by Keyword: Osteoblast
Canal, C., Fontelo, R., Hamouda, I., Guillem-Marti, J., Cvelbar, U., Ginebra, M. P., (2017). Plasma-induced selectivity in bone cancer cells death Free Radical Biology and Medicine 110, 72-80
Background: Current therapies for bone cancers - either primary or metastatic – are difficult to implement and unfortunately not completely effective. An alternative therapy could be found in cold plasmas generated at atmospheric pressure which have already demonstrated selective anti-tumor action in a number of carcinomas and in more relatively rare brain tumors. However, its effects on bone cancer are still unknown. Methods: Herein, we employed an atmospheric pressure plasma jet (APPJ) to validate its selectivity towards osteosarcoma cell line vs. osteoblasts & human mesenchymal stem cells. Results: Cytotoxicity following direct interaction of APPJ with cells is comparable to indirect interaction when only liquid medium is treated and subsequently added to the cells, especially on the long-term (72 h of cell culture). Moreover, following contact of the APPJ treated medium with cells, delayed effects are observed which lead to 100% bone cancer cell death through apoptosis (decreased cell viability with incubation time in contact with APPJ treated medium from 24 h to 72 h), while healthy cells remain fully viable and unaffected by the treatment. Conclusions: The high efficiency of the indirect treatment indicates that an important role is played by the reactive oxygen species (ROS) and reactive nitrogen species (RNS) in the gaseous plasma stage and then transmitted to the liquid phase, which overall lead to lethal and selective action towards osteosarcoma cells. These findings open new pathways for treatment of metastatic bone disease with a minimally invasive approach.
Keywords: Atmospheric pressure plasma jet, Bone cancer, hMSC, HOb, Liquids, Osteoblasts, Osteosarcoma, SaOS-2
Sadowska, J. M., Guillem-Marti, J., Montufar, E. B., Espanol, M., Ginebra, M. P., (2017). Biomimetic versus sintered calcium phosphates: The in vitro behavior of osteoblasts and mesenchymal stem cells Tissue Engineering Part A 23, (23-24), 1297-1309
The fabrication of calcium phosphates using biomimetic routes, namely, precipitation processes at body temperature, results in distinct features compared to conventional sintered calcium phosphate ceramics, such as a high specific surface area (SSA) and micro-or nanometric crystal size. The aim of this article is to analyze the effects of these parameters on cell response, focusing on two bone cell types: rat mesenchymal stem cells (rMSCs) and human osteoblastic cells (SaOS-2). Biomimetic calcium-deficient hydroxyapatite (CDHA) was obtained by a low temperature setting reaction, and Î±-Tricalcium phosphate (Î±-TCP) and Î²-Tricalcium phosphate were subsequently obtained by sintering CDHA either at 1400Â°C or 1100Â°C. Sintered stoichiometric hydroxyapatite (HA) was also prepared using ceramic routes. The materials were characterized in terms of SSA, skeletal density, porosity, and pore size distribution. SaOS-2 cells and rMSCs were seeded either directly on the surfaces of the materials or on glass coverslips subsequently placed on top of the materials to expose the cells to the CaP-induced ionic changes in the culture medium, while avoiding any topography-related effects. CDHA produced higher ionic fluctuations in both cell culture media than sintered ceramics, with a strong decrease of calcium and a release of phosphate. Indirect contact cell cultures revealed that both cell types were sensitive to these ionic modifications, resulting in a decrease in proliferation rate, more marked for CDHA, this effect being more pronounced for rMSCs. In direct contact cultures, good cell adhesion was found on all materials, but, while cells were able to proliferate on the sintered calcium phosphates, cell number was significantly reduced with time on biomimetic CDHA, which was associated to a higher percentage of apoptotic cells. Direct contact of the cells with biomimetic CDHA resulted also in a higher alkaline phosphatase activity for both cell types compared to sintered CaPs, indicating a promotion of the osteoblastic phenotype.
Keywords: Biomimetic hydroxyapatite, Calcium phosphate, Mesenchymal stem cell, Osteoblast
Gustavsson, J., Planell, J., Engel, E., (2013). Ion-selective electrodes to monitor osteoblast-like cellular influence on the extracellular concentration of calcium Journal of Tissue Engineering and Regenerative Medicine 7, (8), 609-620
In bone tissue engineering, the composition of the ionic extracellular environment (IEE) can determine both cellular fate and a biomaterial's development and performance. Therefore, precise control of the IEE and a perfect understanding of the dynamic changes that it can be subject to due to cellular activity is highly desired. To achieve this, we initially monitored how two standard osteoblast-like cell models that expressed either high or low alkaline phosphatase activity - SAOS-2 and MG63 cells, respectively - affected the extracellular concentrations of calcium and phosphate during long-term cultures. It was observed that cellular influence on the IEE varied greatly between the two models and could be linked to the capacity of cells to deposit calcium in the extracellular matrix. Miniaturized ion-selective electrodes that could allow for real-time monitoring of calcium in a minimally invasive way were then constructed. The electrodes were characterized in standard in vitro cell culture environments, prior to being successfully applied for periods of 24h, to record the dynamics of cell-induced deposition of calcium in the extracellular matrix, while using osteogenic media of either high or low concentrations of phosphate. As a result, this study provides the background and technological means for the non-destructive evaluation of the IEE in vitro and allows for the optimization and development of better models of bone tissue construction.
