Viability Of Mesenchymal Stem Cells Research Articles

Biosynthesis of Zinc Oxide Nanoparticles Using Dried Leaves of Camellia sinensis: Methods to Characterize and Assess Their Effects on Mesenchymal Stem Cell Viability.

Stem cell nanotechnology (SCN) is an important scientific field to guide stem cell-based research of nanoparticles. Currently, nanoparticles (NPs) have a rich spectrum regarding the sources from which they are obtained (metallic, polymeric, etc.), the methods of obtaining them (physical, chemical, biological), and their shape, size, electrical charge, etc. properties. It is also essential to expand green synthesis applications for the use of NPs in the field of biomedical sciences. For this purpose, there is a need to produce NPs using biological sources (plant, microorganism, algae, yeast etc.…), characterization and investigation of their effects on biological activities of stem cells. This process involves long and laborious procedures, and there may be differences in methods between individual laboratories.In this protocol, biofabrication and characterization of ZnO NPs using dried leaves of Camellia sinensis is described. This experimental setup includes conventional and novel methods that can be applied to biofabricate and characterize the NPs and to examine the viability, apoptotic, and necrotic effects on human adipose tissue-derived mesenchymal stem cells (ADMSCs) in vitro.

Improved Mesenchymal Stem Cell Viability in High-Stiffness, Translational Cartilage Matrix Hydrogels.

Scaffolds made from cartilage extracellular matrix are promising materials for articular cartilage repair, attributed to their intrinsic bioactivity that may promote chondrogenesis. While several cartilage matrix-based scaffolds have supported chondrogenesis in vitro and/or invivo, it remains a challenge to balance the biological response (e.g., chondroinductivity) with structural (e.g., robust mechanical performance, >1 MPa in compressive stiffness) and translational (e.g., ease of surgical implantation) considerations. Few studies have evaluated encapsulated cell viability within high-stiffness (>1 MPa) hydrogels. We previously fabricated one formulation of a high-stiffness (>3 MPa) pentenoate-functionalized, solubilized, devitalized cartilage (PSDVC) hydrogel that possessed an injectable, paste-like precursor for easy surgical application. In the current study, the characterization of the PSDVC material was expanded by varying the degree of functionalization (i.e., 0.45-1.09 mmol/g) and amount of crosslinker, dithiothreitol (DTT), to improve the reproducibility of the high compressive moduli and evaluate the viability of encapsulated human bone marrow-derived mesenchymal stem cells (hBMSCs) in high-stiffness cartilage matrix hydrogels. Prior to crosslinking, specific formulations functionalized with 0.80 mmol/g or less of pentenoate groups retained a paste-like precursor rheology. After crosslinking, these formulations produced hydrogels with greater than 1 MPa compressive stiffness. However, hBMSCs encapsulated in PSDVC hydrogels with lower functionalization (i.e., 0.57 mmol/g, no crosslinker) had a higher stiffness (i.e., 1.4 MPa) but the lowest viability of encapsulated hBMSCs (i.e., 5%). The middle PSDVC functionalization (i.e., 0.70 mmol/g) with DTT (i.e., 0.50 mmol thiols/g) demonstrated high cell viability (77%), high mechanical performance (1.65 MPa, 31% failure strain), and translational features (i.e., paste-like precursor, 1.5 min crosslinking time). For future evaluations of PSDVC hydrogels in cartilage repair, a middle functionalization (i.e., 0.70-0.80 mmol/g) with the addition of a crosslinker (i.e., 0.50 mmol thiols/g) had a desirable balance of high mechanical performance (i.e., >1 MPa compressive stiffness), high viability, and paste-like precursor for surgical translation.

Rapid Fabrication of Polyvinyl Alcohol Hydrogel Foams With Encapsulated Mesenchymal Stem Cells for Chronic Wound Treatment.

