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Novel antiviral cotton fabrics impregnated with different formulations based on Chitosan (CH), citric acid (CA), and Copper (Cu) were developed. CA was selected as a CH crosslinker agent and Cu salts as enhancers of the polymer antimicrobial activity. The characterization of the polymeric-inorganic formulations was assessed by using atomic absorption spectroscopy, X-ray diffraction, Fourier transform infrared and UV–Vis spectroscopy, as well as thermogravimetric analysis. The achieved data revealed that CuO nanoparticles were formed by means of chitosan and citric acid in the reaction media. The antiviral activity of CH-based formulations against bovine alphaherpesvirus and bovine betacoronavirus was analyzed. Cotton fabrics were impregnated with the selected formulations and the antiviral properties of such textiles were examined before and after 5 to 10 washing cycles. Herpes simplex virus type 1 was selected to analyze the antiviral activities of the functionalized cotton fabrics. The resulting impregnated textiles exhibited integrated properties of good adhesion without substantially modifying their appearance and antiviral efficacy (~ 100%), which enabling to serve as a scalable biocidal layer in protective equipment’s by providing contact killing against pathogens. Thus, the results revealed a viable contribution to the design of functional-active materials based on a natural polymer such as chitosan. This proposal may be considered as a potential tool to inhibit the propagation and dissemination of enveloped viruses, including SARS-CoV-2. Supplementary Information The online version contains supplementary material available at 10.1007/s10904-021-02192-x.

PURPOSE: This study aimed to test the activity of Mn ferrite, hematin-Mn ferrite and colloidal maghemite in decomposition of Orange II (O-II) and Alizarin Red S (ARS) in model aqueous solutions. METHODS: Color removal was explored at room temperature using magnetic stirring with and without a magnetic bar, taking advantage of the solids’ magnetism. Decomposition of H(2)O(2) was also studied separately and as radicals provider in dye decomposition. Catalyst/dye solution was fixed at 10 mg/4 mL. pH and dye concentration were variable. Absorbance was measured during 120 min by UV-Vis. Reuse of catalysts was also performed. RESULTS: Azo dyes such as O-II are more resistant to oxidative removal using hydrogen peroxide than anthraquinone-like ARS. CITMD5 reduced ARS absorbance up to 71.9% when dye was less than 250 mg/L. HEM-Mn-MAG completely decolorized a 62.5 mg/L O-II solution at pH 11 while CITMD5 reached half of that conversion under the same conditions. The highest color removal in O-II/ARS mixtures was obtained with HEM-Mn-MAG, 40% absorbance reduction in 2 h. Mn-MAG is not active to remove O-II in presence of hydrogen peroxide in the 3–9 pH range at rt. CONCLUSIONS: The high activity of Mn-MAG in hydrogen peroxide decomposition may be assigned to the combination of Mn(+2)/Mn(+3) and Fe(+2)/Fe(+3), because the MnO(x) is active in the decomposition of hydrogen peroxide. Mn-MAG can be reused, preserving high activity in this reaction. Mn-based magnetic nanoparticles should be considered as inexpensive materials to treat textile wastewaters. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40201-021-00640-x.

Diclofenac is a commercial non-steroidal anti-inflammatory drug commonlypresent as a pollutant in naturally occurring water sources andwastewaters. In this work, the adsorption of diclofenac onto chitosancoatedmagnetic nanosystems is proposed as a possible tool for remediation.Experimental and theoretical studies have been carried out toreveal the mechanisms associated with diclofenac interactions among allthe components of the nanosystem. Mechanisms are presented, analyzedand discussed. A toxicological study in mice was carried out toevaluate the parameters associated with neurotoxicity of the nanodevice.The elucidation of the mechanisms implied in the adsorption process ofdiclofenac onto magnetic chitosan nanocomposites suggests that diclofenacremediation from water is possible by adsorption onto chitosan.The strategy innovates the commonly used methodologies for diclofenacremediation from pharmaceutical wastes. This magnetic nanotechnologywould not induce damage on the nervous system in a murine model, incase of traces remaining in water sources. Fil: 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; Argentina Fil: Gumilar, Fernanda Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; Argentina Fil: 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; Argentina Fil: 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; Argentina

The problem associated with water availability embodies a great challenge for scientists and the industrial sector. Groundwater appears as an interesting option to contribute to solving this problem. The natural occurrence of fluoride, among other contaminants, may restrict the widespread use of groundwater. Increasing efforts are dedicated to finding out novel, efficient, green, and low-cost technologies that can solve this inconvenience, being those based on adsorption the preferred ones. In this work, nanocomposites based on natural zeolite and magnetite were synthesized and subsequently superficially modified with aluminum and calcium cations. The main objective is to get surface specificity and functionality for fluoride removal from a real groundwater environment. The raw and modified materials were characterized, aiming to determine their physicochemical as well as stability properties. The crystalline pattern was analyzed by XRD; and the composition by atomic absorption spectroscopy. Besides, FTIR and zeta potential were assayed to identify the functional groups and the surface charge, respectively. Data suggested that surface modification did not affect the crystalline structure of constituent materials. Composition data and FTIR analysis allowed to verify only the aluminum incorporation. Zeta potential evidenced critical changes in modified materials. The adsorption performance of both raw materials and nanocomposites, were tested through batch assays using fluoride model solutions. The first did not show adsorption capacity. As a difference, the surface-modified nanocomposites demonstrated high efficiency, reaching around 90% of fluoride removal. Besides, adsorption assays were replicated employing real groundwater samples from Bahia Blanca (Buenos Aires, Argentina) rural region, achieving greatly satisfactory results when the surface-modified nanocomposites were tested.

Gelatin based hydrogels were synthesized by the thawing-freezing method employing gum Arabic as crosslinking agent. The incorporation of cellulose nanowhiskers (NC) was analyzed aiming to reach a control over the solubility/degradation rate, swelling properties and their ability to load anaesthetic drugs. Three concentrations of NC were explored, i.e: 1, 2 and 5%w/w with respect to the gelatin mass. The raw and NC containing hydrogels were well characterized in terms of the main properties regarding the intended application. Hence the swelling behaviour, solubility rate, gel fraction were determined as well as their thermal, morphological and rheological properties. In this work, the obtained biocompatible hydrogels have tested for their potential application in the lidocaine administration during dental practices. This drug has been taken as model between other potential therapeutic agents for buccal treatments such as antibiotics, analgesics, etc. The kinetic and mechanism of LID release were studied by means of available mathematical models. The hydrogels loaded LID here presented would be considered as potential raw materials to the fabrication of buccal patches in order to avoid, or at least minimize, the extensive use of injected anaesthesia during dental treatments. Fil: Favatela, María Florencia. 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; Argentina. Universidad Nacional del Sur. Departamento de Química; Argentina Fil: 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; Argentina. Universidad Nacional del Sur. Departamento de Química; Argentina Fil: Bracone, Melina Ethel. 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; Argentina Fil: Gonzalez, Jimena Soledad. 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; Argentina Fil: Alvarez, María Victoria. 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; Argentina Fil: 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; Argentina. Universidad Nacional del Sur. Departamento de Química; Argentina

