by Keyword: Mesenchymal stem cell
Sadowska, Joanna Maria, Guillem-Marti, Jordi, Espanol, Montserrat, Stähli, Christoph, Döbelin, Nicola, Ginebra, Maria-Pau, (2018). In vitro response of mesenchymal stem cells to biomimetic hydroxyapatite substrates: A new strategy to assess the effect of ion exchange Acta Biomaterialia 76, 319-332
Biomaterials can interact with cells directly, that is, by direct contact of the cells with the material surface, or indirectly, through soluble species that can be released to or uptaken from the surrounding fluids. However, it is difficult to characterise the relevance of this fluid-mediated interaction separately from the topography and composition of the substrate, because they are coupled variables. These fluid-mediated interactions are amplified in the case of highly reactive calcium phosphates (CaPs) such as biomimetic calcium deficient hydroxyapatite (CDHA), particularly in static in vitro cultures. The present work proposes a strategy to decouple the effect of ion exchange from topographical features by adjusting the volume ratio between the cell culture medium and biomaterial (VCM/VB). Increasing this ratio allowed mitigating the drastic ionic exchanges associated to the compositional changes experienced by the material exposed to the cell culture medium. This strategy was validated using rat mesenchymal stem cells (rMSCs) cultured on CDHA and beta-tricalcium phosphate (β-TCP) discs using different VCM/VB ratios. Whereas in the case of β-TCP the cell response was not affected by this ratio, a significant effect on cell adhesion and proliferation was found for the more reactive CDHA. The ionic exchange, produced by CDHA at low VCM/VB, altered cell adhesion due to the reduced number of focal adhesions, caused cell shrinkage and further rMCSs apoptosis. This was mitigated when using a high VCM/VB, which attenuated the changes of calcium and phosphate concentrations in the cell culture medium, resulting in rMSCs spreading and a viability over time. Moreover, rMSCs showed an earlier expression of osteogenic genes on CDHA compared to sintered β-TCP when extracellular calcium fluctuations were reduced.
Statement of Significance: Fluid mediated interactions play a significant role in the bioactivity of calcium phosphates. Ionic exchange is amplified in the case of biomimetic hydroxyapatite, which makes the in vitro characterisation of cell-material interactions especially challenging. The present work proposes a novel and simple strategy to explore the mechanisms of interaction of biomimetic and sintered calcium phosphates with mesenchymal stem cells. The effects of topography and ion exchange are analysed separately by modifying the volume ratio between cell culture medium and biomaterial. High ionic fluctuations interfered in the maturation of focal adhesions, hampering cell adhesion and leading to increased apoptosis and reduced proliferation rate.
Keywords: Calcium phosphates, Mesenchymal stem cells, Intracellular calcium, Cell adhesion
Casanellas, Ignasi, Lagunas, Anna, Tsintzou, Iro, Vida, Yolanda, Collado, Daniel, Pérez-Inestrosa, Ezequiel, Rodríguez-Pereira, Cristina, Magalhaes, Joana, Gorostiza, Pau, Andrades, José A., Becerra, José, Samitier, Josep, (2018). Dendrimer-based uneven nanopatterns to locally control surface adhesiveness: A method to direct chondrogenic differentiation Journal of Visualized Experiments , Bioengineering, (131), e56347
Cellular adhesion and differentiation is conditioned by the nanoscale disposition of the extracellular matrix (ECM) components, with local concentrations having a major effect. Here we present a method to obtain large-scale uneven nanopatterns of arginine-glycine-aspartic acid (RGD)-functionalized dendrimers that permit the nanoscale control of local RGD surface density. Nanopatterns are formed by surface adsorption of dendrimers from solutions at different initial concentrations and are characterized by water contact angle (CA), X-ray photoelectron spectroscopy (XPS), and scanning probe microscopy techniques such as scanning tunneling microscopy (STM) and atomic force microscopy (AFM). The local surface density of RGD is measured using AFM images by means of probability contour maps of minimum interparticle distances and then correlated with cell adhesion response and differentiation. The nanopatterning method presented here is a simple procedure that can be scaled up in a straightforward manner to large surface areas. It is thus fully compatible with cell culture protocols and can be applied to other ligands that exert concentration-dependent effects on cells.
