Displaying publications 1 - 20 of 38 in total

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  1. Fulltext Oxidative stress-induced premature senescence in Wharton's jelly-derived mesenchymal stem cells
    Choo KB, Tai L, Hymavathee KS, Wong CY, Nguyen PN, Huang CJ, et al.
    Int J Med Sci, 2014;11(11):1201-7.
    PMID: 25249788 DOI: 10.7150/ijms.8356
    On in vitro expansion for therapeutic purposes, the regenerative potentials of mesenchymal stem cells (MSCs) decline and rapidly enter pre-mature senescence probably involving oxidative stress. To develop strategies to prevent or slow down the decline of regenerative potentials in MSC culture, it is important to first address damages caused by oxidative stress-induced premature senescence (OSIPS). However, most existing OSIPS study models involve either long-term culture to achieve growth arrest or immediate growth arrest post oxidative agent treatment and are unsuitable for post-induction studies.
    Matched MeSH terms: Mesenchymal Stromal Cells/drug effects
  2. Purification of human adipose-derived stem cells from fat tissues using PLGA/silk screen hybrid membranes
    Chen DC, Chen LY, Ling QD, Wu MH, Wang CT, Suresh Kumar S, et al.
    Biomaterials, 2014 May;35(14):4278-87.
    PMID: 24565521 DOI: 10.1016/j.biomaterials.2014.02.004
    The purification of human adipose-derived stem cells (hADSCs) from human adipose tissue cells (stromal vascular fraction) was investigated using membrane filtration through poly(lactide-co-glycolic acid)/silk screen hybrid membranes. Membrane filtration methods are attractive in regenerative medicine because they reduce the time required to purify hADSCs (i.e., less than 30 min) compared with conventional culture methods, which require 5-12 days. hADSCs expressing the mesenchymal stem cell markers CD44, CD73, and CD90 were concentrated in the permeation solution from the hybrid membranes. Expression of the surface markers CD44, CD73, and CD99 on the cells in the permeation solution from the hybrid membranes, which were obtained using 18 mL of feed solution containing 50 × 10⁴ cells, was statistically significantly higher than that of the primary adipose tissue cells, indicating that the hADSCs can be purified in the permeation solution by the membrane filtration method. Cells expressing the stem cell-associated marker CD34 could be successfully isolated in the permeation solution, whereas CD34⁺ cells could not be purified by the conventional culture method. The hADSCs in the permeation solution demonstrated a superior capacity for osteogenic differentiation based on their alkali phosphatase activity, their osterix gene expression, and the results of mineralization analysis by Alizarin Red S and von Kossa staining compared with the cells from the suspension of human adipose tissue. These results suggest that the hADSCs capable of osteogenic differentiation preferentially permeate through the hybrid membranes.
    Matched MeSH terms: Stromal Cells/drug effects; Mesenchymal Stromal Cells/drug effects
  3. Treat the graft to improve the regenerative ability of the host
    Mamidi MK, Pal R, Govindasamy V, Zakaria Z, Bhonde R
    Med Hypotheses, 2011 Apr;76(4):599-601.
    PMID: 21277690 DOI: 10.1016/j.mehy.2011.01.010
    The staggering number of publications featuring the use of stem cells has revolutionized regenerative medicine research. Preclinical studies indicate that allogeneic human mesenchymal stem cells (MSCs) may be useful for the treatment of several clinical disorders, including sepsis, acute renal failure, acute myocardial infarction, and more recently, acute lung injury (ALI). However, considerable success would not be obtained in clinical trials due to poor survival of transplanted cells under the influence of inflammatory conditions. Despite robust approaches like cellular reprogramming, scaffolds and conditioned media have been tested to overcome this problem; however the success rate of these approaches remain questionable. Recently, pretreatment of bioactive compounds in vitro have been shown to suppress cell apoptosis and promote cell survival. Quite likely a similar phenomenon can take place in vivo. Based on such studies, we hypothesize that MSCs derived from human post-natal tissues could be conditioned and prepared for targeted disease therapy. Depending on the disease condition, the MSCs could be treated prior to delivery with appropriate bioactive compounds to allow them survive longer and perform a better role as biocatalyst. The advantage of this approach could be the tailor made availability of MSCs preconditioned with appropriate bioactive compounds for disease specific therapy. Therefore, the choice of suitable bioactive molecule is likely to enhance the efficacy of targeted stem cell therapy and preconditioning may provide a novel strategy in maximizing biological and functional properties of MSCs.
