Study of the Experimental Conditions and Mechanisms for Diclofenac Loading in Functionalized Magnetic Nanoparticles

Magnetic nanoparticles (MNPs) composed of magnetite coated with oleic acid and functionalized with chitosan have been prepared to the targeted release of the non steroidal anti-inflammatory drug (NSAID) Diclofenac. Two procedures to incorporate the drug were explored: simple adsorption and covalent linkage. The impact of experimental variables such as the nature of the NSAID (commercial versus analytical sodium Diclofenac), its concentration and amount of coupling agent were evaluated in terms of the loading efficiency and the properties of interest of MNPs (size, surface functionality, stability). Loaded and unloaded MNPs were characterized by FTIR-DRIFTS spectroscopy, dynamic light scattering, zeta potential and transmission electron microscopy. UV-visible quantification of Diclofenac was achieved reaching values of loading efficiency between 11 and 27% depending on the experimental conditions. Probable mechanisms for drug-MNPs interactions have been proposed on the base of characterization data. A nanocarrier of size lower than 150 nm, with satisfactory loading skill and high dispersion capability on water was obtained. The release behavior demonstrated to be independent on the presence of an external magnetic field. The properties found in these nanosystems result relevant in view of their effective in vivo implementation.Fil: Agotegaray, Mariela Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur; ArgentinaFil: Lassalle, Verónica Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur; Argentin

Novel hydroxyapatite-biomass nanocomposites for fluoride adsorption

Hydroxyapatite-biomass nanocomposite (HAp-C) was successfully synthesized through a combined ultrasonic/hydrothermal one-pot method and used as a novel adsorbent to remove fluoride ions from groundwater. The obtained HAp-C composite was entirely characterized by TG, FTIR, XRD, SEM, and TEM. The point of zero charge was determined by the drift method. It was found that the HAp partially coats the lignocellulosic matrix. XRD data suggested that biomass incorporation did not affect the crystalline structure of the HAp. FTIR analysis suggests that the bond between hydroxyapatite and biomass is given by coordinating links. The fluoride adsorption on HAp-C was tested through batch assays using model solutions. The effect of contact time, initial fluoride concentration, sorbent dose, pH, and co-existing species on the adsorption capacity was investigated. The results showed that fluoride adsorption capacity increased with contact time and initial fluoride concentration, decreasing with increasing sorbent dose. The maximum experimental adsorption capacity was 10.9 mg F− g−1 at the maximum concentration tested in this work (80 mg L−1). The pH variation (4.5–8.5) did not significantly affect the adsorption efficiency of the nanocomposite (∼90%), while the presence of co-existing species significantly decreased its removal efficiency (∼80%). The fluoride adsorption could be fitted by the Freundlich isotherm, and the adsorption kinetic data followed the pseudo-second-order model. Besides, adsorption assays were replicated using natural groundwater samples from a rural region of the southern Chaco-Pampean plain (Villarino, Buenos Aires, Argentina), registering up to 77.4% removal, reaching a fluoride concentration value (1.16 mg L−1) within the permitted limits.Fil: Scheverin, Verónica Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Horst, María Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Lassalle, Verónica Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentin

A review of magnetic separation of whey proteins and potential application to whey proteins recovery, isolation and utilization

Cheese whey (CW) is a voluminous effluent generatin environmental and economic impact in milk producing countries. Proteins from CW are useful for biotechnological applications. Available procedures to purify CW are complex and expensive. Magnetic nanotechnology emerges as an alternative to attain this goal. Magnetic nanoparticles are easily and economically prepared and can be formulated to selectively bind proteins in whey. Magnetic decantation allows simple and fast protein isolation by means of a magnet. The extra advantage is the possibility to regenerate and reuse the magnetic material in successive cycles. In this contribution, competitiveness of magnetic nanodevices is reviewed as a potential tool for the valorisation and remediation of milk industry wastes. A critical analysis of recompiled data is included comparing magnetic nanomaterials with the current technologies intended for CW treatments. The purpose is to determine the most important factors that carry towards an effective recovery of proteins for diverse applications.Fil: Nicolás, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Ferreira, María Luján. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Lassalle, Verónica Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentin

