218 research outputs found

    Study of the molecular patterning in stem cells exposed to biophysical stimuli: a new vision of regenerative medicine

    Get PDF
    Regenerative medicine is a novel applied field of medical management based on the application of stem cell technology and tissue engineering in order to replace or regenerate human tissues and organs and restore their functions. The regenerative medicine has the prospective to help scientists and clinicians while planning early-intervention treatments for traumatic injury or degenerative diseases, by regrowth or replacement of cells or tissues. However, the challenges in this field are still countless, as (1) which type of cells are suitable (2) which is the best protocol to commit all the stem cells toward a specific phenotype with the 100% of yield, (3) drop cell manipulation. At the same time, physical energy were found capable to interact with cell physiology and increase their performance. In the clinical practice physical therapies enhance the quality and time of spontaneous tissues regeneration. Here, I focused on the effect of physical stimuli by Radio electric asymmetric conveyor (REAC) and Extra corporeal shock wave (SW) and their interaction with cells or stem cell behaviour. In particular, during the modulation of the main molecular patterning controlling cellular senescence, differentiation toward specific phenotypes and proliferation, in order to figure out the targets of action, to enhance their performance for future therapeutic applications

    BMP2 and TGF-ÎČ Cooperate Differently during Synovial-Derived Stem-Cell Chondrogenesis in a Dexamethasone-Dependent Manner

    Get PDF
    Recent studies highlighting mesenchymal stem cell (MSC) epigenetic memory suggest that a different differentiation medium may be required depending on the tissue of origin. As synovial-derived stem cells (SDSCs) attract interest we aimed to investigate the influence of TGF-ÎČ1, BMP-2 and dexamethasone on SDSC chondrogenesis in vitro. We demonstrate that dexamethasone-free medium led to enhanced chondrogenic differentiation at both the mRNA and matrix level. The greatest COL2A1/COL10A1 ratio was detected in cells exposed to a combination medium containing 10 ng/mL BMP-2 and 1 ng/mL TGF-ÎČ1 in the absence of dexamethasone, and this was reflected in the total amount of glycosaminoglycans produced. In summary, dexamethasone-free medium containing BMP-2 and TGF-ÎČ1 may be the most suitable when using SDSCs for cartilage tissue regeneration

    Hemocompatibility of stent materials: alterations in electrical parameters of erythrocyte membranes

    Get PDF
    A Basoli1, C Cametti2, F Ginnari Satriani2, P Mariani3, P Severino31Department of Surgery, "P Stefanini," University of Rome "La Sapienza," Rome, Italy; 2Department of Physics, University of Rome "La Sapienza," Rome Italy; 3Department of Internal Medicine, University of Rome "La Sapienza," Rome, ItalyBackground: It is presently unknown if stents used in the correction of artery stenosis are fully hemocompatible or if their implantation causes alterations at the level of the plasma membrane in red blood cells.Methods: We addressed this important issue by measuring the passive electrical properties of the erythrocyte membrane before and after stent insertion by means of dielectric relaxation spectroscopy in the radiowave frequency range in a series of patients who were undergoing standard surgical treatment of arterial disease.Results: Our findings provide evidence that full hemocompatibility of stents has not yet been reached, and that there are some measurable alterations in the passive electrical behavior of the red blood cell membrane induced by the presence of the stent.Conclusion: It is possible that these changes do not have any physiological significance and simply reflect the intrinsic variability of biological samples. However, caution is urged, and the technique we describe here should be considered when investigating the hemocompatibility of a medical device at a cell membrane level.Keywords: hemocompatibility, stent, arterial disease, cell membran

    Tissue regeneration without stem cell transplantation: Self- Healing potential from ancestral chemistry and physical energies