    Matched MeSH terms: Mesenchymal Stromal Cells/drug effects*
  4. In vitro differences of hydroxyapatite from different resources in simulated body fluid
    Hashim N, Sabudin S, Ibrahim S, Zin NM, Bakar SH, Fazan F
    Med J Malaysia, 2004 May;59 Suppl B:103-4.
    PMID: 15468839
    Hydroxyapatite (HA; Ca10(PO4)6(OH)2), is one of the significant implant materials used in Orthopaedics and Dental applications. However, synthetically produced HA may not be stable under ionic environment, which it will unavoidably encounter during its applications. In this paper, the in vitro effects of three HA materials derived from different resources, i.e. commercial HA (HAC), synthesised HA from pure chemicals (HAS) and synthesised HA from kapur sireh; derived traditionally from natural limestone (HAK), were studied. The HA disc samples were prepared and immersed in simulated body fluid (SBF) for 31-day period. The evaluation conducted focuses on the changes of the pH and the Calcium ion (Ca-ion) and Phosphate ion (P-ion) concentrations in the SBF solution, as well as the XRD and SEM data representing the reactions on the HA materials. From the XRD, it was found that HAK has the smallest crystallite sizes, which in turn affect the pH of the SBF during immersion. The Ca and P-ion concentrations generally decrease over time at different rates for different HA. Upon 1-day immersion in SBF, apatite growth was observed onto all three surfaces, which became more pronounced after 3-day immersion. However, the appetites formed were observed to be different in shapes and sizes. The reasons for the difference in the apatite-crystals and their subsequent effects on cells are still being investigated.
    Matched MeSH terms: Mesenchymal Stromal Cells/drug effects*
  5. Deferoxamine Preconditioning of Neural-Like Cells Derived from Human Wharton's Jelly Mesenchymal Stem Cells as a Strategy to Promote Their Tolerance and Therapeutic Potential: An In Vitro Study
    Nouri F, Salehinejad P, Nematollahi-Mahani SN, Kamarul T, Zarrindast MR, Sharifi AM
    Cell Mol Neurobiol, 2016 Jul;36(5):689-700.
    PMID: 26242172 DOI: 10.1007/s10571-015-0249-8
    Transplantation of neural-like cells is considered as a promising therapeutic strategy developed for neurodegenerative disease in particular for ischemic stroke. Since cell survival is a major concern following cell implantation, a number of studies have underlined the protective effects of preconditioning with hypoxia or hypoxia mimetic pharmacological agents such as deferoxamine (DFO), induced by activation of hypoxia inducible factor-1 (HIF-1) and its target genes. The present study has investigated the effects of DFO preconditioning on some factors involved in cell survival, angiogenesis, and neurogenesis of neural-like cells derived from human Wharton's jelly mesenchymal stem cells (HWJ-MSCs) in presence of hydrogen peroxide (H2O2). HWJ-MSCs were differentiated toward neural-like cells for 14 days and neural cell markers were identified using immunocytochemistry. HWJ-MSC-derived neural-like cells were then treated with 100 µM DFO, as a known hypoxia mimetic agent for 48 h. mRNA and protein expression of HIF-1 target genes including brain-derived neurotrophic factors (BDNF) and vascular endothelial growth factor (VEGF) significantly increased using RT-PCR and Western blotting which were reversed by HIF-1α inhibitor, while, gene expression of Akt-1, Bcl-2, and Bax did not change significantly but pAkt-1 was up-regulated as compared to poor DFO group. However, addition of H2O2 to DFO-treated cells resulted in higher resistance to H2O2-induced cell death. Western blotting analysis also showed significant up-regulation of HIF-1α, BDNF, VEGF, and pAkt-1, and decrease of Bax/Bcl-2 ratio as compared to poor DFO. These results may suggest that DFO preconditioning of HWJ-MSC-derived neural-like cells improves their tolerance and therapeutic potential and might be considered as a valuable strategy to improve cell therapy.
    Matched MeSH terms: Mesenchymal Stromal Cells/drug effects
  6. Fulltext Carica papaya induces in vitro thrombopoietic cytokines secretion by mesenchymal stem cells and haematopoietic cells
    Aziz J, Abu Kassim NL, Abu Kasim NH, Haque N, Rahman MT
    BMC Complement Altern Med, 2015;15:215.
