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Síntesis y caracterización de nanozeolitas silicoaluminofostatos modificadas con calcio y litio y evaluación de sus propiedades osteoinductoras
(Universidad de Chile, 2023)
tejido óseo. Las
zeolitas son materiales nanoporosos que presentan varias propiedades ventajosas para su
uso en biomedicina; sin embargo, su uso en regeneración ósea ha sido menos explorado.
Los estudios reportados hasta ahora muestran que las zeolitas...
Estudio y diseño del proceso de obtención de queratina a partir de pelo canino mediante hidrólisis enzimática
(Universidad de Chile, 2023)
, para ser aprovechada en aplicaciones diversas, desde cosmética hasta biomedicina.
El presente trabajo tiene como propósito estudiar y diseñar el proceso de obtención de queratina a partir de pelo canino mediante hidrólisis enzimática. Para lo anterior...
Obtención de conjugados de péptidos nanopartículas metálicas con potenciales aplicaciones biomédicas
(Universidad de Chile, 2007)
Uno de los avances de la nanotecnología es la aplicación de nanopartículas
metálicas (NPs) en el campo de la biomedicina. Estas NPs en presencia de campos
magnéticos oscilantes (CMO) pueden absorber energía en forma eficaz y disiparla
localmente...
Estudio de los compuestos fenólicos en rocío de la ciudad de Santiago
(Universidad de Chile, 2012)
“Aquí se atienden personas, no nacionalidades” Análisis del proceso de atención de salud de mujeres peruanas, en dos centros de salud pública de la Región Metropolitana
(Universidad de Chile, 2016-05)
/enfermedad/atención desde el punto de vista cultural: Antropología Médica. 30
Sistemas médicos y biomedicina como sistema cultural. ..................................................... 30
El desafío de la migración e interculturalidad en salud...
sistemas de salud convencionales como una herramienta de consolidación de un sistema más equitativo y participativo. Dicha noción de salud intercultural ha sido ampliamente cuestionada pues admite una relación asimétrica, donde la biomedicina tiene la...
sistemas de salud convencionales como una herramienta de consolidación de un sistema más equitativo y participativo. Dicha noción de salud intercultural ha sido ampliamente cuestionada pues admite una relación asimétrica, donde la biomedicina tiene la...
Comparación del cariotipo de distintas cepas de pez cebra (Danio rerio) y una línea ornamental transgénico
(Universidad de Chile, 2014)
estudios
realizados en esta especie y cuyos resultados pueden ser extrapolados a la gran mayoría de
los vertebrados. Se ha logrado modificar genéticamente para utilizarlo en diversas áreas,
desde biomedicina al monitoreo medioambiental y también como peces...
The zebrafish (Danio rerio) is a model organism, widely used in genetic studies due to unique features such as their small size, short generation time and transparency of embryos, among others, all of them provide great advantages to work with this fish, and results of research performed on this species can be extrapolated to the majority of vertebrates. Zebrafish has been genetically modified to be used in diverse areas, such as biomedicine, monitoring environmental and also as ornamental fish. Few cytogenetic studies have been developed on this species, while in transgenic zebrafish there is not cytogenetic research yet. Under this guideline is performed this research, which compare the karyotype of two strains of wild type obtained from laboratories of hatcheries of Agronomy Sciences and Sciences Faculties of University of Chile, and a commercial transgenic ornamental line to define if there are karyotypic differences between them. To do this, metaphases plates were obtained from cells from kidney, which were subjected to karyotypic analysis with staining with Giemsa and staining with propidium iodine to obtain the fluorescent C-banding. Each chromosome karyotype was measured and calculated centromeric index, to be able to finally make the idiogram. All analyzed strains, including the ornamental transgenic line, had the same chromosomal modal numbers 2n = 50, all of them with submetacentric morphology. In general, the C-banding revealed presence of constitutive heterochromatin, mainly in the pericentromeric areas of chromosomes. After this analysis, the wild type strain from Agronomy Faculty presented differences with respect to the wild type of Science Faculty. Metaphases revealed a marked variability in the chromosomes number and morphology of transgenic fish. The results of this report are a contribution to the knowledge of the strains of zebrafish in captivity and open a window for the development of new transgenic zebrafish studies....
