineage, as demonstrated by histochemical staining and on mRNA level. At the highest clinically relevant dose, neither venetoclax (40 nM) nor temozolomide (100 µM) exerted any effects on MSC but clearly inhibited cellular growth of cancer cell lines and primary healthy HSPC, pointing to damage to hematopoietic cells as a major driver of hematotoxicity of these two compounds. Our findings show that besides HSPC, also MSC are sensitive to certain antineoplastic agents, resulting in molecular and functional alterations that may contribute to therapy-related myelosuppression. Understanding these interactions could be helpful for the development of strategies to preserve BM MSC functionality during different kinds of anticancer therapies.

A natural composite hydrogel laden with mesenchymal stromal cells for osteochondral repair: Comparison between casting and 3D bioprinting

Synovial joints, and particularly the osteochondral unit, are prone to lesions, with high risk of degeneration towards osteoarthritis. Various treatment strategies have been developed, including surgical techniques and cellular therapies, but they all show limitations. In this context, tissue engineering approaches, particularly 3D bioprinting, are promising for generating osteochondral tissue substitutes for joint repair. In this work, two biofabrication techniques, casting and extrusion-based 3D bioprinting, of an optimized formulation of a gelatin/alginate/fibrinogen bioink loaded with murine mesenchymal stromal cells (MSCs) were compared for the generation of cartilage and bone substitutes. Cell viability, proliferation and differentiation were characterized. Both techniques showed similar results in terms of viability and proliferation, but only the 3D bioprinted constructs allowed for differentiation towards the chondrogenic or osteogenic lineage using specific culture media. Bioprinting of biphasic osteochondral constructs comprising a cartilage compartment on top of a bone compartment was also explored. The study highlights the potential of our natural composite hydrogel bioink and extrusion-based 3D bioprinting for the generation of osteochondral tissue substitutes. Although further optimizations are needed, the study laid the groundwork for future advancements in osteochondral tissue engineering.

Alternative Ways to Obtain Human Mesenchymal Stem Cells from Embryonic Stem Cells.

Differentiation approaches to obtain mesenchymal stem cells (MSCs) have gradually developed over the last few decades. The problem is that different protocols give different MSC types, making further research difficult. Here, we tried three different approaches to differentiate embryonic stem cells (ESCs) from early mesoderm to MSCs using serum-containing or xeno-free differentiation medium and observed differences in the cells' morphology, doubling rate, ability to form colonies, surface marker analysis, and multilineage differentiation potential of the obtained cell lines. We concluded that the xeno-free medium best fits the criteria of MSCs' morphology, growth kinetics, and surface marker characterization. In contrast, the serum-containing medium gives better potential for further MSC differentiation into osteogenic, chondrogenic, and adipogenic lineages.

Spatiotemporal Analysis of Mesenchymal Stem Cells Fate Determination by Inflammatory Niche Following Soft Tissue Injury at a Single-Cell Level.

Heterotopic ossification (HO), often arising in response to traumatic challenges, results from the aberrant osteochondral differentiation of mesenchymal stem cells (MSCs). Nevertheless, the impact of trauma-induced inflammatory exposure on MSC fate determination remains ambiguous. In this study, the cellular diversity within inflammatory lesions is elucidated, comprising MSCs and several innate and adaptive immune cells. It is observed that quiescent MSCs transition into cycling MSCs, subsequently giving rise to chondrogenic (cMSC) and/or osteogenic (oMSC) lineages within the inflammatory microenvironment following muscle or tendon injuries, as revealed through single-cell RNA sequencing (scRNA-seq), spatial transcriptome and lineage tracing analysis. Moreover, these investigations demonstrate that neutrophils and natural killer (NK) cells enhance transition of quiescent MSCs into cycling MSCs, which is also controlled by M1 macrophages, a subpopulation of macrophages can also stimulate cMSC and oMSC production from cycling MSCs. Additionally, M2 macrophages, CD4+ and CD8+ T lymphocytes are found to promote chondrogenesis. Further analysis demonstrates that immune cells promotes the activation of signaling transducers and activators of transcription (STAT) pathway and phosphoinositide 3 (PI3K)/protein kinase B (AKT) pathway in MSC proliferation and osteochondral progenitors' production, respectively. These findings highlight the dynamics of MSC fate within the inflammatory lesion and unveil the molecular landscape of osteoimmunological interactions, which holds promise for advancing HO treatment.

