664 research outputs found
Boosting the therapeutic efficiency of nanovectors: exocytosis engineering
No full textIn this work, we developed a new general strategy, which we named "exocytosis engineering", to strongly increase the intracellular persistence of nanocarriers and thus the effective dose of transported drugs. The strategy is based on the co-loading of a drug and an exocytosis inhibitor in the nanocarrier, to hinder the high tendency of cells to remove internalized nanocarriers, limiting the pharmacological efficiency of the nanoformulation. In particular, by using a well-known chemotherapeutic drug (doxorubicin) and an efficient exocytosis inhibitor (dimethilamyloride) co-loaded in mesoporous silica nanocarriers, we demonstrated a >6-fold increase in the intracellular dose of the drug (for the same administered dose), achieving a great improvement in its therapeutic action. A strong gain in the cytotoxic effect of the drug was, in fact, observed both in several tumor cell lines and in 3D tumor spheroids. The proposed approach is versatile and broadly applicable to several classes of nanocarriers and drugs, thus opening a fascinating outlook in nanomedicine
Effect of silica nanoparticles with variable size and surface functionalization on human endothelial cell viability and angiogenic activity
No full textSilica nanoparticles could be promising delivery vehicles for drug targeting or gene therapy. However, few studies have been undertaken to determine the biological behavior effects of silica nanoparticles on primary endothelial cells. Here we investigated uptake, cytotoxicity and angiogenic properties of silica nanoparticle with positive and negative surface charge and sizes ranging from 25 to 115 nm in primary human umbilical vein endothelial cells. Dynamic light scattering measurements and nanoparticle tracking analysis were used to estimate the dispersion status of nanoparticles in cell culture media, which was a key aspect to understand the results of the in vitro cellular uptake experiments. Nanoparticles were taken up by primary endothelial cells in a size-dependent manner according to their degree of agglomeration occurring after transfer in cell culture media. Functionalization of the particle surface with positively charged groups enhanced the in vitro cellular uptake, compared to negatively charged nanoparticles. However, this effect was contrasted by the tendency of particles to form agglomerates, leading to lower internalization efficiency. Silica nanoparticle uptake did not affect cell viability and cell membrane integrity. More interestingly, positively and negatively charged 25 nm nanoparticles did not influence capillary-like tube formation and angiogenic sprouting, compared to controls. Considering the increasing interest in nanomaterials for several biomedical applications, a careful study of nanoparticle-endothelial cells interactions is of high relevance to assess possible risks associated to silica nanoparticle exposure and their possible applications in nanomedicine as safe and effective nanocarriers for vascular transport of therapeutic agents
Results of UV laser application on biological material
No full textALT’01 International Conference on Advanced Laser Technologies. D.C. Dumitras, M. Dinescu and V.I. Konov (Editors); A.M. Prokhorov (Chair)
Constraining the Dark Sector with the Mono-jet signature with the ATLAS detector at the LHC
No full textThis proceeding is written according to the poster presented at LHCP-2021. A work about the reinterpretation of the search for final states with at least one energetic jet and missing transverse momentum in the context of dark sector models with long-lived neutral particles was there presented. Results are based on139 fb−1of data collected in pp collisions at centre of mass energy of 13 TeV by theATLAS experiment during Run-2 at LHC. Decays of the Standard Model Higgs boson and of anew neutral heavy scalar mediator into long-lived particles are investigated in different channels. The resulting constraints generally extend those from dedicated searches at large proper lifetimesThis work presents the reinterpretation of the search for final states with at least one energetic jet and missing transverse momentum in the context of dark sector models with long-lived neutral particles was there presented. Results are based on139 fb−1of data collected in pp collisions at centre of mass energy of 13 TeV by the ATLAS experiment during Run-2 at LHC. Decays of the Standard Model Higgs boson and of anew neutral heavy scalar mediator into long-lived particles are investigated in different channels. The resulting constraints generally extend those from dedicated searches at large proper lifetime
Optical and morphological properties of infrared emitting functionalized silica nanoparticles
No full textThe loading process of functionalized silica nanoparticles was investigated in order to obtain nanoparticles
having functional groups on their surface and Near-Infrared (NIR) emission properties. The NIR
emission induced by O2 loading was studied in silica nanoparticles, produced by pyrogenic and microemulsion
methods, with size ranging from 20 to 120 nm. Loading was carried out by thermal treatments
in O2 atmosphere up to 400 C and 90 bar. The effects of the thermal treatments on the NIR emission and
on the structural properties were studied by luminescence and Raman techniques, whereas the
morphological features were investigated by Transmission Electron Microscopy and Atomic Force Microscopy.
