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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Transforming growth factor beta (TGF-β) isomers influence cell detachment of MG-63 bone cells

Sefat, Farshid, Khaghani, Seyed A., Nejatian, T., Genedy, Mohamed A., Abdeldayem, Ali I.A., Moghaddam, Z.S., Denyer, Morgan C.T., Youseffi, Mansour 20 August 2015 (has links)
Bone repair and wound healing are modulated by different stimuli. There is evidence that Transforming Growth Factor-beta (TGF-β) super-family of cytokines have significant effects on bone structure by regulating the replication and differentiation of chondrocytes, osteoblasts and osteoclasts. There is also significant evidence that interactions with extracellular matrix molecules influence cell behaviour. In this study cell surface attachment was examined via a trypsinization assay using various TGF-β isomers in which the time taken to trypsinize cells from the surface provided a means of assessing the strength of attachment. Three TGF-β isomers (TGF-β1, 2 and 3), four combined forms (TGF-β(1 + 2), TGF-β(1 + 3), TGF-β(2 + 3) and TGF-β(1 + 2 + 3)) along with four different controls (BSA, HCl, BSA/HCl and negative control) were investigated in this study. The results indicated that treatment with TGF-β1, 2, 3 and HCl decreased cell attachment, however, this effect was significantly greater in the case of TGF-β3 (p < 0.001) indicating perhaps that TGF-β3 does not act alone in cell detachment, but instead functions synergistically with signalling pathways that are dependent on the availability of hydrogen ions. Widefield Surface Plasmon Resonance (WSPR) microscope was also used to investigate cell surface interactions.
2

Efetividade de scaffolds de poli (butileno adipato-co-tereftalato) / nanohidroxiapatita obtidos por eletrofiação para aplicação biomédica: avaliação in vitro / Effectivenes of novel scaffolds poly (butylene adipate-co-terephthalate) / nanohydroxyapatite obtained by electrospinning for biomedical application: in vitro evaluation

