Tracking soluble and nanoparticulated titanium released in vivo from metal dental implant debris using (single-particle)-ICP-MS

Background: This work studies the presence of the Ti, Al and V metal ions and Ti nanoparticles released from the debris produced by the implantoplasty, a surgical procedure used in the clinic, in rat organs. Methods: The sample preparation for total Ti determination was carefully optimized using microsampling inserts to minimize the dilution during the acid attack of the lyophilized tissues by a microwave-assisted acid digestion method. An enzymatic digestion method was optimized and applied to the different tissue samples in order to extract the titanium nanoparticles for the single-particle ICP-MS analysis.Results: A statistically significant increase was found for Ti concentrations from control to experimental groups for several of the studied tissues, being and particularly significant in the case of brain and spleen. Al and V concentrations were detected in all tissues but they were not different when comparing control and experimental animals, except for V in brain. The possible presence of Ti-containing nanoparticles mobilized from the implantoplasty debris was tested using enzymatic digestions and SP-ICP-MS. The presence of Ti-containing nanoparticles was observed in all the analyzed tissues, however, differences on the Ti mass per particle were found between the blanks and the digested tissue and between control and experimental animals in some organs.Conclusion: The developed methodologies, both for ionic and nanoparticulated metal contents in rat organs, have shown the possible increase in the levels of Ti both as ions and nanoparticles in rats subjected to implantoplasty

Ion release and local effects of titanium metal particles from dental implants: an experimental study in rats

Background: The objective of this study was to evaluate the accumulation of ions in blood and organs caused by Ti metal particles in a mandibular defect in rats, together with a description of the local reaction of oral tissues to these titanium alloy debris. Methods: Twenty Sprague-Dawley rats were randomly distributed into three groups: an experimental group with a mandibular bone defect filled with metallic debris obtained by implantoplasty; a positive control group; and a negative control group. Thirty days after surgery, the rats were euthanized and perilesional tissue surrounding the mandibular defect was removed, together with the lungs, spleen, liver and brain. Two blood samples were collected: immediately before surgery and before euthanasia. The perilesional tissue was histologically analyzed using hematoxylin-eosin staining, and titanium, aluminum and vanadium ion concentrations in blood and organs were measured by TQ-ICP-MS. Descriptive and bivariate analyses of the data were performed. Results: All rats with implanted metal debris showed metal particles and a bone fracture callus on the osseous defect. The metal particles were surrounded by a foreign body reaction characterized by the presence of histiocytes and multinucleated giant cells. The experimental group had a significant higher concentration of Ti ions in all studied organs except lung tissue (p < 0.05). In addition, there were more V ions in the brain in the experimental group (p = 0.008). Conclusions: Although further studies are required to confirm the clinical relevance of these results, Ti metal particles in the jaw might increase the concentration of metal ions in vital organs and induce a foreign body reaction. This article is protected by copyright. All rights reserved. Keywords: Ion release; Ti6Al4V; implantoplasty; metal particles; peri-implantitis; titanium

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

El empleo de metalofármacos como potenciales agentes tumorales: estudios de incorporación y reactividad en modelos celulares