    PMID: 26152209 DOI: 10.1186/s12906-015-0749-6
    Use of Carica papaya leaf extracts, reported to improve thrombocyte counts in dengue patients, demands further analysis on the underlying mechanism of its thrombopoietic cytokines induction
    Matched MeSH terms: Mesenchymal Stromal Cells/drug effects*
  7. Fulltext Effects of serum reduction and VEGF supplementation on angiogenic potential of human adipose stromal cells in vitro
    Chua KH, Raduan F, Wan Safwani WK, Manzor NF, Pingguan-Murphy B, Sathapan S
    Cell Prolif, 2013 Jun;46(3):300-11.
    PMID: 23672290 DOI: 10.1111/cpr.12029
    OBJECTIVES: This study investigated effects of reduced serum condition and vascular endothelial growth factor (VEGF) on angiogenic potential of adipose stromal cells (ASCs) in vitro.

    MATERIALS AND METHODS: Adipose stromal cells were cultured in three different types of medium: (i) F12/DMEM (FD) supplemented with 10% FBS from passage 0 (P0) to P6; (ii) FD supplemented with 2% FBS at P6; and (iii) FD supplemented with 2% FBS plus 50 ng/ml of VEGF at P6. Morphological changes and growth rate of ASCs were recorded. Changes in stemness, angiogenic and endogenic genes' expressions were analysed using Real-Time PCR.

    RESULTS: Adipose stromal cells changed from fibroblast-like shape when cultured in 10% FBS medium to polygonal when cultured in 2% FBS plus VEGF-supplemented medium. Their growth rate was lower in 2% FBS medium, but increased with addition of VEGF. Real-Time PCR showed that ASCs maintained most of their stemness and angiogenic genes' expression in 10% FBS at P1, P5 and P6, but this increased significantly in 2% FBS at P6. Endogenic genes expression such as PECAM-1, VE chaderin and VEGFR-2 decreased after serial passage in 10% FBS, but increased significantly at P6 in 2% FBS. Addition of VEGF did not cause any significant change in gene expression level.

    CONCLUSION: Adipose stromal cells had greater angiogenic potential when cultured in reduced serum conditions. VEGF did not enhance their angiogenic potential in 2% FBS-supplemented medium.

    Matched MeSH terms: Mesenchymal Stromal Cells/drug effects*
  8. Cytoprotective effects of antioxidant supplementation on mesenchymal stem cell therapy
    Panahi M, Rahimi B, Rahimi G, Yew Low T, Saraygord-Afshari N, Alizadeh E
    J Cell Physiol, 2020 10;235(10):6462-6495.
    PMID: 32239727 DOI: 10.1002/jcp.29660
    Mesenchymal stem cells (MSCs) are earmarked as perfect candidates for cell therapy and tissue engineering due to their capacity to differentiate into different cell types. However, their potential for application in regenerative medicine declines when the levels of the reactive oxygen and nitrogen species (RONS) increase from the physiological levels, a phenomenon which is at least inevitable in ex vivo cultures and air-exposed damaged tissues. Increased levels of RONS can alter the patterns of osteogenic and adipogenic differentiation and inhibit proliferation, as well. Besides, oxidative stress enhances senescence and cell death, thus lowering the success rates of the MSC engraftment. Hence, in this review, we have selected some representatives of antioxidants and newly emerged nano antioxidants in three main categories, including chemical compounds, biometabolites, and protein precursors/proteins, which are proved to be effective in the treatment of MSCs. We will focus on how antioxidants can be applied to optimize the clinical usage of the MSCs and their associated signaling pathways. We have also reviewed several paralleled properties of some antioxidants and nano antioxidants which can be simultaneously used in real-time imaging, scaffolding techniques, and other applications in addition to their primary antioxidative function.
    Matched MeSH terms: Mesenchymal Stromal Cells/drug effects*
  9. Effect of EGF and FGF on the expansion properties of human umbilical cord mesenchymal cells
    Salehinejad P, Alitheen NB, Mandegary A, Nematollahi-Mahani SN, Janzamin E
    In Vitro Cell Dev Biol Anim, 2013 Aug;49(7):515-23.