Wastewater produced by the anthropogenic activity (agricultural, industrial, etc.) leads to a great variety of dangerous pollutants as dyes, heavy metals, hydrocarbons, nutrients, arsenic, and medical wastes that must be treated before threatening life and the ecosystem. Between many technologies pursuing that goal, adsorption phenomena and its combination with other methodologies have turned in one of the preferred strategies to assess the wastewater remediation. This procedure involves a solid–liquid interface being efficient, low cost, and highly versatile to assess the remediation of diverse media by eliminating pollutants of different chemical nature. Likely important is the use of nontoxic adsorbents, for obvious reasons. Fortunately, a number of biomaterials based on polysaccharides are actually employed or investigated as potential adsorbent material to cleanup wastewater. For instance, cationic polysaccharides as chitosan; anionic as alginates, pectin, carrageenans, Gellan, gum arabic, and Xanthan; and neutral as amylopectin, cellulose, and guar gum find interesting properties to provide a solution to specific environmental problems. Their behavior and efficiency commonly derive from the kind of interactions that may have with the pollutants. Besides, the combination of such biopolymers with other moieties (organic or inorganic) expands their practical possibilities increasing their efficiency. This chapter deals with the most recent advances in the application of polysaccharides in the field of water remediation with special emphasis on the relation between kind of polymer and the specific contaminant that may eliminate from aqueous media. This focus includes the investigation regarding composites materials prepared from polysaccharides and diverse compounds to improve their adsorption or even remediation properties. Finally, a section regarding the emergent contaminants and the potential role of polysaccharides in their elimination is included as a topic that continuously grows in interest and updates.

People with weakened immune systems are at risk of developing candidiasis which is a fungal infection caused by several species of Candida genus. In this work, polymeric nanoparticles containing miconazole nitrate and the anesthetic lidocaine clorhydrate were developed. Miconazole was chosen as a typical drug to treat buccopharyngeal candidiasis whereas lidocaine may be useful in the management of the pain burning, and pruritus caused by the infection. Nanoparticles were synthesized using chitosan and gelatin at different ratios ranging from 10:90 to 90:10. The nano-systems presented nanometric size (between 80 and 300 nm in water; with polydispersion index ranging from 0.120 to 0.596), and positive Z potential (between 20.11 and 37.12 mV). The determined encapsulation efficiency ranges from 65 to 99% or 34 to 91% for miconazole nitrate and lidocaine clorhydrate, respectively. X-ray diffraction and DSC analysis suggested that both drugs were in amorphous state in the nanoparticles. Finally, the systems fitted best the Korsmeyer-Peppas model showing that the release from the nanoparticles was through diffusion allowing a sustained release of both drugs and prolonged the activity of miconazole nitrate over time against Candida albicans for at least 24 h.

Colorectal cancer (CRC) is a major cause of cancer death with a high probability of treatment failure. Doxorubicin (DOXO) is an efficient antitumor drug; however, most CRC cells show resistance to its effects. Magnetic nanoparticles (MNPs) are potential cancer management tools that can serve as diagnostic agents and also can optimize and personalize treatments. This work aims to evaluate the aptitude of magnetic nanotheranostics composed of magnetite (Fe3O4) nanoparticles coated with folic acid intended to the sustained release of DOXO. The administration of DOXO by means of these MNPs resulted in the enhancement of cell death respect to the free drug administration. Chromatin compaction and cytoplasmic protrusions were observed. Mitochondrial transmembrane potential disruption and increased PARP protein cleavage confirmed apoptosis. The nanosystem was also tested as a vectoring tool by exposing it to the stimuli of a static magnetic field in vitro. CRC-related magnetic nanotechnology still remains in pre-clinical trials. In this context, this contribution expands the knowledge of the behavior of MNPs in contact with in vitro models and proposes the nanodevices studied here as potential theranostic agents for the monitoring of the progress of CRC and the evolution of its treatment.

Scientific and technological researches are devoted to obtain materials capable of retaining different kinds of pollutants, contributing to contamination solutions. In this context, hydrogels have emerged as great candidates because of their excellent absorption properties as well as good mechanical, thermal and chemical properties. More specifically, ferrogels (magnetic gels) present the extra advantage of being easily manipulated by a permanent magnet. Here, we present the results derived from the application of ferrogels as efficient tools to extract heavy metal pollutants from wastewater samples. The gels were prepared following the method of freezing and thawing of a polyvinyl alcohol aqueous solution with magnetic nanoparticles coated with polyacrylic acid. Ferrogels were fully characterized and their ability to retain Cu2+ and Cd2+, as model heavy metals, was studied. Thus kinetics and mechanisms of adsorption were evaluated and modeled. The concentration of MNPs on the PVA matrix was key to improve the adsorption capability (approximately the double of retention is improved by the MNPs addition). The adsorption kinetics was determined as pseudo-second order model, whereas the Langmuir model was the most appropriate to explain the behavior of the gels. Finally reuse ability was evaluated to determine the real potential of these materials, the ferrogels demonstrated high efficiency up to about five cycles, retaining about 80–90% of their initial adsorption capability. All the results indicated that the materials are promising candidates able to compete with the commercial technology regarding to water remediation. Fil: Areal, Maria Pia. Universidad Nacional de Mar del Plata; Argentina Fil: Arciniegas Vaca, Magda Lorena. 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; Argentina Fil: 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; Argentina Fil: 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; Argentina Fil: Sánchez, Francisco Homero. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina Fil: 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; Argentina Fil: Gonzalez, Jimena Soledad. 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; Argentina

Nanodevices based on magnetite functionalized with folic acid (FA) with improved properties to be employed as theranostics in various types of cancer are here proposed. Two methodologies for FA incorporation were explored aiming to reach suitable loading efficiency as well as adequate stability of nanosystems in physiological media. To this end, simple adsorption and covalent binding of FA and some experimental conditions derived from both procedures were studied. A thorough physicochemical characterization was performed using all the formulations. The mechanism of the interaction between FA and magnetite nanoparticles (MNPs) was elucidated from characterization results supported by theoretical studies using spin-polarized density functional theory (DFT). Both data coincide in that the selective functional group of FA (pteridine group) remained available after FA binding MNPs. Such studies also demonstrated that any of FA carboxylate groups could be available to potentially link other molecule (i.e therapeutic agents). Besides, other issues that are not normally accomplished in reported articles were included; i.e the stability according to two different criteria: size evolution (expressed as hydrodynamic diameter) as a function of time in aqueous media; and the capacity FA retention in PBS, pH = 7.4. Recovered data indicated that the samples are stable at least 15 days in water and 4 h in buffer without significant modifications of their properties. The feasibility of these formulations to interact with simulated physiological fluid was also assayed. The results revealed that protein corona was formed around all the tested formulations leading to more stable nanodevices in terms of their hydrodynamic sizes and size evolution along the time. To complete the theranostic characteristic, Doxorubicin was added to the MNPs@FA by physical adsorption, to provide the therapeutic function. The satisfactory incorporation was verified by FTIR spectroscopy. Fil: Azcona, Pamela Liliana. 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; Argentina Fil: López Corral, Ignacio. 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; Argentina Fil: 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; Argentina