A Magnetic Hydrochar Nanocomposite as a Potential Adsorbent of Emerging Pollutants

Water pollution is of worldwide concern due to its importance as an essential resource for life. Industrial and urbanistic growth are anthropogenic activities that have caused an increase of undesirable compounds in water. In the last decade, emerging pollutants have become of great interest since, at very low concentrations (µg/L and ng/L), they exhibit a hazardous effect on wildlife, aquatic ecosystems, and human organisms. One group of emerging pollutants that are a matter of study are pharmaceuticals. Their high consumption rate and their inappropriate disposal have led to their detection in wastewater treatment plant influent, effluent, surface water, and drinking water. In consequence, numerous technologies have been developed to efficiently treat these pollutants. Adsorption appears as an easy and cost-effective technology. One of the most used adsorbents of emerging pollutants removal are carbonbased materials such as hydrochars. This study aims to use a magnetic hydrochar nanocomposite to be employed as an adsorbent for diclofenac removal. Kinetics models and the adsorption efficiency in real water samples were analyzed. For this purpose, a magnetic hydrochar nanocomposite was synthesized through the hydrothermal carbonization (HTC) technique hybridized to co-precipitation to add the magnetic component into the hydrochar, based on iron oxide nanoparticles. The hydrochar was obtained from sunflower husk residue as the precursor. TEM, TGA, FTIR, Zeta potential as a function of pH, DLS, BET technique, and elemental analysis were employed to characterize the material in terms of composition and chemical structure. Adsorption kinetics were carried out in distilled water and real water at room temperature, pH of 5.5 for distilled water and natural pH for real water samples, 1:1 adsorbent: adsorbate dosage ratio, contact times from 10-120 minutes, and 50% dosage concentration of DCF. Results have demonstrated that magnetic hydrochar presents superparamagnetic properties with a saturation magnetization value of 55.28 emu/g. Besides, it is mesoporous with a surface area of 55.52 m2/g. It is composed of magnetite nanoparticles incorporated into the hydrochar matrix as can be proven by TEM micrographs, FTIR spectra, and zeta potential. On the other hand, kinetic studies were carried out using DCF models finding percent removal efficiencies up to 85.34% after 80 minutes of contact time. In addition, after 120 minutes of contact time, desorption of emerging pollutants from active sites took place which indicated that the material got saturated after that t time. In real water samples, percent removal efficiencies decrease up to 57.39%, ascribable to a possible mechanism of competitive adsorption of organic or inorganic compounds, ions for active sites of the magnetic hydrochar. The main suggested adsorption mechanism between the magnetic hydrochar and diclofenac include hydrophobic and electrostatic interactions as well as hydrogen bonds. It can be concluded that the magnetic hydrochar nanocomposite could be valorized into a by-product which appears as an efficient adsorbent for DCF removal as a model emerging pollutant. These results are being complemented by modifying experimental variables such as pollutant’s initial concentration, adsorbent: adsorbate dosage ratio, and temperature. Currently, adsorption assays of other emerging pollutants are being been carried out.Fil: Burbano Patiño, Aura Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Horst, María Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Lassalle, Verónica Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Agotegaray, Mariela Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaInternational Conference on Hazardous Waste Management and Water Treatment ICHWMWTVeneciaItaliaWorld Academy of Science, Engineering and Technolog

Fabrication of ferrogels using different magnetic nanoparticles and their performance on protein adsorption

Magnetic biomaterials were prepared using magnetite and chitosan-coated magnetite nanoparticles (CSNPs) dispersed in poly(vinyl alcohol) gels. Two different methods were developed to obtain ferrogels: in situ co-precipitation of magnetite (Ferro-IS) and by adding previously synthesized CSNPs to the neat matrix (Ferro-CSNPs). In both cases, the crosslinking was carried out by freezing −thawing (F-T). The as-prepared materials as well as precursor CSNPs were characterized by Fourier transform infrared spectroscopy, electronic microscopy (scanning and transmission), X-ray diffraction, ζ potential, dynamic light scattering, thermogravimetric analysis, differential scanning calorimetry and magnetic properties. The performance of these gels as protein adsorbents was evaluated. Batch adsorption experiments were carried out using bovine serum albumin (BSA) as a model. Substantially different adsorption behaviour was found using Ferro-IS and Ferro-CSNPs. This was assigned to dissimilar bonding mechanisms of BSA to the ferrogel matrix. Hence, biomaterials potentially useful in drug delivery as well as in protein purification fields may be prepared by a relatively simple, non-toxic and low cost method.Fil: Gonzalez, Jimena Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación en Ciencia y Tecnología de Materiales (i); ArgentinaFil: Nicolás, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; ArgentinaFil: Ferreira, Maria Lujan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Planta Piloto de Ingeniería Química (i); ArgentinaFil: Avena, Marcelo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; ArgentinaFil: Lassalle, Verónica Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; ArgentinaFil: Alvarez, Vera Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación en Ciencia y Tecnología de Materiales (i); Argentin

