Materiales-híbridos fibrilares en base a polímeros biodegradables

El hueso, para su estudio, se puede considerar tanto un tejido como una estructura, ya que desempeña dos funciones básicas: (i) control del metabolismo mineral de Ca, P y Mg (función fisiológica) y, (ii) sostén y protección de órganos (función mecánica). Como el material estructural primario del cuerpo, el mismo debe soportar una variedad de condiciones de carga estáticas y dinámicas; lo cual le es posible debido a la alta complejidad de su estructura altamente organizada.El tejido óseo es un compuesto de fibras de colágeno resistentes, aunque flexibles, reforzadas con nanocristales de fosfato cálcico. Esta estructura compuesta le da una rigidez mucho mayor que el resto de los tejidos mientras que le proporciona una tenacidad a la fractura y resistencia al daño sorprendentemente altas. La complejidad mecánica del tejido óseo, compuesto de hueso cortical y hueso trabecular, ambos con comportamientos mecánicos distintos, supera la de la mayoría de los materiales utilizados en ingeniería y por tal motivo su reemplazo por un material funcional es prácticamente imposible.Las dificultades clínicas que radican en la incapacidad de restaurar, frente a una pérdida de masa, la funcionalidad del tejido óseo mediante la sustitución sumado al deterioro de la micro-arquitectura ósea o pérdidas cualitativas de tejido asociadas a ciertas patologías, motivan la necesidad de investigar el modo de regenerar tejido nativo. El objetivo es guiar la formación de hueso sano necesario y suficiente para cubrir los defectos óseos, así como también brindar un soporte adecuado para alojar las prótesis. La ingeniería de tejido en las últimas décadas se ha convertido en un área de la ciencia que nos despliega una opción para la regeneración ósea en lugar de la sustitución mediante el uso de estructuras tridimensionales (3D) o matrices enriquecidas que pueden proveer de manera autóloga el sistema de reparación y regeneración de hueso a grandes volúmenes: biorreactores óseos.Estos sistemas se han convertido día a día en la opción más considerada y consisten en el acoplamiento y organización de células, andamios y complementos fisiológicos que simulen el ambiente tisular. Con la combinación adecuada de estos factores es posible obtener la respuesta celular adecuada hacia la regeneración funcional de tejido, siendo el andamio la estructura de sostén mecánico de todo el sistema.Considerando lo mencionado, durante el presente trabajo se plantearon los siguientes objetivos específicos con el objetivo general de crear una estructura con potencial aplicación como biorreactor óseo: (1) estudiar la respuesta potencial de regeneración celular ósea ante la presencia de nanorodillos de hidroxiapatita (HA) sintética; componente fundamental de la structura u andamio a preparar. (2) Determinar las propiedades e interacciones de los nanorodillos de HA con una proteína derivada de la hidrolisis de colágeno (gelatina); la organización de este sistema compuesto será la base estructural del andamio. (3) Construir y caracterizar un andamio basado en los componentes mencionados en la búsqueda del desarrollo de un biorreactor óseo.Para cumplir con los objetivos planteados, en primer lugar, se estudió la viabilidad, proliferación, adhesión y diferenciación en linaje osteogénico de células madre derivadas de tejido adiposo humano cultivadas en presencia de recubrimientos de dos tipos de nanorodillos de hidroxiapatita. Estos aspectos fueron analizados mediante técnicas de cuantificación de la actividad metabólica celular, actividad de la fosfatasa alcalina, cuantificación de la expresión génica, determinación de depósitos de fosfato de calcio y observación de las células adheridas.En segunda instancia, mediante el análisis de la viscosidad y densidad de soluciones con diferentes concentraciones de gelatina y cantidades de nanorodillos de hidroxiapatita mantenidas a distintas temperaturas se estudió la organización hidrodinámica de nuestro sistema. Esta sección fue complementada con estudios de espectroscopía y microscopía óptica.Como tercer paso se seleccionó una de las soluciones estudiadas, a la cual se le añadió un agente entrecruzante para obtener andamios a partir de un proceso de liofilizado. Estos andamios fueron luego caracterizados estructuralmente utilizando técnicas como microscopía electrónica de barrido, microscopía electrónica de transmisión de alta resolución, difracción de rayos X, espectroscopía infrarroja, espectroscopía fotoelectrónica de rayos X y calorimetría diferencial de barrido. Por otro lado se hicieron estudios en soluciones fisiológicas simuladas de degradación y bioactividad. En la parte final de nuestro trabajo, se realizaron estudios acerca de la porosidad, almacenamiento de solventes y propiedades mecánicas de los andamios construidos.Como resultado de este estudio, se obtuvieron andamios conformados a partir de una hidroxiapatita sintética similar a la apatita ósea, capaz de inducir proliferación y diferenciación celular, combinada con gelatina y un agente entrecruzante que presentan propiedades mecánicas comparables con las encontradas en tejidos óseos y características estructurales