Nanocolumnar coatings on implants exhibiting antibacterial properties

Trabajo presentado en la 2nd International Conference on Nanomaterials Applied to Life Sciences 2020 (NALS 2020), celebrada en Madrid (España), del 29 al 31 de enero de 2020Addressing the problem of infection from the very first stage, i.e. inhibiting the formation of the bacterial biofilm, is a crucial step to prevent implant rejection. Nanocolumnar coatings exhibiting antibacterial properties have been fabricated by oblique deposition with magnetron sputtering [1]. The formation of nanocolumns (Fig.1) is the result of the effects of atomic shadowing when the atoms reach the surface along an inclined direction [2]. This technique is environmentally friendly: it is carried out at RT and does not involve chemical products (no recycling problems). Such methodology have been tested in a semiindustrial scale reactor, successfully coating in a single step the two sides of fixation plates for bone fractures [3]. Several in vitro experiments have been performed: analysis of bacterial adhesion and biofilm formation, analysis of osteoblast proliferation and mitochondrial activity, and osteoblasts–bacteria competitive growth scenarios, the latter also named “Race for the Surface” competition. In all these cases, the coatings show an opposite behavior toward osteoblast and bacterial proliferation [1,3]. Moreover, they are effective against Gram positive (S. aureus) and Gram negative (E. coli) bacteria [4]. Finally, when a synergic route is followed and the coatings are functionalized with Te nanorods, the antibacterial properties are enhanced, since Te adds contact-killing (Fig. 2), i.e. bactericidal effect, whilst the biocompatibility is preserved [4].MINECO and Fundación Domingo Martínez for funding. J.M.G.-M. thanks the Fulbright Commissio

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Synergic antibacterial coatings combining titanium nanocolumns and tellurium nanorods

Trabajo presentado en el XV Congreso Nacional de Materiales: Surface science and engineering for advanced applications, celebrado en Salamanca (España), del 4 al 6 de julio de 2018Peer reviewe

Recubrimientos nanocolumnares de titanio con propiedades antibacterianas

Trabajo presentado en el V Congreso Nacional de Nanotecnología (CNN2018), celebradi en Pucón (Chile), del 25 al 29 de noviembre de 2018Peer reviewe

Recubrimientos nanocolumnares de titanio con propiedades antibacterianas

Trabajo presentado en el V Congreso Nacional de Nanotecnología (CNN2018), celebradi en Pucón (Chile), del 25 al 29 de noviembre de 2018Peer reviewe

Synergic antibacterial coatings combining titanium nanocolumns and tellurium nanorods

Trabajo presentado en el XV Congreso Nacional de Materiales: Surface science and engineering for advanced applications, celebrado en Salamanca (España), del 4 al 6 de julio de 2018Peer reviewe

Synergic antibacterial coatings combining Ti nanocolumns and Te nanorods

Trabajo presentado en el 1st Spanish Conference on Biomedical Aplications of Nanomaterials, celebrado en Madrid, los días 7 y 8 de junio de 2018The glancing angle deposition technique by magnetron sputtering is a scalable technique that allows the production of nanostructured coatings in large areas [1]. In recent works, we have shown that nanocolumnar coatings made of Ti were successfully prepared with this method [2] and how they exhibited selective behavior towards osteoblast and Staphylococcus aureus (S. a.) proliferation [3]: the biocompatibility towards human cells was preserved, whilst the adherence and proliferation of S. a. were dramatically reduced, not only with commercial strains but also with clinical ones coming from infected patients. In this new work, not only Gram-positive bacteria but also Gram-negative ones (E. Coli) have been used to test the response of different coatings fabricated in two set-ups, one of them being a semi-industrial equipment, in order to check the robustness of this approach. Moreover, Te nanorods were synthesized on top of the nanocolumns (see Fig.) using a hydrothermal and environmentally-friendly approach. It will be shown that the antibacterial behavior is enhanced when this synergic route combining Ti nanocolumns and Te nanorods is used, especially in the case of long nanocolumns. Furthermore, all the coatings remain biocompatible for human cells and allow for their proliferation.Funding from MINECO (MAT2014-59772-C2-1), Fundación Domingo Martínez, and Fulbright Commission is acknowledged.Peer reviewe

Synergic antibacterial coatings combining titanium nanocolumns and tellurium nanorods