Coronavirus and Herpes simplex virus type 1 stability in surgical masks and gowns

Introducción: Durante la actual pandemia de COVID-19 han surgido muchas controversias e interrogantes respecto de la persistencia de la actividad viral en distintas superficies. Para el área de salud, ha sido un gran desafío lograr optimizar los usos de equipos de protección personal (EPP), teniendo en cuenta la incertidumbre acerca de la estabilidad de las partículas virales sobre distintas superficies. Objetivos: Analizar la estabilidad viral en barbijos quirúrgicos y batas descartables. Materiales y métodos: Se emplearon barbijos quirúrgicos tricapa comerciales y batas aprobados por ANMAT a los cuales se los inoculó artificialmente con cantidades definidas de virus herpes simplex tipo I (HSV-1) y de coronavirus bovino (BCoV) en condiciones ambientales estrictamente establecidas, o se los expuso a pacientes COVID positivos para luego evaluar la infectividad viral residual o remanente mediante la técnica de UFP (unidad formadora de placa) y por la aparición de ECP (efecto citopático) en cultivos celulares infectados con el virus residual. Resultados: El tiempo de inactivación fue dependiente de la dosis infectiva inicial; para las dosis máximas estudiadas, los virus inoculados artificialmente permanecen viables hasta 72 horas, sin embargo, en la bata expuesta a pacientes COVID positivo, no se pudo recuperar la actividad viral luego de las 16 horas. Conclusiones: El tiempo de inactivación viral depende de la dosis infectiva inicial bajo las mismas condiciones ambientales. Mientras más alta es la dosis infectiva, más tiempo tardará en inactivarse el inóculo. Con dosis superiores a las esperadas naturalmente, el tiempo de inactivación de la actividad viral es de 72 horas.Introduction. During the current COVID-19 pandemic, many controversies and questions have arisen regarding the persistence of viral activity on different surfaces. In particular, for the health area, it has been a great challenge to optimize the uses of the personal protective equipment, even more so taking into account the uncertainty about the stability of viral particles on different surfaces. Objectives. To analyze viral stability in surgical masks and disposable gowns. Materials and methods. Commercial three-layer surgical masks and gowns approved by the Argentine Agency of Medicines, Food and Medical Technology (ANMAT) were artificially inoculated with defined amounts of herpes simplex virus type I (HSV-1) and bovine coronavirus (BCoV) under strictly established environmental conditions, or exposed to COVID-positive patients. Then, residual or remnant viral infectivity was evaluated using the PFU technique and by the appearance of cytopathic effects in cell cultures infected with residual virus. Results. The inactivation time was dependent on the initial infective dose. For the maximum doses studied, the artificially inoculated viruses remained viable for up to 72 hours. However, in the gowns exposed to COVID-positive patients, no viral activity was recovered after 4 h. Conclusions. Under the same environmental conditions, the viral inactivation time depends on the initial infective dose. The higher the infective dose, the longer it will take for the inoculum to become inactivated. With doses higher than those naturally expected, the inactivation time of viral activity is 72 hours.Fil: Ayala Peña, Victoria Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Scolaro, Luis Alberto. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Alvarez, Vera 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: Lassalle, Verónica Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentin

Coronavirus and Herpes simplex virus type 1 stability in surgical masks and gowns