A novel magnetic hydrochar composed of nanosized magnetite (Fe3O4) particles supported on a hydrochar matrix was synthesized via hydrothermal carbonization of sunflower husk, employing phosphoric acid as the activating agent. An exhaustive characterization of the hydrochars and the magnetic hydrochar was undertaken to identify, mainly, the mechanism by which the iron oxide nanoparticles interact with the hydrochar matrix. The magnetic hydrochar exhibited superparamagnetic properties with a saturation magnetization of 55,21 emu/g. BET surface area and pore diameter of the magnetic hydrochar were found to be 55.25 m2/g and 10,49 nm respectively which are in accordance with mesoporous materials. Fourier transform infrared spectroscopy and z potential characterization suggest that the main mechanisms of interaction between the magnetite nanoparticles and the hydrochar matrix were coulombic ones, where carboxyl and hydroxyl oxygen-containing functional groups of the hydrochar were more likely to interact with the iron oxide nanoparticles.

Efficient adsorbent ferrogels based on gelatin and dextrose was synthetized by using freeze-thawing technique. Two different methodologies of magnetic particles incorporation were developed. An exhaustive morphological and thermal characterization of hydro and ferrogels was achieved. The performance of ferrogel in water remediation was tested using Cd(II) as model contaminant. The adsorption ability was evaluated as a function of: pH, initial heavy metal concentration and contact time. The maximum adsorption capacity was 35 mg of Cd(II)/g of adsorbent. Ferrogel was regenerated by washing with distilled water, maintaining efficiency of almost 30% after the fourth cycle Fil: 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; Argentina Fil: Ninago, Mario Daniel. 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; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Química; Argentina Fil: 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; Argentina

Two types of bentonites were modified using a cleaner method to prepare aluminum-pillared clays. This methodology involved a purifying stage, an intercalation process, and a microwave irradiation step at low energy power. Structural changes induced by pillaring process were demonstrated by thermal behavior, as well as morphological characterization. The effect of pillaring process on thermal stability of clays was studied, and the mass lost associated with the dehydroxylation of the octahedral clay sheets was not detected for modified bentonites. In addition, an analysis of their chemical composition and crystalline structure was also performed. Concerning industrial applications of these bentonites, two potential uses were proposed: (1) as reinforcement of different polymers matrices such as thermoplastic starch (TPS), high-density polyethylene (HDPE), and poly (styrene-b-butadiene-b-styrene), SBS; and (2) as removal agent for cadmium (Cd) species present in wastewaters. Bentonite particles reinforced thermoplastic starch matrix and increased ultraviolet barrier capacity of HDPE composites. Besides, bentonites improved the mechanical performance and modified barrier properties of SBS. Regarding effluents purification, an adequate Cd adsorption from aqueous solutions was observed (77%), proving their feasibility to be used as non-conventional removal agents.

Colorectal cancer (CRC) remains a leading cause of cancer death. Nanotechnology has focused on reaching more effective treatments. In this concern, magnetic nanoparticles (MNPs) have been studied for a wide range of biomedical applications related to CRC, such as diagnostic imaging, drug delivery and thermal therapy. However, limited research is currently found in the open literature that refers to nanosystems combining all these mentioned areas (theranostics). When developing nanosystems intended as theranostics applied to CRC, possible variations between patients must be considered. Therefore, multiple in vitro assays are required as guidance for future preclinical and clinical trials. The objective of this contribution is to evaluate the available and recent literature regarding the interactions of MNP and CRC models, aiming to critically analyze the information given by the commonly used assays and evaluate the data provided by each one with a view to implementing this novel technology in CRC diagnostics and therapy.

In this work, iron oxide-based magnetic nanoparticles (MNPs) stabilized by polyacrylic acid (PAA) polymer were prepared and characterized as a continuation of a previous research already reported. MNPs composed by pure magnetite cores having good magnetic properties were developed, thus achieving an improvement in the modified coprecipitation method used. The photocatalytic activity of the nanoparticles towards acid orange 7 (AO7), under both radiation types, UV-Vis and LED-Vis, was tested. Pollutant degradation percentages of 64 and 37 % were obtained by using UV-Vis and LED-Vis radiation, respectively. Fil: Sanchez, Laura Mabel. 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; Argentina Fil: Ochoa Rodríguez, Pablo Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Tecnología Química. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Tecnología Química; Argentina Fil: Actis, Daniel Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina Fil: Elías, Verónica Rita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Tecnología Química. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Tecnología Química; Argentina Fil: Eimer, Griselda Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Tecnología Química. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Tecnología Química; Argentina Fil: 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; Argentina Fil: 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; Argentina

Hydrogels (HGs) based on gelatin and crosslinked with gum Arabic have been prepared by the thaw–freezing method, employing two different concentrations of gum Arabic (15 and 50% w/w). Magnetic gels or ferrogels (FGs) were prepared by applying the breath in method to incorporate iron oxide magnetic nanoparticles to the HG matrix. The obtained HG and FG were characterized by XRD, FTIR, and SEM, and the FG composition was estimated by atomic absorption spectroscopy in terms of Fe content. The adsorption of crude oil onto HG and FG was explored achieving very satisfactory results. FG was regenerated by washing with toluene, maintaining efficiency of almost 90% after the fourth cycle. Equilibrium studies were performed to determine the capacity of the prepared FG for adsorption of crude oil from seawater synthetic solutions. The experiments were carried out as a function of different initial concentrations of oil residue (24 to 240 mg/L) exploring different contact times. Equilibrium data were found to fit very well with the Sips models. The kinetic data adsorption of oil onto the FG-15 was better fitted by a pseudo-second-order kinetic indicating that at the initial stages of adsorption, external mass transfer could control the whole rate of the crude oil uptake while intraparticle diffusion controlled the global rate of adsorption at later stages. The obtained results showed that the FG prepared by employing 15% of gum Arabic as the crosslinker (FG-15) has a high removal efficiency of crude oil reaching 1.53 g/g of FG at pH 5.5 and 0.59 g/g for oil/water emulsions in the order of 0.1 g/L. The magnetic properties extend its application. The reached data suggest that the materials presented here may be useful to further the design of systems or devices intended for the remediation of petroleum spills and/or its derivatives in marine water as well as other surfaces such as polluted rocks or soil. Fil: Scheverín, 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; Argentina Fil: Fossati, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; Argentina Fil: 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; Argentina Fil: 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; Argentina Fil: Jacobo, Silvia Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; Argentina