Chronic wounds present a major healthcare challenge around the world, and significant hurdles remain in their effective treatment due to limitations in accessible treatment options. Mesenchymal stem cells (MSCs) with multifunctional differentiation and modulatory properties have been delivered to chronic wounds to enhance closure but have limited engraftment when delivered without a scaffold. In this study, hybrid porous hydrogel foams composed of modified polyvinyl alcohol and gelatin were developed that are suitable for rapid and facile MSC encapsulation, fully degradable, and supportive of wound healing. Rapid fabrication and encapsulation within porous foams was achieved using a cytocompatible gas blowing process. The hybrid hydrogels have tunable degradation rates based on chemistry, with complete mass loss achieved within 2-6 weeks, which is compatible with chronic wound closure rates. High encapsulated A375 epithelial cell and MSC viability with maintained cell functionality over 2 weeks reveals the potential of these hydrogels to serve as cell delivery systems for chronic wound treatment. An exvivo porcine skin wound model demonstrated enhanced healing after application of cell-laden hydrogel foams. Overall, hybrid hydrogel foams with encapsulated therapeutic cells have the capacity for robust wound healing and are a promising platform for chronic wound dressings.

Bone-derived nanoparticles (BNPs) enhance osteogenic differentiation via Notch signaling.

Mesenchymal stem cell (MSC)-based bone tissue regeneration has gained significant attention due to the excellent differentiation capacity and immunomodulatory activity of MSCs. Enhancing osteogenesis regulation is crucial for improving the therapeutic efficacy of MSC-based regeneration. By utilizing the regenerative capacity of bone ECM and the functionality of nanoparticles, we recently engineered bone-based nanoparticles (BNPs) from decellularized porcine bones. The effects of internalization of BNPs on MSC viability, proliferation, and osteogenic differentiation were first investigated and compared at different time points. The phenotypic behaviors, including cell number, proliferation, and differentiation were characterized and compared. By incorporating a LNA/DNA nanobiosensor and MSC live cell imaging, we monitored and compared Notch ligand delta-like 4 (Dll4) expression dynamics in the cytoplasm and nucleus during osteogenic differentiation. Pharmacological interventions are used to inhibit Notch signaling to examine the mechanisms involved. The results suggest that Notch inhibition mediates the osteogenic process, with reduced expression of early and late stage differentiation markers (ALP and calcium mineralization). The internalization of BNPs led to an increase in Dll4 expression, exhibiting a time-dependent pattern that aligned with enhanced cell proliferation and differentiation. Our findings indicate that the observed changes in BNP-treated cells during osteogenic differentiation could be associated with elevated levels of Dll4 mRNA expression. In summary, this study provides new insights into MSC osteogenic differentiation and the molecular mechanisms through which BNPs stimulate this process. The results indicate that BNPs influence osteogenesis by modulating Notch ligand Dll4 expression, demonstrating a potential link between Notch signaling and the proteins present in BNPs.

Revisiting Fat Graft Harvesting and Processing Technique to Optimize Its Regenerative Potential.

The use of fat grafting has expanded to include cell and tissue regeneration, necessitating investigations to ensure the viability of stromal and adipose-derived mesenchymal stem cells (ASCs) within the transferred fat parcels. This study explored the impact of harvesting technique and centrifugation on the viability of stromal cells and ASCs in lipoaspirate. Fat was harvested from patients undergoing fat grafting using 2 types of liposuction cannula: (A) a 3-mm blunt tip cannula with 3 smooth holes and (B) a 2.4-mm, sharp point port, multihole blunt tip cannula. Fat from cannula B underwent different processing methods: no centrifugation, 300g, 600g, and 900g centrifugation. Stromal cells were isolated, quantified, and evaluated for viability. ASCs were cultured from these samples to confirm survival. Lipoaspirates from 21 patients were analyzed. The mean stromal cell counts were 0.937 × 109 ± 0.346 × 109/mL for cannula A and 0.734 × 109 ± 0.266 × 109/mL for cannula B (P = 0.684), with viabilities of 98.79% and 98.22% (P = 0.631), respectively. ASCs isolated and after 2-passage culture were also higher for cannula A. Stromal cell quantification and viability were lowest in the noncentrifuged group (P < 0.05) and highest in the 600g centrifugation group. Fat harvesting using cannulas A and B showed no significant difference in stromal cell yield or viability. Handheld syringe liposuction preserved stromal vascular fraction cell and ASC viability. Centrifugation at different speeds did not significantly affect stromal cell viability.