    Get PDF
    open6noThe authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: funded by Eldor Lab, Milan, Italy, and AMeC (Associazione Medicina e ComplessitĂ ), Via Valdirivo 19, 34100 Trieste, Italy.The human body constantly regenerates after damage due to the self-renewing and differentiating properties of its resident stem cells. To recover the damaged tissues and regenerate functional organs, scientific research in the field of regenerative medicine is firmly trying to understand the molecular mechanisms through which the regenerative potential of stem cells may be unfolded into a clinical application. The finding that some organisms are capable of regenerative processes and the study of conserved evolutionary patterns in tissue regeneration may lead to the identification of natural molecules of ancestral species capable to extend their regenerative potential to human tissues. Such a possibility has also been strongly suggested as a result of the use of physical energies, such as electromagnetic fields and mechanical vibrations in human adult stem cells. Results from scientific studies on stem cell modulation confirm the possibility to afford a chemical manipulation of stem cell fate in vitro and pave the way to the use of natural molecules, as well as electromagnetic fields and mechanical vibrations to target human stem cells in their niche inside the body, enhancing human natural ability for self-healing.openFacchin, Federica; Bianconi, Eva; Canaider, Silvia; Basoli, Valentina; Biava, Pier Mario; Ventura, CarloFacchin, Federica; Bianconi, Eva; Canaider, Silvia; Basoli, Valentina; Biava, Pier Mario; Ventura, Carl

    Ensaiando lugares de escuta: diĂĄlogos entre a psicologia e o conceito de lugar de fala

    Get PDF
    In order to respond ethically to the emergency demand of the places of speech, we pro-pose the discussion of a "locus of listening" of the subjects of privileges. We play a game with the word "listening" of psychology, "therapeutic / psychological listening", to go be-yond the term restricted to the instrument of psychologists and bring the urgency of lis-tening as an exercise of "otherness." We make an interdisciplinary movement by aligning a concept that comes from feminism with another from psychology, because we believe that such a dialogue is extremely important for a contemporary psychology that positions itself politically and ethically in the face of the oppressions of gender, race, class and culture. At the same time this discussion may contribute to a better comprehension to the ques-tion about “locus of enunciation” (place of speech), so currently debated.Com o intuito de responder eticamente a demanda de emergĂȘncia dos lugares de fala, problematizaremos neste trabalho o “lugar de escuta” desde as posiçÔes de privilĂ©gios. Fazemos um jogo com o conceito “escuta” da psicologia, a “escuta terapĂȘuti-ca/psicolĂłgica”, para ir mais alĂ©m do termo restrito ao instrumento dos psicĂłlogos e tra-zer a urgĂȘncia da escuta enquanto um exercĂ­cio de “alteridade”. Fazemos um movimen-to interdisciplinar de aliar um conceito que vem dos estudos feministas com outro prove-niente do campo da psicologia pois acreditamos que tal diĂĄlogo Ă© extremamente impor-tante para uma psicologia contemporĂąnea que se posicione polĂ­tica e eticamente diante das opressĂ”es de gĂȘnero, raça e classe. Acreditamos tambĂ©m que tal discussĂŁo pode con-tribuir para uma melhor compreensĂŁo da questĂŁo do lugar de fala, tĂŁo debatido atual-mente

    Spin-coated La0.8Sr0.2Ga0.8Mg0.2O3-ÎŽ Electrolyte on Infiltrated Anodes for Direct Methane Fuel Cells

    Get PDF
    Dense micrometric La0.8Sr0.2Ga0.8Mg0.2O3-Ύ (LSGM) films were deposited by spin-coating on porous LSGM scaffolds characterized by homogeneous pore structure. Porous anodes were infiltrated with aqueous nickel and nickel/copper nitrate solutions, dried and fired at 700°C. Homogeneous metal coating with proper interconnection was observed by SEM, chemical stability was confirmed by XRD, and electrical characterization of anodic substrates was performed. Catalytic activity of different anodes was evaluated ex-situ in a quartz micro-reactor fed with CH4:CO2 mixtureat range 650 and 700°C. To investigate the redox properties of the metallic phases, the anodic substrates were subjected to redox ageing cycles and characterized by H2-TPR

