Browsing by Author "Morales, Javier O."

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    Light-induced release of the cardioprotective peptide angiotensin-(1-9) from thermosensitive liposomes with gold nanoclusters
    (2020) Bejarano, Julian; Rojas, Aldo; Ramirez Sagredo, Andrea; Riveros, Ana L.; Morales Zavala, Francisco; Flores, Yvo; Riquelme, Jaime A.; Guzman, Fanny; Araya, Eyleen; Chiong, Mario; Ocaranza, María Paz; Morales, Javier O.; Villamizar Sarmiento, Maria Gabriela; Sanchez, Gina; Lavandero, Sergio; Kogan, Marcelo J.
    Angiotensin-(1-9), a component of the non-canonical renin-angiotensin system, has a short half-life in blood. This peptide has shown to prevent and/or attenuate hypertension and cardiovascular remodeling. A controlled release of angiotensin-(1-9) is needed for its delivery to the heart. Our aim was to develop a drug delivery system for angiotensin-(1-9). Thermosensitive liposomes (LipoTherm) were prepared with gold nanoclusters (LipoThermAuNC) to increase the stability and reach a temporal and spatial control of angiotensin-(1-9) release. Encapsulation efficiencies of nearly 50% were achieved in LipoTherm, reaching a total angiotensin-(1-9) loading of around 180 mu M. This angiotensin-(1-9)-loaded LipoTherm sized around 100 nm and exhibited a phase transition temperature of 43.C. AuNC were grown on LipoTherm and the new hybrid nanosystem showed energy absorption in the near-infrared (NIR) wavelength range. By NIR laser irradiation, a controlled release of angiotensin-(1-9) was achieved from the LipoTherm-AuNC nanosystem. These nanosystems did not show any cytotoxic effect on cultured cardiomyocytes. Biological activity of angiotensin-(1-9) released from the LipoTherm-AuNCbased nanosystem was confirmed using an ex vivo Langendorff heart model.
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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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    Poloxamer 188-Coated Ammonium Methacrylate Copolymer Nanocarriers Enhance Loperamide Permeability across Pgp-Expressing Epithelia
    (AMER CHEMICAL SOC, 2021) Catalan Figueroa, Johanna; García Alcalde, Mauricio Andrés; Cayazzo Contreras, Pilar Andrea; Boisset, Constanza B.; Gonzalez, Pablo M.; Fiedler, Jenny L.; Perez, Mariela F.; Morales, Javier O.
    Loperamide is a mu-opioid agonist with poor gastrointestinal absorption, mainly because of its modest aqueous solubility and being a P-glycoprotein (Pgp) efflux substrate. Nevertheless, studies associated with therapeutic effects strongly suggest that loperamide holds potential pharmacological advantages over traditional mu-opioid agonists commonly used for analgesia. Thus, in this Communication, we assessed in MDCK-hMDR1 cell lines the effects over loperamide uptake and efflux ratio, when loaded into Eudragit RS (ERS) nanocarriers coated with poloxamer 188 (P188). ERS was chosen for enhancing loperamide aqueous dispersibility and P188 as a potential negative Pgp modulator. In uptake assays, it was observed that Pgp limited the accumulation of loperamide into cells and that preincubation with P188, but not coincubation, led to increasing loperamide uptake at a similar extent of Pgp pharmacological inhibition. On the other hand, the efflux ratio displayed no alterations when Pgp was pharmacologically inhibited, whereas ERS/P188 nanocarriers effectively enhanced loperamide uptake and absorptive transepithelial transport. The latter suggests that loperamide transport across cells is significantly influenced by the presence of the unstirred water layer (UWL), which could hinder the visualization of Pgp-efflux effects during transport assays. Thus, results in this work highlight that formulating loperamide into this nanocarrier enhances its uptake and transport permeability.