    PMID: 23708920 DOI: 10.1007/s11626-013-9631-3
    Mesenchymal stem cells have been increasingly introduced to have great potential in regenerative medicine, immunotherapy, and gene therapy due to their unique properties of self-renewal and differentiation into multiple cell lineages. Studies have shown that these properties may be limited and changed by senescence-associated growth arrest under different culture conditions. This study aimed to present the ability of some growth factors on human umbilical cord mesenchymal (hUCM) cells expansion and telomerase activity. To optimize hUCM cell growth, epidermal growth factor (EGF) and fibroblast growth factor (FGF) were utilized in culture media, and the ability of these growth factors on the expression of the telomerase reverse transcriptase (TERT) gene and cell cycle phases was investigated. TERT mRNA expression increased in the hUCM cells treated by EGF and FGF. So, the untreated hUCM cells expressed 30.49 ± 7.15% of TERT, while EGF-treated cells expressed 51.82 ± 12.96% and FGF-treated cells expressed 33.77 ± 11.55% of TERT. Exposure of hUCM cells to EGF or FGF also promoted the progression of cells from G1 to S phase of the cell cycle and induced them to decrease the number of cells entering the G2/M phase. Our study showed that EGF and, to a lesser extent, FGF amplify the proliferation and expansion of hUCM cells.
    Matched MeSH terms: Mesenchymal Stromal Cells/drug effects*
  10. Mesenchymal stem cells facilitate cardiac differentiation in Sox2-expressing cardiac C-kit cells in coculture
    Leong YY, Ng WH, Umar Fuaad MZ, Ng CT, Ramasamy R, Lim V, et al.
    J Cell Biochem, 2019 06;120(6):9104-9116.
    PMID: 30548289 DOI: 10.1002/jcb.28186
    Stem cell therapy offers hope to reconstitute injured myocardium and salvage heart from failing. A recent approach using combinations of derived Cardiac-derived c-kit expressing cells (CCs) and mesenchymal stem cells (MSCs) in transplantation improved infarcted hearts with a greater functional outcome, but the effects of MSCs on CCs remain to be elucidated. We used a novel two-step protocol to clonogenically amplify colony forming c-kit expressing cells from 4- to 6-week-old C57BL/6N mice. This method yielded highly proliferative and clonogenic CCs with an average population doubling time of 17.2 ± 0.2, of which 80% were at the G1 phase. We identified two distinctly different CC populations based on its Sox2 expression, which was found to inversely related to their nkx2.5 and gata4 expression. To study CCs after MSC coculture, we developed micron-sized particles of iron oxide-based magnetic reisolation method to separate CCs from MSCs for subsequent analysis. Through validation using the sex and species mismatch CC-MSC coculture method, we confirmed that the purity of the reisolated cells was greater than 85%. In coculture experiment, we found that MSCs prominently enhanced Ctni and Mef2c expressions in Sox2 pos CCs after the induction of cardiac differentiation, and the level was higher than that of conditioned medium Sox2 pos CCs. However, these effects were not found in Sox2 neg CCs. Immunofluorescence labeling confirmed the presence of cardiac-like cells within Sox2 pos CCs after differentiation, identified by its cardiac troponin I and α-sarcomeric actinin expressions. In conclusion, this study shows that MSCs enhance CC differentiation toward cardiac myocytes. This enhancement is dependent on CC stemness state, which is determined by Sox2 expression.
    Matched MeSH terms: Mesenchymal Stromal Cells/drug effects*
  11. Effect of 17β-estradiol on mediators involved in mesenchymal stromal cell trafficking in cell therapy of diabetes
    Mirzamohammadi S, Aali E, Najafi R, Kamarul T, Mehrabani M, Aminzadeh A, et al.
    Cytotherapy, 2015 Jan;17(1):46-57.
    PMID: 25457279 DOI: 10.1016/j.jcyt.2014.06.009
    Mesenchymal stromal cells (MSCs) have shown great promise for cell therapy of a wide range of diseases such as diabetes. However, insufficient viability of transplanted cells reaching to damaged tissues has limited their potential therapeutic effects. Expression of estrogen receptors on stem cells may suggest a role for 17β-estradiol (E2) in regulating some functions in these cells. There is evidence that E2 enhances homing of stem cells. Induction of hypoxia-inducible factor-1α (HIF-1α) by E2 and the profound effect of HIF-1α on migration of cells have previously been demonstrated. We investigated the effect of E2 on major mediators involved in trafficking and subsequent homing of MSCs both in vitro and in vivo in diabetic rats.
