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The use of β-Titanium alloys to fabricate metal implants with Young's modulus that resembles bone tissues is presented as an alternative to commercially pure titanium or α-Titanium alloys, although it is still necessary to introduce proper implant porosity to reach the Young's modulus of cortical bones. In this work, porous samples were fabricated by loose sintering (0 MPa) and compared to samples manufactured at 1000 MPa, both sintered under the same conditions. Raw powders and sintered samples of the β-Titanium alloy, Ti35Nb7Zr5Ta, were characterized in detail in terms of both physicochemical and microstructural properties. Moreover, the tribo-mechanical behavior of sintered samples was evaluated by performing ultrasound technique, instrumented micro-indentation (P-h curves), and scratch tests. The bio-functional behavior was studied by impedance spectroscopy and contact angle measurements. The results allowed the evaluation of the limits of conventional powder metallurgy (percentage of porosity, size, and morphology of pores), as well as the influence of the porosity and chemical composition to achieve a better biomechanical and bio-functional behavior that would guarantee bone requirements. The Ti35Nb7Zr5Ta alloy showed relatively high electrical impedance values compared to commercially pure titanium, indicating an improved bio-corrosion behavior. Furthermore, wettability measurements indicated that porous disks fabricated by loose sintering exhibit higher hydrophilicity, often associated with a better antibacterial response.

Tooth loss is common in patients struggling with dental cavities, periodontal diseases, and tumors, as well as those who abuse tobacco or drugs. In this scenario, dental implants have become the primary treatment option for complete or partial tooth loss. Dental implant failure can be caused by stress shielding phenomenon, poor osseointegration, or to bacterial infections. In the present study, a joint solution to these limitations is proposed using a variety of porous β-titanium substrates using powder Ti35Nb7Zr5Ta alloy and employing the spacer-holder approach (ammonium bicarbonate) to obtain a variety of porosity percentage (30, 40, and 50 vol%), and pore diameters in 100–200 μm, that has been characterized in terms of its size distribution, density, morphology, chemical composition, compaction ability and Vickers micro-hardness. Furthermore, porosity, microstructure (Archimedes and image analysis) and tribomechanical behavior (P-h curves and scratch tests) experiments were performed to study and characterize the porous substrates. Polyvinyl alcohol (PVA)/poly-ε-caprolactone (PCL) containing silver nanoparticles (AgNPs), as antibacterial composite, was employed to infiltrate β-Ti disks. Scanning electron microscopy was used to determine the coating morphology, thickness, and infiltration of the porous substrates. Wettability and SBF experiments were also carried out to investigate hydrophobicity and potential biofunctionality. The results suggested how the porosity of the β-Ti alloy affects the mechanical characteristics and the wettability of the substrate that was successfully infiltrated to exert an antimicrobial behavior.

Articular cartilage (AC) has a low ability for endogenous repair, and current treatments are not completely efficient in generating strong and healthy repair tissue. As a result, there is a great deal of interest in cartilage repair and recovery of joint function due to the aging population and the increasing frequency of cartilage degradation and osteoarthritis. Thus, the search for better and more efficient strategies to regenerate articular cartilage to repair the joints in patients with osteoarthritis is a critical motivation. Biomaterials, which are made of natural or synthetic polymers, or a mixture of the two, serve as a scaffold for tissue regeneration. Cartilage tissue engineering (TE) seeks to develop a treatment that can effectively repair damaged AC caused by trauma or disease. In cartilage TE, scaffolds that provide a 3D environment like native articular cartilage for cells to proliferate, attach, and hence ensure tissue regeneration success are needed. For optimal cell activities, which is associated with proper cartilage regeneration, these scaffolds must meet all necessary criteria, including adequate architectural, physicochemical, and biological properties. This study briefly explores the evolution of scaffolds constructed of synthetic polymers and hybrid materials for cartilage tissue engineering. Initially, general information on AC is presented, as well as a review of medical approaches to treating cartilage injuries or disease. Following that, the requirements for scaffolds in tissue regeneration, specific materials, and techniques for producing them are briefly discussed.

In photocatalysis, surface engineered CeO2 could be vital due to oxygen vacancies arise from multiple valency, i.e. Ce3+ and Ce4+. This study reports photocatalytic properties of g-C3N4/CeO2 composite synthesized by a facile method in the presence of l-arginine. Physicochemical properties of g-C3N4/CeO2 material were analyzed through various characterization techniques such as XRD, UV–Vis, physisorption, etc., and correlated with its photocatalytic activity. Observed bandgap of the synthesized composite material was in the visible region, around 2.8 eV which is less than that of typical ceria, but higher than bandgap of exfoliated g-C3N4. On the further side, N doping into CeO2 was confirmed through XPS analysis. It is estimated that synthesis method aided for the N doping, which further played key role in lowering the bandgap of g-C3N4/CeO2 composite. Finally, Photocatalytic activity of g-C3N4/CeO2 composite was analyzed through degradation of an herbicide i.e. diuron, and the study revealed the good performance of the catalyst. Keywords: CeO2, Graphitic carbon nitride, Photocatalysis, N doping, Herbicide

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.