In this contribution, magnetite nanoparticles coated with citric acid and Cu2+ ions in different proportions were employed as adsorbents for removing proteins from cheese whey. Characterization included FTIR, Zeta potential measurements, hydrodynamic diameter determination and microscopy. Protein concentration in whey was reduced between 14 and 60% depending on the composition of the magnetic adsorbent. The protein-loaded particles were isolated by magnetic decantation and washed with NaCl to achieve protein desorption. 53% of adsorbed proteins could be recovered from Cu/citric acid/magnetite whereas only 24% was recovered from citric acid-magnetite using 2 M NaCl as eluent. Electrophoresis analysis revealed that the main protein in NaCl washing was β-lactoglobulin. Proteins were mostly covalently crosslinked onto citric acid/magnetite, while ionic interactions governed linking of proteins onto Cu/citric acid/magnetite, considering easiness of elution with NaCl. The materials herein developed emerge as an interesting alternative for both whey protein purification and β-lactoglobulin recovery. 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; Argentina Fil: 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; Argentina Fil: 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; Argentina

The role Beta-cyclodextrin (βCD) on improving biocompatibility on healthy cellular and animal models was studied upon a formulation obtained from the development of a simple coating procedure. The obtained nanosystems were thoroughly characterized by FTIR, TGA, atomic absorption spectroscopy, dynamic light scattering and zeta potential, TEM/HR-TEM and magnetic properties. βCD might interact with the magnetic core through hosting OA. It is feasible that the nanocomposite is formed by nanoparticles of MG@OA dispersed in a βCD matrix. The evaluation of βCD role on biocompatibility was performed on two healthy models. To this end, in vivo studies were carried out on Caenorhabditis elegans. Locomotion and progeny were evaluated after exposure animals to MG, MG@OA, and MG@OA-βCD (10 to 500 µg/mL). The influence of βCD on cytotoxicity was explored in vitro on healthy rat aortic endothelial cells, avoiding alteration in the results derived from the use of transformed cell lines. Biological studies demonstrated that βCD attaching improves MG biocompatibility. Fil: 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; Argentina Fil: Blanco, María Gabriela. 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; Argentina Fil: Campelo, Adrián Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; Argentina Fil: García, Elba Ana. 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; Argentina Fil: Zysler, Roberto Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro. Archivo Histórico del Centro Atómico Bariloche e Instituto Balseiro | Universidad Nacional de Cuyo. Instituto Balseiro. Archivo Histórico del Centro Atómico Bariloche e Instituto Balseiro.; Argentina Fil: Massheimer, Virginia Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; Argentina Fil: De Rosa, María José. 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; Argentina Fil: 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; Argentina

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; Argentina Fil: 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; Argentina Fil: 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; Argentina

The aim of this manuscript was to study the application of a new method of protein quantification in Candida antarctica lipase B commercial solutions. Error sources associated to the traditional Bradford technique were demonstrated. Eight biocatalysts based on C. antarctica lipase B (CALB) immobilized onto magnetite nanoparticles were used. Magnetite nanoparticles were coated with chitosan (CHIT) and modified with glutaraldehyde (GLUT) and aminopropyltriethoxysilane (APTS). Later, CALB was adsorbed on the modified support. The proposed novel protein quantification method included the determination of sulfur (from protein in CALB solution) by means of Atomic Emission by Inductive Coupling Plasma (AE-ICP). Four different protocols were applied combining AE-ICP and classical Bradford assays, besides Carbon, Hydrogen and Nitrogen (CHN) analysis. The calculated error in protein content using the "classic" Bradford method with bovine serum albumin as standard ranged from 400 to 1200% when protein in CALB solution was quantified. These errors were calculated considering as "true protein content values" the results of the amount of immobilized protein obtained with the improved method. The optimum quantification procedure involved the combination of Bradford method, ICP and CHN analysis.

Monodisperse magnetite nanoparticles (MNPs) with controlled sizes and shapes were prepared. The synthesis was carried out by traditional and inverted co-precipitation method with some modifications such as presence of visible light, room temperature and absence of inert atmosphere. Sodium dodecyl sulphate (SDS) was employed as stabilizer. The mentioned experimental parameters were conveniently adjusted to obtain suitable MNPs, to be efficiently employed in biomedical applications. In particular the size, shape, surface charge and magnetic properties were evaluated. MNPs were thoroughly characterized. From characterization data, it emerged that the inverted co-precipitation in presence of visible light rendered mainly nanorods. Modifying the SDS concentration the shape was tuned from nanorods to nanospheres and finally, at higher concentrations, nanocubes were obtained. All prepared formulations resulted hydrophilic. This property was justified in terms of the stabilization mechanism of SDS.Stability of MNPs aqueous dispersions was evaluated regarding to the variation of hydrodynamic diameter as a function of the time. In this regard, all the formulations resulted stable during, at least, 30 days. The prepared nanosystems exhibited satisfactory magnetic properties with saturation magnetization slightly lower than raw magnetite.The combination of size, shape, surface charge, hidrophilicity and magnetic behaviour make the magnetic nanosystems here obtained highly suitable and promising to diagnostic and therapeutic applications. Fil: Azcona, Pamela Liliana. 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; Argentina Fil: Zysler, Roberto Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina Fil: 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; Argentina

Magnetic nanotheranostics were designed from iron oxide nanoparticles functionalized with folic acid (FA) and loaded with doxorubicin (Doxo) as a therapeutic agent. The incorporation of Doxo was carefully examined to attain a satisfactory drug loading efficiency. The magnet-guiding ability was examined in vitro. To achieve this, a novel continuous flow system was fabricated to quantify the amount of MNPs retained in the magnet site in an environment and under conditions mimicking the bloodstream. The obtained data suggest that almost 21% of the total circulating nanoparticles accumulated in the target site after 45 min of assay. Such amount ensured the doses of Doxo commonly employed during in vivo studies. The release of Doxo was analysed by implementing an original procedure devoted to simulate the pathways followed by MNPs once intravenously administered. From these studies, reliable data on the amount of drug that effectively reached the target site were obtained. The efficiency of the nanosystems as selective contrast agents in MRI was analysed using clinical 1.5 T equipment. Their potential as T2 weighted contrast media was demonstrated. The data collected within this work appear as the former initial stage to validate the nanotheranostics before in vivo evaluation of this novel technology. Fil: Azcona, Pamela Liliana. 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; Argentina 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; Argentina Fil: Grunhut, Marcos. 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; Argentina Fil: 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; Argentina