Santana-Melo, Gabriela de Fátima [UNESP] 01 February 2016 (has links)
Submitted by GABRIELA DE FÁTIMA SANTANA-MELO (gabrieladsantana@yahoo.com.br) on 2016-05-15T23:21:48Z No. of bitstreams: 1 Tese Gabriela F. Santana-Melo.pdf: 2618239 bytes, checksum: 2bf460d87225bef3f4ce02747616a638 (MD5) / Rejected by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br), reason: Solicitamos que realize uma nova submissão seguindo as orientações abaixo: No campo “Versão a ser disponibilizada online imediatamente” foi informado que seria disponibilizado o texto completo porém no campo “Data para a disponibilização do texto completo” foi informado que o texto completo deverá ser disponibilizado apenas 6 meses após a defesa. Caso opte pela disponibilização do texto completo apenas 6 meses após a defesa selecione no campo “Versão a ser disponibilizada online imediatamente” a opção “Texto parcial”. Esta opção é utilizada caso você tenha planos de publicar seu trabalho em periódicos científicos ou em formato de livro, por exemplo e fará com que apenas as páginas pré-textuais, introdução, considerações e referências sejam disponibilizadas. Se optar por disponibilizar o texto completo de seu trabalho imediatamente selecione no campo “Data para a disponibilização do texto completo” a opção “Não se aplica (texto completo)”. Isso fará com que seu trabalho seja disponibilizado na íntegra no Repositório Institucional UNESP. Por favor, corrija esta informação realizando uma nova submissão. Agradecemos a compreensão. on 2016-05-18T18:11:13Z (GMT) / Submitted by GABRIELA DE FÁTIMA SANTANA-MELO (gabrieladsantana@yahoo.com.br) on 2016-07-08T17:12:34Z No. of bitstreams: 1 Tese Gabriela F. Santana-Melo.pdf: 2618239 bytes, checksum: 2bf460d87225bef3f4ce02747616a638 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-07-11T14:52:41Z (GMT) No. of bitstreams: 1 santanamelo_gf_dr_sjc.pdf: 2618239 bytes, checksum: 2bf460d87225bef3f4ce02747616a638 (MD5) / Made available in DSpace on 2016-07-11T14:52:41Z (GMT). No. of bitstreams: 1 santanamelo_gf_dr_sjc.pdf: 2618239 bytes, checksum: 2bf460d87225bef3f4ce02747616a638 (MD5) Previous issue date: 2016-02-01 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A necessidade da fabricação de novos biomateriais que possam, além de mimetizar o tecido ósseo, fornecer resistências mecânicas favoráveis próximas às do tecido ósseo natural têm despertado interesse de pesquisadores com o objetivo de melhorar a qualidade de vida de pessoas que sofreram algum tipo de lesão. Scaffolds de nanofibras poliméricas fabricados por eletrofiação apresentam características tridimensionais (3D) e poros interconectados que permitem a colonização de toda a superfície 3D por células com a consequente formação de tecidos. O scaffold de poli (butileno adipato-co-tereftalato) (PBAT) mostra-se um biomaterial promissor para regeneração óssea, porém tem sido pouco explorado até a data. Embora do uso da HA seja consagrado para uso biomédico, sua utilização em polímeros ainda é pouco estudada, principalmente em associação ao PBAT. Desta forma, o objetivo deste estudo foi avaliar a efetividade in vitro de scaffolds poliméricos (PBAT) com incorporação de nanopartículas de HA (nHAp) em diferentes concentrações, produzidos por eletrofiação, por meio da bioatividade celular e expressão gênica de osteoblast-like MG63. Células (MG63) foram cultivadas sobre scaffolds de PBAT; PBAT/3%nHAp e PBAT/5% nHAp e sem a presença dos mesmos (controle) e avaliadas pelos testes qualitativo (MEV) e quantitativo de adesão e proliferação celular (1 e 7 dias e aos 1, 3, 7, 14 e 21 dias, respectivamente), citotoxicidade celular (1, 3 e 7 dias), corante vermelho de alizarina e formação de mineralização (14 dias) e análise da expressão de genes relacionados à osteogênese por qRT-PCR aos 7, 14 e 21 dias de cultura celular. Os dados foram analisados estatisticamente por variância (ANOVA) e Tukey (p<0,05). Os scaffolds de PBAT e PBAT/nHAp não apresentaram efeito citotóxico e sua arquitetura tridimensional influenciou positivamente na adesão e proliferaçãocelular, formação de matriz mineralizada bem como em alguns períodos na expressão dos genes ALP, Col I, Runx2, OC e OPN em relação ao grupo controle. O efeito osteocondutor e osteoindutor da nHAp promoveu melhor resposta celular nos scaffolds de PBAT/nHAp, independente da concentração. Esses resultados demonstram a efetividade in vitro dos scaffolds de PBAT e PBAT/nHAp, apresentando grande potencial para aplicação biomédica. / The need for the manufacture of new biomaterials that may, in addition to mimic to bone tissue, providing favorable mechanical strength close to natural bone have aroused the interest of researchers in order to improve the quality of life of people who have suffered some kind of injury. Scaffolds polymer nanofibers fabricated by electrospinning have three dimensional features (3D) and interconnected pores that allow the colonization of the entire 3D surface of cells with the consequent formation of tissue. Poly (butylene adipate-co-terephthalate) (PABT) scaffold showed to be a promising biomaterial for bone regeneration, however, has been underexplored to date. Although the use of HA is consecrated to biomedical use, their use in polymers is not well known, especially in association with PBAT. The aim of this study was evaluating in vitro effectiveness of polymeric (PABT) scaffolds with incorporated HA (nHAp) nanoparticles, obtained by electrospinning, through cellular bioactivity and osteoblast-like MG63 gene expression. MG63 cells were grown on PABT; PABT/3%nHAp and PABT/5%nHAp scaffolds and without their presence (control), and evaluated by qualitative (MEV) and quantitative tests of cell adhesion and proliferation (1 and 7 days and at 1, 3, 7, 14 and 21 days, respectively), cell cytotoxicity (1, 3 and 7 days), alizarin red dye and mineralization formation (14 days) and expression of genes related to osteogenesis by qRT-PCR to 7, 14 and 21 days of cell culture. Data were statistically analyzed by variance (ANOVA) and Tukey test (p<0.05). The PBAT and PBAT/nHAp scaffolds showed no cytotoxic effect and its three-dimensional architecture influenced positively in the cell adhesion and proliferation, mineralized matrix formation as well as in some periods the expression of genes ALP, Col I, Runx2, OC and OPN in relation the control group. The osteoconductive and osteoinductive effect of nHAp promoted better cellular response in scaffolds of PABT/nHAp independent of concentration. These results demonstrate the in vitro effectiveness of PABT and PABT/nHAp scaffolds, presenting great potential for biomedical application.
3