The zebrafish (Danio rerio) is a model organism, widely used in genetic studies due to unique features such as their small size, short generation time and transparency of embryos, among others, all of them provide great advantages to work with this fish, and results of research performed on this species can be extrapolated to the majority of vertebrates. Zebrafish has been genetically modified to be used in diverse areas, such as biomedicine, monitoring environmental and also as ornamental fish. Few cytogenetic studies have been developed on this species, while in transgenic zebrafish there is not cytogenetic research yet. Under this guideline is performed this research, which compare the karyotype of two strains of wild type obtained from laboratories of hatcheries of Agronomy Sciences and Sciences Faculties of University of Chile, and a commercial transgenic ornamental line to define if there are karyotypic differences between them. To do this, metaphases plates were obtained from cells from kidney, which were subjected to karyotypic analysis with staining with Giemsa and staining with propidium iodine to obtain the fluorescent C-banding. Each chromosome karyotype was measured and calculated centromeric index, to be able to finally make the idiogram. All analyzed strains, including the ornamental transgenic line, had the same chromosomal modal numbers 2n = 50, all of them with submetacentric morphology. In general, the C-banding revealed presence of constitutive heterochromatin, mainly in the pericentromeric areas of chromosomes. After this analysis, the wild type strain from Agronomy Faculty presented differences with respect to the wild type of Science Faculty. Metaphases revealed a marked variability in the chromosomes number and morphology of transgenic fish. The results of this report are a contribution to the knowledge of the strains of zebrafish in captivity and open a window for the development of new transgenic zebrafish studies....
Efecto de la curvatura de nanopartículas de oro funcionalizadas y su influencia sobre la agregación del péptido β-amiloide
(Universidad de Chile, 2021)
) han sido utilizadas en diferentes aplicaciones en biomedicina y se han propuesto su uso para tratar la EA mediante la inhibición de la agregación de Aβ. Sin embargo, cómo la curvatura de las NPO puede afectar el mecanismo de agregación de Aβ aún se...
Alzheimer’s disease is one of the most important neurodegenerative illness and the most common kind of dementia. One of the hallmarks of this disease is the aggregation process of amyloid-β peptide (Aβ). In physiological conditions, the Aβ monomer is maintained in a soluble form but in pathological conditions it begins to aggregate, producing different toxic intermediaries until generating the Aβ fibrils and senile plaques. Thus, the Aβ aggregation process has become in a main strategy to inhibit, but all these strategies have failed because they cannot either reach an adequate concentration in the brain or cross the brain blood barrier. Gold nanoparticles (GNP) have been used for different applications in biomedicine and proposed to treat Alzheimer´s disease (EA) through the inhibition of Aβ peptide aggregation. However, how the GNP’s curvature affects the mechanism of Aβ aggregation is not yet well understood. In this work, we characterized two different GNP’s curvature, a flat gold nanoprisms (GNPr) and curved gold nanospheres (GNS), and functionalized with poly ethilenglycol (PEG) to stabilized them. Then, we evaluate and studied the effect of these GNP on in vitro Aβ42 fibril formation by using ThT-based kinetic assay and global fitting analysis with several models of aggregation. Whereas GNPr accelerated the aggregation process and maintained the molecular mechanism of aggregation, GNS decelerated the aggregation process and modify the molecular mechanism to fragmentation/secondary nucleation regarding the control situation. By transmission electronic microscopy, it was observed the GNP’s shape was found to modify length’s population of Aβ42 fibril: longer fibrils in presence of GNPr and shorter fibrils with GNS. These results were explained by a differential interaction between Aβ peptide with each GNP’s curvature observed by Raman spectroscopy. While the flat shape of GNPr exposed hydrophobic amino acids of Aβ peptide that participate in accelerating the aggregation process, the curved shape of GNS hided these amino acids and hindered the proper interaction decelerating the fibrillation. Thus, this study provides the role of the GNP’s curvature and their molecular mechanisms on the Aβ aggregation process...