apropiadas para su consideración como biorreactor. Además, los estudios de bioactividad y degradación de los andamios también arrojaron resultados prometedores para su aplicación en ingeniería de tejidos óseos.The bone, for its study, could be considered both a tissue and a structure, since it performs two basic functions: (i) control of Ca, P and Mg mineral metabolism (physiological function) and, (ii) support and protection of organs (mechanical function). As the primary structural material of the body, it must withstand a variety of static and dynamic loading conditions; which is possible due to the high complexity of its highly organized structure. Bone tissue is a composite of tough but flexible collagen fibers reinforced with calcium phosphate nanocrystals. This composite structure gives it a much greater rigidity than the rest of tissues while providing surprisingly high fracture toughness and damage resistance. The mechanical complexity of the bone tissue, which is composed of cortical bone and trabecular bone, each with different mechanical behaviors, surpasses that of most materials used in engineering and for that reason its replacement by a functional material is practically impossible. The clinical difficulties that arise from the inability to restore, in a loss of mass, the functionality of the bone tissue through the substitution, added to the deterioration of the bone micro architecture or qualitative losses of tissue associated with certain pathologies, motivate the need to investigate the way to regenerate native tissue. The goal is to guide the formation of necessary and sufficient healthy bone to cover the defects, as well as to provide adequate support to accommodate the prostheses. In the last decades, tissue engineering has become an area of science that offers us an option for bone regeneration, instead of replacement, through the use of three-dimensional structures (3D) or enriched matrices that can provide an autologous system of repair and regeneration of bone to large volumes: bone bioreactors. Currently these systems have become a more considered option and consist in the coupling and organization of cells, scaffolds and physiological supplements that simulate the tissue environment. With the adequate combination of these factors it is possible to obtain the adequate cellular response towards the functional regeneration of tissue, a scaffold being the mechanical support structure of the whole system. Considering the above, the following specific objectives of the present work were set out with the general aim of creating a structure with potential application as a bone bioreactor: (1) to study the potential response of bone cell regeneration to the presence of synthetic hydroxyapatite nanorods (HA); a fundamental component of the scaffold to be prepared (2) to determine the properties and interactions of HA nanorods with a protein derived from the hydrolysis of collagen (gelatin); the organization of this system will be the structural basis of the scaffold (3) to construct and characterize a scaffold based on the components mentioned in the search for the development of a bone bioreactor. First, the viability, proliferation, adhesion and differentiation in osteogenic lineage of stem cells derived from human adipose tissue cultured in the presence of coatings of two types of hydroxyapatite nanorods were studied. These aspects were analyzed by quantification techniques of cellular metabolic activity, alkaline phosphatase activity, quantification of gene expression, determination of calcium phosphate deposits and observation of adhered cells. In the second instance, the hydrodynamic organization of our system was studied by analyzing the viscosity and density of solutions with different concentrations of gelatin and amounts of hydroxyapatite nanorods maintained at different temperatures. This section was supplemented with spectroscopy and optical microscopy studies. As a third step, a crosslinking agent was added to a selected solution, in order to obtain scaffolds from a freeze-drying process. These scaffolds were then structurally characterized using techniques such as scanning electron microscopy, high resolution transmission electron microscopy, X-ray diffraction, infrared spectroscopy, X-ray photoelectron spectroscopy and differential scanning calorimetry. On the other hand degradation and bioactivity studies were carried out in simulated physiological solutions. In the final part of our work, porosity, solvent storage and mechanical properties of constructed the scaffolds were studied. As a result of this study, scaffolds were obtained from a synthetic hydroxyapatite, similar to the bone apatite and capable of inducing cell proliferation and differentiation, combined with gelatin and a crosslinking agent. These structures presented mechanical properties comparable to those found in bone tissues and structural properties suitable for consideration as a bioreactor. In addition, studies of bioactivity and scaffold degradation also yielded promising results for application in bone tissue engineering.Fil: Sartuqui, Javier. Autor; . 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