Doxorubicin (DOXO) is a chemotherapeutic agent widely used for the treatment of solid tumors and hematologic malignancies in both adults and children. However, DOXO causes short- and long-term cardiotoxicity and others undesirable side effects, such as nephrotoxicity and neurotoxicity. Magnetic nanoparticles (MNPs) allow the delivery of drugs specifically to target place, employing an external magnet. Moreover, they may act as contrast agents in MRI providing information on the diagnostic of diverse pathologies. In this way, two functions may be combined in a unique nanosystem known as theranostic. Also, the MNPs can be modified with folic acid (MNPs@FA) to increase the uptake by cancer cells that overexpress the FA receptors. In previous works, our collaborators obtained and characterized MNPs, MNPs@FA, and MNPs@FA@DOXO. It is essential to study the biosafety of nanotheranostic, and there is no published study of Fe 3 O 4 nanoparticles developmental toxicity. Because of that, this work aimed to study the in vivo toxicity and biocompatibility of DOXO, MNPs@FA, and MNPs@FA@DOXO using zebrafish embryo and larvae as an animal model. Viability, developmental toxicity, changes in spontaneous movement (neurotoxicity), changes in cardiac rhythm (cardiotoxicity), and efficiency of DOXO-uptake were studied. While the 48-h treatment with 50 μg/mL of DOXO resulted in a 30% larvae death and the development of significant morphological abnormalities, the treatment with MNPs@FA@DOXO and MNPs@FA did not reduce the viability and did not cause developmental abnormalities. Besides, the MNPs@FA@DOXO reduced the cardiotoxicity and promoted a more rapid and significant uptake of DOXO by zebrafish larvae., Instituto Multidisciplinario de Biología Celular

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 Plata

Magnetic nanoparticles (MNPs), based on iron oxide (magnetite) and ferrogel of gelatin and MNPs, were employed as efficient tools for the removal of heavy metals and nutrients from water samples from Bahia Blanca estuarine (BBE). An exhaustive adsorption performance of Cu, NO3 −, and NO2 − was conducted in batch using model solutions aiming to adjust the adsorption conditions. Adsorption studies using water simulating the real samples were also performed. Both kinds of nanomaterials demonstrated an efficiency between 60 and 80%, and 85% for the removal of heavy metals and NO3 − and NO2 −, respectively. Similar adsorption assays were performed using BBE water samples, employing the experimental conditions explored with model and simulated water. The reached efficiency was 30 and 45% for heavy metal and nutrient removal, respectively, using nanoparticles; meanwhile, ferrogels displayed a removal capacity around 50?60%. The nanoparticles showed structural instability by the leaching of iron to the medium after the adsorption processes. Ferrogels remained almost inalterable in terms of their integrity during the adsorption time. These materials showed satisfactory perspectives regarding their reuse possibilities. They were used for almost five repeated cycles of adsorption without losing efficiency on the adsorption. The results of this study suggest that MNPs and FGs appear as versatile and promising materials that may be considered as valid alternatives to the actual tools for the remediation of real water samples. Fil: 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; Argentina Fil: Pizzano, Aldana. 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; Argentina Fil: Spetter, Carla Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Nacional del Sur. Departamento de Química; Argentina Fil: 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; Argentina

The immobilization of Candida antarctica lipase B (CALB) was carried out using glutaraldehyde (GLUT) and/or 3-aminopropyl-triethoxisilane (APTS). The aim of this work was to elucidate the role of these crosslinkers/functionalizers on the efficiency of the prepared nanosized catalysts in solvent-free oleic acid esterification.A series of biocatalysts were prepared in presence or absence of GLUT and APTS. The impact of the amount of initial CALB was also explored. An experimental design was utilized to study the variables that maximize biocatalyst activity.A strong dependence of enzymatic activity with the nominal amount of GLUT as well as the final protein/CALB loading was found. Nominal quantity of APTS did not affect catalyst́s activity when used in combination with GLUT. Additional studies demonstrated that stability during storage was mainly dependent on the enzyme loading. The optimum biocatalyst was reused 6 cycles without mass loss. Biocatalyst́s performance decreased with reuse. Mechanisms justifying these results were proposed.The role of GLUT and APTS on stability during storage and on differences between initial enzymatic activity and the performance in the reaction after two months was discussed. The problem of mixed interaction of CALB (covalent bonding plus simple adsorption) was carefully addressed to explain leaching of the lipaseLeaching and stability on storage should be included in the analysis of modifiers impact when support́s modifiers are used. The fresh and stored biocatalyst enzymatic activity has to be addressed looking at the practical aspects of implementation in technological settings. Fil: Nicolás, Paula. 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; Argentina Fil: 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; Argentina Fil: 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; Argentina

Cardiovascular complications derivate from atherosclerosis are the main cause of death in western world. An early detection of vulnerable atherosclerotic plaques is primordial for a better care of patients suffering the pathology. In this context nanotechnology has emerged as a promising tool to achieve this goal. Nanoparticles based on magnetic iron oxide (MNPs) have been extensively studied in cardiovascular diseases diagnosis, as well as in the treatment and diagnostic of other pathologies. The present review aims to describe and analyze the most current literature regarding to this topic, offering the level of detail required to reproduce the experimental tasks providing a critical input of the latest available reports. The current diagnostic features are presented and compared, highlighting their advantages and disadvantages. Information on novel technology intended to this purpose is also recompiled and in deep analyzed. Special emphasis is placed in magnetic nanotechnology, remarking the possibility to assess selective and multifunctional systems to the early detection of artherosclerotic pathologies. Finally, in view of the state of the art, the future perspectives about the trends on MNPs in artherosclerorsis diagnostic and treatment have also been addressed. 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; Argentina Fil: 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; Argentina

In this study, one–step co-precipitation method was conveniently adapted to obtain novel nanomaterials based on Gum Arabic and magnetite. Two synthesis procedures were evaluated: one employing the solid biopolymer in the co-precipitation media; a second using an aqueous solution of the polysaccharide. An exhaustive characterization of both formulations was performed using several specific techniques. The obtained data confirmed the successful incorporation of the gum Arabic on the magnetic core. Values of hydrodynamic diameters, measured by dynamic light scattering, in aqueous dispersions were about 70–80 nm, while sizes lower than 20 nm were registered by TEM microscopy. Surface charge of gum Arabic coated magnetic nanoparticles was significantly different from the corresponding to raw materials (magnetite and GA). This fact confirmed the formation of hybrid nanosystems with novel and specific properties. The potential utility of these materials was tested regarding to magnetic hyperthermia therapy under radiofrequency fields. Magnetocalorimetric measurements were performed in a wide range of field amplitude and frequency. Specific absorption rate of 218 W/gFe was determined at field frequency of 260 kHz and amplitude of 52 kA/m. These results demonstrate their viability to be applied in tumor ablation treatments. Using the linear response theory and restricting field parameters to the accepted biomedical window, maximum useful value of 74 w/gFe is predicted at 417 kHz and 12 kA/m. Fil: 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; Argentina Fil: Coral, Diego Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina Fil: Fernández van Raap, Marcela Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina Fil: Alvarez, Mariana. 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; Argentina Fil: 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; Argentina

