Desarrollo de nanosistemas lipídicos para la liberación controlada de metalofármacos de platino(II) para el tratamiento de tumores colorrectales

Los complejos a base de platino son agentes quimioterapéuticos eficientes que han demostrado su actividad anticancerígena contra varios tipos de cáncer. Sin em-bargo, se deben considerar muchos desafíos para producir formulaciones derivadas de fármacos de platino novedosas y eficientes. La resistencia intrínseca o adquirida, la toxicidad limitante de la dosis, la degradación del fármaco, la baja solubilidad y, en consecuencia, la baja biodisponibilidad, se presentan como algunas de los aspectos que limitan las aplicaciones clínicas de los nuevos fármacos de platino. Estudios recientes muestran que ha habido un gran interés en desarrollar nuevas formulaciones de estos fármacos, para asegurar una mejor administración y ampliar el aspecto terapéutico. En este sentido, los nuevos avances en el desarrollo de vehículos para la administración de fármacos de platino ayudarán a aumentar su estabilidad y biodisponibilidad, junto con la reducción de su degradación y los efectos tóxicos secundarios indeseables que limitan su uso. En el presente trabajo de Tesis Doctoral se han desarrollado dos sistemas de libe-ración (pasivo y activo) para el 8-QO-Pt, que aparece como un prometedor complejo de platino con actividad antitumoral, a la vez que un interesante modelo de estudio para fármacos poco solubles en agua. El primer sistema fue diseñado en base al lípido de ésteres cetílicos (SS) con la presencia de dos aceites líquidos diferentes: triglicérido cáprico o aceite de oliva, para la liberación controlada y lenta en el colon que garantiza la biodistribución de las na-nopartículas como tales, al mismo tiempo que liberan su cargamento. Aunque este sis-tema no pudo mostrar una actividad antitumoral superior sobre el fármaco libre, sí mostró efectos anticancerígenos comparables a él, pero sin los efectos deletéreos que se le relacionan y con una actividad biocida mejorada sobre las células cancerosas. En el segundo sistema, la formulación con triglicéridos cápricos que demostró mejores efectos en el primer sistema, se funcionalizó con riboflavina para generar un sistema de sitio-dirección activo. En este estudio se han desarrollado e investigado por primera vez sistemas NLC con riboflavina dirigida a la liberación controlada de fár-macos. Los resultados son superiores a los sistemas anticancerígenos dirigidos a RFV publicados en literatura y a la acción del fármaco libre tanto en monocapa como en modelos 3D de cáncer colorrectal. Además, la formulación inhibió la migración celular de los esferoides multicelulares de colon, lo que demuestra que el sistema NLC con riboflavina dirigida evidenció también propiedades antimetastásicas.Facultad de Ciencias Exacta

8-Hydroxyquinoline platinum(ii) loaded nanostructured lipid carriers: synthesis, physicochemical characterization and evaluation of antitumor activity

Every year the incidence of cancer and the death rate are increasing worldwide. The drug 8-hydroxyquinoline platinum(II) [PtCl(8-O-quinoline)(dmso)] (8HQ-Pt) has been identified as a promising antitumor complex. Nanostructured lipid carriers (NLC) are second-generation drug nanocarrier systems that have superior advantages over other kinds of colloidal carrier systems. 8HQ-Pt compound loaded NLC formulations of cetyl esters (SS) were synthesized via ultrasonication in the presence of two different liquid oils: capric triglyceride, or olive oil. The physicochemical and microscopic characterizations of NLC were analyzed via dynamic light scattering (DLS), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and X-ray diffraction analysis (XRD). In vitro drug release and cytotoxicity, cell uptake and apoptosis assays against the human colon cancer cell line HT-29 were investigated. The results showed that NLCs indicated a narrow size distribution and a mean particle diameter in the range of 136?159 nm. The thermal characteristic analysis confirmed the stability of NLCs up to 185 °C. Encapsulation efficiencies of the 8HQ-Pt compound in NLCs were about 80% and the 8HQ-Pt compound in the formulations showed a controlled release profile during 72 h. The release profiles of these two different formulations and the antitumor effect on the HT-29 cell line were compared with those of the free 8HQ-Pt compound. The cellular uptake of two different NLC groups was proved by fluorescence microscopy and the presence of capric triglyceride liquid oil in the formulation increased the intracellular drug delivery capacity when compared with olive oil.Fil: Boztepe, Tugce. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Scioli Montoto, Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencas Exactas. Laboratorio de Investigación y Desarrollo de Bioactivos; ArgentinaFil: Ruiz, María Esperanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencas Exactas. Laboratorio de Investigación y Desarrollo de Bioactivos; ArgentinaFil: Alvarez, Valeria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Castro, Guillermo Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Leon, Ignacio Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentin