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-1259771 M.E.C. (Spain) 2004/00001203 (RYC-2004-001497)

Vibrio harveyi has been reported as the dominant heterotrophic bacterial species in western Mediterranean coastal areas during warm seasons, and is recognized as an economically significant pathogen for the aquaculture industry. The present work aimed to evaluate the pathogenicity of a V. harveyi strain isolated from ascitic fluid collected from cultured gilthead seabream and then used in a challenge experiment involving the two most important fish species in Mediterranean aquaculture: gilthead seabream, Sparus aurata and European seabass, Dicentrarchus labrax. The ascitic fluid from diseased juvenile seabreams, previously vaccinated against Photobacterium damselae and Vibrio anguillarum, was extracted and bacteria cultivated for isolation and characterization. Additionally, different tissues were sampled for histological evaluation and description. Significant histopathological responses were observed in hepatic and mucosal tissues. One of the strains isolated from ascitic fluid, IRTA 17-43, was selected for a bacterial challenge. Additionally, the attenuation of virulence through sequential passage of the strain on solid media was also assessed. In parallel, a co-habitation trial was performed in order to evaluate the possible transfer of the bacteria between injected and healthy individuals. Pathogenicity trials in gilthead seabream resulted in only 25% mortality when injected with 10 CFU mL, whereas, for European seabass, a mortality of 95% was recorded, with clear signs of vibriosis. When passed sequentially on solid media, the strain IRTA-17-43 showed a decrease of 35% in cumulative mortality for European seabass. No apparent transmission of the pathogen occurred during the co-habitation trial for both species. In conclusion, although few external signs of V. harveyi are observed in vaccinated carriers, internal effects of the infection were clear and severe. Although no horizontal transfer of infection was observed, the risk of occurrence between carriers and immunosuppressed individuals or between different species should be considered. This further validates that the establishment of a good health management system within fish farms is of major importance in order to avoid the onset of disease outbreaks., This work has been supported by the project “Nutritional strategies for the improvement of productive performance: the use of functional feeds and health diets in aquaculture (DIETAplus)”, funded by JACUMAR (Ministry of Agriculture, Fisheries and Environment of Spain, MAPAMA) and FEMP (EU), and the MedAID project (Grant agreement No 727315), funded by the European Union‘s Horizon 2020 research and innovation program. Joana P. Firmino have been subsidized by the Industrial PhD program of the Generalitat de Catalunya and TECNOVIT-FARMFAES.

The present work describes the preparation of stable organic nanoparticles with potential use as “smart” drug delivery systems capable of encapsulating lipophilic molecules to exert their therapeutic action under the appropriate stimulus. A well-defined self-assembly hydrophilic-hydrophobic di-block copolymer has been synthesized via atom transfer radical polymerization (ATRP). The hydrophilic block is based on a random copolymer with DMA and HEMA units, while the hydrophobic component is a linear random copolymer of DEA and FMA. Stabilization of the nanoparticles by means of core cross-linking is addressed by Diels-Alder reactions between the furan rings of the hydrophobic blocks and the synthesized bisdienophiles; the influence of both the cross-linking agent and the degree of cross-linking in the process is discussed. The incorporation of a therapeutic agent (pilocarpine) and a lipophilic fluorescent molecule (pyrene) is evaluated. When pyrene was immersed into the micelles, there was a significant boost of the fluorescence emission (from 10- to 40-fold), due to the hydrophobic environment of the inner part of the nanoparticles. Pilocarpine is also able to be encapsulated by the prepared systems. Drug release is triggered by a reduction in the pH of the media and is strongly dependent on the degree of cross-linking achieved., We thank the Junta de Andalucía (Grant P12-FQM-1553) of Spain for financial support.

The antioxidant activity of a new series of alkyl hydroxytyrosyl ethers was evaluated by the Rancimat test in a lipophilic food matrix and by the FRAP, ABTS and DPPH assays in a hydrophilic medium, and compared to free hydroxytyrosol (HTy), butylhydroxytoluene (BHT) and α-tocopherol. All methods used to assess the antioxidant activity of the new compounds emphasised the importance of the ortho-diphenolic structure on the maintenance of the high antioxidant activity associated with free HTy. The results obtained support the ‘polar paradox’ since the antioxidant activity of the lipophilic hydroxytyrosyl ethers was slightly lower in bulk oils and higher in hydrophilic media in comparison with their reference HTy. Although the length of the alkyl chain did not significantly affect the antioxidant activity in bulk oils, it did have a positive influence in hydrophilic medium for ethers with a short alkyl chain (methyl, ethyl and propyl), while ethers with longer alkyl chain (butyl, hexyl, octyl, dodecyl and octadecyl) maintained or even decreased their antioxidant activity, probably due to the steric effect of the side chains. In conclusion, these results show the strong antioxidant activity of a new group of lipophilic HTy derivatives that satisfies the food industry demands for new antioxidants with potential use as functional ingredients to improve the quality and nutritional properties of foods., This work was supported by Grants AGL2007-66373/ALI and Project CSD2007-00063 from Programa Consolider-Ingenio from the Spanish Ministry of Education and Science (CICYT) and Grant RTA2007-00036-00-00 from the Research National Institute of Food, Agriculture and Technology (INIA). G.P.C. is a predoctoral fellow of the Research National Institute of Food, Agriculture and Technology (INIA).