Multiscale inorganic hierarchically materials: towards an improved orthopaedic regenerative medicine

Bone is a biologically and structurally complex multifunctional tissue. It dynamically responds to biochemical, mechanical and electrical signals by remodelling itself so that maximum strength and toughness are along the lines of the greatest applied stress. The challenge is to develop an orthopaedic biomaterial that emulates the micro- and nano-structural elements and compositions of bone to locally match the properties of the host tissue resulting in a biologically fixed implant. Looking for the ideal implant, the convergence of life and materials sciences occurs. Researchers in many different fields apply their expertise to improve implantable devices and regenerative medicine. Materials of all kinds, but especially hierarchical nano-materials, are being exploited. The application of nano-materials with hierarchical design to calcified tissue reconstructive medicine involve intricate systems including scaffolds with multifaceted shapes that provides temporary mechanical function; materials with nano-topography modifications that guarantee their integration to tissues and that possesses functionalized surfaces to deliver biologic factors to stimulate tissue growth in a controlled, safe, and rapid manner. Also materials that should degrade on a timeline matched to the time it takes to grow tissues are prepared. These implantable device systems are multifunctional and require specific design techniques coupled with several material manufacturing processes that can be integrated to achieve the design that can address the required multifunctionality. For such reasons, even though the concept shift from synthetic implants and tissue grafts to regenerative-medicine-based tissue reconstruction has been assured for well over a decade, the reality has yet to emerge. In this paper, we review the recent approaches to create enhanced bioactive materials. Their design and manufacturing processes as well as the challenges to integrate them to engineer hierarchical inorganic materials for their practical application in calcified tissue reparation are evaluated.Fil: Ruso, Juan Manuel. Universidad de Santiago de Compostela; EspañaFil: Sartuqui, Javier. 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: Messina, Paula Verónica. 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

Effect of ceria on the organization and bio-ability of anatase fullerene-like crystals

The nanostructure and the oxygen storage capacity against reactive oxygen species (ROS) are essential features to take into account during the design of a new material that will be used as the basis of novel therapeutic technologies. Here we evaluate the incorporation of nano-ceria, which has a demonstrated ability to scavenge free radicals under physiological conditions comparable to those observed for superoxide dismutase and catalase, to TiO2 crystalline assemblies. The material was planned to merge the scavenging properties of CeO2 on a specifically designed structured TiO2 substrate. The presence of Ce atoms has a clear influence in the materials' morphologies, distorting anatase crystal lattice and inducing the formation of fullerene-like structures. The cytotoxicity of the materials against L929 fibroblasts after 24 hours of cell culture was evaluated. Both structural and oxidative properties of the materials have a clear effect on fibroblast viability; in fact it was demonstrated that cellular proliferation can be modulated varying the Ce3+/Ti4+ molar ratio.Fil: Gravina, Noel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur; ArgentinaFil: Ruso, Juan Manuel. Universidad de Santiago de Compostela; EspañaFil: Mbeh, Doris Antoinette. École Polytechnique De Montréal; CanadáFil: Yahia, L'Hocine. École Polytechnique De Montréal; CanadáFil: Merhi Yahye. University Of Montreal; CanadáFil: Sartuqui, Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur; ArgentinaFil: Messina, Paula Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur; Argentin