A Comparative Analysis of the Age-dependent Features of Mesenchymal Stem Cells from Buffalo Adipose Tissue

Background: Mesenchymal stem cells are a potential candidate for regenerative medicine. Many factors may influence the physiological characteristics of stem cells that may lead to the alteration in their potential. Methods: The impact of age on mesenchymal stem cell characteristics was investigated in older buffaloes (aged over 10 years) and compared to younger counterparts (aged less than 2 years). Following isolation through enzymatic digestion, the mesenchymal stem cells were cultured in DMEM containing 12.5% FBS and antibiotics. Different variables indicating stem cell characteristics were evaluated at subsequent cultures. Result: The results revealed both groups displayed positive staining for alkaline phosphatase (AP) and expressed stem cell markers, including CD73, CD105 and OCT4, while remain negative for CD34. Furthermore, both sets of stem cells demonstrated the ability to differentiate into adipogenic, osteogenicand chondrogenic lineages. There were no notable variations observed between the two groups in terms of the cell yield, percentages of senescent cells, necrotic cells, dead cells and the apoptotic index. Expression of the P53 gene in RT-PCR amplicon in both groups confirms that stem cells are dividing normally as healthy cells and not tumor cells. Consequently, it was concluded from the present investigation that the age of the animal does not influence the characteristics of mesenchymal stem cells derived from adipose tissue. Thus, the stem cells derived from older and younger buffaloes are suited equally as a cell source for regenerative therapeutics.

Comparison of infant bone marrow- and umbilical cord-derived mesenchymal stem cells in multilineage differentiation

We compared infant bone marrow-derived mesenchymal stem cells (infant BMSCs) with umbilical cord-derived mesenchymal stem cells (UCSCs) by assessing multilineage differentiation. Proliferation was gauged through changes in cell numbers and doubling time. Senescence-related genes (p16, p21, and p53), senescence-associated β-galactosidase (SA-β-gal), and γH2AX immunofluorescence determined senescence presence. Superoxide dismutases (SODs) and genes related to various differentiations were analyzed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Differentiation was confirmed through histochemical, immunohistochemical, and immunofluorescence staining. Infant BMSCs surpassed UCSCs in proliferation. Infant BMSCs exhibited lower senescence-related gene expression at late passages, upregulated antioxidant enzymes during early passages, and reduced SA-β-gal staining. Chondrogenic gene expression (SOX9, COL2, and COL10) was enhanced in infant BMSCs, along with improved immunohistochemical staining. Infant BMSCs showed higher expression of osteogenic (ALP and OCN) and adipogenic (PPARγ and LPL) genes, confirmed by histochemical staining. However, UCSCs had higher expression of tenogenic genes (MMP3, SCX, DCN, and TNC). Hepatogenic differentiation potential was similar, with no significant difference in hepatogenic gene expression (ALB and TAT). Compared to UCSCs, infant BMSCs demonstrated superior proliferation, reduced senescence, increased antioxidant capacity, and enhanced differentiation potential toward chondrogenic, osteogenic, and adipogenic lineages.