Design, Synthesis, Characterization, and Evaluation of the Anti-HT-29 Colorectal Cell Line Activity of Novel 8-Oxyquinolinate-Platinum(II)-Loaded Nanostructured Lipid Carriers Targeted with Riboflavin

Colorectal cancer is occasionally called colon or rectal cancer, depending on where cancer begins to form, and is the second leading cause of cancer death among both men and women. The platinum-based [PtCl(8-O-quinolinate)(dmso)] (8-QO-Pt) compound has demonstrated encouraging anticancer activity. Three different systems of 8-QO-Pt-encapsulated nanostructured lipid carriers (NLCs) with riboflavin (RFV) were investigated. NLCs of myristyl myristate were synthesized by ultrasonication in the presence of RFV. RFV-decorated nanoparticles displayed a spherical shape and a narrow size dispersion in the range of 144–175 nm mean particle diameter. The 8-QO-Pt-loaded formulations of NLC/RFV with more than 70% encapsulation efficiency showed sustained in vitro release for 24 h. Cytotoxicity, cell uptake, and apoptosis were evaluated in the HT-29 human colorectal adenocarcinoma cell line. The results revealed that 8-QO-Pt-loaded formulations of NLC/RFV showed higher cytotoxicity than the free 8-QO-Pt compound at 5.0 µM. All three systems exhibited different levels of cellular internalization. Moreover, the hemotoxicity assay showed the safety profile of the formulations (less than 3.7%). Taken together, RFV-targeted NLC systems for drug delivery have been investigated for the first time in our study and the results are promising for the future of chemotherapy in colon cancer treatmen

Thermonuclear X-ray Bursts with late secondary peaks observed from 4U 1608-52

We report the temporal and spectral analysis of three thermonuclear X-ray bursts from 4U 1608-52, observed by the Neutron Star Interior Composition Explorer (NICER) during and just after the outburst observed from the source in 2020. In two of the X-ray bursts, we detect secondary peaks, 30 and 18 seconds after the initial peaks. The secondary peaks show a fast rise exponential decay-like shape resembling a thermonuclear X-ray burst. Time-resolved X-ray spectral analysis reveals that the peak flux, blackbody temperature, and apparent emitting radius values of the initial peaks are in agreement with X-ray bursts previously observed from 4U 1608-52, while the same values for the secondary peaks tend toward the lower end of the distribution of bursts observed from this source. The third X-ray burst, which happened during much lower accretion rates did not show any evidence for a deviation from an exponential decay and was significantly brighter than the previous bursts. We present the properties of the secondary peaks and discuss the events within the framework of short recurrence time bursts or bursts with secondary peaks. We find that the current observations do not fit in standard scenarios and challenge our understanding of flame spreading.Comment: Accepted for publication in the Astrophysical Journa

Design, Synthesis, Characterization, and Evaluation of the Anti-HT-29 Colorectal Cell Line Activity of Novel 8-Oxyquinolinate-Platinum(II)-Loaded Nanostructured Lipid Carriers Targeted with Riboflavin