Use of pigmentary centers Sympterygia bonapartii (Chondrichthyes Rajidae) as a tool of pollution bioanalytical

Los centros pigmentarios (CPs)se han documentado en anfibios y peces. En estos últimos, aparecen después de la primera alimentación y consisten en la acumulación de pigmentos en células fagocíticas que se asocian con sinusoides y/o centros linfoides en el bazo,el hígado y el pronefros. Han sido utilizados como bioindicadores de contaminación en los peces. La raya marmorada, Sympterygia bonapartii (Müller & Henle, 1841), es un componente habitual del estuario de Bahía Blanca, ecosistema que ha sufrido diferentes presiones de impacto ambiental a lo largo de los últimos 15 años. Se trata de un condrictio bentónico ovíparo que desova en el estuario a fines de primavera y verano. Por sus hábitos bentónicos se lo considera un buen modelo para monitorear el impacto antropogénico en el ecosistema estuarial. El objetivo principal de este estudio fue ensayar la utilización de los CPs de bazo e hígado de Sympterygia bonapartii como bioindicadores de calidad ambiental, bajo un modelo de tratamientocontrol, tomando a la Bahía San Blas como área control de referencia. Se detalló la estructura histológica de los CPs presentes en el bazo e hígado de S. bonapartii. Luego se compararon las posibles diferencias cuali y cuantitativas en los CPs debido a factores ambientales y no ambientales. Se analizaron un total de 52 ejemplares, 27 (20 hembras y 7 machos) se capturaron en el estuario de Bahía Blanca y 25 (16 hembras y 9 machos) en Bahía San Blas.The pigments centres (CPs) have been documented in amphibious and fi sh. On these last ones, they appear after the fi rst feeding and consist in pigments accumulation of phagocytic cells that associate with sinusoid and/or lymphoid centres on spleen, liver and the pronefros. These have been used as pollution bioindicators on fi sh. The skate, Sympterygia bonapartii (Müller & Henle, 1841), is a usual specimen from Bahía Blanca’s estuary, ecosystem that has suff ered diff erent environmental impact for the past 15 years. This is a bentonic oviparous condictrius which lays eggs in the estuary at the end of spring and summer. Due its bentonic habits, it’s considered a fi ne model to monitor the men’s impact on the estuarial ecosystem. The main objective of this research was to rehearse the use of the spleen and liver’s CPs of Sympterygia bonapartii as environmental bioindicators. This was made following a model of control treatment that takes Bahía San Blas as a referential control area. The histological structure of CPs in spleen and liver of S. bonapartii was determined. After this analysis, the possible qualitative and cuantitative diff erences due to environmental or no environmental infl uences were compared. A number of 52 individuals were analyzed from which 27 (20 females and 7 males) were brought from Bahía Blanca’s estuary. The other 25 individuals (16 females and 9 males) were captured in Bahía San Blas.Fil: Uibrig, Román Armando. Universidad Nacional del Sur; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Galeano, Noelia Adelina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Sur; ArgentinaFil: Schwerdt, Carla Belén. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Sur; ArgentinaFil: Mas, Javier Diego. Universidad Nacional del Sur; ArgentinaFil: Sartuqui, Javier. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Sur; ArgentinaFil: Guagliardo, Silvia Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Sur; ArgentinaFil: Acebal, María Florencia. Universidad Nacional del Sur; ArgentinaFil: Paolillo, Melisa Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Sur; ArgentinaFil: Tanzola, Rubén Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Sur; Argentin