Effect of cigarette smoke on the proliferation, viability, gene expression, and cellular functions of adipose-derived mesenchymal stem cells from smoking and non-smoking donors.

Cigarette smoking negatively impacts mesenchymal stem cell functionality, including proliferation, viability, and differentiation potential. Adipose-derived mesenchymal stem cells (ADMSCs) are increasingly used for therapeutic purposes, but the specific effects of smoking in vivo on these cells are poorly understood. This study investigates the effects of cigarette smoke on the proliferation, viability, gene expression, and cellular functions of ADMSCs from smoking and non-smoking donors. In this study, ADMSCs were isolated from healthy smokers and non-smokers, and cell proliferation was assessed using the MTT assay, viability with apoptosis assays, mitochondrial membrane potential (MMP), and gene expression related to oxidative stress and cellular functions. Cell cycle analysis was also conducted. Our findings reveal a significant decrease in the proliferation of ADMSCs from smokers. Apoptosis assays showed reduced viable cells in smokers without a significant change in MMP, suggesting alternative pathways contributing to decreased viability. Gene expression analysis indicated the upregulation of genes associated with oxidative stress response and cellular defense mechanisms and the downregulation of genes related to inflammatory signaling, detoxification, and cellular metabolism. Cell cycle analysis indicates cycle arrest or delay in smokers, possibly due to stress and potential DNA damage. Smoking negatively affects ADMSCs' proliferation, viability, and function through oxidative stress and gene expression alterations. These findings highlight the importance of considering smoking status in ADMSC therapies and the need for further research to mitigate the effect of smoking on stem cells.

Metformin Modulates Cell Oxidative Stress to Mitigate Corticosteroid-Induced Suppression of Osteogenesis in a 3D Model.

Corticosteroids provide well-established therapeutic benefits; however, they are also accompanied by adverse effects on bone. Metformin is a widely used medication for managing type 2 diabetes mellitus. Recent studies have highlighted additional therapeutic benefits of metformin, particularly concerning bone health and oxidative stress. This research investigates the effects of prednisolone on cellular metabolic functions and bone formation using a 3D in vitro model. Then, we demonstrate the potential therapeutic effects of metformin on oxidative stress and the formation of calcified matrix due to corticosteroids. Human mesenchymal stem cells (MSCs) and macrophages were cultured in a 3D GelMA scaffold and stimulated with prednisolone, with and without metformin. The adverse effects of prednisolone and metformin's therapeutic effect(s) were assessed by analyzing cell viability, osteogenesis markers, bone mineralization, and inflammatory markers. Oxidative stress was measured by evaluating reactive oxygen species (ROS) levels and ATP production. Prednisolone exhibited cytotoxic effects, reducing the viability of MSCs and macrophages. Lower osteogenesis potential was also detected in the MSC group. Metformin positively affected cell functions, including enhanced osteoblast activity and increased bone mineralization. Furthermore, metformin effectively reduced oxidative stress, as evidenced by decreased ROS levels and increased ATP production. These findings indicate that metformin protects against oxidative damage, thus supporting osteogenesis. Metformin exhibits promising therapeutic potential beyond its role in diabetes management. The capacity to alleviate oxidative stress highlights the potential of metformin in supporting bone formation in inflammatory environments.

Comprehensive Evaluation of Decellularized Dental Pulp as a New Biomaterial for Regeneration of the Pulp-Dentin Complex