Colorectal cancer is occasionally called colon or rectal cancer, depending on where cancer begins to form, and is the second leading cause of cancer death among both men and women. The platinum-based [PtCl(8-O-quinolinate)(dmso)] (8-QO-Pt) compound has demonstrated encouraging anticancer activity. Three different systems of 8-QO-Pt-encapsulated nanostructured lipid carriers (NLCs) with riboflavin (RFV) were investigated. NLCs of myristyl myristate were synthesized by ultrasonication in the presence of RFV. RFV-decorated nanoparticles displayed a spherical shape and a narrow size dispersion in the range of 144–175 nm mean particle diameter. The 8-QO-Pt-loaded formulations of NLC/RFV with more than 70% encapsulation efficiency showed sustained in vitro release for 24 h. Cytotoxicity, cell uptake, and apoptosis were evaluated in the HT-29 human colorectal adenocarcinoma cell line. The results revealed that 8-QO-Pt-loaded formulations of NLC/RFV showed higher cytotoxicity than the free 8-QO-Pt compound at 5.0 M. All three systems exhibited different levels of cellular internalization. Moreover, the hemotoxicity assay showed the safety profile of the formulations (less than 3.7%). Taken together, RFV-targeted NLC systems for drug delivery have been investigated for the first time in our study and the results are promising for the future of chemotherapy in colon cancer treatment.Centro de Investigación y Desarrollo en Fermentaciones IndustrialesLaboratorio de Investigación y Desarrollo de BioactivosCentro de Química InorgánicaInstituto de Genética Veterinari

Investigation of the influence of high glucose on molecular and genetic responses: an in vitro study using a human intestine model

Abstract Background Dietary glucose consumption has increased worldwide. Long-term high glucose intake contributes to the development of obesity and type 2 diabetes mellitus (T2DM). Obese people tend to eat glucose-containing foods, which can lead to an addiction to glucose, increased glucose levels in the blood and intestine lumen, and exposure of intestinal enterocytes to high dietary glucose. Recent studies have documented a role for enterocytes in glucose sensing. However, the molecular and genetic relationship between high glucose levels and intestinal enterocytes has not been determined. We aimed to identify relevant target genes and molecular pathways regulated by high glucose in a well-established in vitro epithelial cell culture model of the human intestinal system (Caco-2 cells). Methods Cells were grown in a medium containing 5.5 and 25 mM glucose in a bicameral culture system for 21 days to mimic the human intestine. Transepithelial electrical resistance was used to control monolayer formation and polarization of the cells. Total RNA was isolated, and genome-wide mRNA expression profiles were determined. Molecular pathways were analyzed using the DAVID bioinformatics program. Gene expression levels were confirmed by quantitative reverse transcription polymerase chain reaction (RT-qPCR). Results Microarray gene expression data demonstrated that 679 genes (297 upregulated, 382 downregulated) were affected by high glucose treatment. Bioinformatics analysis indicated that intracellular protein export (p = 0.0069) and ubiquitin-mediated proteolysis (p = 0.024) pathways were induced, whereas glycolysis/gluconeogenesis (p < 0.0001), pentose phosphate (p = 0.0043), and fructose-mannose metabolism (p = 0.013) pathways were downregulated, in response to high glucose. Microarray analysis of gene expression showed that high glucose significantly induced mRNA expression levels of thioredoxin-interacting protein (TXNIP, p = 0.0001) and lipocalin 15 (LCN15, p = 0.0016) and reduced those of ATP-binding cassette, sub-family A member 1 (ABCA1, p = 0.0004), and iroquois homeobox 3 (IRX3, p = 0.0001). Conclusions To our knowledge, this is the first investigation of high glucose-regulated molecular responses in an intestinal enterocyte model. Our findings identify new target genes that may be important in the intestinal glucose absorption and metabolism during high glucose consumption

Additional file 2: of Investigation of the influence of high glucose on molecular and genetic responses: an in vitro study using a human intestine model

Table S2. The list of the significantly downregulated genes under high glucose treatment condition (382 genes). (XLSX 89 kb

Additional file 8: of Investigation of the influence of high glucose on molecular and genetic responses: an in vitro study using a human intestine model

Figure S5. Fructose and Mannose Metabolism Pathway (Downregulated). (TIFF 857 kb

Additional file 4: of Investigation of the influence of high glucose on molecular and genetic responses: an in vitro study using a human intestine model

Figure S1. Ubiquitin mediated proteolysis Pathway (Upregulated). (TIFF 497 kb

Additional file 5: of Investigation of the influence of high glucose on molecular and genetic responses: an in vitro study using a human intestine model

Figure S2. Intracellular protein export pathway (Upregulated). (TIFF 872 kb