Our data show that silica nanoparticles produced by pyrogenic technique can be loaded with
O2 at lower temperature than the ones obtained by microemulsion and have a higher luminescence
intensity due to the internal porosity of the latter. The treatments do not affect the nanosize of the
microemulsion particles and provide NIR emitting probes of selected size. Post-processing surface
functionalization of the pyrogenic nanoparticles does not affect their emission properties and provides
high efficiency NIR emitters with functionalized surface
PMA-Induced THP-1 Macrophage Differentiation is Not Impaired by Citrate-Coated Platinum Nanoparticles
No full textThe innate immune system consists of several complex cellular and molecular mechanisms. During inflammatory responses, blood-circulating monocytes are driven to the sites of inflammation, where they differentiate into tissue macrophages. The research of novel nanomaterials applied to biomedical sciences is often limited by their toxicity or dangerous interactions with the immune cell functions. Platinum nanoparticles (PtNPs) have shown efficient antioxidant properties within several cells, but information on their potential harmful role in the monocyte-to-macrophage differentiation process is still unknown. Here, we studied the morphology and the release of cytokines in PMA-differentiated THP-1 pre-treated with 5 nm PtNPs. Although NP endocytosis was evident, we did not find differences in the cellular structure or in the release of inflammatory cytokines and chemokines compared to cells differentiated in PtNP-free medium. However, the administration of PtNPs to previously differentiated THP-1 induced massive phagocytosis of the PtNPs and a slight metabolism decrease at higher doses. Further investigation using undifferentiated and differentiated neutrophil-like HL60 confirmed the harmlessness of PtNPs with non-adherent innate immune cells. Our results demonstrate that citrate-coated PtNPs are not toxic with these immune cell lines, and do not affect the PMA-stimulated THP-1 macrophage differentiation process in vitro
Background and Overview of Physical Anthropology at INAH
No full textLeón, Nicolás (1912); “Voto particular del Sr. Dr. D. Nicolás León como comisionado para identificar los restos del General Insurgente D. Mariano Matamoros”, Boletín del Museo Nacional de Arqueología, Historia y Etnología, t. 1. núm., 8, febrero, México, Imprenta del Museo Nacional, pp. 145-148.——— (1922); “La antropología física y la antropometría en México”, Anales del Museo Nacional de Arqueología, Historia y Etnografía, época IV, t. 1, México, Imprenta del Museo Nacional, pp. 99-136.López, Sergio, Carmen Pijoan y María Elena Salas (2003); “III. Funcionamiento por áreas 1. La investigación científica a) ‘Antropología física’”, en Julio César Olivé Negrete y Bolfy Cottom (coords.), INAH. Una historia, vol. 1 3ª ed., México, INAH, pp. 109-118.Pompa y Padilla, José Antonio (1988); La antropología en México. Panorama histórico, Tomo 3 Las cuestiones medulares. Antropología física, lingüística, arqueología y etnohistoria. “Los estudios odontológicos”, México, INAH (Biblioteca del INAH), pp. 49-60.Pompa y Padilla, José Antonio (coord.) (2012); “Análisis de antropología física”, en Los Restos de los héroes en el Monumento a la Independencia, t. II, México, INAH/INEHRM, pp. 183-356.Rivermar Pérez, Leticia (1987); La antropología en México. Panorama histórico, Tomo 2 Los Hechos y los Dichos. “En el marasmo de una rebelión cataclísmica (1911- 1920)”, México, INAH (Biblioteca del INAH), pp. 90-131.Salas Cuesta, María Elena del Pilar (coord.) (1988); Molino del Rey: historia de un monumento, México, INAH (Científica, 170).Suárez Cortés, Blanca Estela (1987); La antropología en México Panorama histórico, Tomo 2 Los Hechos y los Dichos. “Las interpretaciones positivas del pasado y el presente (1880-1910) marco institucional”, México, INAH (Biblioteca del INAH), pp. 13-88.Contribución que busca compartir un punto de vista con relación al desarrollo de la antropología