A simple two-step drug encapsulation method was developed to obtain biocompatible magnetic nanocarriers for the potential targeted treatment of diverse diseases. The nanodevice consists of a magnetite core coated with chitosan (Chit@MNPs) as a platform for diclofenac (Dic) loading as a model drug (Dic-Chit@MNPs). Mechanistic and experimental conditions related to drug incorporation and quantification are further addressed. This multi-disciplinary study aims to elucidate the toxicological impact of the MNPs at hematological, vascular, neurological and behavioral levels. Blood compatibility assays revealed that MNPs did not affect either erythrosedimentation rates or erythrocyte integrity at the evaluated doses (1, 10 and 100 μg mL-1). A microscopic evaluation of blood smears indicated that MNPs did not induce morphological changes in blood cells. Platelet aggregation was not affected by MNPs either and just a slight diminution was observed with Dic-Chit@MNPs, an effect possibly due to diclofenac. The examined formulations did not exert cytotoxicity on rat aortic endothelial cells and no changes in cell viability or their capacity to synthesize NO were observed. Behavioral and functional nervous system parameters in a functional observational battery were assessed after a subacute treatment of mice with Chit@MNPs. The urine pools of the exposed group were decreased. Nephritis and an increased number of megakaryocytes in the spleen were observed in the histopathological studies. Sub-acute exposure to Chit@MNPs did not produce significant changes in the parameters used to evaluate neurobehavioral toxicity. The aspects focused on within this manuscript are relevant at the pre-clinical level providing new and novel knowledge concerning the biocompatibility of magnetic nanodevices for biomedical applications. Fil: 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; Argentina Fil: Campelo, Adrián Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; Argentina Fil: Zysler, Roberto Daniel. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina Fil: Gumilar, Fernanda Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; Argentina Fil: Bras, Cristina Liliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; Argentina Fil: Gandini, Norberto Ariel. 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; Argentina Fil: Minetti, A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; Argentina Fil: Massheimer, Virginia Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; Argentina Fil: 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; Argentina

Fil: Gonzalez, Jimena Soledad. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Mar del Plata. Instituto de Investigacion en Ciencia y Tecnologia de Materiales (i); Argentina

Biomedical applications of solid silica-coated magnetite nanoparticles are not highly reported in literature. Conventional biomedical uses are almost restricted to diagnostic issues. Other magnetic-silica materials such as mesoporous were last explored as target drug delivery.

Coating of magnetic nanoparticles is strongly required in order to obtain nanocarriers with suitable properties in terms of stability (low aggregation in aqueous media), surface functionality, and magnetism. Silica appears as an attractive compound to assess these goals. Among preventing aggregation, it is able to provide biocompatibility and the easy linkage of multiple ligands to specific applications.

Silicon dioxide, SiO2, is commonly known as silica. It may be found polymerized alone or in combination with other metals known as silicates.

The lack of enough knowledge about the biological impact of silica-coated magnetic nanoparticles makes these systems non well-explored devices. However, the potential they have in terms of biomedical applications is really huge. Therefore, several applications in medicine are waiting to be explored and developed for silica-coated magnetic nanoparticles.

Nanoparticles (NPs) with magnetic properties based on magnetite (Fe3O4, MAG) modified with oleic acid (OA), chitosan (CS) and bovine serum albumin (BSA) have been prepared. A versatile method of synthesis was employed, involving two steps: (i) co-precipitation of MAG; and (ii) nanoprecipitation of macromolecules on as-formed MAG NPs. Experimental variables have been explored to determine the set of conditions that ensure suitable properties of NPs in terms of their size, functionality and magnetic properties. It was found that the presence of OA in Fe+2/Fe+3 solutions yields MAG NPs with lower aggregation levels, while increasing initial amounts of OA may change the capability of NPs to disperse in aqueous or organic media by modifying the stabilization mechanism. Incorporation of CS was verified through Fourier transform IR spectroscopy. This biopolymer stabilizes NPs by electrostatic repulsions leading to stable ferrofluids and minimal fraction of recoverable solid NPs. BSA was successfully added to NP formulations, increasing their functionality and probably their biocompatibility. In this case too stable ferrofluids were obtained, where BSA acts as a polyelectrolyte. From the proposed methodology it is possible to achieve a wide range of NPs magnetically active intended for several applications. The required properties may be obtained by varying experimental conditions. Fil: Nicolás, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Planta Piloto de Ingeniería Química (i); Argentina. Universidad Nacional del Sur; Argentina Fil: Saleta, Martin Eduardo. Comisión Nacional de Energía Atómica. Gerencia del Area de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche); Argentina Fil: Troiani, Horacio Esteban. Comisión Nacional de Energía Atómica. Gerencia del Area de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche); Argentina Fil: Zysler, Roberto Daniel. Comisión Nacional de Energía Atómica. Gerencia del Area de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche); Argentina Fil: 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; Argentina Fil: Ferreira, Maria Lujan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Planta Piloto de Ingeniería Química (i); Argentina. Universidad Nacional del Sur; Argentina

Chitosan coating on magnetic nanoparticles (MNPs) was studied on biological systems as a first step toward the application in the biomedical field as drug-targeted nanosystems. Composition of MNPs consists of magnetite functionalized with oleic acid and coated with the biopolymer chitosan or glutaraldehyde-crosslinked chitosan. The influence of the biopolymeric coating has been evaluated by in vitro and in vivo assays on the effects of these MNPs on rat aortic endothelial cells (ECs) viability and on the random tissue distribution in mice. Results were correlated with the physicochemical properties of the nanoparticles. Nitric oxide (NO) production by ECs was determined, considering that endothelial NO represents one of the major markers of ECs function. Cell viability was studied by MTT assay. Different doses of the MNPs (1, 10 and 100 μg/mL) were assayed, revealing that MNPs coated with non-cross-linked chitosan for 6 and 24 h did not affect neither NO production nor cell viability. However, a significant decrease in cell viability was observed after 36 h treatment with the highest dose of this nanocarrier. It was also revealed that the presence and dose of glutaraldehyde in the MNPs structureimpact on the cytotoxicity. The study of the acute tissue distribution was performed acutely in mice after 24 h of an intraperitoneal injection of the MNPs and sub acutely, after 28 days of weekly administration. Both formulations greatly avoided the initial clearance by the reticuloendothelial system (RES) in liver. Biological properties found for N1 and N2 in the performed assays reveal that chitosan coating improves biocompatibility of MNPs turning these magnetic nanosystems as promising devices for targeted drug delivery. Fil: 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; Argentina Fil: Campelo, Adrián Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; Argentina Fil: Zysler, Roberto Daniel. Comision Nacional de Energía Atómica. Gerencia de Área Investigaciones y Aplicaciones no Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Física de Metales; Argentina Fil: Gumilar, Fernanda Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; Argentina Fil: Bras, Cristina Liliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; Argentina Fil: Minetti, Silvia Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; Argentina Fil: Massheimer, Virginia Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; Argentina Fil: 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; Argentina