Keywords: Extracellular ions, Ion-selective electrode, MG63, Mineralization, Osteoblasts, Saos-2, Sensor, Tissue engineering
Navarro, M., Pu, F., Hunt, J. A., (2012). The significance of the host inflammatory response on the therapeutic efficacy of cell therapies utilising human adult stem cells Experimental Cell Research 318, (4), 361-370
Controlling the fate of implanted hMSCs is one of the major drawbacks to be overcome to realize tissue engineering strategies. In particular, the effect of the inflammatory environment on hMSCs behaviour is poorly understood. Studying and mimicking the inflammatory process in vitro is a very complex and challenging task that involves multiple variables. This research addressed the questions using in vitro co-cultures of primary derived hMSCs together with human peripheral blood mononucleated cells (PBMCs); the latter are key agents in the inflammatory process. This work explored the in vitro phenotypic changes of hMSCs in co-culture direct contact with monocytes and lymphocytes isolated from blood using both basal and osteogenic medium. Our findings indicated that hMSCs maintained their undifferentiated phenotype and pluripotency despite the contact with PBMCs. Moreover, hMSCs demonstrated increased proliferation and were able to differentiate specifically down the osteogenic lineage pathway. Providing significant crucial evidence to support the hypothesis that inflammation and host defence mechanisms could be utilised rather than avoided and combated to provide for the successful therapeutic application of stem cell therapies.
Keywords: Co-culture, Inflammation, Mesenchymal stem cells, Monocytes, Osteoblasts
Byrne, Damien P., Lacroix, Damien, Prendergast, Patrick J., (2011). Simulation of fracture healing in the tibia: Mechanoregulation of cell activity using a lattice modeling approach Journal of Orthopaedic Research 29, (10), 1496-1503
In this study, a three-dimensional (3D) computational simulation of bone regeneration was performed in a human tibia under realistic muscle loading. The simulation was achieved using a discrete lattice modeling approach combined with a mechanoregulation algorithm to describe the cellular processes involved in the healing process namely proliferation, migration, apoptosis, and differentiation of cells. The main phases of fracture healing were predicted by the simulation, including the bone resorption phase, and there was a qualitative agreement between the temporal changes in interfragmentary strain and bending stiffness by comparison to experimental data and clinical results. Bone healing was simulated beyond the reparative phase by modeling the transition of woven bone into lamellar bone. Because the simulation has been shown to work with realistic anatomical 3D geometry and muscle loading, it demonstrates the potential of simulation tools for patient-specific pre-operative treatment planning.
Keywords: Tissue differentiation, Computational analysis, Mechanical conditions, Bone regeneration, Weight-bearing, Proliferation, Osteoblast, Stiffness, Ingrowth, Scaffold
Comelles, J., Estevez, M., Martinez, E., Samitier, J., (2010). The role of surface energy of technical polymers in serum protein adsorption and MG-63 cells adhesion Nanomedicine: Nanotechnology Biology and Medicine 6, (1), 44-51
Polymeric materials are widely used as supports for cell culturing in medical implants and as scaffolds for tissue regeneration. However, novel applications in the biosensor field require materials to be compatible with cell growth and at the same time be suitable for technological processing. Technological polymers are key materials in the fabrication of disposable parts and other sensing elements. As such, it is essential to characterize the surface properties of technological polymers, especially after processing and sterilization. It is also important to understand how technological polymers affect cell behavior when in contact with polymer materials. Therefore, the aim of this research was to study how surface energy and surface roughness affect the biocompatibility of three polymeric materials widely used in research and industry: poly (methyl methacrylate), polystyrene, and poly(dimethylsiloxane). Glass was used as the control material. From the Clinical Editor: Polymeric materials are widely used as supports for cell culturing in medical implants and as scaffolds for tissue regeneration. The aim of this research is to study how surface energy and surface roughness affect the biocompatibility of three polymeric materials widely used in research and industry: poly(methylmethacrylate) (PMMA), polystyrene (PS), and poly(dimethylsiloxane) (PDMS).