RETINOBLASTOMA CELLS OVEREXPRESSING THE MRPS18-2 PROTEIN COULD BE DIFFERENTIATED in vitro

The mitochondrial ribosomal protein MRPS18-2 is involved in cell cycle regulation through its interaction with the retinoblastoma-associated protein, RB. Earlier we have shown that this protein plays an important role in homeostasis of normal and tumor cells, embryogenesis, and in the maintenance of cell stemness. We also found that the MRPS18-2 protein is transactivated by a transcription factor KLF4, one of the Yamanaka factors, inducing cell pluripotency. The aim of the present work was to study the functional consequences of overexpression of the MRPS18-2 and RB proteins in the retinoblastoma cell line (WERI RB 27), concerning putative directed differentiation in vitro. Methods. Direct multipotent differentiation was conducted with cocktails of chemicals for osteogenic, chondrogenic, and adipogenic lineages. Ca+2 ions were stained with Alizarin Red, triglycerides – with Oil Red O, and glycosaminoglycans - with Alcian blue. Results. Parental cells WERI RB-27 did not differentiate upon treatment with any of chemical cocktails, cells remained in suspension and did not change morphology. At the same time, cells that overexpressed MRPS18-2 have demonstrated their differentiation ability into osteo-, chondro-, and adipo-lineages. Conclusions. Thus, we have shown that overexpression of the MRPS18-2 protein in WERI RB 27 cells leads to changes in cell morphology and to ability of the directed multipotent differentiation in vitro. Hence, the MRPS18-2 protein plays a significant role in cancerogenesis and cell stemness.

A Review of Stem Cell Attributes Derived from the Oral Cavity

Oral cavity stem cells (OCSCs) have been the focus of intense scientific efforts due to their accessibility and stem cell properties. The present work aims to compare the different characteristics of 6 types of dental stem cells derived from the oral cavity: dental pulp stem cells (DPSC), stem cells from human exfoliated deciduous teeth (SHED), periodontal ligament stem cells (PDLSC), stem cells from the apical papilla (SCAP), bone marrow mesenchymal stem cells (BMSC), and gingival mesenchymal stem cells (GMSC). Using immunofluorescence and real-time polymerase chain reaction techniques, we analysed the cells for stem cell, differentiation, adhesion, and extracellular matrix markers; the ability to proliferate in vitro; and multilineage differentiation potential. Markers such as vimentin, CD44, alkaline phosphatase, CD146, CD271, CD49f, Oct 3/4, Sox 9, FGF7, nestin, and BMP4 showed significant differences in expression levels, highlighting the heterogeneity and unique characteristics of each cell type. At the same time, we confirmed that all cell types successfully differentiated into osteogenic, chondrogenic, or adipose lineages, with different readiness. In conclusion, our study reveals the distinct properties and potential applications of various dental-derived stem cells. These findings contribute to a deeper understanding of OCSCs and their significance in future clinical applications.

Turning Trash Into Treasure: A Simple Protocol for Human Mesenchymal Stromal Cell Isolation From Used Bone Marrow Collection Kits.

The therapeutic potential of mesenchymal stromal cells (MSCs) has been extensively investigated in both preclinical and clinical settings. Recent years have witnessed the emergence of numerous isolation protocols and culture techniques, ranging from the selection of subpopulations to preserve stemness to preconditioning strategies aimed at enhancing therapeutic efficacy, tailored to the specific tissue source. In this protocol, we present a straightforward and cost-effective method for isolating human MSCs (hMSCs) from discarded bone marrow collection kits (comprising bag and filter systems) originally intended for removing impurities and unwanted cellular debris from the collected bone marrow aspirate, ensuring the purity of the stem cell population during stem cell transplantation. Utilizing basic laboratory equipment, we demonstrate the isolation of hMSCs, highlighting the expression of specific surface antigens, and multilineage differentiation into adipogenic, osteogenic, and chondrogenic lineages in vitro. This sustainable and resource-efficient approach not only contributes to reducing medical waste but also holds promise for advancing regenerative medicine applications. © 2024 Wiley Periodicals LLC. Basic Protocol 1: Isolation of human mesenchymal stromal cells from bone marrow collection kits Basic Protocol 2: Culture of human mesenchymal stromal cells Basic Protocol 3: Characterization of human mesenchymal stromal cells with flow cytometry analysis Basic Protocol 4: Characterization of human mesenchymal stromal cells with multilineage differentiation under in vitro conditions.