The synthesis and characterization of biocatalysts based on lipase from Rhizomucor miehei (RML) immobilized on chitosan-based supports were investigated. The enzyme was immobilized on chitosan following two strategies: (i) physical adsorption; and (ii) covalent bonding using glutaraldehyde. The content of enzyme bound in the supports, as precipitable protein, was analyzed using UV/visible methods. FTIR-ATR spectroscopy was employed to characterize the prepared biocatalysts, as well the native enzyme and a commercial biocatalyst Lipozyme RM IM, used as reference materials. Analysis of the amide I′ signal allowed to follow the changes in the secondary structure of the enzyme after binding to the support and its thermal stability. The hydrolysis of ethyl stearate monitored in situ by FTIR-ATR was used as a test reaction. Results showed that RML was bound to Chit and Glut–Chit with minor changes in its secondary structure, thermal stability and enzymatic activity in a selected reaction test.

A simple and effective method is proposed to synthesize chitosan/magnetite (CS/MAG) and cellulose/magnetite (CEL/MAG) composites. Biopolymers were employed in bulk during the co-precipitation of magnetite, avoiding the problems associated to the polymer's solubility. FTIR and XRD analysis revealed that the polymeric template was perfectly integrated to the crystalline structure of magnetite. Measurements of zeta (Z) potential indicated that new materials present different charged surfaces depending on the biopolymer. SEM/TEM and dynamic light scattering (DLS) results demonstrated that particulated materials with average diameters lower than 1 μm were obtained. The magnetic properties of such composites were qualitatively verified. The as-obtained hybrids composites were tested for proteins adsorption using bovine serum albumin (BSA) and insulin (Ins) as models. It was found that CS/MAG was a better protein adsorbent than CEL/MAG. One important drawback of CEL/MAG was the lack of stability under the proteins adsorption conditions.

Background: Controlled release of medicaments from biodegradable polymers remains the most convenient way for their sustained release. Although a number of articles have been published, experimental work involving the preparation of polymer-based carriers and release procedures are not described with sufficient level of detail to allow other researchers to reproduce the experiments and to compare published results with their own. In this contribution the experimental background of the entrapment and release of insulin from PLGA carriers is described and the problems found at each step related to UV/Visible method used to quantify them are addressed in detail. Results: The quantification of entrapped insulin by UV/visible methods was affected by aggregation. The design of the release experiment influenced the results regarding the entrapment efficiency (EE) and the maximum percentage of released insulin. It was also found that the presence of colloidal polymeric particles, insufficient centrifugation times and the kind of solvent used in the release test might lead to mistakes in the percentage of liberated insulin when UV/visible based methods are employed. Conclusions: This contribution demonstrates that serious discrepancies in the EE and percentage of released protein may arise if some key experimental factors are not taken into account. Therefore, the analysis presented here tries to point out important aspects of this topic currently not reported, unnoticed or not properly analyzed in the open literature. The results are useful for the entrapment of any protein on any polymeric device using UV/visible based methods to quantify them. © 2009 Society of Chemical Industry. Fil: Lassalle, Verónica Leticia. 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; Argentina Fil: 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; Argentina

BACKGROUND: Enzymes have received increasing attention as biocatalysts. The poly(lactic) acid (PLA) has been widely employed in biomedical applications and PLA synthesis by a ‘green route’ is of particular interest. Here the aim is to prepare PLA using lipases, focusing on optimization of the procedure. The effects of the type and concentration of lipase, type of reaction, solvent, and time on the recovery of solid polyester, conversion rate and molecular weight have been explored. Pseudomonas cepacia (PCL), Porcine pancreatic lipase (PPL) and immobilized CAL‐B were used as biocatalysts. RESULTS: CAL‐B was the most effective biocatalyst, with 60% LA conversion and 55% recovered solid polymer; PCL and PPL gave rise to poor recovery of polymer. A novel thermal treatment was successfully employed to enhance the molecular weight Mn of PLA. CONCLUSIONS: This work offers a set of optimal conditions to synthesize PLA as a function of the lipase used. Information of this nature is currently not available in the literature, thus the findings here are a valuable tool for any researcher in this topic and a state‐of‐the‐art contribution in terms of the best biocatalyst and the best conditions for PLA synthesis. Copyright © 2008 Society of Chemical Industry Fil: 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; Argentina Fil: 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; Argentina

The controlled release of medicaments remains the most convenient way of drug delivery. Therefore, a wide variety of reports can be found in the open literature dealing with drug delivery systems. In particular, the use of nano- and microparticles devices has received special attention during the past two decades. PLA and its copolymers with GA and/or PEG appear as the preferred substrates to fabricate these devices. The methods of fabrication of these particles will be reviewed in this article, describing in detail the experimental variables associated with each one with regard to the influence of them on the performance of the particles as drug carriers. An analysis of the relationship between the method of preparation and the kind of drug to encapsulate is also included. Furthermore, certain issues involved in the addition of other monomeric substrates than lactic acid to the particles formulation as well as novel devices, other than nano- and microparticles, will be discussed in the present work considering the published literature available. © 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Fil: 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; Argentina Fil: 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; Argentina

Fil: Lassalle, Veronica Leticia. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Bahia Blanca. Planta Piloto de Ingenieria Quimica. Universidad Nacional del Sur. Planta Piloto de Ingenieria Quimica; Argentina

New magnetic devices consisting of magnetite functionalized with oleic acid and Chitosan have been synthesized and employed to the loading of Diclofenac as potential tool for treatment of targeted inflammatory diseases. Magnetic loaded and un-loaded nanoparticles have been thoroughly characterized by infrared spectroscopy, ransmission electron microscopy, determination of hydrodynamic diameter by Dynamic light scattering and zeta potential measurements at different pH conditions. A study of the release of Diclofenac has been performed in vitro and available mathematical models have been used to determine the release kinetic. Both properties and release data reveal that this nanomagnetic platform would be suitable for in vivo assays. Fil: 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; Argentina Fil: Palma, Santiago Daniel. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: 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; Argentina