Objective: To develop a detergent-enzymatic method and evaluate the quality of a decellularized pulp scaffold for regenerative endodontics.Materials and methods: Biomaterial and mesenchymal stem cells (MSCs) were derived from dental pulp that was obtained following third molar extraction indicated for orthodontic reasons in patients aged 14-18 years. The detergent-enzymatic method enabled to obtain a decellularized scaffold from pulp samples. The proliferative activity and viability of dental pulp-derived MSCs were assessed using trypan blue staining and XTT assay. To assess tissue response, Wistar rats underwent subcutaneous implantation of native and decellularized dental pulp. Explanted samples were stained with hematoxylin-eosin on days 7 and 14.Results: The detergent-enzymatic treatment of the dental pulp demonstrated the absence of nuclear material, whereas the histoarchitecture of the dental pulp was disturbed. The DNA content in the sample of the decellularized scaffold was 22.79 ± 2.1 ng/mg of tissue; the amount of DNA in the native sample was 78.5 ± 5.4 ng/mg of tissue. According to XTT assay results, no cytotoxicity of the decellularized scaffold against MSCs was found. Biopsy specimens of the rats with implanted decellularized dental pulp were characterized by no signs of inflammation.Conclusions: The study results will enable to create a biomaterial that can be the base of a tissue-engineered structure of the dental pulp and be used for the regeneration of the pulp-dentin complex.

The effect of resveratrol on the viability of rat bone marrow mesenchymal stem cells

Background and aimResveratrol is a plant polyphenol that has antioxidant properties. In this research, in order to better understand the role of resveratrol on bone, the effect of different doses of resveratrol on the viability, proliferation, differentiation and biochemical factors of rat bone marrow mesenchyme stem cells (MSCs) was investigated. MethodsTo evaluate the ability of proliferation and differentiation, the MSCs were cultured up to three passages and were placed in culture media without osteogenic stimulation. At first to investigation the proliferation ability, the viability was evaluated by MTT test and trypan blue staining with 7.5, 15 and 30 mg/L treatment doses after 12, 24 and 36 hours. Then, to investigation the differentiation ability, the effect of 7.5, 15, and 30 mg/L treatment doses was assessed on the viability, electrolyte levels, and the activity of LDH, AST, ALP and ALT enzymes in differentiated cells after 5, 10, 15, and 21 days. To investigation the differentiation ability, the effect of 7.5, 15, and 30 mg/L treatment doses was assessed on the viability, electrolyte levels, and the activity of Lactate dehydrogenase (LDH), Aspartate aminotransferase (AST), Alkaline phosphatase (ALP) and alanine aminotransferase (ALT) enzymes in differentiated cells after 5, 10, 15, and 21 days. The data were analyzed by ANOVA and Tukey's test, and p<0.05 was considered as a significant level. ResultsThe obtained results showed that in mesenchyme cells, the level of viability does not change in low dose of resveratrol, however increase in the time followed by decrease in the activity of metabolic enzymes (ALP, ALT and AST P<0.5) and subsequently viability (p<0.05), and this trend was reversed with increasing resveratrol concentration (significant differences among 5 days and others). ConclusionThe effect of resveratrol depends on the type of cell and the treatment conditions, so it was shown in this study that the sensitivity of mesenchymal cells is higher than that of osteoblast cells. In addition, high doses of resveratrol had a positive effect on bone differentiation, so high doses of resveratrol can have a beneficial role on the health of mesenchymal cells and their differentiation into osteoblasts.

Enhanced bioactivity and anticancer properties of mesoporous La2O3-doped CaO-P2O5-SiO2 bioactive system for bone regeneration applications