Osteogenic differentiation of canine adipose derived mesenchymal stem cells on B‐TCP and B‐TCP/Collagen biomaterials

Mesenchymal stem cells are adult stem cells that can differentiate into osteogenic, chondrogenic, adipogenic and myogenic lineages. In orthopedics and traumatology, mesenchymal stem cells, combined with biomaterials, are used mainly for treating bone fractures and diseases in humans and animals. This study aims to promote the growth, proliferation, and osteogenic differentiation of mesenchymal stem cells isolated from the adipose tissue of canines on B‐TCP (Beta‐tricalcium phosphate) and B‐TCP/Collagen biomaterials. MTT analysis was performed to test the cell adhesion and proliferation on B‐TCP and B‐TCP/Collagen biomaterials used to mimic the extracellular matrix of three‐dimensional bone tissue. Scanning electron microscope analysis was performed to show general surface characters of BTCP and B‐TCP /Collagen biomaterials. The osteoinductive capacities of the BTCP and B‐TCP/Collagen biomaterials were determined by alkaline phosphatase and Von Kossa stainings, and RT‐PCR analysis. The ALP activity of the B‐TCP/Col containing material was significantly higher than the B‐TCP in the early days. In terms of gene expression, there were no significant differences except 14thday SPARC gene expression. The results of Von Kossa staining indicated that BTCP/ Col has above the desired level degradation capacity. As a result of this research, although it is advantageous in terms of alkaline phosphatase activity and osteogenic gene expression compared to B‐TCP material, it is thought that B‐TCP/Collagen biomaterial should be developed for use in bone tissue engineering due to its high degradation property.

Abstract 3359: HEY1::NCOA2 fusion disturbs the transcriptional program of chondrogenic differentiation and activates oncogenes in mesenchymal chondrosarcoma tumorigenesis

Abstract Mesenchymal chondrosarcoma (MCS) is a rare high-grade mesenchymal neoplasm occurring in bone and soft tissue. It accounts for 2%~10% of all chondrosarcomas and affects mainly adolescents and young adults. Genetically, this tumor is characterized by the recurrent HEY1::NCOA2 fusion. To functionally characterize the fusion in MCS tumorigenesis, we generated stably transduced iPSC-derived mesenchymal stem cells (iPSC-MSC) with inducible expression of HEY1::NCOA2. We previously demonstrated that the expression of HEY1::NCOA2 significantly enhanced cell proliferation, upregulated PDGFB/PI3K/AKT signaling, and induced genes that are involved in chondrocyte differentiation. In this study, we evaluated the impact on chondrogenic lineage differentiation and dysregulated pathways resulting from HEY1::NCOA2 expression and further elaborated oncogenic pathways in MCS tumorigenesis. We first successfully established the differentiation culture of inducing iPSC-MSC on chondrogenic lineage differentiation, showing an increase in glycosaminoglycans and the expression of differentiation markers (COL1A1, COL2A1, ACAN, COMP, SOX9 and COL10A1) at 7-, 14-, and 21-days post treatment with differentiation medium. The iPSC-MSC-HEY1::NCOA2 cells and control cells were cultured for chondrogenic lineage differentiation. During differentiation culture, we collected cells from each condition at multiple time points to (1) monitor the expression of differentiation markers and (2) perform transcriptomic profiling. Principal component analysis showed that cells with the expression of HEY1::NCOA2 possessed a distinct feature from parental cells and control cells, however, HEY1::NCOA2 did not simply suppress chondrogenic differentiation. The differential gene expression indicated that HEY1::NCOA2 fusion disrupted genes related to fine tuning of chondrogenic differentiation (SOX9, COMP, and IGF1) and activated oncogenes (PDGFB, BCL2, CCND1, IGF2, etc.). Notably, we demonstrated that both BCL2 (an anti-apoptotic protein) and COMP (possess antiapoptotic function that protects chondrocytes against death and blocks activation of caspase 3) were directly targeted and consistently upregulated by HEY1::NCOA2 fusion. In addition, the functional classification of genes (n=86) consistently increased with HEY1:: NCOA2 expression through differentiation of the chondrogenic lineage demonstrated that the PI3K/AKT pathway was the most significantly enriched, which further supports targeting the PDGFB/PI3K/AKT axis in MCS therapy. Together, this study sheds light on how HEY1::NCOA2 fusion shapes key mechanisms of chondrogenic differentiation and exerts oncogenic activation. Our findings provide the rationale for anti-apoptosis along with anti-PDGFB/PI3K/AKT signaling in the treatment of mesenchymal chondrosarcoma. Citation Format: Wenqing Qi, Wojciech Rosikiewicz, Beisi Xu, Lu Wang. HEY1::NCOA2 fusion disturbs the transcriptional program of chondrogenic differentiation and activates oncogenes in mesenchymal chondrosarcoma tumorigenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3359.