Keywords: Bioengineering, Dendrimer, Nanopattern, Arginine-Glycine-Aspartic Acid (RGD), Atomic Force Microscopy (AFM), Cell Adhesion, Mesenchymal Stem Cells (Mscs), Chondrogenesis
Bianchi, M. V., Awaja, F., Altankov, G., (2017). Dynamic adhesive environment alters the differentiation potential of young and ageing mesenchymal stem cells Materials Science and Engineering: C 78, 467-474
Engineering dynamic stem cell niche-like environment offers opportunity to obtain better control of the fate of stem cells. We identified, for the first time, that periodic changes in the adhesive environment of human adipose derived mesenchymal stem cells (ADSCs) alters dramatically their asymmetric division but not their ability for symmetric renewal. Hereby, we used smart thermo-responsive polymer (PNIPAM) to create a dynamic adhesive environment for ADSCs by applying periodic temperature cycles to perturb adsorbed adhesive proteins to substratum interaction. Cumulative population doubling time (CPDT) curves showed insignificant decline in the symmetric cell growth studied for up to 13th passages accompanied with small changes in the overall cell morphology and moderately declined fibronectin (FN) matrix deposition probably as a functional consequence of ADSCs ageing. However, a substantial alteration in the differentiation potential of ADSCs from both early and late passages (3rd and 14th, respectively) was found when the cells were switched to osteogenic differentiation conditions. This behavior was evidenced by the significantly altered alkaline phosphatase activity and Ca deposition (Alizarin red) assayed at 3, 14 and 21 day in comparison to the control samples of regular TC polystyrene processed under same temperature settings.
Keywords: Cell ageing, Dynamic adhesive environment, Extracellular matrix, Mesenchymal stem cells, PNIPAM, Stem cell niche, Symmetric and asymmetric cell growth, Thermo-cycling, Thermo-responsive polymer
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
Gugutkov, D., Awaja, F., Belemezova, K., Keremidarska, M., Krasteva, N., Kuyrkchiev, S., GallegoFerrer, G., Seker, S., Elcin, A. E., Elcin, Y. M., Altankov, G., (2017). Osteogenic differentiation of mesenchymal stem cells using hybrid nanofibers with different configurations and dimensionality Journal of Biomedical Materials Research - Part A , 105, (7), 2065-2074
Novel hybrid, fibrinogen/polylactic acid (FBG/PLA) nanofibers with different configuration (random vs. aligned) and dimensionality (2D vs.3D environment) were used to control the overall behaviour and the osteogenic differentiation of human Adipose Derived Mesenchymal Stem Cells (ADMSCs). Aligned nanofibers in both the 2D and 3D configurations are proved to be favoured for osteo-differentiation. Morphologically we found that on randomly configured nanofibers, the cells developed a stellate-like morphology with multiple projections, however, time-lapse analysis showed significantly diminished cell movements. Conversely, an elongated cell shape with advanced cell spreading and extended actin cytoskeleton accompanied with significantly increased cell mobility were observed when cells attached on aligned nanofibers. Moreover, a clear tendency for higher alkaline phosphatase activity was also found on aligned fibres when ADMSCs were switched to osteogenic induction medium. The strongest accumulation of Alizarin red (AR) and von Kossa stain at 21 day of culture in osteogenic medium were found on 3D aligned constructs while the rest showed lower and rather undistinguishable activity. Quantitative reverse transcription-polymerase chain reaction analysis for Osteopontin (OSP) and RUNX 2 generally confirmed this trend showing favourable expression of osteogenic genes activity in 3D environment particularly in aligned configuration.