Pharmaceutical Formulations of Amiodarone: Past, Present and Future

Discovered in 1961, Amiodarone [(2-butylbenzofuran-3-yl 4-(2-diethylaminoethoxy)-3,5-di-iodophenyl ketone)] (AMI) is a cationic amphiphilic molecule which belongs to class III antiarrhythmic drugs and therefore, it is used in the treatment of a wide range of cardiac arrhythmias. Severe adverse effects are provoked by this drug due to its accumulation in other organs than the heart. In addition, further adverse effects are also produced by some of the excipients used to increase its stability and solubility in the pharmaceutical carriers. These non-active substances play a crucial role in the formulations and therefore, an appropriate selection of them and the techniques used for the Corresponding Author formulations development could avoid or decrease the occurrence of adverse effects. Consequently, it is necessary to work on the evolution of pharmaceutical dosage forms of AMI in order to improve the life quality of treated patients. There is a large list of approved formulations of AMI, among them: oral tablets, oral solutions and solutions for intravenous infusion. Currently, liposomes and nanoparticles loaded with AMI have been developed. In this context, this book chapter deals with the state of art of AMI formulations and the perspectives for future dosage forms.Fil: Benedini, Luciano Alejandro. 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: Sartuqui, Javier. 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: Messina, Paula Verónica. 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

Nanotechnology for the Obtention of Natural Origin Materials and Environmentally Friendly Synthesis Applied to Tissue Engineering

It is undeniable the increasing and current need to develop not only green materials and products but environmentally friendly and high-quality methods to synthesize them. In this sense, regarding the environmental impact, it is unquestionable the advantages of the utilization of natural materials and methods for synthesis. Naturally derived and recycled biomaterials applied in tissue engineering are advantageous over petroleum-derived ones mainly because of their biodegradability and sustainability. Specially, naturally derived compounds gain importance in these medical uses due to their capability to induce surrounding tissue and cell ingrowth in the implant site or to serve as temporary scaffolds for cell transplantation. Also, researchers are able to customize these biomaterials at the nanoscale in their physicochemical aspect considering each specific condition required by each respective application. On the other hand, interest in thenovel use of engineered living materials as biofactories and decellularization technique to produce nanomaterials has vastly increased. Additionally, significant technological advances have been made in the use of environmentally friendly synthesis methods including clean cross-linking, non-solvent-induced phase separation for membrane obtention, electrospinning, centrifugal electrospin, and solid free-form fabrication. All of them focused on avoiding the disposal of solvents and toxic materials. This chapter provides an overview of sustainable nanomaterials applied in tissue engineering from a diversity of sources and eco-friendly novel strategies of synthesis.Fil: D'elía, Noelia Laura. 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: Sartuqui, Javier. 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: Postemsky, Pablo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; ArgentinaFil: Messina, Paula Verónica. 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

Bone healing process induced by nanoscale features of biomaterials: overview and future trends

From a biomechanical point of view, bone tissue itself can be described as a nanocomposite of organic (mainly collagen) and inorganic (mainly calcium phosphates) components hierarchically organized from the nano- to the macroscale. Nanostructured biomaterials mimicking the native bone architecture are a new tendency in orthopedic technology since they play a cardinal role in bone regeneration: their chemical and structural similarity to the natural tissue and their comparable size to biomolecules and bio-microstructures provide with enormous possibilities to induce desirable biological responses. Along this chapter, an overview of the current knowledge of bone tissue regeneration is discussed focusing on the importance of nanometer-sized entities, their structure and chemical aspects that might enhance bone healing. Consequently, high emphasis is concentrated on the existing state of the art in nanotechnology in order to be able to narrow the gap between current design strategies and submicron tissue elements to obtain new biomaterials with improved properties.Fil: Gravina, Noel. 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: D'elía, Noelia Laura. 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: Sartuqui, Javier. 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: Messina, Paula Verónica. 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

Nanostructured hydroxyapatite networks: Synergy of physical and chemical cues to induce an osteogenic fate in an additive-free medium