Investigation of the differentiation potential of pericyte cells as an alternative source of mesenchymal stem cells

BackgroundThe mesenchymal stem cells (MSCs) with characterized by their multipotency and capacity to differentiate into various tissue cell types, have led to their incorporation in regenerative medicine research. However, the limited numbers of MSCs in the human body and their diverse differentiation capabilities in tissues highlight the need for exploring alternative regenerative cell sources. In this study, therefore, we conducted molecular level examinations to determine whether pericytes, specialized cell communities situated near blood vessels, could serve as a substitute for human bone marrow-derived mesenchymal stem cells (hBM-MSCs). In this context, the potential application of pericytes surrounds the vessels when MSCs are insufficient for functional purposes. MethodsThe pericytes utilized in this investigation were derived from the placenta and characterized at the third passage. Similarly, the hBM-MSCs were also characterized at the third passage. The pluripotent properties of the two cell types were assessed at the gene expression level. Thereafter, both pericytes and hBM-MSCs were directed towards adipogenic, osteogenic and chondrogenic differentiation. The cells in both groups were examined on days 7, 14, and, 21 and their differentiation status was compared both immunohistochemically and through gene expression analysis. ResultsUpon comparing the pluripotency characteristics of placental pericytes and hBM-MSCs, it was discovered that there was a substantial upregulation of the pluripotency genes FoxD3, Sox2, ZPF42, UTF1, and, Lin28 in both cell types. However, no significant expression of the genes Msx1, Nr6a1, Pdx1, and, GATA6 was observed in either cell type. It was also noted that pericytes differentiate into adipogenic, osteogenic and, chondrogenic lineages similar to hBM-MSCs. DiscussionAs a result, it has been determined that pericytes exhibit high differentiation and proliferation properties similar to those of MSCs, and therefore can be considered a suitable alternative cell source for regenerative medicine and tissue engineering research, in cases where MSCs are not available or insufficient. It is notable that pericytes have been suggested as a potential substitute in studies where MSCs are lacking.

THE POTENTIAL OF MAGNESIUM-BASED MICRO CYLINDER FOR CARTILAGE AND BONE REGENERATION UTILIZING AN IN VITRO OSTEOARTHRITIS MODEL

Osteoarthritis (OA) is an inflammatory disease affecting the complete synovial joint including the cartilage layer and the subchondral bone plate. Due to the multifactorial causes and the not yet completely resolved molecular mechanisms, it lacks a gold standard treatment to mitigate OA. Hence, biomaterials capable of delaying or preventing OA are a promising alternative or supplement to antiphlogistic and surgical interventions. Magnesium (Mg) and its alloys are among the promising biomaterials with osteoinductive effects. This work investigated the impact of Mg micro cylinders (length ≈of 1.0 mm and width of 0.5 mm) in vitro, in favoring joint regeneration together with preventing OA progression. Therefore, a mesenchymal stem cell line (SCP-1) was applied in order to assess the compatibility of the degradable material. Furthermore, an in vitro OA model utilizing SCP-1 cells based on the supplementation of the cytokines; IL-1β, TNF-α was established and disclosed the capability of Mg microparticles in differentiating SCP-1 cells into chondrogenic and osteogenic lineages proven through extracellular matrix staining and gene marker analysis. A concentration above 10 mM revealed a reduction in the cell viability by 50 %. An increase in the expression of collagens especially and proteoglycans (COL2A1, Aggrecan) as extracellular matrix proteins as well as an increase in osteogenic marker (ALP, BMP2) favoring the mineralization process were observed. The inflammatory condition reduced the viability and productivity of the applied stem cell line. However, the application of Mg microparticles induced a cell recovery and reduction of inflammation marker such as MMP1 and IL6. The cytocompatible and the ability of Mg microparticles in supporting bone and cartilage repair mechanisms in vitro even under inflammatory conditions make biodegradable Mg microparticles a suitable implant material to treat OA therapy.Acknowledgements: This project OAMag was funded by the German Research Foundation (project number 404534760). The author thank Dr. Björn Wiese (hereon) for the production of Mg based material and Prof. Böcker (MUM Musculoskeletal University Center Munich) for the provision of SCP-1 cell line.