Keywords: Mesenchymal stem cells, Nanofibers, Osteogenic, Fibrinogen, Cell movements
Zhao, M., Altankov, G., Grabiec, U., Bennett, M., Salmeron-Sanchez, M., Dehghani, F., Groth, T., (2016). Molecular composition of GAG-collagen I multilayers affects remodeling of terminal layers and osteogenic differentiation of adipose-derived stem cells Acta Biomaterialia 41, 86-99
The effect of molecular composition of multilayers, by pairing type I collagen (Col I) with either hyaluronic acid (HA) or chondroitin sulfate (CS) was studied regarding the osteogenic differentiation of adhering human adipose-derived stem cells (hADSCs). Polyelectrolyte multilayer (PEM) formation was based primarily on ion pairing and on additional intrinsic cross-linking through imine bond formation with Col I replacing native by oxidized HA (oHA) or CS (oCS). Significant amounts of Col I fibrils were found on both native and oxidized CS-based PEMs, resulting in higher water contact angles and surface potential under physiological condition, while much less organized Col I was detected in either HA-based multilayers, which were more hydrophilic and negatively charged. An important finding was that hADSCs remodeled Col I at the terminal layers of PEMs by mechanical reorganization and pericellular proteolytic degradation, being more pronounced on CS-based PEMs. This was in accordance with the higher quantity of Col I deposition in this system, accompanied by more cell spreading, focal adhesions (FA) formation and significant Î±2Î²1 integrin recruitment compared to HA-based PEMs. Both CS-based PEMs caused also an increased fibronectin (FN) secretion and cell growth. Furthermore, significant calcium phosphate deposition, enhanced ALP, Col I and Runx2 expression were observed in hADSCs on CS-based PEMs, particularly on oCS-containing one. Overall, multilayer composition can be used to direct cell-matrix interactions, and hence stem cell fates showing for the first time that PEMs made of biogenic polyelectrolytes undergo significant remodeling of terminal protein layers, which seems to enable cells to form a more adequate extracellular matrix-like environment. Statement of Significance: Natural polymer derived polyelectrolyte multilayers (PEMs) have been recently applied to adjust biomaterials to meet specific tissue demands. However, the effect of molecular composition of multilayers on both surface properties and cellular response, especially the fate of human adipose derived stem cells (hADSCs) upon osteogenic differentiation has not been studied extensively, yet. In addition, no studies exist that investigate a potential cell-dependent remodeling of PEMs made of extracellular matrix (ECM) components like collagens and glycosaminoglycans (GAGs). Furthermore, there is no knowledge whether the ability of cells to remodel PEM components may provide an added value regarding cell growth and differentiation. Finally, it has not been explored yet, how intrinsic cross-linking of ECM derived polyelectrolytes that improve the stability of PEMs will affect the differentiation potential of hADSCs. The current work aims to address these questions and found that the type of GAG has a strong effect on properties of multilayers and osteogenic differentiation of hADSCs. Additionally, we also show for the first time that PEMs made of biogenic polyelectrolytes undergo significant remodeling of terminal layers as completely new finding, which allows cells to form an ECM-like environment supporting differentiation upon osteogenic lineage. The finding of this work may open new avenues of application of PEM systems made by layer by layer (LbL) technique in tissue engineering and regenerative medicine.