Effect of the antidepressant mirtazapine on intracellular Ca2+ signals and proliferation of prostate cancer PC3 and osteosarcoma MG63 cells

Pan, Chih-chuan 12 July 2005 (has links)
The effects of the antidepressant mirtazapine on cytosolic Ca2+ concentrations ([Ca2+]i) in human prostate cancer PC3 cells and human osteosarcoma MG63 cells were measured by Ca2+-sensitive fluorescent probe fura-2. In Ca2+-containing medium, mirtazapine induced [Ca2+]i rises in a concentration-dependent manner in both PC3 and MG63 cells. Removal of extracellular Ca2+ inhibited the mirtazapine-induced Ca2+ signal. In Ca2+-free medium, thapsigargin (an inhibitor of the endoplasmic reticulum Ca2+-ATPase pump) induced [Ca2+]i rises by passively depleting the endoplasmic reticulum Ca2+ store, after which the increasing effect of mirtazapine (1.5 mM) on [Ca2+]i was reduced. Conversely, pretreatment with mirtazapine decreased thapsigargin-induced [Ca2+]i rises in PC3 and MG63 cells. When PC3 cells were pretreated with U73122, a phospholipase C inhibitor, mirtazapine-induced [Ca2+]i rises were inhibited by 47%. But in MG63 cells, 2 mM U73122 did not change mirtazapine-induced [Ca2+]i rises. These finding suggest that mirtazapine-induced [Ca2+]i rises were caused both by extracellular Ca2+ influx and intracellular depletion of the endoplasmic reticulum Ca2+ stores. Furthermore, the mechanism of mirtazapine-induced Ca2+ release may be different between PC3 and MG63 cells. Additionally, cell proliferation assays suggest that overnight incubation with higher concentrations of mirtazapine decreased cell viability in a concentration-dependent manner.
4

Kompozitní stomatologické biomateriály - struktura, analýza a vlastnosti / Composite Dental Biomaterials - Structure, Analysis and Properties

Matoušek, Aleš January 2012 (has links)
The aim of this work is to define relations between grain size and bioaktivity of oxide ceramics, specifically ZrO2, Al2O3 and HA. Ceramic materials with grain size from 100 nm up to 10 m, with various surface roughness, were tested for its bioactivity. Ceramography analysis was performed for all tested materials to precisely describe microstructures. Biological properties of the ceramic materials were tested via dilation tests directly in-vitro and by in-vitro extraction. Three cell culturing lines: osteoblast MG63, fibroblast L929, and epithelioid HeLa, were used for our testing. An influence of the grain size on the biological response was only found for the ceramic materials which had been thermally etched. The thermally etched nanocrystalline samples had larger areas covered by cells than ceramics with coarse grain microstructure. Biological tests on layered composites Al2O3×ZrO2 showed the cell selection determined by the type of material, where ZrO2 surfaces were preferably covered. Improved biological response of nanocrystalline ZrO2 was demonstrated on ceramic ZrO2, Al2O3 and SiO2 substrates with nanocrystalline coating of ZrO2. In this work a novel technological process for the formation of defect-free coatings was developed. Sintered coatings were tested using in-vitro technique with cell line HeLa, L929 and MG63 for up to 72 hours. The results of the biological tests of nanocrystalline coatings were consistent with results from the bulk nanocrystalline thermally etched ZrO2 ceramics.

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