física, principalmente en el ámbito institucional, desde la perspectiva del lugar de observación, que puede coincidir o no con la de los lectores. Cada uno hemos tenido distintos momentos, experiencias y circunstancias con las que conformamos nuestra visión de la realidad que percibimos y tratamos así de entender algunas tendencias de la disciplina antropofísica, tanto en el pasado como hacia donde me parece que se dirige.This contribution seeks to share a point of view regarding the development of physical anthropology, mainly in the institutional sphere, from the perspective of place of observation, which might coincide or not with that of readers. Each of us has had different moments, experiences, and circumstances that shape our vision of the reality we perceive and thus we try to understand some of the trends in the discipline of physical anthropology, both in the past and towards where I think it is headed
Particle size affects the cytosolic delivery of membranotropic peptide-functionalized platinum nanozymes
No full textDelivery of therapeutic agents inside the cytosol, avoiding the confinement in endo-lysosomal compartments and their degradative environment, is one of the key targets of nanomedicine to gain the maximum remedial effects. Current approaches based on cell penetrating peptides (CPPs), despite improving the cellular uptake efficiency of nanocarriers, have shown controversial results in terms of intracellular localization. To elucidate the delivery potential of CPPs, in this work we analyzed the role of the particle size in influencing the ability of a membranotropic peptide, namely gH625, to escape the endo-lysosomal pathway and deliver the particles in the cytosol. To this aim, we carried out a systematic assessment of the cellular uptake and distribution of monodisperse platinum nanoparticles (PtNPs), having different diameters (2.5, 5 and 20 nm) and citrate capping or gH625 peptide functionalization. The presence of gH625 significantly increased the amount of internalized NPs in human cervix epithelioid carcinoma cells, as a function of particle size. However, scanning transmission electron microscopy (STEM) and electron tomography (ET) revealed a prevalent confinement of PtNPs within vesicular structures, regardless of the particle size and surface functionalization. Only in the case of the smallest 2.5 nm particles, the membranotropic peptide was able to partly maintain its functionality, enabling cytosolic delivery of a small fraction of internalized PtNPs, though particle agglomeration in culture medium limited single-particle transport across the cell membrane. Interestingly, membrane crossing by 2.5 nm functionalized-PtNPs seemed to occur by diffusion through the lipid bilayer, with no apparent membrane damage. For larger particle sizes (>= 5 nm), their hindrance likely blocked the membranotropic mechanism. Combining the enhanced uptake and partial cytosolic delivery promoted by gH625, we were able to achieve a strong improvement of the antioxidant nanozyme function of 2.5 nm PtNPs, decreasing both the endogenous ROS level and its overproduction following an external oxidative insult
Antagonistic Fashion. The Last Generations after Japanese Post-atomic Wave
No full textThe essay "Antagonistic Fashion. The Last Generations after the Japanese Post-atomic Wave" deals with the latest radical trends and
current inclinations labelled as anti-pop, anti-form, anti-glam, in a word, anti-fashion. The prefix “anti” is to be intended as a banner
of contrast and opposition in respect to mainstream fashion canons. Drawing from a methodological frame rooted in the phenomenology of styles, from which she borrows a historical-critical structure usually applied to the arts, the author marks the trends of some designers’ latest generations (such as Carol Christian Poell, Maurizio Altieri, Issei Fujita, Boris Bidjan Saberi, Damir
Doma) who are on the same wavelength as that of the research started by Yohji Yamamoto, Rei Kawakubo and Issey Miyake
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