Keywords: Collagen reorganization, Glycosaminoglycans, Layer-by-layer technique, Mesenchymal stem cells, Osteogenic differentiation
Forget, J., Awaja, F., Gugutkov, D., Gustavsson, J., Gallego Ferrer, G., Coelho-Sampaio, T., Hochman-Mendez, C., Salmeron-Sánchez, M., Altankov, G., (2016). Differentiation of human mesenchymal stem cells toward quality cartilage using fibrinogen-based nanofibers Macromolecular Bioscience , 16, (9), 1348-1359
Mimicking the complex intricacies of the extra cellular matrix including 3D configurations and aligned fibrous structures were traditionally perused for producing cartilage tissue from stem cells. This study shows that human adipose derived mesenchymal stem cells (hADMSCs) establishes significant chondrogenic differentiation and may generate quality cartilage when cultured on 2D and randomly oriented fibrinogen/poly-lactic acid nanofibers compared to 3D sandwich-like environments. The adhering cells show well-developed focal adhesion complexes and actin cytoskeleton arrangements confirming the proper cellular interaction with either random or aligned nanofibers. However, quantitative reverse transcription-polymerase chain reaction analysis for Collagen 2 and Collagen 10 genes expression confirms favorable chondrogenic response of hADMSCs on random nanofibers and shows substantially higher efficacy of their differentiation in 2D configuration versus 3D constructs. These findings introduce a new direction for cartilage tissue engineering through providing a simple platform for the routine generation of transplantable stem cells derived articular cartilage replacement that might improve joint function.
Keywords: Cartilage, Chondrogenic response, Collagen, FBG/PLA nanofibers, Mesenchymal stem cells
Sánchez-Ferrero, Aitor, Mata, Álvaro, Mateos-Timoneda, Miguel A., Rodríguez-Cabello, José C., Alonso, Matilde, Planell, Josep, Engel, Elisabeth, (2015). Development of tailored and self-mineralizing citric acid-crosslinked hydrogels for in situ bone regeneration Biomaterials , 68, 42-53
Bone tissue engineering demands alternatives overcoming the limitations of traditional approaches in the context of a constantly aging global population. In the present study, elastin-like recombinamers hydrogels were produced by means of carbodiimide-catalyzed crosslinking with citric acid, a molecule suggested to be essential for bone nanostructure. By systematically studying the effect of the relative abundance of reactive species on gelation and hydrogel properties such as functional groups content, degradation and structure, we were able to understand and to control the crosslinking reaction to achieve hydrogels mimicking the fibrillary nature of the extracellular matrix. By studying the effect of polymer concentration on scaffold mechanical properties, we were able to produce hydrogels with a stiffness value of 36.13 ± 10.72 kPa, previously suggested to be osteoinductive. Microstructured and mechanically-tailored hydrogels supported the growth of human mesenchymal stem cells and led to higher osteopontin expression in comparison to their non-tailored counterparts. Additionally, tailored hydrogels were able to rapidly self-mineralize in biomimetic conditions, evidencing that citric acid was successfully used both as a crosslinker and a bioactive molecule providing polymers with calcium phosphate nucleation capacity.
Keywords: Biomimetic material, Biomineralisation, Bone tissue engineering, Cross-linking, Hydrogel, Mesenchymal stem cell
Vila, O. F., Martino, M. M., Nebuloni, L., Kuhn, G., Pérez-Amodio, S., Müller, R., Hubbell, J. A., Rubio, N., Blanco, J., (2014). Bioluminescent and micro-computed tomography imaging of bone repair induced by fibrin-binding growth factors Acta Biomaterialia 10, (10), 4377-4389
In this work we have evaluated the capacity of bone morphogenetic protein-2 (BMP-2) and fibrin-binding platelet-derived growth factor-BB (PDGF-BB) to support cell growth and induce bone regeneration using two different imaging technologies to improve the understanding of structural and organizational processes participating in tissue repair. Human mesenchymal stem cells from adipose tissue (hAMSCs) expressing two luciferase genes, one under the control of the cytomegalovirus (CMV) promoter and the other under the control of a tissue-specific promoter (osteocalcin or platelet endothelial cell adhesion molecule), were seeded in fibrin matrices containing BMP-2 and fibrin-binding PDGF-BB, and further implanted intramuscularly or in a mouse calvarial defect. Then, cell growth and bone regeneration were monitored by bioluminescence imaging (BLI) to analyze the evolution of target gene expression, indicative of cell differentiation towards the osteoblastic and endothelial lineages. Non-invasive imaging was supplemented with micro-computed tomography (Î¼CT) to evaluate bone regeneration and high-resolution Î¼CT of vascular casts. Results from BLI showed hAMSC growth during the first week in all cases, followed by a rapid decrease in cell number; as well as an increment of osteocalcin but not PECAM-1 expression 3 weeks after implantation. Results from Î¼CT show that the delivery of BMP-2 and PDGF-BB by fibrin induced the formation of more bone and improves vascularization, resulting in more abundant and thicker vessels, in comparison with controls. Although the inclusion of hAMSCs in the fibrin matrices made no significant difference in any of these parameters, there was a significant increment in the connectivity of the vascular network in defects treated with hAMSCs.
