Design of highly stabilized nanocomposite inks based on biodegradable polymer-matrix and gold nanoparticles for Inkjet Printing

Nowadays there is a worldwide growing interest in the Inkjet Printing technology owing to its potentially high levels of geometrical complexity, personalization and resolution. There is also social concern about usage, disposal and accumulation of plastic materials. In this work, it is shown that sugar-based biodegradable polyurethane polymers exhibit outstanding properties as polymer-matrix for gold nanoparticles composites. These materials could reach exceptional stabilization levels, and demonstrated potential as novel robust inks for Inkjet based Printing. Furthermore, a physical comparison among different polymers is discussed based on stability and printability experiments to search for the best ink candidate. The University of Seville logo was printed by employing those inks, and the presence of gold was confirmed by ToF-SIMS. This approach has the potential to open new routes and applications for fabrication of enhanced biomedical nanometallic-sensors using stabilized AuNP.Spanish Ministerio de Economía y Competitividad MINECO, (Grants Nos. CTQ2016- 78703-P and MAT2016-78703-P)Junta de Andalucía (Consolidation Grant for Research Group FQM135 and 2017/FQM-386, P-2018/809)University of Seville (V y VI Plan Propio PP2016-5937

Biofunctional and Tribo-mechanical Behavior of Porous Titanium Substrates Coated with a Bioactive Glass Bilayer (45S5 ‒ 1393)

Porous substrates of commercially pure titanium have been coated with a novel bilayer of bioactive glasses, 45S5 and 1393, to improve the osseointegration and solve the stress-shielding phenomenon of titanium partial implants. The porosity of the substrates, the scratch resistance and bioactivity of the coating have been evaluated. Results are discussed in terms of stiffness and yield strength of the substrates, as well as the chemical composition, thickness and design of the bioglass coating (monolithic vs. bilayer). The role of the pores was a crucial issue in the anchoring of the coating, both in porosity percentage (30 and 60 vol. %) and pore range size (100 – 200 and 355 ‒ 500 μm). The study was focused on the adhesion and infiltration of a 1393 bioglass layer (in contact with a porous titanium substrate), in combination with the biofunctionality of the 45S5 bioglass layer (surrounded by the host bone tissue), as 1393 bioglass enhances the adherence, while 45S5 bioglass promotes higher bioactivity. This bioactivity of the raw powder was initially estimated by nuclear magnetic resonance, through the evaluation of the chemical environments, and confirmed by the formation of hydroxyapatite, when immersed in simulated body fluid. Results revealed that the substrate with 30 vol. % of porosity and a range of 355 ‒ 500 μm pore size, coated with this novel bioactive glass bilayer, presented the best combination in terms of mechanical and biofunctional properties.Junta de Andalucía–FEDER (Spain) Project Ref. US-1259771Ministerio de Ciencia y Educación (Spain) Project 2004/00001203 (RYC-2004-001497

Porous titanium substrates coated with a bilayer of bioactive glasses

Porous titanium substrates coated by dripping-sedimentation technique with a novel bilayer of (45S5 / 1393) bioactive glasses are proposed to overcome some limitations of the use of titanium for implants, such as the stress shielding and the poor osseointegration. Composition, thickness, roughness and micromechanical behavior (P-h curves) of the coating and the influence of the porous titanium substrates have been characterized. Best results were found for the substrate with 30 vol.% of porosity and a range size of 355 ‒ 500 μm, since it enhanced the mechanical and biofunctional behavior, due to the good adhesion of the 1393 bioglass to the substrate and the greater bioactivity of the 45S5 bioglass, which would be in contact with the bone.Junta de Andalucía–FEDER (Spain) US-1259771M.E.C. (Spain) 2004/00001203 (RYC-2004-001497

Procedimiento para la preparación de fosfinas y óxidos de fosfinas quirales a partir de fosfinatos de di-O-aquiliden y di-O- ariliden-α-D-glucofuranosilo.