    Matched MeSH terms: Mesenchymal Stromal Cells/drug effects*
  12. Fulltext A comparative study on morphochemical properties and osteogenic cell differentiation within bone graft and coral graft culture systems
    Puvaneswary S, Balaji Raghavendran HR, Ibrahim NS, Murali MR, Merican AM, Kamarul T
    Int J Med Sci, 2013;10(12):1608-14.
    PMID: 24151432 DOI: 10.7150/ijms.6496
    The objective of this study was to compare the morphological and chemical composition of bone graft (BG) and coral graft (CG) as well as their osteogenic differentiation potential using rabbit mesenchymal stem cells (rMSCs) in vitro. SEM analysis of BG and CG revealed that the pores in these grafts were interconnected, and their micro-CT confirmed pore sizes in the range of 107-315 µm and 103-514 µm with a total porosity of 92% and 94%, respectively. EDS analysis indicated that the level of calcium in CG was relatively higher than that in BG. FTIR of BG and CG confirmed the presence of functional groups corresponding to carbonyl, aromatic, alkyl, and alkane groups. XRD results revealed that the phase content of the inorganic layer comprised highly crystalline form of calcium carbonate and carbon. Atomic force microscopy analysis showed CG had better surface roughness compared to BG. In addition, significantly higher levels of osteogenic differentiation markers, namely, alkaline phosphatase (ALP), Osteocalcin (OC) levels, and Osteonectin and Runx2, Integrin gene expression were detected in the CG cultures, when compared with those in the BG cultures. In conclusion, our results demonstrate that the osteogenic differentiation of rMSCs is relatively superior in coral graft than in bone graft culture system.
    Matched MeSH terms: Mesenchymal Stromal Cells/drug effects
  13. Autogenic feeder free system from differentiated mesenchymal progenitor cells, maintains pluripotency of the MEL-1 human embryonic stem cells
    Khoo TS, Hamidah Hussin N, Then SM, Jamal R
    Differentiation, 2013 Feb;85(3):110-8.
    PMID: 23722082 DOI: 10.1016/j.diff.2013.01.004
    Human embryonic stem cells (hESc) are known for its pluripotency and self renewal capability, thus possess great potential in regenerative medicine. However, the lack of suitable xenofree extracellular matrix substrate inhibits further applications or the use of hESc in cell-based therapy. In this study, we described a new differentiation method, which generates a homogeneous population of mesenchymal progenitor cells (hESc-MPC) from hESc via epithelial-mesenchymal transition. The extracellular matrix (ECM) proteins from hESc-MPC had in turn supported the undifferentiated expansion of hESc. Immunocytochemistry and flow cytometry characterization of hESc-MPC revealed the presence of early mesenchymal markers. Tandem mass spectometry analysis of ECM produced by hESc-MPC revealed the presence of a mixture of extracellular proteins which includes tenascin C, fibronectin, and vitronectin. The pluripotency of hESc (MEL-1) cultured on the ECM was maintained as shown by the expression of pluripotent genes (FoxD3, Oct-4, Tdgf1, Sox-2, Nanog, hTERT, Rex1), protein markers (SSEA-3, SSEA-4, TRA-1-81, TRA-1-60, Oct-4) and the ability to differentiate into cells representative of ectoderm, endoderm and mesoderm. In summary, we have established a xeno-free autogenic feeder free system to support undifferentiated expansion of hESc, which could be of clinical relevance.
    Matched MeSH terms: Mesenchymal Stromal Cells/drug effects
  14. Effect of growth differentiation factor 5 on the proliferation and tenogenic differentiation potential of human mesenchymal stem cells in vitro
    Tan SL, Ahmad RE, Ahmad TS, Merican AM, Abbas AA, Ng WM, et al.
    Cells Tissues Organs (Print), 2012;196(4):325-38.