Bioactive samples having composition x.La2O3.(43-x)CaO.15P2O5.42SiO2 (x=0,1,2,3 mol%) were successfully synthesized in the laboratory via the sol-gel method. These samples have been analysed using X-ray diffraction, Fourier Transform Infrared spectroscopy, and Field Emission Scanning Electron Microscopy with Energy Dispersive X-ray analysis, both before and after immersion in simulated body fluid. The outcomes clearly reveal the formation of hydroxyapatite within one day of in vitro analysis in samples doped with lanthanum oxide. Using Brunauer-Emmett and Teller technique, increase in surface area for doped samples has been observed. Additionally, it has been found that all samples are mesoporous in nature having pore sizes in the range of 6-13 nm. The prepared samples are loaded with ciprofloxacin, a fluoroquinolone antibiotic to study their drug release properties in phosphate buffer saline by employing UV-Visible spectroscopy. The Higuchi model demonstrated the best fit with the in vitro drug release profile, which displayed the highest correlation value. To ensure the samples are non-toxic, biocompatibility studies have been performed using alamarBlue, Pico green and live-dead cells assays. All samples show excellent cell viability and better proliferation of rat mesenchymal stem cells. The anti-cancer property of the doped samples has also been evaluated using MTT assay on Ehrlich ascites carcinoma cell line. All the samples have exhibited significant growth inhibition towards the cancerous cell line. Phase-contrast and fluorescence microscopy studies on EAC cancer cell line treated with the doped samples have displayed the characteristic features of cell death. Also, flow cytometric analysis reveal decreased mitochondrial membrane potential for all the samples which also indicates features of cancer cell death. Extensive efforts were made to determine the optimal chemical composition of the prepared samples for their further use in bone implants. The synthesized compositions possess the potential for bone regeneration treatments and addressing breast cancer bone metastasis due to their bioactivity, high surface area, mesoporous nature, anticancer properties and appreciable cell viability.

Sustained release of heparin from PLLA micropartricles for tissue engineering applications

Heparin holds promise for cardiac tissue engineering, but challenges such as hematoma or bleeding and accumulation in tissue caused by excessive release, and short half-life persist. The present study aimed to introduce a reliable mechanism for the prolonged heparin release from a biocompatible polymer carrier. The designed system must ensure that heparin retains its bioactivity over time while preventing premature release. Heparin was encapsulated within poly (L-lactic acid) microparticles using the double emulsion method, with polyvinyl alcohol employed as the stabilizer. The encapsulation efficiency of heparin in the microparticles was calculated as 25.56 %. The functionality of the design was evaluated using Attenuated Total Reflection Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, and Energy Dispersive X-ray Spectroscopy. Drug release and microparticle degradation studies were conducted alongside cell viability tests. The particle sizes ranged from 5 to 10 ± 2.53 μm, with evidence suggesting that heparin promotes the smaller particle formation. The system demonstrated a consistent drug release profile over six weeks with a release rate of 54 % by week two and 97.65 % by week six. The degradation of heparin-loaded microparticles reached less than 50 % by week six, and the loading of heparin did not significantly affect the degradation behavior of the PLLA microparticles in PBS. Furthermore, heparin concentrations between 200 and 400 μg/ml enhanced the viability of Placenta-derived Mesenchymal Stem Cells and H9c2. These findings suggest that the system could be considered as an effective vehicle for sustained heparin delivery across a spectrum of biological applications, particularly in cardiac tissue engineering.

Dual-Function Femtosecond Laser: β-TCP Structuring and AgNP Synthesis via Photoreduction with Azorean Green Tea for Enhanced Osteointegration and Antibacterial Properties.

β-Tricalcium phosphate (β-TCP) is a well-established biomaterial for bone regeneration, highly regarded for its biocompatibility and osteoconductivity. However, its clinical efficacy is often compromised by susceptibility to bacterial infections. In this study, we address this limitation by integrating femtosecond (fs)-laser processing with the concurrent synthesis of silver nanoparticles (AgNPs) mediated by Azorean green tea leaf extract (GTLE), which is known for its rich antioxidant and anti-inflammatory properties. The fs laser was employed to modify the surface of β-TCP scaffolds by varying scanning velocities, fluences, and patterns. The resulting patterns, formed at lower scanning velocities, display organized nanostructures, along with enhanced roughness and wettability, as characterized by Scanning Electron Microscopy (SEM), optical profilometry, and contact angle measurements. Concurrently, the femtosecond laser facilitated the photoreduction of silver ions in the presence of GTLE, enabling the efficient synthesis of small, spherical AgNPs, as confirmed by UV-vis spectroscopy, Transmission Electron Microscopy (TEM), and Fourier Transform Infrared Spectroscopy (FTIR). The resulting AgNP-embedded β-TCP scaffolds exhibited a significantly improved cell viability and elongation of human bone marrow mesenchymal stem cells (hBM-MSCs), alongside significant antibacterial activity against Staphylococcus aureus (S. aureus). This study underscores the transformative potential of combining femtosecond laser surface modification with GTLE-mediated AgNP synthesis, presenting a novel and effective strategy for enhancing the performance of β-TCP scaffolds in bone-tissue engineering.