Nanoscale topography plays a central role in adult-stem-cell-niches. In this study we have demonstrated that by an accurate material design, mimicking the composition and structure of bone extracellular matrix, it is possible to guide human adipose stem cells (hASCs) to attain an osteogenic commitment, in vitro, without the requirement of soluble additives or grow factors. Alkaline Phosphatase (ALP) activity and Alizarin Red S test demonstrated that hASCs cultured onto hydroxyapatite frameworks dry-coating differentiated into mature osteoblasts even in the absence of specific inducing factors. Optical and electron scanning microscopic (SEM) observations revealed a direct cellular-material interaction that indicated an appropriate communication between nanotopographical features and the integrin receptors in the cell´s focal adhesions. Real-time quantitative PCR (RT-qPCR) analysis confirmed the expression of specific markers of pre-osteoblast and mature osteoblast stages as osterix (OSX), osteopontin (OPN), osteocalcin (OC) and; specific markers of extracellular matrix maturation and mineralization stages as alkaline phosphatase (ALPL), collagen type I alpha 1 (COL1A1) and osteonectin (ON). Osteoprotegerin (OPG), ALPL, COL1A1, and sclerostin (SOST) expressions were up regulated compared to osteogenic differentiation media conditions.Fil: Sartuqui, Javier. 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: Gardin, C.. Università di Padova; ItaliaFil: Ferroni, L.. Università di Padova; ItaliaFil: Zavan, B.. Università di Padova; ItaliaFil: Messina, Paula Verónica. 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

Development and characterisation of bilayered periosteum-inspired composite membranes based on sodium alginate-hydroxyapatite nanoparticles

Background and aim: Membranes for guided bone regeneration should have a mechanical structure and a chemical composition suitable for mimicking biological structures. In this work, we pursue the develop- ment of periosteum-inspired bilayered membranes obtained by crosslinking alginate with different amounts of nanohydroxyapatite. Experiments: Alginate-nanohydroxyapatite interaction was studied by rheology and infrared spectroscopy measurements. The membranes were characterized regarding their tensile strength, degrada- tion and surface morphology. Finally, cell cultures were performed on each side of the membranes. Findings: The ionic bonding between alginate polysaccharide networks and nanohydroxyapatite was proven, and had a clear effect in the strength and microstructure of the hydrogels. Distinct surface charac- teristics were achieved on each side of the membranes, resulting in a highly porous fibrous side and a mineral-rich side with higher roughness and lower porosity. Moreover, the effect of amount of nanohydroxyapatite was reflected in a decrease of the membranes’ plasticity and an increment of degradation rate. Finally, it was proved that osteoblast-like cells proliferated and differentiated on the mineral-rich side, specially when a higher amount of nanohydroxyapatite was used, whereas fibroblasts-like cells were able to proliferate on the fibrous side. These periosteum-inspired membranes are promising biomaterials for guided tissue regeneration applications

Photoluminescent SBA-16 Rhombic Dodecahedral Particles: Assembly, Characterization, and ab Initio Modeling

Nowadays, the use of polyhedral instead of spherical particles as building blocks of engineering new materials has become an area of particular effort in the scientific community. Therefore, fabricating in a reproducible manner large amounts of uniform crystal-like particles is a huge challenge. In this work we report a low reagent-consuming BINARY surfactant templated method mediated by a hydrothermal treatment as a facile and controllable route for the synthesis of crystal-like rombdodecahedral particles exhibiting SBA-16 mesoporosity. It was determined that the hydrothermal treatment conditions were a key point upon the final material morphology, surface area, microporosity, wall thickness, and mesopore width. As a consequence of their internal mesoporosity order, rhombic dodecahedral synthesized particles exhibited highly efficient ultraviolet absorptions and photoluminescence emissions at room temperature. Conducting experimental and theoretical comparative studies allowed us to infer that the presence of intrinsic defects confined into an ordered mesoporous structure plays a very important role in semiconductor materials. The information presented here is expected to be useful, giving new, accurate information, for the construction of novel technological devices.Fil: Ruso, Juan Manuel. Universidad de Santiago de Compostela; EspañaFil: Pardo, Victor. Universidad de Santiago de Compostela; EspañaFil: Sartuqui, Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur; ArgentinaFil: Gravina, Noel. Universidad Nacional del Sur; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; ArgentinaFil: D'elía, Noelia Laura. Universidad Nacional del Sur; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; ArgentinaFil: Pieroni, Olga Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur; ArgentinaFil: Messina, Paula Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur; Argentin