    PMID: 22653337
    The use of growth differentiation factor 5 (GDF-5) in damaged tendons has been shown to improve tendon repair. It has been hypothesized that further improvements may be achieved when GDF-5 is used to promote cell proliferation and induce tenogenic differentiation in human bone marrow-derived mesenchymal stem cells (hMSCs). However, the optimal conditions required to produce these effects on hMSCs have not been demonstrated in previous studies. A study to determine cell proliferation and tenogenic differentiation in hMSCs exposed to different concentrations of GDF-5 (0, 5, 25, 50, 100 and 500 ng/ml) was thus conducted. No significant changes were observed in the cell proliferation rate in hMSCs treated at different concentrations of GDF-5. GDF-5 appeared to induce tenogenic differentiation at 100 ng/ml, as reflected by (1) a significant increase in total collagen expression, similar to that of the primary native human tenocyte culture; (2) a significant upregulation in candidate tenogenic marker gene expression, i.e. scleraxis, tenascin-C and type-I collagen; (3) the ratio of type-I collagen to type-III collagen expression was elevated to levels similar to that of human tenocyte cultures, and (4) a significant downregulation of the non-tenogenic marker genes runt-related transcription factor 2 and sex determining region Y (SRY)-box 9 at day 7 of GDF-5 induction, further excluding hMSC differentiation into other lineages. In conclusion, GDF-5 does not alter the proliferation rates of hMSCs, but, instead, induces an optimal tenogenic differentiation response at 100 ng/ml.
    Matched MeSH terms: Mesenchymal Stromal Cells/drug effects*
  15. Human platelet lysate permits scale-up of dental pulp stromal cells for clinical applications
    Govindasamy V, Ronald VS, Abdullah AN, Ganesan Nathan KR, Aziz ZA, Abdullah M, et al.
    Cytotherapy, 2011 Nov;13(10):1221-33.
    PMID: 21929379 DOI: 10.3109/14653249.2011.602337
    BACKGROUND AIMS. Dental pulp stromal cells (DPSC) are considered to be a promising source of stem cells in the field of regenerative therapy. However, the usage of DPSC in transplantation requires large-scale expansion to cater for the need for clinical quantity without compromising current good manufacturing practice (cGMP). Existing protocols for cell culturing make use of fetal bovine serum (FBS) as a nutritional supplement. Unfortunately, FBS is an undesirable additive to cells because it carries the risk of transmitting viral and prion diseases. Therefore, the present study was undertaken to examine the efficacy of human platelet lysate (HPL) as a substitute for FBS in a large-scale set-up. METHODS. We expanded the DPSC in Dulbecco's modified Eagle's medium-knock-out (DMEM-KO) with either 10% FBS or 10% HPL, and studied the characteristics of DPSC at pre- (T25 culture flask) and post- (5-STACK chamber) large-scale expansion in terms of their identity, quality, functionality, molecular signatures and cytogenetic stability. RESULTS. In both pre- and post-large-scale expansion, DPSC expanded in HPL showed extensive proliferation of cells (c. 2-fold) compared with FBS; the purity, immune phenotype, colony-forming unit potential and differentiation were comparable. Furthermore, to understand the gene expression profiling, the transcriptomes and cytogenetics of DPSC expanded under HPL and FBS were compared, revealing similar expression profiles. CONCLUSIONS. We present a highly economized expansion of DPSC in HPL, yielding double the amount of cells while retaining their basic characteristics during a shorter time period under cGMP conditions, making it suitable for therapeutic applications.
    Matched MeSH terms: Mesenchymal Stromal Cells/drug effects
  16. Effects of fluoride-modified titanium surfaces on osteoblast proliferation and gene expression
    Isa ZM, Schneider GB, Zaharias R, Seabold D, Stanford CM
    Int J Oral Maxillofac Implants, 2006 Mar-Apr;21(2):203-11.
    PMID: 16634490
    PURPOSE: The objective of this study was to test the hypothesis that fluoride-modified titanium surfaces would enhance osteoblast differentiation. Osteoblast growth on a moderately rough etched fluoride-modified titanium surface (alteration in cellular differentiation) was compared to osteoblast growth on the same surface grit-blasted with titanium dioxide. The potential role of nanometer-level alterations on cell shape and subsequent differentiation was then compared.
    MATERIALS AND METHODS: Human embryonic palatal mesenchymal (HEPM) cultures were incubated on the respective surfaces for 1, 3, and 7 days, followed by analysis for cell proliferation, alkaline phosphatase (ALP) -specific activity, and mRNA steady-state expression for bone-related genes (ALP, type I collagen, osteocalcin, bone sialoprotein [BSP] II, Cbfa1, and osterix) by real-time polymerase chain reaction (PCR).