Effect of Mesenchymal Stem Cell–Derived Extracellular Vesicles Induced by Advanced Glycation End Products on Energy Metabolism in Vascular Endothelial Cells

IntroductionAdvanced glycation end products (AGEs) play a critical role in the development of vascular diseases in diabetes. While stem cell therapies often involve exposure to AGEs, the impact of this environment on extracellular vesicles (EVs) and endothelial cell metabolism remains unclear. MethodsHuman umbilical cord mesenchymal stem cells (MSC) were treated with either 0 ng/mL or 100 ng/mL AGEs in a serum-free medium for 48 hours, after which MSC-EVs were isolated. The EVs were characterized for morphology, particle size, and protein markers of MSC-EVs, and performed miRNA sequencing to identify differentially expressed miRNAs. MSC-EVs were co-cultured with HUVEC cells to assess effects on cell viability, metabolic activity, oxidative stress, and antioxidant capacity. Tube formation and glucose transporter protein analyses were conducted to evaluate the angiogenic ability and glucose metabolism capacity. ResultsMSC-EVs ranged from 30 to 150 nm, consistenting with exosomal properties. AGEs treatment reduced MSC viability but had minimal effect on EV morphology and protein markers. miRNAs sequencing showed downregulation of hsa-miR-223-3p, hsa-miR-126-3p_R-1, with upregulation of hsa-miR-574-5p, implicating changes in glycolytic and oxidative phosphorylation pathways. MSC-EVs treated with AGEs decreased HUVEC viability (P<0.05), pH (P<0.05), ATP metabolism (P<0.05), glucose metabolism (P<0.05), while enhancing glycolysis processes, including glycolytic activity, capacity, and reserve (P<0.05). This likely resulted from impaired mitochondrial function, including reduced ATP production, maximal respiration, basal respiration, and spare respiratory capacity (P<0.05), or increased ROS (P<0.05) and G6PD activity (P<0.05). Additionally, AGEs reduced GLUT1, GLUT3, GLUT4, and SCO2 expression (P<0.05), along with angiogenic capacity (P<0.05) in HUVEC cells. ConclusionExposure to AGEs diminishes the therapeutic potential of MSC-derived EVs by disrupting energy metabolism and promoting metabolic reprogramming in endothelial cells. These findings suggest that adjusting the dosage or frequency of MSC-EVs may enhance their efficacy for treating diabetes-related vascular conditions. Further research is warranted to evaluate AGEs' broader impact on various cell types and metabolic pathways for improved exosome-based therapies.

Injectable Glucose-Releasing Microgels Enhance the Survival and Therapeutic Potential of Transplanted MSCs Under Ischemic Conditions.

Mesenchymal stem cell (MSC)-based therapies show potential to treat ischemic diseases owing to their versatile functions. However, sustaining MSC viability and therapeutic efficacy in ischemic tissues postengraftment remains a significant challenge. This is because, although MSCs are metabolically flexible, they fail to adapt to hypoxic conditions in the absence of glucose, leading to cell death. To overcome these issues, it is aimed to establish an injectable glucose delivery system using starch and amyloglucosidase embedded in alginate microgels. Here, starch/amyloglucosidase (S/A) microgels are engineered to continuously release glucose for seven days via enzymatic hydrolysis, thereby supporting MSC functions under ischemic conditions. In vitro tests under oxygen/glucose-deprived conditions revealed that the S/A microgels not only maintained the viability and intracellular energy but also enhanced the pro-angiogenic and immunomodulatory functions of MSCs. In vivo data further confirmed the pro-survival and pro-angiogenic effects of S/A microgels on MSCs following subcutaneous engraftment in mice. Overall, the developed S/A microgel significantly enhanced the survival and therapeutic potential of MSCs via sustained glucose delivery, highlighting its potential use in advancing MSC-based therapies for ischemic conditions.