Trabajo presentado en el Materials Science and Engineering (MSE) European Congress, celebrado en Darmstant (Alemania), del 26 al 28 de septiembre de 2018The glancing angle deposition technique by magnetron sputtering is a scalable technique that allows the production of nanostructured coatings in large areas [1]. In recent works, we have shown that nanocolumnar coatings made of titanium were successfully prepared with this method [2] and how the adherence and proliferation of Staphylococcus aureus were dramatically reduced while the biocompatibility towards human cells was preserved [3]. In this new work, not only Gram-positive bacteria but also Gram-negative ones (E. Coli) have been used to test the response of different coatings fabricated in two set-ups, one of them being a semi-industrial equipment, in order to check the robustness of this approach. Moreover, tellurium nanorods have been synthesized on top of the nanocolumns using a hydrothermal and environmentally-friendly approach. It will be shown that the antibacterial behavior is enhanced when this synergic route combining titanium nanocolumns and tellurium nanorods is used, especially in the case of long nanocolumns. Furthermore, all the coatings remain biocompatible for human cells and allow for their proliferation. References: [1] A. Barranco et al., Perspectives on oblique angle deposition of thin films: From fundamentals to devices. Progress in Materials Science 76 (2016) 59¿153. [2] R. Alvarez et al., Nanostructured Ti thin films by magnetron sputtering at oblique angles. J. Phys. D: Appl. Phys. 49 (2016) 045303 (10pp.). [3] I. Izquierdo-Barba et al., Nanocolumnar coatings with selective behavior towards osteoblast and Staphylococcus aureus proliferation. Acta Biomaterialia 15 (2015) 20-28.Peer reviewe

Synergic antibacterial coatings combining titanium nanocolumns and tellurium nanorods

Anocolumnar titanium coatings have been fabricated in two sputtering systems with very different characteristics (a laboratory setup and semi-industrial equipment), thus possessing different morphologies (150 nm long columns tilted 20° from the normal and 300 nm long ones tilted 40°, respectively). These coatings exhibit similar antibacterial properties against Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli) bacteria. When a synergic route is followed and these coatings are functionalized with tellurium (Te) nanorods, the antibacterial properties are enhanced, especially for the long nanocolumns case. The biocompatibility is preserved in all the nanostructured coatings.Funding from MINECO (MAT2014-59772-C2-1-P, MAT2014-59772-C2-2-P and MAT2011-29194-C02-02) and Fundación Domingo Martínez is acknowledged. J.M. G.-M. thanks MECD (PRX16/00383) and Fulbright Commission for his stay at Northeastern University. We also acknowledge the service from the MiNa Laboratory at IMN funded by CM (S2013/ICE2822), MINECO (CSIC13-4E-1794) and the EU (FEDER, FSE).Peer reviewe

Eco-friendly synthesis of Te nanostructures with antibacterial and anticancer properties

Trabajo presentado en el 2nd Spanish Conference on Biomedical Applications of Nanomaterials (SBAN), celebrado en Madrid (España) los días 6 y 7 de junio de 2019Bacterial infections and cancer are two of the most significant issues that the current healthcare system should tackle nowadays. Traditional routes for the synthesis of the different compounds, drugs and nanostructures that are developed as potential solutions for those problems usually have several limitations, such as the use of harsh chemicals and production of toxic by-products with limited biocompatibility. In that sense, green chemistry offers a suitable approach, with safe and environmentally friendly manufacturing and minimal use of toxic chemicals. In this work, effective green routes for the synthesis of Te nanostructures are presented, based on hydrothermal or microwave-assisted reactions employing either starch [1], either citric juice (from orange, lemon or lime) [2] as unique reducing and stabilizing agents. The nanostructures were extensively characterized in terms of morphology, surface chemistry and composition, by means of transmission electron microscopy (TEM), scanning electron microscopy (SEM) with energy-dispersive X-ray analysis (EDX), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Depending on the fabrication parameters, long nanowires, nanorods or cubic shaped nanoparticles were obtained. These Te nanostructures showed antibacterial activity against both Gram-negative and -positive bacteria in a range of concentrations from 5 to 50 μg mL−1. Cytotoxicity studies were accomplished, showing a dose-dependent anticancer effect towards human melanoma cells for concentrations up to 100 μg mL−1, remaining cytocompatible towards human healthy fibroblast cells at concentrations below 50 μg mL−1 for the majority of Te morphologies. These antibacterial and anticancer properties were correlated with the production of reactive oxygen species (ROS). This study suggests that green chemistry approaches for producing Te nanostructures may not only reduce adverse environmental effects resulting from traditional synthetic chemistry methods, but can be effective in interesting health care applications