Keywords: Angiogenesis, Bioluminescence imaging, Bone regeneration, Fibrin, Mesenchymal stem cell
Mendes, A. C., Smith, K. H., Tejeda-Montes, E., Engel, E., Reis, R. L., Azevedo, H. S., Mata, Alvaro, (2013). Co-assembled and microfabricated bioactive membranes Advanced Functional Materials , 23, (4), 430-438
The fabrication of hierarchical and bioactive self-supporting membranes, which integrate physical and biomolecular elements, using a single-step process that combines molecular self-assembly with soft lithography is reported. A positively charged multidomain peptide (with or without the cell-adhesive sequence arginine-glycine-aspartic acid-serine (RGDS)) self-assembles with hyaluronic acid (HA), an anionic biopolymer. Optimization of the assembling conditions enables the realization of membranes with well-controlled and easily tunable features at multiple size scales including peptide sequence, building-block co-assembly, membrane thickness, bioactive epitope availability, and topographical pattern morphology. Membrane structure, morphology, and bioactivity are investigated according to temperature, assembly time, and variations in the experimental setup. Furthermore, to evaluate the physical and biomolecular signaling of the self-assembled microfabricated membranes, rat mesenchymal stem cells are cultured on membranes exhibiting various densities of RGDS and different topographical patterns. Cell adhesion, spreading, and morphology are significantly affected by the surface topographical patterns and the different concentrations of RGDS. The versatility of the combined bottom-up and top-down fabrication processes described may permit the development of hierarchical macrostructures with precise biomolecular and physical properties and the opportunity to fine tune them with spatiotemporal control.
Keywords: Membrane scaffolds, Mesenchymal stem cells, Microfabrication, Self-assembly, Topography
Almendros, Isaac, Carreras, Alba, Montserrat, Josep M., Gozal, David, Navajas, Daniel, Farre, Ramon, (2012). Potential role of adult stem cells in obstructive sleep apnea Frontiers in Neurology , 3, 1-6
Adult stem cells are undifferentiated cells that can be mobilized from the bone marrow or other organs, home into injured tissues and differentiate into different cell phenotypes to serve in a repairing capacity. Furthermore, these cells can respond to inflammation and oxidative stress by exhibiting immunomodulatory properties. The protective and reparative roles of mesenchymal stem cells (MSCs), very small embryonic-like stem cells (VSELs) and endothelial progenitor cells (EPCs) have primarily been examined and characterized in auto-immune and cardiovascular diseases. Obstructive sleep apnea (OSA) is a very prevalent disease (4-5% of adult population and 2-3% of children) characterized by an abnormal increase in upper airway collapsibility. Recurrent airway obstructions elicit arterial oxygen desaturations, increased inspiratory efforts and sleep fragmentation, which have been associated with important long-term neurocognitive, metabolic, and cardiovascular consequences. Since inflammation, oxidative stress and endothelial dysfunction are key factors in the development of the morbid consequences of OSA, bone marrow-derived stem cells could be important modulators of the morbid phenotype by affording a protective role. This mini-review is focused on the recent data available on EPCs, VSELs and MSCs in both animal models and patients with OSA.