Quercetin relieves compression-induced cell death and lumbar disc degeneration by stabilizing HIF1A protein

BackgroundLumbar disc degeneration (LDD) is a prevalent condition characterized by the decreased viability and functional impairment of nucleus pulposus mesenchymal stem cells (NPMSCs). Shaoyao-Gancao decoction (SGD), a traditional Chinese medicine formula, has been used to treat LDD, but its active components and mechanisms are unclear. MethodsAn integrative network pharmacology and transcriptome analysis were conducted to identify bioactive compounds in SGD that could target LDD. NPMSCs were cultured under mechanical compression as a cellular model of LDD. A rat model of annulus fibrosus needle-puncture was established to induce intervertebral disc degeneration. The effects of quercetin, a predicted active component, on alleviating compression-induced NPMSC death and LDD were evaluated in vitro and in vivo. ResultsThe analysis identified hypoxia-inducible factor 1-alpha (HIF1A) as a potential target of quercetin in LDD. HIF1A was upregulated in degenerated human disc samples and compression-treated NPMSCs. Quercetin treatment alleviated compression-induced oxidative stress, apoptosis, and loss of viability in NPMSCs by stabilizing HIF1A. The protective effects of quercetin were abrogated by HIF1A inhibition. In the rat model, quercetin ameliorated intervertebral disc degeneration. ConclusionOur study identified HIF1A as a protective factor against compression-induced cell death in NPMSCs. Quercetin, a bioactive compound found in the traditional Chinese medicine formula SGD, improved the survival of NPMSCs and alleviated LDD progression by stabilizing HIF1A. Targeting the HIF1A pathway through natural compounds like quercetin could represent a promising strategy for the clinical management of LDD and potentially other degenerative disc diseases.

P21-76 Effects of tobacco heating products on viability, proliferation and cytokine production of mesenchymal stem cells isolated from periodontal ligament

P21-76 Effects of tobacco heating products on viability, proliferation and cytokine production of mesenchymal stem cells isolated from periodontal ligament

Design and characterization of novel Ti-8Mo-xFe-yCu alloys as implant materials: Evaluation of biocompatibility, mechanical properties, and antibacterial potential

Titanium and its alloys are highly desirable materials for biomedical metallic implants due to their superior specific strength, excellent corrosion resistance, and exceptional biocompatibility. Among these alloys, Ti6Al4V is widely used in practical biomedical applications because it offers an excellent combination of strength, fracture toughness, and corrosion resistance. However, recent research has revealed limitations in its biocompatibility attributed to the presence of toxic elements such as Al and V. In addition, it has been reported that Ti6Al4V is costly due to the addition of Vanadium and has the potential for post-implant inflammation. As a result, researchers have been investigating new biomedical beta-Ti alloys using biocompatible, affordable, and easily accessible beta-stabilizers like Mo, Fe, and Cu, to achieve similar performance as Ti6Al4V alloys. The present study aims to develop a novel biomedical alloy through the arc melting method, to obtain an implant material possessing low elastic moduli, biocompatibility, and antibacterial properties to mitigate the risk of post-implant inflammation. Microstructural analysis was conducted using microscopy and x-ray diffraction, while the mechanical properties were evaluated through micro vickers hardness testing machine and elastic moduli measurement utilizing the impulse excitation technique. Cytotoxicity assessment was performed using the (Cell Counting Kit-8) CCK-8 method, followed by an examination of the alloy's antibacterial properties using the point counting method. β-Ti single phase was obtained in this study with the addition of ≥1% Fe and ≥1% Cu. The Ti-8Mo-2Fe-2Cu alloy was found to have the lowest elastic moduli of 95 GPa. Electrochemical measurements show that the Ti-8Mo- xFe- yCu alloys have a lower corrosion current density of around 0.319–2.317 µA/cm2 compared to Ti6Al4V of 16.543 µA/cm2. The Ti-8Mo-1Fe-3Cu, Ti-8Mo-3Fe-1Cu, and Ti-8Mo-3Fe-3Cu alloys have comparable biocompatibility with Ti6Al4V with the viability of mesenchymal stem cells (MSCs) above 75% and have a positive antibacterial response. Ti-8Mo-3Fe-3Cu alloy demonstrates the most favorable blend of microstructure, mechanical attributes, corrosion resistance, cell viability, and antibacterial properties as an alternate biomaterial for implant applications.