Keywords: Thin-films, Poly(methyl methacrylate), Osteoblast adhesion, Electron-microscopy, Fibronectin, Polystyrene, Oly(dimethylsiloxane), Biocompatibility, Hydroxyapatite, Behavior
Estevez, M., Fernandez-Ulibarri, I., Martinez, E., Egea, G., Samitier, J., (2010). Changes in the internal organization of the cell by microstructured substrates Soft Matter 6, (3), 582-590
Surface features at the micro and nanometre scale have been shown to influence and even determine cell behaviour and cytoskeleton organization through direct mechanotransductive pathways. Much less is known about the function and internal distribution of organelles of cells grown on topographically modified surfaces. In this study, the nanoimprint lithography technique was used to manufacture poly(methyl methacrylate) (PMMA) sheets with a variety of features in the micrometre size range. Normal rat kidney (NRK) fibroblasts were cultured on these substrates and immunofluorescence staining assays were performed to visualize cell adhesion, the organization of the cytoskeleton and the morphology and subcellular positioning of the Golgi complex. The results show that different topographic features at the micrometric scale induce different rearrangements of the cell cytoskeleton, which in turn alter the positioning and morphology of the Golgi complex. Microposts and microholes alter the mechanical stability of the Golgi complex by modifying the actin cytoskeleton organization leading to the compaction of the organelle. These findings prove that physically modified surfaces are a valuable tool with which to study the dynamics of cell cytoskeleton organization and its subsequent repercussion on internal cell organization and associated function.
Keywords: Actin stress fibers, Golgi-complex, Focal adhesions, Cytoskeletal organization, Osteoblast adhesion, Mammalian-cells, Micron-scale, Nanoscale, Dynamics, Rho
Engel, E., Martinez, E., Mills, C. A., Funes, M., Planell, J. A., Samitier, J., (2009). Mesenchymal stem cell differentiation on microstructured poly (methyl methacrylate) substrates Annals of Anatomy-Anatomischer Anzeiger 191, (1), 136-144
Recent studies on 2D substrates have revealed the importance of surface properties in affecting cell behaviour. In particular, surface topography appears to influence and direct cell migration. The development of new technologies of hot embossing and micro-imprinting has made it possible to study cell interactions with controlled micro features and to determine how these features can affect cell behaviour. Several studies have been carried out on the effect of microstructures on cell adhesion, cell guidance and cell proliferation. However, there is still a lack of knowledge on how these features affect mesenchymal stem cell differentiation. This study was designed to evaluate whether highly controlled microstructures on PMMA could induce rMSC differentiation into an osteogenic lineage. Structured PMMA was seeded with rMSC and cell number; cell morphology and cell differentiation were evaluated. Results confirm that microstructures not only affect cell proliferation and alignment but also have a synergistic effect with osteogenic medium on rMSC differentiation into mature osteoblasts.
Keywords: Mesenchymal stem cells, Osteoblasts, Topography, Microstructures
Engel, E., Del Valle, S., Aparicio, C., Altankov, G., Asin, L., Planell, J. A., Ginebra, M. P., (2008). Discerning the role of topography and ion exchange in cell response of bioactive tissue engineering scaffolds Tissue Engineering Part A 14, (8), 1341-1351
Surface topography is known to have an influence on osteoblast activity. However, in the case of bioactive materials, topographical changes can affect also ion exchange properties. This makes the problem more complex, since it is often difficult to separate the strictly topographical effects from the effects of ionic fluctuations in the medium. The scope of this paper is to analyze the simultaneous effect of topography and topography-mediated ion exchange on the initial cellular behavior of osteoblastic-like cells cultured on bioactive tissue engineering substrates. Two apatitic substrates with identical chemical composition but different micro/nanostructural features were obtained by low-temperature setting of a calcium phosphate cement. MG63 osteoblastic-like cells were cultured either in direct contact with the substrates or with their extracts. A strong and permanent decrease of calcium concentration in the culture medium, dependent on substrate topography, was detected. A major effect of the substrate microstructure on cell proliferation was observed, explained in part by the topography-mediated ion exchange, but not specifically by the ionic Ca(2+) fluctuations. Cell differentiation was strongly enhanced when cells were cultured on the finer substrate. This effect was not explained by the chemical modification of the medium, but rather suggested a strictly topographical effect.