Procedimiento para la preparación de fosfinas y óxidos de fosfinas quirales a partir de fosfinatos de di-O-aquiliden y di-O- ariliden-α-D-glucofuranosilo. El objeto de la presente invención es un procedimiento para la preparación de compuestos de fósforo quirales, fundamentalmente fosfinas y ´óxidos de fosfinas, seg´un un procedimiento de síntesis asimétrica de fosfinatos, obtenidos por reacción de alcoholes derivados de 1,2;5,6-di-O-alquiliden (y di- O-ariliden)- α-D-glucofuranosa con cloruros de dialquil-(diaril y alquilaril) fosfinilo y catalizando con aminas terciarias. Por primera vez, se obtienen, con alta pureza ´óptica, cada uno de los fosfinatos con configuración opuesta en el fósforo. El procedimiento podrá aplicarse para la obtención de compuestos de fósforo ´ópticamente activos (o.a.) de utilidad en quimioterapia, síntesis asimétrica y catálisis asimétrica.Españ

Influence of the porosity and type of bioglass on the micro-mechanical and bioactive behavior of coated porous titanium substrates

In this study, the best equilibrium among adherence, micro-mechanical properties and coating bioactivity of bioactive glasses (45S5 and 1393) on porous titanium substrates has been explored and their potential uses for bone tissue implants. Porous titanium discs with different porosities (30 and 60 vol.%) and pore size distributions (100–200 and 355–500 µm) were utilized to rationalize their influence on both properties and performance. It was corroborated that porous samples produced a reduction in micro-hardness (~ 2000–4000 N/mm2) and the elastic modulus (~25–50 GPa), obtaining values closer to those of human bones, as well as induced a beneficial role to integrate the coatings. On one hand, bioglass 1393 presented greater capacity for pore infiltration while 45S5 was more bioactive. The results explained the better adherence and microhardness for bioglass 1393 and the significant formation of hydroxyapatite and calcium phosphates of bioglass 45S5, confirmed by 29Si MAS NMR.Ministerio de Ciencia e Innovación PID2019-109371GB-I00Junta de Andalucía US-125977

Hábitos y normas de seguridad recomendadas en un laboratorio de entorno químico

Las nuevas normativas que la Legislación impone relativas a los hábitos saludables y de seguridad que deben cumplirse en los laboratorios, han supuesto una revolución muy positiva en estos entornos de trabajo. Estos cambios están siendo posibles, gracias a la introducción de mejores infraestructuras, que están posibilitando al investigador la integración en su trabajo de nuevas maneras de trabajar, encaminadas a minimizar tanto los riesgos de accidentes como el impacto de sus investigaciones en el medioambiente. Las normas que se exponen a continuación han sido elaboradas por la Comisión de Prevención de Riesgos del Departamento de Química Orgánica y Farmacéutica, de la Facultad de Farmacia de Sevilla, con objeto de ser de seguidas por todos sus miembros. Estas normas son completamente extrapolables a cualquier laboratorio de entorno químico, en el que convivan por un lado disolventes orgánicos o inorgánicos y reactivos químicos, y por otro, personal altamente cualificado o de nueva incorporación a este tipo de entornos. El documento se divide en varias partes: 1) Normas de obligado cumplimiento, 2) Recomendaciones, y 3) Formulario de aceptación de las Normas de Trabajo anteriores

Latest Trends in Surface Modification for Dental Implantology: Innovative Developments and Analytical Applications

An increase in the world population and its life expectancy, as well as the ongoing concern about our physical appearance, have elevated the relevance of dental implantology in recent decades. Engineering strategies to improve the survival rate of dental implants have been widely investigated, focusing on implant material composition, geometry (usually guided to reduce stiffness), and interface surrounding tissues. Although efforts to develop different implant surface modifications are being applied in commercial dental prostheses today, the inclusion of surface coatings has gained special interest, as they can be tailored to efficiently enhance osseointegration, as well as to reduce bacterial-related infection, minimizing peri-implantitis appearance and its associated risks. The use of biomaterials to replace teeth has highlighted the need for the development of reliable analytical methods to assess the therapeutic benefits of implants. This literature review considers the state-of-the-art strategies for surface modification or coating and analytical methodologies for increasing the survival rate for teeth restoration.Ministerio de Ciencia e Innovación PID2019-109371GB-I00Junta de Andalucía PAIDI 2020, P20_00671Universidad de Sevilla US-1380878, PPI505/2020, PPI532/202