    MiR200 and MiR302: Two big families influencing stem cell behavior

    Get PDF
    In this review, we described different factors that modulate pluripotency in stem cells, in particular we aimed at following the steps of two large families of miRNAs: the miR-200 family and the miR-302 family. We analyzed some factors tuning stem cells behavior as TGF-\uce\ub2, which plays a pivotal role in pluripotency inhibition together with specific miRNAs, reactive oxygen species (ROS), but also hypoxia, and physical stimuli, such as ad hoc conveyed electromagnetic fields. TGF-\uce\ub2 plays a crucial role in the suppression of pluripotency thus influencing the achievement of a specific phenotype. ROS concentration can modulate TGF-\uce\ub2 activation that in turns down regulates miR-200 and miR-302. These two miRNAs are usually requested to maintain pluripotency, while they are down-regulated during the acquirement of a specific cellular phenotype. Moreover, also physical stimuli, such as extremely-low frequency electromagnetic fields or high-frequency electromagnetic fields conveyed with a radioelectric asymmetric conveyer (REAC), and hypoxia can deeply influence stem cell behavior by inducing the appearance of specific phenotypes, as well as a direct reprogramming of somatic cells. Unraveling the molecular mechanisms underlying the complex interplay between externally applied stimuli and epigenetic events could disclose novel target molecules to commit stem cell fate

    Development of a new system of solid ionic conductors based on multi-doped ceria for application in IT-SOFCs

    Get PDF
    Nanosized multi-doped ceria with composition Ce0.8Nd0.0025Sm0.0025Gd0.005Dy0.095Y0.095O2-ή (CNSGDY) as perspective solid ionic conductor was obtained by modified glycine-nitrate procedure (MGNP) and room temperature self-propagating reaction (SPRT). The pressed pellets of both powders were sintered at 1550°C for 2 h in an air atmosphere. The obtained sintered samples were characterized by XRPD, Raman spectroscopy, FESEM, EDS and EIS methods. Despite a high temperature of sintering, XRPD and FESEM analyses of the samples confirmed appropriate dimensions of grains with fluorite structure. Overall concentration of introduced dopants (x = 0.2) in the structure of CeO2 after the sintering process was confirmed by EDS analysis. After sintering, Raman spectroscopy confirmed retention of the oxygen vacancies in the ceria lattice, which is in accordance with the improvement of ionic conductivity of solid ionic conductors. The highest value of total conductivity was obtained for the sintered MGNP sample at 700°C (4.22 × 10−2 S cm−1), with the corresponding activation energy of 0.26 eV

    Gellan hydrogel as a powerful tool in paper cleaning process: a detailed study

    Get PDF
    Hypothesis: Wet cleaning of ancient papers is one of the most critical steps during a conservation treatment. It is used to improve the optical qualities of a graphic work and remove dust and by-products resulting from cellulose degradation. Nevertheless, washing treatment usually involves a substantial impact on the original morphological structure of paper and can sometimes be dangerous for water sensitive inks and pigments. Experiments: The use of rigid hydrogel of Gellan gum as an alternative paper cleaning treatment is developed. The application of a rigid hydrogel minimizes damages caused by the use of water, and therefore is much more respectful for the original integrity of ancient paper. Findings: Gellan hydrogel has been used to clean paper samples belonging to different centuries (from XVI to XIX) and therefore, characterized by a different story in terms of degradation condition and paper composition. Several techniques, such as high-performance liquid chromatography, Fourier transform infrared spectroscopy, scanning electron microscopy and pH measurements, has been employed to assess the effectiveness and safety of the proposed cleaning method

    Stem cell senescence: effects of REAC technology on telomerase-independent and telomerase-dependent pathways

    Get PDF
    Decline in the gene expression of senescence repressor Bmi1, and telomerase, together with telomere shortening, underlay senescence of stem cells cultured for multiple passages. Here, we investigated whether the impairment of senescence preventing mechanisms can be efficiently counteracted by exposure of human adipose-derived stem cells to radio electric asymmetrically conveyed fields by an innovative technology, named Radio Electric Asymmetric Conveyer (REAC). Due to REAC exposure, the number of stem cells positively stained for senescence associated ß-galactosidase was significantly reduced along multiple culturing passages. After a 90-day culture, REAC-treated cells exhibited significantly higher transcription of Bmi1 and enhanced expression of other stem cell pluripotency genes and related proteins, compared to unexposed cells. Transcription of the catalytic telomerase subunit (TERT) was also increased in REAC-treated cells at all passages. Moreover, while telomere shortening occurred at early passages in both REAC-treated and untreated cells, a significant rescue of telomere length could be observed at late passages only in REAC-exposed cells. Thus, REAC-asymmetrically conveyed radio electric fields acted on a gene and protein expression program of both telomerase-independent and telomerase-dependent patterning to optimize stem cell ability to cope with senescence progression
    • 

    corecore