Alzheimer’s disease is one of the most important neurodegenerative illness and the most common kind of dementia. One of the hallmarks of this disease is the aggregation process of amyloid-β peptide (Aβ). In physiological conditions, the Aβ monomer is maintained in a soluble form but in pathological conditions it begins to aggregate, producing different toxic intermediaries until generating the Aβ fibrils and senile plaques. Thus, the Aβ aggregation process has become in a main strategy to inhibit, but all these strategies have failed because they cannot either reach an adequate concentration in the brain or cross the brain blood barrier. Gold nanoparticles (GNP) have been used for different applications in biomedicine and proposed to treat Alzheimer´s disease (EA) through the inhibition of Aβ peptide aggregation. However, how the GNP’s curvature affects the mechanism of Aβ aggregation is not yet well understood. In this work, we characterized two different GNP’s curvature, a flat gold nanoprisms (GNPr) and curved gold nanospheres (GNS), and functionalized with poly ethilenglycol (PEG) to stabilized them. Then, we evaluate and studied the effect of these GNP on in vitro Aβ42 fibril formation by using ThT-based kinetic assay and global fitting analysis with several models of aggregation. Whereas GNPr accelerated the aggregation process and maintained the molecular mechanism of aggregation, GNS decelerated the aggregation process and modify the molecular mechanism to fragmentation/secondary nucleation regarding the control situation. By transmission electronic microscopy, it was observed the GNP’s shape was found to modify length’s population of Aβ42 fibril: longer fibrils in presence of GNPr and shorter fibrils with GNS. These results were explained by a differential interaction between Aβ peptide with each GNP’s curvature observed by Raman spectroscopy. While the flat shape of GNPr exposed hydrophobic amino acids of Aβ peptide that participate in accelerating the aggregation process, the curved shape of GNS hided these amino acids and hindered the proper interaction decelerating the fibrillation. Thus, this study provides the role of the GNP’s curvature and their molecular mechanisms on the Aβ aggregation process...
Camino a la interculturalidad: la experiencia Mapuche Lafkenche en el tratamiento de la salud mental, en el Hospital Intercultural Kallvu Llanka de Cañete
(Universidad de Chile, 2023)
tratamiento y finalmente, conceptos abstractos referidos sólo por profesionales del hospital.
Se concluye que las experiencias asociadas a las distintas modalidades de atención proviene de la biomedicina, de adecuaciones con pertinencia cultural articulado...
El rol de la industria biotecnológica en la sofisticación y diversificación de la matriz productiva chilena -dificultades y propuestas para su desarrollo
(Universidad de Chile, 2019)
Metropolitana, seguida por las regiones de Valparaíso y la del Biobío. Su desarrollo se distribuye actualmente entre la biomedicina (39%), recursos naturales (34%) y su aplicación industrial (26%). Su desarrollo ha sido impulsado principalmente por el Estado de...
Biocompatibilización de nanopartículas metálicas con copolimeros de quitosano
(Universidad de ChileCyberDocs, 2010)
menos en una de sus dimensiones, tamaños de entre 1 y 100 nm). Los nanomateriales presentan interesantes propiedades que los convierten en una herramienta útil para la biomedicina. Un ejemplo de ello son las nanopartículas de oro (Au-NPs) que absorben la...
