Browsing by Author "Morales-Zavala, Francisco"

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    Differential Detection of Amyloid Aggregates in Old Animals Using Gold Nanorods by Computerized Tomography: A Pharmacokinetic and Bioaccumulation Study
    (2023) Jara-Guajardo, Pedro; Morales-Zavala, Francisco; Bolanos, Karen; Giralt, Ernest; Araya, Eyleen; Acosta, Gerardo A.; Albericio, Fernando; Alvarez, Alejandra R.; Kogan, Marcelo J.
    Introduction: The development of new materials and tools for radiology is key to the implementation of this diagnostic technique in clinics. In this work, we evaluated the differential accumulation of peptide-functionalized GNRs in a transgenic animal model (APPswe/PSENd1E9) of Alzheimer's disease (AD) by computed tomography (CT) and measured the pharmacokinetic parameters and bioaccumulation of the nanosystem.Methods: The GNRs were functionalized with two peptides, Ang2 and D1, which conferred on them the properties of crossing the blood-brain barrier and binding to amyloid aggregates, respectively, thus making them a diagnostic tool with great potential for AD. The nanosystem was administered intravenously in APPswe/PSEN1dE9 model mice of 4-, 8- and 18-months of age, and the accumulation of gold nanoparticles was observed by computed tomography (CT). The gold accumulation and biodistribution were determined by atomic absorption.Results: Our findings indicated that 18-month-old animals treated with our nanosystem (GNR-D1/Ang2) displayed noticeable differences in CT signals compared to those treated with a control nanosystem (GNR-Ang2). However, no such distinctions were observed in younger animals. This suggests that our nanosystem holds the potential to effectively detect AD pathology.Discussion: These results support the future development of gold nanoparticle-based technology as a more effective and accessible alternative for the diagnosis of AD and represent a significant advance in the development of gold nanoparticle applications in disease diagnosis.
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    Gold Nanoparticles Mediate Improved Detection of β-amyloid Aggregates by Fluorescence
    (2020) Jara-Guajardo, Pedro; Cabrera, Pablo; Celis, Freddy; Soler, Monica; Berlanga, Isadora; Parra-Munoz, Nicole; Acosta, Gerardo; Albericio, Fernando; Guzman, Fanny; Campos, Marcelo; Alvarez, Alejandra; Morales-Zavala, Francisco; Kogan, Marcelo J.
    The early detection of the amyloid beta peptide aggregates involved in Alzheimer's disease is crucial to test new potential treatments. In this research, we improved the detection of amyloid beta peptide aggregates in vitro and ex vivo by fluorescence combining the use of CRANAD-2 and gold nanorods (GNRs) by the surface enhancement fluorescence effect. We synthetized GNRs and modified their surface with HS-PEG-OMe and HS-PEG-COOH and functionalized them with the D1 peptide, which has the capability to selectively bind to amyloid beta peptide. For an in vitro detection of amyloid beta peptide, we co-incubated amyloid beta peptide aggregates with the probe CRANAD-2 and GNR-PEG-D1 observing an increase in the intensity of the fluorescence signal attributed to surface enhancement fluorescence. Furthermore, the surface enhancement fluorescence effect was observed in brain slices of transgenic mice with Alzheimer's disease co-incubated with CRANAD-2 and GNR-PEG-D1. An increase in the fluorescence signal was observed allowing the detection of aggregates that cannot be detected with the single use of CRANAD-2. Gold nanoparticles allowed an improvement in the detection of the amyloid aggregated by fluorescence in vitro and ex vivo.
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    Nanoparticles for diagnosis and therapy of atherosclerosis and myocardial infarction : evolution toward prospective theranostic approaches
    (2018) Bejarano, Julian; Navarro-Marquez, Mario; Morales-Zavala, Francisco; Morales, Javier O.; Garcia-Carvajal, Ivonne; Araya-Fuentes, Eyleen; Flores, Yvo; Verdejo Pinochet, Hugo; Castro Gálvez, Pablo Federico; Lavandero, Sergio; Kogan, Marcelo J.
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    Peptide Targeted Gold Nanoplatform Carrying miR-145 Induces Antitumoral Effects in Ovarian Cancer Cells
    (2022) Salas-Huenuleo, Edison; Hernandez, Andrea; Lobos-Gonzalez, Lorena; Polakovicova, Iva; Morales-Zavala, Francisco; Araya, Eyleen; Celis, Freddy; Romero, Carmen; Kogan, Marcelo J.
    One of the recent attractive therapeutic approaches for cancer treatment is restoring downregulated microRNAs. They play an essential muti-regulatory role in cellular processes such as proliferation, differentiation, survival, apoptosis, cell cycle, angiogenesis, and metastasis, among others. In this study, a gold nanoplatform (GNPF) carrying miR-145, a downregulated microRNA in many cancer types, including epithelial ovarian cancer, was designed and synthesized. For targeting purposes, the GNPF was functionalized with the FSH33 peptide, which provided selectivity for ovarian cancer, and loaded with the miR-145 to obtain the nanosystem GNPF-miR-145. The GNPF-mir-145 was selectively incorporated in A2780 and SKOV3 cells and significantly inhibited cell viability and migration and exhibited proliferative and anchor-independent growth capacities. Moreover, it diminished VEGF release and reduced the spheroid size of ovarian cancer through the damage of cell membranes, thus decreasing cell viability and possibly activating apoptosis. These results provide important advances in developing miR-based therapies using nanoparticles as selective vectors and provide approaches for in vivo evaluation.
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    Surface enhanced fluorescence effect improves the in vivo detection of amyloid aggregates
    (2022) Cabrera, Pablo; Jara-Guajardo, Pedro; Oyarzun, Maria Paz; Parra-Munoz, Nicole; Campos, Aldo; Soler, Monica; Alvarez, Alejandra; Morales-Zavala, Francisco; Araya, Eyleen; Minniti, Alicia N.; Aldunate, Rebeca; Kogan, Marcelo J.
    The beta-amyloid (A beta) peptide is one of the key etiological agents in Alzheimer's disease (AD). The in vivo detection of A beta species is challenging in all stages of the illness. Currently, the development of fluorescent probes allows the detection of A beta in animal models in the near-infrared region (NIR). However, considering future applications in biomedicine, it is relevant to develop strategies to improve detection of amyloid aggregates using NIR probes. An innovative approach to increase the fluorescence signal of these fluorophores is the use of plasmonic gold nanoparticles (surface-enhanced fluorescence effect). In this work, we improved the detection of A beta aggregates in C. elegans and mouse models of AD by co-administering functionalized gold nanorods (GNRs-PEG-D1) with the fluorescent probes CRANAD-2 or CRANAD-58, which bind selectively to different amyloid species (soluble and insoluble). This work shows that GNRs improve the detection of A beta using NIR probes in vivo. (C) 2022 Published by Elsevier Inc.