    RESULTS: The different surfaces did not alter the mRNA expression for ALP, type I collagen, osterix, osteocalcin, or BSP II. However, Cbfa1 expression on the fluoride-modified titanium surface was significantly higher (P < .001) at 1 week. The number of cells on this surface was 20% lower than the number of cells on the surface TiO2-blasted with 25-microm particles but not significantly different from the number of cells on the surface TiO2-blasted with 125-microm particles. Cells grown on all the titanium surfaces expressed similar levels of ALP activity.
    CONCLUSIONS: The results indicated that a fluoride-modified surface topography, in synergy with surface roughness, may have a greater influence on the level of expression of Cbfa1 (a key regulator for osteogenesis) than the unmodified titanium surfaces studied.
    Matched MeSH terms: Mesenchymal Stromal Cells/drug effects
  17. Cytotoxic evaluation of hydroxyapatite-filled and silica/hydroxyapatite-filled acrylate-based restorative composite resins: An in vitro study
    Chadda H, Naveen SV, Mohan S, Satapathy BK, Ray AR, Kamarul T
    J Prosthet Dent, 2016 Jul;116(1):129-35.
    PMID: 26873771 DOI: 10.1016/j.prosdent.2015.12.013
    STATEMENT OF PROBLEM: Although the physical and mechanical properties of hydroxyapatite-filled dental restorative composite resins have been examined, the biocompatibility of these materials has not been studied in detail.

    PURPOSE: The purpose of this in vitro study was to analyze the toxicity of acrylate-based restorative composite resins filled with hydroxyapatite and a silica/hydroxyapatite combination.

    MATERIAL AND METHODS: Five different restorative materials based on bisphenol A-glycidyl methacrylate (bis-GMA) and tri-ethylene glycol dimethacrylate (TEGDMA) were developed: unfilled (H0), hydroxyapatite-filled (H30, H50), and silica/hydroxyapatite-filled (SH30, SH50) composite resins. These were tested for in vitro cytotoxicity by using human bone marrow mesenchymal stromal cells. Surface morphology, elemental composition, and functional groups were determined by scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX), and Fourier-transformed infrared spectroscopy (FTIR). The spectra normalization, baseline corrections, and peak integration were carried out by OPUS v4.0 software.

    RESULTS: Both in vitro cytotoxicity results and SEM analysis indicated that the composite resins developed were nontoxic and supported cell adherence. Elemental analysis with EDX revealed the presence of carbon, oxygen, calcium, silicon, and gold, while the presence of methacrylate, hydroxyl, and methylene functional groups was confirmed through FTIR analysis.

    CONCLUSIONS: The characterization and compatibility studies showed that these hydroxyapatite-filled and silica/hydroxyapatite-filled bis-GMA/TEGDMA-based restorative composite resins are nontoxic to human bone marrow mesenchymal stromal cells and show a favorable biologic response, making them potential biomaterials.

    Matched MeSH terms: Mesenchymal Stromal Cells/drug effects
  18. Application of Ti3 C2 MXene Quantum Dots for Immunomodulation and Regenerative Medicine
    Rafieerad A, Yan W, Sequiera GL, Sareen N, Abu-El-Rub E, Moudgil M, et al.
    Adv Healthc Mater, 2019 08;8(16):e1900569.
    PMID: 31265217 DOI: 10.1002/adhm.201900569
    Inflammation is tightly linked to tissue injury. In regenerative medicine, immune activation plays a key role in rejection of transplanted stem cells and reduces the efficacy of stem cell therapies. Next-generation smart biomaterials are reported to possess multiple biologic properties for tissue repair. Here, the first use of 0D titanium carbide (Ti3 C2 ) MXene quantum dots (MQDs) for immunomodulation is presented with the goal of enhancing material-based tissue repair after injury. MQDs possess intrinsic immunomodulatory properties and selectively reduce activation of human CD4+ IFN-γ+ T-lymphocytes (control 87.1 ± 2.0%, MQDs 68.3 ± 5.4%) while promoting expansion of immunosuppressive CD4+ CD25+ FoxP3+ regulatory T-cells (control 5.5 ± 0.7%, MQDs 8.5 ± 0.8%) in a stimulated lymphocyte population. Furthermore, MQDs are biocompatible with bone marrow-derived mesenchymal stem cells and induced pluripotent stem cell-derived fibroblasts. Finally, Ti3 C2 MQDs are incorporated into a chitosan-based hydrogel to create a 3D platform with enhanced physicochemical properties for stem cell delivery and tissue repair. This composite hydrogel demonstrates increased conductivity while maintaining injectability and thermosensitivity. These findings suggest that this new class of biomaterials may help bridge the translational gap in material and stem cell-based therapies for tissue repair and treatment of inflammatory and degenerative diseases.