Photobiomodulation Effect of Diode Laser on Differentiation of Osteoprogenitor Cells in Rat Bone Marrow.

Bone marrow cells contain nonhematopoietic cells with the ability to differentiate into osteogenic, chondrogenic, and adipogenic lineages. Mechanical stress influences osteoblast differentiation of bone marrow cells into osteogenic, chondrogenic, and adipogenic lineages, measurable as the abundance of alkaline phosphatase-positive (ALP+) colony-forming unit-fibroblasts (CFU-F); however, the effect of diode laser irradiation on osteoblast differentiation is unknown. The aim of this study was to analyze the effects of photobiomodulation on the osteogenic differentiation of mesenchymal stem cells in the bone marrow, using the CFU-F assay. Bone marrow cells isolated from rat tibiae were cultured and irradiated with a diode laser (wavelength 808 nm) at a total energy of 0 J (control), 50 J, and 150 J. On day 7 after irradiation, ALP+ CFU-F were most abundant in the 50 J group and the least abundant in the 150 J group. Mineralized nodule formation was observed after long-term culture (21 days). Compared with the control group, there were significantly more nodules in the 50 J group and significantly fewer nodules in the 150 J group. Osteocalcin mRNA expression was highest in the 50 J group, and there was no difference between the control and 150 J groups. Irradiation with 50 J was effective in stimulating osteogenesis in bone marrow stem cells. These findings suggest that diode laser irradiation can induce osteogenesis in rat bone marrow cells in an energy-dependent manner, and appears suitable for application in bone regeneration therapy.

3D-printed biomimetic scaffolds loaded with ADSCs and BMP-2 for enhanced rotator cuff repair.

Rotator cuff tear repair poses significant challenges due to the complex gradient interface structure. In the face of disease-related disruptions in the tendon-bone interface (TBI), the strategy of constructing a biomimetic scaffold is a promising avenue. A novel 3D-printed rotator cuff scaffold loaded adipose stem cells (ADSCs), bone morphogenetic protein-2 (BMP-2), and collagen type I (COL I). The efficiency of the slow-release BMP-2 design depended on the dopamine-hyaluronic acid (HAD) and BMP-2 reaction. The cumulative release of BMP-2 was 44.97 ± 5.45% at 4 weeks. The 3D-printed bilayer scaffold, incorporating COL I and BMP-2, effectively promoted the differentiation of ADSCs into osteogenic, tenogenic, and chondrogenic lineages in vitro. The combination of 3D-printed bioactive scaffolds and ADSCs demonstrated a superior repair effect on rotator cuff injuries in vivo. Therefore, these findings indicates that the 3D-printed biomimetic scaffold loaded with ADSCs and BMP-2 holds potential as a promising graft for TBI healing.

Considerations for enhanced mesenchymal stromal/stem cell myogenic commitment invitro.

The generation of tissue from stem cells is an alluring concept as it holds a number of potential applications in clinical therapeutics and regenerative medicine. Mesenchymal stromal/stem cells (MSCs) can be isolated from a number of different somatic sources, and have the capacity to differentiate into adipogenic, osteogenic, chondrogenic, and myogenic lineages. Although the first three have been extensively investigated, there remains a paucity of literature on the latter. This review looks at the various strategies available invitro to enhance harvested MSC commitment and differentiation into the myogenic pathway. These include chemical inducers, myogenic-enhancing cell culture substrates, and mechanical and dynamic culturing conditions. Drawing on information from embryonic and postnatal myogenesis from somites, satellite, and myogenic progenitor cells, the mechanisms behind the chemical and mechanical induction strategies can be studied, and the sequential gene and signaling cascades can be used to monitor the progression of myogenic differentiation in the laboratory. Increased understanding of the stimuli and signaling mechanisms in the initial stages of MSC myogenic commitment will provide tools with which we can enhance their differentiation efficacy and advance the process to clinical translation.