Despite of the great scientific and technological advances, there are several diseases that still doesn´t have an early and effective method of diagnosis and treatment. Because of that, today it is exploring about the use of new materials and technologies to solve this issue. In this sense, it is important to mention the development in nanotechnology which is an area of the science dedicated to control and develop materials on nanometric scale (include materials with at least one dimension of size between 1 to 100 nm). This nanomaterials exhibit new properties, an example are the gold nanoparticles (Au-NPs), that are capable of absorbing energy supplied and dissipate it locally, beside its capacity of distribute easily by all the organism due to their small size. For this reason in our laboratory it is investigated the potential use of AuNPs for the treatment and diagnosis of Alzheimer´s disease. One example is the conjugation of AuNPs with the peptide CLPFFD that recognizes the toxic aggregates of Aβ present in the brain of patients that suffer Alzheimer’s disease with the propose to destroy the mentioned aggregates. However, such nanoparticles show adverse effects, because of the negative superficial charge present in them, that could generate thrombogenicity and opsonisation, been easily captured by Mononuclear Phagocytic System (MPS), impeding their arrival to the therapeutic target. For this reason after an injection of nanoparticles the percentage of the injected dose that reaches the brain is very low being necessary to improve the drug delivery for future pharmaceutical applications. In the present thesis, to avoid these side effects, the nanoparticles will be capped polymers derivated from chitosan (Qo). Nevertheless, this polymer shows a high value of superficial energy, involving a thrombogenic effect. That´s why, in this thesis work, Qo was cross-linked with polysiloxane (PMS), a polymer with low superficial energy, expecting a decreasing in this energy, and use it to recover the Au-NPs. This reaction was possible by the use of a cross-linking agent, EDC, whom is capable to activate the carboxyl group of the PMS, to react with the amine group of Qo. The obtained copolymers were characterized by thermogravimetry, infrared spectroscopy and contact angle measures. On the other hand, the thrombogenic effects of the polymers were evaluated by means of a coagulation assay and their effects on cell viability on human neuroblastome cells were evaluated using MTS assay. In summary, in this work it was obtained crosslinked derivates polymers from chitosan that shows a lower surface energy with respect to Qo. The copolymerization of Qo with PMS lead to the elimination of the thrombogenic effects and to a diminution of the effects on the cell viability. These copolymers were used for capping the AuNPs, obtaining nanocomposites, that did not show thrombogenic effects and neither a reduction of cell viability. These nanocomposites presented a positive charge which could contribute to avoid interaction with MPS which is very relevant for future pharmaceutical applications...
Despite of the great scientific and technological advances, there are several diseases that still doesn´t have an early and effective method of diagnosis and treatment. Because of that, today it is exploring about the use of new materials and technologies to solve this issue. In this sense, it is important to mention the development in nanotechnology which is an area of the science dedicated to control and develop materials on nanometric scale (include materials with at least one dimension of size between 1 to 100 nm). This nanomaterials exhibit new properties, an example are the gold nanoparticles (Au-NPs), that are capable of absorbing energy supplied and dissipate it locally, beside its capacity of distribute easily by all the organism due to their small size. For this reason in our laboratory it is investigated the potential use of AuNPs for the treatment and diagnosis of Alzheimer´s disease. One example is the conjugation of AuNPs with the peptide CLPFFD that recognizes the toxic aggregates of Aβ present in the brain of patients that suffer Alzheimer’s disease with the propose to destroy the mentioned aggregates. However, such nanoparticles show adverse effects, because of the negative superficial charge present in them, that could generate thrombogenicity and opsonisation, been easily captured by Mononuclear Phagocytic System (MPS), impeding their arrival to the therapeutic target. For this reason after an injection of nanoparticles the percentage of the injected dose that reaches the brain is very low being necessary to improve the drug delivery for future pharmaceutical applications. In the present thesis, to avoid these side effects, the nanoparticles will be capped polymers derivated from chitosan (Qo). Nevertheless, this polymer shows a high value of superficial energy, involving a thrombogenic effect. That´s why, in this thesis work, Qo was cross-linked with polysiloxane (PMS), a polymer with low superficial energy, expecting a decreasing in this energy, and use it to recover the Au-NPs. This reaction was possible by the use of a cross-linking agent, EDC, whom is capable to activate the carboxyl group of the PMS, to react with the amine group of Qo. The obtained copolymers were characterized by thermogravimetry, infrared spectroscopy and contact angle measures. On the other hand, the thrombogenic effects of the polymers were evaluated by means of a coagulation assay and their effects on cell viability on human neuroblastome cells were evaluated using MTS assay. In summary, in this work it was obtained crosslinked derivates polymers from chitosan that shows a lower surface energy with respect to Qo. The copolymerization of Qo with PMS lead to the elimination of the thrombogenic effects and to a diminution of the effects on the cell viability. These copolymers were used for capping the AuNPs, obtaining nanocomposites, that did not show thrombogenic effects and neither a reduction of cell viability. These nanocomposites presented a positive charge which could contribute to avoid interaction with MPS which is very relevant for future pharmaceutical applications...