Person: Montalvo Quirós, Sandra
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First Name
Sandra
Last Name
Montalvo Quirós
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Químicas
Department
Química Analítica
Area
Química Analítica
Identifiers
4 results
Search Results
Now showing 1 - 4 of 4
Item Mesoporous silica nanoparticles containing silver as novel antimycobacterial agents against Mycobacterium tuberculosis(Colloids and Surfaces B: Biointerfaces, 2020) Montalvo Quirós, Sandra; Gómez Graña, Sergio; Vallet Regí, María Dulce Nombre; Prados Rosales, Rafael; González Ortiz, Blanca; Luque García, José LuisTuberculosis remains today a major public health issue with a total of 9 million new cases and 2 million deaths annually. The lack of an effective vaccine and the increasing emergence of new strains of Mycobacterium tuberculosis (Mtb) highly resistant to antibiotics, anticipate a complicated scenario in the near future. The use of nanoparticles features as an alternative to antibiotics in tackling this problem due to their potential effectiveness in resistant bacterial strains. In this context, silver nanoparticles have demonstrated high bactericidal efficacy,although their use is limited by their relatively high toxicity, which calls for the design of nanocarriers that allow silver based nanoparticles to be safely delivered to the target cells or tissues. In this work mesoporous silica nanoparticles are used as carriers of silver based nanoparticles as antimycobacterial agent against Mtb. Two different synthetic approaches have been used to afford, on the one hand, a 2D hexagonal mesoporous silica nanosystem which contains silver bromide nanoparticles distributed all through the silica network and, on the other hand, a core@shell nanosystem with metallic silver nanoparticles as core and mesoporous silica shell in a radial mesoporous rearrangement. Both materials have demonstrated good antimycobacterial capacity in in vitro test using Mtb, being lower the minimum inhibitory concentration for the nanosystem which contains silver bromide. Therefore, the interaction of this material with the mycobacterial cell has been studied by cryo-electron microscopy, establishing a direct connection between the antimycobactericidal effect observed and the damage induced in the cell envelope.Item Combination of bioanalytical approaches and quantitative proteomics for the elucidation of the toxicity mechanisms associated to TiO2 nanoparticles exposure in human keratinocytes(Food and Chemical Toxicology, 2019) Montalvo Quirós, Sandra; Luque García, José LuisTitanium dioxide nanoparticles (TiO2-NPs) are being used in several consumer products. The high refractive index of nano-scaled titanium dioxide particles allows them to protect from UV radiation, and so, they can be found as one of the main components of cosmetics and suncreens. Many studies have reported the potential toxicological effects associated to TiO2-NPs such as ROS generation, DNA damage, apoptosis and cell cycle arrest, among others. The continuous and systematic use of TiO2-NPs in cosmetic products requires a full comprehension of the risks involving their sustained contact with the human skin. Thus, it is important to evaluate not only the hazardous effects but to elucidate the biomolecular mechanisms involved in such effects. Based on this premises, we have evaluated the potential toxicity of TiO2-NPs using a human epithelial cell culture (HaCaT cells) as in-vitro model, together with different bioanalytical approaches and mass spectrometry-based quantitative proteomics, to gain a deeper insight into the molecular mechanisms of toxicity associated to TiO2-NPs exposure.Item Mesoporous Silica Nanoparticles as a Potential Platform for Vaccine Development against Tuberculosis(Pharmaceutics, 2020) Montalvo Quirós, Sandra; Vallet Regí, María Dulce Nombre; Palacios, Ainhoa; Anguita, Juan; Prados-Rosales, Rafael C.; González Ortiz, Blanca; Luque García, José LuisThe increasing emergence of new strains of Mycobacterium tuberculosis (Mtb) highly resistant to antibiotics constitute a public health issue, since tuberculosis still constitutes the primary cause of death in the world due to bacterial infection. Mtb has been shown to produce membrane-derived extracellular vesicles (EVs) containing proteins responsible for modulating the pathological immune response after infection. These natural vesicles were considered a promising alternative to the development of novel vaccines. However, their use was compromised by the observed lack of reproducibility between preparations. In this work, with the aim of developing nanosystems mimicking the extracellular vesicles produced by Mtb, mesoporous silica nanoparticles (MSNs) have been used as nanocarriers of immunomodulatory and vesicle-associated proteins (Ag85B, LprG and LprA). These novel nanosystems have been designed and extensively characterized, demonstrating the effectiveness of the covalent anchorage of the immunomodulatory proteins to the surface of the MSNs. The immunostimulatory capacity of the designed nanosystems has been demonstrated by measuring the levels of pro- (TNF) and anti-inflammatory (IL-10) cytokines in exposed macrophages. These results open a new possibility for the development of more complex nanosystems, including additional vesicle components or even antitubercular drugs, thus allowing for the combination of immunomodulatory and bactericidal effects against Mtb.Item Cancer cell targeting and therapeutic delivery of silver nanoparticles by mesoporous silica nanocarriers: insights into the action mechanisms by quantitative proteomics(Nanoscale, 2019) Montalvo Quirós, Sandra; Aragoneses Carzorla, Guillermo; García-Alcalde, Laura; Vallet Regí, María Dulce Nombre; González, Blanca; Luque García, José LuisThe aim of the present work is to provide an approach to safely deliver silver nanoparticles (AgNPs) as cytotoxic agents into cancer cells, and to provide a deeper insight into the cellular mechanisms affected by such targeted delivery. The use of mesoporous silica nanoparticles (MSNs) as nanovehicles decorated with transferrin (Tf, targeting agent) provides a nanoplatform for the nucleation and immobilization of AgNPs (MSNs-Tf-AgNPs). We have performed the physico-chemical characterization of the nanosystems and evaluated their therapeutic potential using bioanalytical strategies to estimate the efficiency of the targeting, the degree of cellular internalization in two cell lines with different TfR expression, and the cytotoxic effects of the delivered AgNPs. In addition, cellular localization of the nanosystems in cells has been evaluated by a transmission electron microscopy analysis of ultrathin sections of Human hepatocarcinoma (HepG2) cells exposed to MSNs-Tf-AgNPs. The in vitro assays demonstrate that only the nanosystem functionalized with Tf is able to transport the AgNPs inside the cells which overexpress transferrin receptors. Therefore, this novel nanosystem is able to deliver AgNPs specifically to cancer cells overexpressing Tf receptors and offers the possibility of a targeted therapy using reduced doses of silver nanoparticles as cytotoxic agents. Then, a quantitative proteomic experiment validated through the analysis of gene expression has been performed to identify the action molecular mechanisms associated with the chemotherapeutic potential of the MSNs-Tf-AgNPs nanocarriers.