    Matched MeSH terms: Mesenchymal Stromal Cells/drug effects
  19. Fulltext Collagen type I promotes osteogenic differentiation of amniotic membrane-derived mesenchymal stromal cells in basal and induction media
    Akhir HM, Teoh PL
    Biosci Rep, 2020 12 23;40(12).
    PMID: 33245097 DOI: 10.1042/BSR20201325
    Collagen has been widely shown to promote osteogenesis of bone marrow mesenchymal stromal cells (BM-MSCs). Due to the invasive procedure of obtaining BM-MSCs, MSCs from other tissues have emerged as a promising alternative for regenerative therapy. MSCs originated from different sources, exhibiting different differentiation potentials. Therefore, the applicability of collagen type I (COL), combining with amniotic membrane (AM)-MSCs was examined through proliferation and differentiation assays together with the expression of surface markers and genes associated with stemness and differentiation under basal or induction conditions. No increase in cell growth was observed because AM-MSCs might be directed toward spontaneous osteogenesis. This was evidenced by the calcium deposition and elevated expression of osteogenic genes when AM-MSCs were cultured in collagen plate with basal media. Under the osteogenic condition, reciprocal expression of OCN and CEBPA suggested a shift toward adipogenesis. Surprisingly, adipogenic genes were not elevated upon adipogenic induction, although oil droplets deposition was observed. In conclusion, our findings demonstrated that collagen causes spontaneous osteogenesis in AM-MSCs. However, the presence of exogenous inductors could shift the direction of adipo-osteogenic gene regulatory network modulated by collagen.
    Matched MeSH terms: Mesenchymal Stromal Cells/drug effects*
  20. Fulltext Fate of tenogenic differentiation potential of human bone marrow stromal cells by uniaxial stretching affected by stretch-activated calcium channel agonist gadolinium
    Nam HY, Balaji Raghavendran HR, Pingguan-Murphy B, Abbas AA, Merican AM, Kamarul T
    PLoS One, 2017;12(6):e0178117.
    PMID: 28654695 DOI: 10.1371/journal.pone.0178117
    The role for mechanical stimulation in the control of cell fate has been previously proposed, suggesting that there may be a role of mechanical conditioning in directing mesenchymal stromal cells (MSCs) towards specific lineage for tissue engineering applications. Although previous studies have reported that calcium signalling is involved in regulating many cellular processes in many cell types, its role in managing cellular responses to tensile loading (mechanotransduction) of MSCs has not been fully elucidated. In order to establish this, we disrupted calcium signalling by blocking stretch-activated calcium channel (SACC) in human MSCs (hMSCs) in vitro. Passaged-2 hMSCs were exposed to cyclic tensile loading (1 Hz + 8% for 6, 24, 48, and 72 hours) in the presence of the SACC blocker, gadolinium. Analyses include image observations of immunochemistry and immunofluorescence staining from extracellular matrix (ECM) production, and measuring related tenogenic and apoptosis gene marker expression. Uniaxial tensile loading increased the expression of tenogenic markers and ECM production. However, exposure to strain in the presence of 20 μM gadolinium reduced the induction of almost all tenogenic markers and ECM staining, suggesting that SACC acts as a mechanosensor in strain-induced hMSC tenogenic differentiation process. Although cell death was observed in prolonged stretching, it did not appear to be apoptosis mediated. In conclusion, the knowledge gained in this study by elucidating the role of calcium in MSC mechanotransduction processes, and that in prolonged stretching results in non-apoptosis mediated cell death may be potential useful for regenerative medicine applications.
    Matched MeSH terms: Mesenchymal Stromal Cells/drug effects*
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