Keywords: Mesenchymal Stem Cells, Sleep Apnea, Endothelial progenitor cells, Very Small-like Embryonic Stem Cells, Adult bone-marrow derived stem cells
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
Aguirre, A., Planell, J. A., Engel, E., (2010). Dynamics of bone marrow-derived endothelial progenitor cell/mesenchymal stem cell interaction in co-culture and its implications in angiogenesis Biochemical and Biophysical Research Communications , 400, (2), 284-291
Tissue engineering aims to regenerate tissues and organs by using cell and biomaterial-based approaches. One of the current challenges in the field is to promote proper vascularization in the implant to prevent cell death and promote host integration. Bone marrow endothelial progenitor cells (BM-EPCs) and mesenchymal stem cells (MSCs) are bone marrow resident stem cells widely employed for proangiogenic applications. In vivo, they are likely to interact frequently both in the bone marrow and at sites of injury. In this study, the physical and biochemical interactions between BM-EPCs and MSCs in an in vitro co-culture system were investigated to further clarify their roles in vascularization. BM-EPC/MSC co-cultures established close cell-cell contacts soon after seeding and self-assembled to form elongated structures at 3 days. Besides direct contact, cells also exhibited vesicle transport phenomena. When co-cultured in Matrigel, tube formation was greatly enhanced even in serum-starved, growth factor free medium. Both MSCs and BM-EPCs contributed to these tubes. However, cell proliferation was greatly reduced in co-culture and morphological differences were observed. Gene expression and cluster analysis for wide panel of angiogenesis-related transcripts demonstrated up-regulation of angiogenic markers but down-regulation of many other cytokines. These data suggest that cross-talk occurs in between BM-EPCs and MSCs through paracrine and direct cell contact mechanisms leading to modulation of the angiogenic response.
Keywords: Bone marrow, Endothelial progenitor cell, Co-culture, Mesenchymal stem cell, Angiogenesis
Carreras, A., Almendros, I., Acerbi, I., Montserrat, J. M., Navajas, D., Farre, R., (2009). Obstructive apneas induce early release of mesenchymal stem cells into circulating blood Sleep , 32, (1), 117-119
STUDY OBJECTIVES: To investigate whether noninvasive application of recurrent airway obstructions induces early release of mesenchymal stem cells into the circulating blood in a rat model of obstructive sleep apnea. DESIGN: Prospective controlled animal study. SETTING: University laboratory. PATIENTS OR PARTICIPANTS: Twenty male Sprague-Dawley rats (250-300 g). INTERVENTIONS: A specially designed nasal mask was applied to the anesthetized rats. Ten rats were subjected to a pattern of recurrent obstructive apneas (60 per hour, lasting 15 seconds each) for 5 hours. Ten anesthetized rats were used as controls. MEASUREMENTS AND RESULTS: Mesenchymal stem cells from the blood and bone marrow samples were isolated and cultured to count the total number of colony-forming unit fibroblasts (CFU-F) of adherent cells after 9 days in culture. The number of CFU-F from circulating blood was significantly (P = 0.02) higher in the rats subjected to recurrent obstructive apneas (5.00 +/- 1.16; mean +/- SEM) than in controls (1.70 +/- 0.72). No significant (P = 0.54) differences were observed in CFU-F from bone marrow. CONCLUSIONS: Application of a pattern of airway obstructions similar to those experienced by patients with sleep apnea induced an early mobilization of mesenchymal stem cells into circulating blood.
Keywords: Adipocytes/cytology, Animals, Blood Cell Count, Bone Marrow Cells/ cytology, Cell Adhesion/physiology, Cell Count, Cell Differentiation/physiology, Cell Division/physiology, Disease Models, Animal, Fibroblasts/cytology, Male, Mesenchymal Stem Cells/ cytology, Osteocytes/cytology, Rats, Rats, Sprague-Dawley, Sleep Apnea, Obstructive/ blood, Stem Cells/cytology
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