Introducción: Durante la actual pandemia de COVID-19 han surgido muchas controversias e interrogantes respecto de la persistencia de la actividad viral en distintas superficies. Para el área de salud, ha sido un gran desafío lograr optimizar los usos de equipos de protección personal (EPP), teniendo en cuenta la incertidumbre acerca de la estabilidad de las partículas virales sobre distintas superficies. Objetivos: Analizar la estabilidad viral en barbijos quirúrgicos y batas descartables. Materiales y métodos: Se emplearon barbijos quirúrgicos tricapa comerciales y batas aprobados por ANMAT a los cuales se los inoculó artificialmente con cantidades definidas de virus herpes simplex tipo I (HSV-1) y de coronavirus bovino (BCoV) en condiciones ambientales estrictamente establecidas, o se los expuso a pacientes COVID positivos para luego evaluar la infectividad viral residual o remanente mediante la técnica de UFP (unidad formadora de placa) y por la aparición de ECP (efecto citopático) en cultivos celulares infectados con el virus residual. Resultados: El tiempo de inactivación fue dependiente de la dosis infectiva inicial; para las dosis máximas estudiadas, los virus inoculados artificialmente permanecen viables hasta 72 horas, sin embargo, en la bata expuesta a pacientes COVID positivo, no se pudo recuperar la actividad viral luego de las 16 horas. Conclusiones: El tiempo de inactivación viral depende de la dosis infectiva inicial bajo las mismas condiciones ambientales. Mientras más alta es la dosis infectiva, más tiempo tardará en inactivarse el inóculo. Con dosis superiores a las esperadas naturalmente, el tiempo de inactivación de la actividad viral es de 72 horas.Introduction. During the current COVID-19 pandemic, many controversies and questions have arisen regarding the persistence of viral activity on different surfaces. In particular, for the health area, it has been a great challenge to optimize the uses of the personal protective equipment, even more so taking into account the uncertainty about the stability of viral particles on different surfaces. Objectives. To analyze viral stability in surgical masks and disposable gowns. Materials and methods. Commercial three-layer surgical masks and gowns approved by the Argentine Agency of Medicines, Food and Medical Technology (ANMAT) were artificially inoculated with defined amounts of herpes simplex virus type I (HSV-1) and bovine coronavirus (BCoV) under strictly established environmental conditions, or exposed to COVID-positive patients. Then, residual or remnant viral infectivity was evaluated using the PFU technique and by the appearance of cytopathic effects in cell cultures infected with residual virus. Results. The inactivation time was dependent on the initial infective dose. For the maximum doses studied, the artificially inoculated viruses remained viable for up to 72 hours. However, in the gowns exposed to COVID-positive patients, no viral activity was recovered after 4 h. Conclusions. Under the same environmental conditions, the viral inactivation time depends on the initial infective dose. The higher the infective dose, the longer it will take for the inoculum to become inactivated. With doses higher than those naturally expected, the inactivation time of viral activity is 72 hours.Fil: Ayala Peña, Victoria Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Scolaro, Luis Alberto. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Alvarez, Vera 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: Lassalle, Verónica Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentin

Biomedical Applications of Iron Oxide Nanoparticles: Current Insights Progress and Perspectives

The enormous development of nanomaterials technology and the immediate response of many areas of science, research, and practice to their possible application has led to the publication of thousands of scientific papers, books, and reports. This vast amount of information requires careful classification and order, especially for specifically targeted practical needs. Therefore, the present review aims to summarize to some extent the role of iron oxide nanoparticles in biomedical research. Summarizing the fundamental properties of the magnetic iron oxide nanoparticles, the review’s next focus was to classify research studies related to applying these particles for cancer diagnostics and therapy (similar to photothermal therapy, hyperthermia), in nano theranostics, multimodal therapy. Special attention is paid to research studies dealing with the opportunities of combining different nanomaterials to achieve optimal systems for biomedical application. In this regard, original data about the synthesis and characterization of nanolipidic magnetic hybrid systems are included as an example. The last section of the review is dedicated to the capacities of magnetite-based magnetic nanoparticles for the management of oncological diseases.Fil: Montiel Schneider, María Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Martín, María Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Otarola, Jessica Johana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Vakarelska, Ekaterina. University of Sofia; BulgariaFil: Simeonov, Vasil. University of Sofia; BulgariaFil: Lassalle, Verónica Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Nedyalkova, Miroslava. University of Sofia; Bulgari