Candida antarctica Lipase B was successfully immobilized on magnetite (Fe3O4) nanoparticles functionalized with chitosan and glutaraldehyde. The obtained magnetic catalyst was characterized and its performance was evaluated in solvent-free synthesis of ethyl oleate at room temperature. The performance of this biocatalyst was compared with the commercial Novozym 435, as a tool to estimate the efficiency of immobilization. It was found that using 33 mg of the biocatalyst it was possible to reach almost the same activity that was obtained using 12 mg of Novozym 435. Furthermore, this new biocatalyst presents the advantages of not being degraded by short alcohols, being easily recovered from the reaction media by magnetic decantation, and low fabrication cost. The possibility of reutilization was also studied, keeping a significant activity up to eight cycles. A special sampling protocol was also developed for the multiphasic reaction system, to assure accurate results. This novel biocatalyst is an interesting alternative for potential industrial applications, considering the above-mentioned advantages. Fil: Nicolás, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Planta Piloto de Ingeniería Química (i); Argentina. Universidad Nacional del Sur; Argentina Fil: 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; Argentina Fil: Ferreira, Maria Lujan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Planta Piloto de Ingeniería Química (i); Argentina. Universidad Nacional del Sur; Argentina

BACKGROUND: Drug delivery systems (DDS) were designed using insulin as model drug and poly (lactic-co-glycolic) copolymers (PLGA) as polymeric matrix. The carriers were synthesized by direct self-assembly of the insulin and the polyester under mild conditions. RESULTS: The kind and level of association between the protein and the polymer were studied using computational methods (combined MM2/PM3) and spectroscopic tools (Fourier transform infrared (FTIR), energy dispersive X-ray (EDX) and X-ray fluorescence spectroscopy (XFS)). The effect of the number average molecular weight (Mn) of the copolymer on the association efficiency (AE) drug-polymer as well as on the release profile has been explored. Mathematical models were used to predict the insulin release kinetic and mechanism. CONCLUSIONS: Satisfactory protein/PLGA association efficiencies (between 77 and 99%) were registered depending on the Mn of the PLGA. Hydrophobic and hydrophilic interactions were detected between the protein and the polymeric network by computational analysis. In vitro release studies demonstrated that copolyesters of about 8600 and 1500 Da were suitable for the gradual release of insulin while PLGA oligomers of average molecular weight between 700 and 800 Da were unsuitable as DDS. The insulin release kinetics fits well with the Korsmeyer model, following the anomalous transport mechanism. © 2010 Society of Chemical Industry. Fil: 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; Argentina Fil: 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; Argentina

The copolymerization of lactic and glycolic acid (PLGA) using Candida antarctica lipase B as biocatalyst has been achieved with the aim to generate useful biomedical materials. The influence of the reaction conditions, such as solvent and temperature, on the enzyme's catalytic activity was studied to optimize the synthetic procedure. The evaluated parameters were the conversion, the isolated PLGA and the number average molecular weight (M(n)). The identification and purity of the products were assessed by FTIR and NMR. The conversion was determined using analytical titration and the M(n) through end-group analysis. It was found that PLGA oligomers were obtained with satisfactory conversion levels when isopropyl ether was employed as solvent. The use of toluene increased the M(n) but decreased the isolated polyester. Higher percentages of recovered PLGA were reached increasing the temperature from 60 to 80 degrees C using toluene, while a reduction in the M(n) was evidenced under these conditions.

A styrene-butadiene-styrene (SBS) block co-polymer was functionalized using different amounts of N-carbamyl maleamic acid (NCMA) and benzoyl peroxide as initiator. NCMA, which is a bifunctional monomer, was synthesized in our laboratories. The concentration of NCMA used in the functionalization of SBS ranged from 0.5 to 3% (w/w) based on the co-polymer mass. Benzoyloxy radicals generated from the thermal decomposition of benzoyl peroxide initiated the grafting reaction. The concentration of the initiator was kept constant at 0.076% (w/w). FT-IR spectroscopy was used to determine the amount of NCMA effectively grafted onto the SBS. The maximum amount of monomer grafted was about 0.3% (w/w) when the SBS was modified with 1% (w/w) NCMA. The effect of grafting on the surface properties and the adhesion to polyurethane adhesive of the modified SBS were evaluated. Contact angle values were obtained using liquid droplets. When the concentration of the NCMA used in the grafting reaction was 1% (w/w), the contact angles with water on original and modified SBS were 95° and 77°, respectively. Adhesion properties were evaluated by standard peel tests employing a commercial polyurethane adhesive. The modified SBS having the largest amount of NCMA displayed a T-peel strength value 5-times higher than the corresponding value measured with the original SBS. Fil: Lassalle, Verónica Leticia. 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; Argentina Fil: Failla, Marcelo Daniel. 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; Argentina Fil: Valles, Enrique Marcelo. 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; Argentina Fil: Martín Martínez, José Miguel. Universidad de Alicante; España

In this work, the issue on whether dynamic magnetic properties of polydispersed magnetic colloids modeled using physical magnitudes derived from quasi-static magnetic measurement can be extrapolated to analyze specific absorption rate data acquired at high amplitudes and frequencies of excitation fields is addressed. To this end, we have analyzed two colloids of magnetite nanoparticles coated with oleic acid and chitosan in water displaying, under a radiofrequency field, high and low specific heat power release. Both colloids are alike in terms of liquid carrier, surfactant and magnetic phase composition but differ on the nanoparticle structuring. The colloid displaying low specific dissipation consists of spaced magnetic nanoparticles of mean size around 4.8 nm inside a large chitosan particle of 52.5 nm. The one displaying high specific dissipation consists of clusters of magnetic nanoparticles of mean size around 9.7 nm inside a chitosan particle of 48.6 nm. The experimental evaluation of Néel and Brown relaxation times (∼10−10 s and 10−4 s, respectively) indicate that the nanoparticles in both colloids magnetically relax by Néel mechanism. The isothermal magnetization curves analysis for this mechanism show that the magnetic nanoparticles behave in the interacting superparamagnetic regime. The specific absorption rates were determined calorimetrically at 260 kHz and up to 52 kA/m and were well modeled within linear response theory using the anisotropy density energy retrieved from quasi-static magnetic measurement, validating their use to predict heating ability of a given polydispersed particle suspension. Our findings provide new insight in the validity of quasi-static magnetic characterization to analyze the high frequency behavior of polydispersed colloids within the framework of the linear response and Wohlfarth theories and indicate that dipolar interactions play a key role being their strength larger for the colloid displaying higher dissipation, i.e., improving the heating efficiency of the nanoparticles for magnetic fluid hyperthermia., Instituto de Física La Plata