Keywords: Alkaline Phosphatase/metabolism, Bone Cements/pharmacology, Calcium/metabolism, Calcium Phosphates/pharmacology, Cell Adhesion/drug effects, Cell Differentiation/drug effects, Cell Proliferation/drug effects, Cell Shape/drug effects, Cells, Cultured, Culture Media, Durapatite/pharmacology, Humans, Interferometry, Ion Exchange, Materials Testing, Osteoblasts/ cytology/drug effects/enzymology/ultrastructure, Phosphorus/metabolism, Powders, Tissue Engineering, Tissue Scaffolds
Martinez, E., Engel, E., Lopez-Iglesias, C., Mills, C. A., Planell, J. A., Samitier, J., (2008). Focused ion beam/scanning electron microscopy characterization of cell behavior on polymer micro-/nanopatterned substrates: A study of cell-substrate interactions Micron 39, (2), 111-116
Topographic micro and nanostructures can play an interesting role in cell behaviour when cells are cultured on these kinds of patterned substrates. It is especially relevant to investigate the influence of the nanometric dimensions topographic features on cell morphology, proliferation, migration and differentiation. To this end, some of the most recent fabrication technologies, developed for the microelectronics industry, can be used to produce well-defined micro and nanopatterns on biocompatible polymer substrates. In this work, osteoblast-like cells are grown on poly(methyl methacrylate) substrates patterned by nanoimprint lithography techniques. Examination of the cell-substrate interface can reveal important details about the cell morphology and the distribution of the focal contacts on the substrate surface. For this purpose, a combination of focused ion beam milling and scanning electron microscopy techniques has been used to image the cell-substrate interface. This technique, if applied to samples prepared by freeze-drying methods, allows high-resolution imaging of cross-sections through the cell and the substrate, where the interactions between the nanopatterned substrate, the cell and the extracellular matrix, which are normally hidden by the bulk of the cell, can be studied.
Keywords: Electron microscopy, Interface, Nanotopography, Osteoblast, Adhesion molecule, Cell morphology
Charles-Harris, M., Koch, M. A., Navarro, M., Lacroix, D., Engel, E., Planell, J. A., (2008). A PLA/calcium phosphate degradable composite material for bone tissue engineering: an in vitro study Journal of Materials Science-Materials in Medicine 19, (4), 1503-1513
Biodegradable polymers reinforced with an inorganic phase such as calcium phosphate glasses may be a promising approach to fulfil the challenging requirements presented by 3D porous scaffolds for tissue engineering. Scaffolds' success depends mainly on their biological behaviour. This work is aimed to the in vitro study of polylactic acid (PLA)/CaP glass 3D porous constructs for bone regeneration. The scaffolds were elaborated using two different techniques, namely solvent-casting and phase-separation. The effect of scaffolds' micro and macrostructure on the biological response of these scaffolds was assayed. Cell proliferation, differentiation and morphology within the scaffolds were studied. Furthermore, polymer/glass scaffolds were seeded under dynamic conditions in a custom-made perfusion bioreactor. Results indicate that the final architecture of the solvent-cast or phase separated scaffolds have a significant effect on cells' behaviour. Solvent-cast scaffolds seem to be the best candidates for bone tissue engineering. Besides, dynamic seeding yielded a higher seeding efficiency in comparison with the static method.
Keywords: Biocompatible Materials/ chemistry, Bone and Bones/ metabolism, Calcium Phosphates/ chemistry, Cell Differentiation, Cell Proliferation, Humans, Lactic Acid/ chemistry, Microscopy, Confocal, Microscopy, Electron, Scanning, Osteoblasts/metabolism, Permeability, Polymers/ chemistry, Porosity, Solvents/chemistry, Tissue Engineering/ methods
Gustavsson, J., Altankov, G., Errachid, A., Samitier, J., Planell, J. A., Engel, E., (2008). Surface modifications of silicon nitride for cellular biosensor applications Journal of Materials Science-Materials in Medicine 19, (4), 1839-1850
Thin films of silicon nitride (Si3N4) can be used in several kinds of micro-sized biosensors as a material to monitor fine environmental changes related to the process of bone formation in vitro. We found however that Si3N4 does not provide optimal conditions for osseointegration as osteoblast-like MG-63 cells tend to detach from the surface when cultured over confluence. Therefore Si3N4 was modified with self-assembled monolayers bearing functional end groups of primary amine (NH2) and carboxyl (COOH) respectively. Both these modifications enhanced the interaction with confluent cell layers and thus improve osseointegration over Si3N4. Furthermore it was observed that the NH2 functionality increased the adsorption of fibronectin (FN), promoted cell proliferation, but delayed the differentiation. We also studied the fate of pre-adsorbed and secreted FN from cells to learn more about the impact of above functionalities for the development of provisional extracellular matrix on materials interface. Taken together our data supports that Si3N4 has low tissue integration but good cellular biocompatibility and thus is appropriate in cellular biosensor applications such as the ion-sensitive field effect transistor (ISFET). COOH and NH2 chemistries generally improve the interfacial tissue interaction with the sensor and they are therefore suitable substrates for monitoring cellular growth or matrix deposition using electrical impedance spectroscopy.
Keywords: Adsorption, Amines/chemistry, Biocompatible Materials/ chemistry, Biosensing Techniques, Cell Differentiation, Cell Line, Cell Proliferation, Electric Impedance, Extracellular Matrix/metabolism, Fibronectins/chemistry, Humans, Materials Testing, Osteoblasts/ cytology, Silicon Compounds/ chemistry, Surface Properties