Nanotechnology in Veterinary Sciences: Magnetic nanosystems development based in fu

Las nanopartículas magnéticas (NPMs) a base de magnetita (Fe3O4) recubiertas con sílica encuentran diversas aplicaciones en el campo de la nanotecnología biomédica, debido a su estabilidad en medio acuoso. Sin embargo, la inercia de la sílica en cuanto a su reactividad limita la incorporación de funcionalizantes específicos como fármacos y otros ligandos de interés. El desafío de este trabajo se centra en obtener NPMs biocompatibles recubiertas con sílica y gelatina para ser aplicadas como agentes teranósticos en diversos campos biomédicos, incluso en medicina veterinaria. La terapia fotodinámica representa una alternativa y un complemento a la quimio y radioterapia, herramientas convencionales para el tratamiento de diferentes patologías como las oncológicas. Consiste en la utilización de moléculas fotosensibles que, al ser activadas con luz de una determinada longitud de onda, transfieren su exceso de energía a moléculas de oxígeno vecinas. Este fenómeno genera especies reactivas de oxígeno tóxicas para las células. De este modo, la incorporación de un agente fotosensible a las NPMs de sílica funcionalizadas con gelatina facilitaría su transporte específico hacia las células afectadas a partir del efecto de un campo magnético externo. Esto resultaría en un teranóstico funcional tanto para el diagnóstico (mediante RMI) como para el tratamiento (fototerapia). En este trabajo se exploraron diversas condiciones experimentales a partir de NPMs de magnetita recubierta con ácido cítrico y sílica para la deposición de gelatina a partir del método de co-precipitación. Se obtuvo una formulación óptima que fue caracterizada integralmente desde el punto de vista fisicoquímico. Como molécula fotosensible se seleccionó al azul de metileno (AM) y se exploraron dos vías para su incorporación a las NPMs: 1-adsorción simple durante 24 horas y 2-encapsulamiento. La evaluación de ambos procedimientos reveló la incorporación exitosa del agente fotosensible, obteniéndose nanosistemas magnéticos con potenciales propiedades teranósticas aplicables en el campo veterinario.Fil: Agotegarary, Mariela Alejandra. Universidad Nacional del Sur. Departamento de Química; ArgentinaFil: Andreocci, Emanuel. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Kudra, Duska. Universidad de Banka Luka; Bosnia y HerzegovinaFil: Montiel Schneider, María Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Lassalle, Verónica Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentin

Selective contrast agents with potential to the earlier detection of tumors: Insights on synthetic pathways, physicochemical properties and performance in MRI assays

Magnetic iron oxide nanoparticles (MNPs) have been prepared and stabilized with three organic acids (tartaric, malic and ascorbic) in order to obtain biocompatible and water dispersible MNPs with potential to bind specifically to tumoral cancer cells. An in deep characterization was performed aiming to verify the presence and effect of the coating and stabilizer on MNPs surface. Besides the mechanisms followed by the different acids to bind MNPs were elucidated and used to justify the differences in the physicochemical properties of each formulation. Data related to characterization revealed that MNPs coated with ascorbic acid (MNPs-AA) resulted the most suitable in terms of their size, surface charge and stability along the time. Besides, ascorbic acid may be recognized by GLUTs receptors that are overexpressed in several kinds of tumoral cells. Therefore, MNPs-AA was selected to explore its performance in both MRI and in vitro assays using human colon cancer cells HCT 116. MRI experiments were performed in clinical equipment using a series of aqueous dispersions of MNPs-AA that were evaluated as T2 contrast agent. The T2- weighted images obtained as well as the calculated r2, indicated that MNPs-AA could act as efficient T2 contrast agent for MRI. Regarding in vitro assays, MNPs-AA did not alter the cellular function neither exert cytotoxicity using the three explored doses. The internalization of the nanoparticles on the cellular structure was confirmed quanti and qualitatively using atomic absorption spectroscopy and Prussian blue techniques respectively. From these results, it emerges that ascorbic acid coated-magnetite nanoparticles may be used as alternative contrast agent to avoid or minimize some toxicological issues related to the widely used gadolinium.Instituto de Física La Plat