Bioactive Bilayer Glass Coating on Porous Titanium Substrates with Enhanced Biofunctional and Tribomechanical Behavior

The use of porous titanium samples fabricated by space-holder powder metallurgy with bioactive coatings has already been reported to prevent resorption of the bone surrounding the implant and improve osseointegration, respectively. However, the presence of pores as well as the poor adherence and the brittle behavior inherent to glassy coatings affect the service behavior of implants fabricated from these samples. Therefore, they need to be optimized. In this work, 50 vol.% of porosity titanium substrates were manufactured with different pore range size (100–200 and 355–500 µm) spacer particles and coated with a bilayer of bioactive glasses (45S5/1393). The effect of the pores on the tribomechanical properties and infiltration of the bioactive glass 1393 along with the bioactivity of the bioactive glass 45S5 were evaluated by instrumented micro-indentation and scratch tests and the formation of hydroxyapatite in simulated body fluid. The results obtained were very promising as potential implants for the replacement of small tumors in cortical bone tissues, mainly due to the smaller pores that present an improved biomechanical and biofunctional balance.Ministry of Science and Innovation of Spain grant PID2019-109371GB-I00Junta de Andalucía-FEDER (Spain) Project US-1259771Junta de Andalucía-FEDER (Spain) Project US-1380878Junta de Andalucía (Spain) Project PAIDI 2020 P20_0067

Dynamics and numerical simulations to predict empirical antibiotic treatment of multi-resistant Pseudomonas aeruginosa infection

This work discloses an epidemiological mathematical model to predict an empirical treatment for dogs infected by Pseudomonas aeruginosa. This dangerous pathogen is one of the leading causes of multi-resistant infections and can be transmitted from dogs to humans. Numerical simulations and appropriated codes were developed using Matlab software to gather information concerning long-time dynamics of the susceptible, infected and recovered individuals. All data compiled from the mathematical model was used to provide an appropriated antibiotic sensitivity panel for this specific infection. In this study, several variables have been included in this model to predict which treatment should be prescribed in emergency cases, when there is no time to perform an antibiogram or the cost of it could not be assumed. In particular, we highlight the use of this model aiming to become part of the convenient toolbox of Public Health research and decision-making in the design of the mitigation strategy of bacterial pathogens

Synthesis and deposition of silver nanoparticles on porous titanium substrates for biomedical applications

Ti implants are highly biocompatible and allow orderly bone growth but, unfortunately, in the first five years after implantation, 5–10% of them fail due to poor osseointegration and to the presence of bacterial infections in prosthesis. Silver nanoparticles have been described to damage bacterial cell via prolonged release of Ag+ ions as a mode of action when immobilized on a surface. In this work, two routes to synthetize silver nanoparticles have been proposed including, on the one hand, a NaBH4-reduction and, on the other hand, a citrate-reduction combined with a stabilized biodegradable polymer. The deposition of these nanomaterials on porous Ti substrates previously fabricated using the space-holder technique (40 vol% and two size distributions, 100–200 and 355–500 μm) was investigated to aim for the best match. Before the deposition of nanoparticles accomplished by immersion, a silanization treatment of the substrate surface was carried out. After silver nanoparticles were deposited on the porous Ti substrates, microstructural characteristics and antibacterial behavior were evaluated against the proliferation of Staphylococcus aureus on the AgNPs functionalized substrates. Finally, the preliminary qualitative analysis showed the presence of inhibitory halos, being more relevant in the substrates with larger pores.Ministry of Science and Innovation of Spain PID2019-109371GB-I00Junta de Andalucía–FEDER (Spain) US-1259771Junta de Andalucía-Proyecto de Excelencia (Spain) P18-FR-203