In vitro evaluation of the biocompatibility and bioactivity of a SLM-fabricated NiTi alloy with superior tensile property

Because nickel-titanium (NiTi) alloys have unique functions, such as superelasticity, shape memory, and hysteresis similar to bone in the loading-unloading cycles of their recoverable deformations. They likely offer good bone integration, a low loosening rate, individual customization, and ease of insertion. Due to the poor processability of NITI, traditional methods cannot manufacture NiTi products with complex shapes. Orthopedic NiTi implants need to show an adequate fracture elongation of at least 8%. Additive manufacturing can be used to prepare NiTi implants with complex structures and tunable porosity. However, as previously reported, additively manufactured NiTi alloys could only exhibit a maximum tensile fracture strain of 7%. In new reports, a selective laser melting (SLM)–NiTi alloy has shown greater tensile strain (15.6%). Nevertheless, due to the unique microstructure of additive manufacturing NiTi that differs from traditional NITI, the biocompatibility of SLM-NITI manufactured by this new process requires further evaluation In this study, the effects of the improved NiTi alloy on bone marrow mesenchymal stem cell (BMSC) proliferation, adhesion, and cell viability were investigated via in vitro studies. A commercial Ti-6Al-4V alloy was studied side-by-side for comparison. Like the Ti-6Al-4V alloy, the SLM-NiTi alloy exhibited low cytotoxicity toward BMSCs and similar effect on cell adhesion or cell viability. This study demonstrates that the new SLM-NiTi alloy, which has exhibited improved mechanical properties, also displays excellent biocompatibility. Therefore, this alloy may be a superior implant material in biomedical implantation.Graphical

Acrylate-Based PEG Hydrogels with Ultrafast Biodegradability for 3D Cell Culture.

Poly(ethylene glycol) (PEG)-based hydrogels are particularly challenging to degrade, which hinders efficient cell harvesting within the gel matrix. Here, highly branched copolymers of PEG methyl ether acrylate (PEGMA) and disulfide diacrylate (DSDA) (PEG-DS) with short primary chains and multiple pendent vinyl groups were synthesized by a "vinyl oligomer combination" approach. PEG-DS readily cross-links with thiolated gelatin (Gel-SH) to form hydrogels. Results demonstrate that shortening the primary chains of PEG-DS significantly enhances the viability of bone marrow mesenchymal stem cells (BMSCs) by up to 193.2%. Importantly, DS junctions can be easily cleaved into short primary chains using dithiothreitol (DTT), triggering ultrafast degradation of PEG-DS/Gel-SH hydrogels within 2 min under mild conditions and release of the encapsulated BMSCs. This study establishes a novel strategy to enhance the degradation of acrylate-based PEG hydrogels for three-dimensional (3D) cell culture and harvesting. These findings expand the potential applications of such hydrogels in various biomedical fields.

In vitro degradation of a chitosan-based osteochondral construct points to a transient effect on cellular viability

Bioresorbable chitosan scaffolds have shown potential for osteochondral repair applications. Thein vivodegradation of chitosan, mediated by lysozyme and releasing glucosamine, enables progressive replacement by ingrowing tissue. Here the degradation process of a chitosan-nHA based bioresorbable scaffold was investigated for mass loss, mechanical properties and degradation products released from the scaffold when subjected to clinically relevant enzyme concentrations. The scaffold showed accelerated mass loss during the early stages of degradation but without substantial reduction in mechanical strength or structure deterioration. Although not cytotoxic, the medium in which the scaffold was degraded for over 2 weeks showed a transient decrease in mesenchymal stem cell viability, and the main degradation product (glucosamine) demonstrated a possible adverse effect on viability when added at its peak concentration. This study has implications for the design and biomedical application of chitosan scaffolds, underlining the importance of modelling degradation products to determine suitability for clinical translation.