Efectos de la irradiación con láser de diodo de 970 m sobre la morfología, la proliferación y la diferenciación de las células madre mesenquimales gingivales

Objective: The objective of this study was to investigate the morphology, proliferation, and differentiation of gingival mesenchymal stem cells (GMSCs) irradiated with a 970 nm Diode Laser (LLLT). It is essential to validate the efficacy of treatment, optimize irradiation conditions and guarantee the safety and quality of stem cells for future use in dental applications. Materials and Methods: GMSCs were cultured in standard conditions and irradiated with a Diode laser (970 nm, 0.5W) with an energy density of 9J/cm2. Cell proliferation was assessed with the WST-1 proliferation kit. GMSCs were differentiated into chondrogenic and osteogenic lineages. Cell morphology was performed with Hematoxylin/eosin staining, and quantitative nuclear analysis was done. Cell viability was monitored with trypan blue testing. Results: GMSCs subjected to irradiation demonstrated a significant increase in proliferation at 72 hours compared to the non-irradiated controls (p=0.027). This indicates that the 970 nm diode laser has a stimulatory effect on the proliferation of GMSCs. LLLT-stimulated GMSCs exhibited the ability to differentiate into chondrogenic and osteogenic lineages. A substantial decrease in cell viability was observed 24 hours after irradiation (p=0.024). However, after 48 hours, the cell viability recovered without any significant differences. This indicates that there might be a temporary negative impact on cell viability immediately following irradiation, but the cells were able to recover and regain their viability over time. Conclusions: This study support that irradiation with a 970 nm diode laser could stimulate the proliferation of GMSCs, maintain their ability to differentiate into chondrogenic and osteogenic lineages, and has minimal impact on the mor- phological characteristics of the cells. These results support the potential use of NIR Lasers in combination with GMSCs as a promising strategy for dental treatments. Keywords: Photobiomodulation; semiconductor lasers; Mesenchymal stem cells; Gingiva; Cell Proliferation; Safety.

Actuation of Soft Thermoresponsive Hydrogels Mechanically Stimulates Osteogenesis in Human Mesenchymal Stem Cells without Biochemical Factors.

Mesenchymal stem cells (MSCs) have the potential to differentiate into multiple lineages and can be harvested relatively easily from adults, making them a promising cell source for regenerative therapies. While it is well-known how to consistently differentiate MSCs into adipose, chondrogenic, and osteogenic lineages by treatment with biochemical factors, the number of studies exploring how to achieve this with mechanical signals is limited. A relatively unexplored area is the effect of cyclic forces on the MSC differentiation. Recently, our group developed a thermoresponsive N-ethyl acrylamide/N-isopropylacrylamide (NIPAM/NEAM) hydrogel supplemented with gold nanorods that are able to convert near-infrared light into heat. Using light pulses allows for local hydrogel collapse and swelling with physiologically relevant force and frequency. In this study, MSCs are cultured on this hydrogel system with a patterned surface and exposed to intermittent or continuous actuation of the hydrogel for 3 days to study the effect of actuation on MSC differentiation. First, cells are harvested from the bone marrow of three donors and tested for their MSC phenotype, meeting the following criteria: the harvested cells are adherent and demonstrate a fibroblast-like bipolar morphology. They lack the expression of CD34 and CD45 but do express CD73, CD90, and CD105. Additionally, their differentiation potential into adipogenic, chondrogenic, and osteogenic lineages is validated by the addition of standardized differentiation media. Next, MSCs are exposed to intermittent or continuous actuation, which leads to a significantly enhanced cell spreading compared to nonactuated cells. Moreover, actuation results in nuclear translocation of Runt-related transcription factor 2 and the Yes-associated protein. Together, these results indicate that cyclic mechanical stimulation on a soft, ridged substrate modulates the MSC fate commitment in the direction of osteogenesis.