Tesis con mención internacionalEl cisplatino es un fármaco que se emplea para el tratamiento de una gran variedad de tumores sólidos, entre los que se encuentran el cáncer de ovario, de vejiga, o de pulmón, siendo especialmente eficaz para el tratamiento del cáncer de testículo. Sin embargo, presenta una elevada toxicidad y problemas de resistencia, tanto intrínseca como adquirida, que se presenta en el 50% de los pacientes. Se estima, en este sentido, que la resistencia a la quimioterapia es la causa de más del 90% de las muertes por cáncer. Aún no se conocen con detalle los mecanismos que dan lugar a esta resistencia, pero se sabe que son complejos y multifactoriales, por lo que se hace necesario el desarrollo de metodologías que permitan ampliar los conocimientos científicos de las causas que llevan a esta resistencia. Asimismo, el desarrollo de nuevos fármacos que, manteniendo la eficacia del cisplatino, limiten su toxicidad y las resistencias es de gran importancia, junto con metodologías analíticas que permitan estudiar las respuestas a estos tratamientos a nivel celular. Por todo ello, el objetivo general de la presente Tesis Doctoral ha sido el de desarrollar metodologías analíticas para estudiar las interacciones de metalofármacos con biomoléculas en cultivos celulares, utilizando para ello como herramienta principal el ICP-MS en combinación con diferentes técnicas analíticas que permitan estudiar estas interacciones a distintos niveles. Los estudios desarrollados se han centrado en el estudio comparativo del grado de incorporación celular del cisplatino y dos análogos, el oxaliplatino y el Pyrodach-2, este último en estudios clínicos, así como la determinación estructural de los aductos que forman con el ADN mediante técnicas de espectrometría de masas molecular. Un estudio similar, se llevó a cabo para estudiar las interacciones con el ADN de varios complejos de rutenio que podrían tener un modo de acción similar. Además, la incorporación del cisplatino no solo se estudió de forma global, sino que se desarrollaron diferentes estrategias para estudiar el contenido de Pt en cada célula individual. Para ello, las células se introdujeron en el sistema de ICP-MS mediante nebulización neumática, pero también se exploraron metodologías como la ablación láser y la generación de microgotas para este fin. Finalmente, se estudió la formación de aductos de forma más específica en las regiones teloméricas de los cromosomas, y se propuso una metodología para cuantificar la enzima telomerasa, encargada de su alargamiento y cuya actividad se ve influida, probablemente, por la presencia de aductos de cisplatino en los telómeros. A continuación, se resumen los resultados más importantes de estos estudios: - Se ha desarrollado un sistema de análisis por inyección en flujo basado en ICP-MS para la cuantificación de la concentración global de un metalofármaco en cultivos celulares referido al peso total de células secas que ha permitido comparar la incorporación celular de los fármacos de Pt estudiados. Asimismo, el empleo de técnicas híbridas de cromatografía de líquidos con ICP-MS y técnicas de espectrometría de masas moleculares han permitido dilucidar las estructuras de los aductos formados por los fármacos de platino y los potenciales fármacos de rutenio con el ADN. - Se ha puesto a punto y caracterizado un sistema de introducción de muestra mediante nebulización neumática para el análisis individual de células tumorales tratadas con cisplatino, que se ha aplicado también a levaduras enriquecidas en selenio, obteniendo mejores eficiencias para la introducción de células que muchos estudios publicados. - Se ha estudiado, de forma preliminar, otros sistemas de introducción de células individuales, mediante ablación láser y generación de microgotas. Para la primera técnica, se han resuelto algunos problemas relacionados con la contaminación y se ha concluído que la técnica del barrido superficial podría ser la más adecuada si se pueden encontrar las condiciones de estandarización necesarias. En cuanto a la generación de microgotas, se ha obtenido el límite de detección potencial de Pt en células individuales, pero la caracterización no se ha podido llevar a cabo completamente. - Se ha aplicado, asimismo, la técnica de LA-ICP-MS para realizar un mapeo de la distribución del Pt en una célula tumoral tratada con cisplatino. Se han obtenido imágenes de varias células mediante esta técnica. \item Se ha desarrollado un método que permite aislar las regiones teloméricas a partir de muestras de ADN genómico de cultivos celulares, con lo que se ha podido cuantificar la cantidad de Pt unida al ADN telomérico. - Finalmente, se ha puesto a punto una estrategia de marcaje metálico con el reactivo MeCAT-IA de un oligonucleótido de ADN para sintetizar una sonda de hibridación que permita cuantificar la enzima telomerasa mediante una metodología que combina su purificación mediante inmunoprecipitación con su cuantificación mediante ICP-MS a través del metal de la sonda de hibridación. Un cambio forzoso en el anticuerpo no ha permitido una caracterización completa de la estrategia, aunque se muestra como una estrategia prometedora alternativa al ELISA tradicional que permitiría cuantificar únicamente la fracción activa de la enzima

Combined single cell and single particle ICP-TQ-MS analysis to quantitatively evaluate the uptake and biotransformation of tellurium nanoparticles in bacteria

Assessing the impact of nanoparticles in living systems implies a proper evaluation of their behaviour at single-cell level. Due to the small size of nanoparticles, their accumulation, transformation and location within single cells is challenging. In this work, the combination of single cell/single particle triple quadrupole inductively coupled plasma mass spectrometry (SC/SP-ICP-TQ-MS) analysis along with X-ray diffraction (XRD) and transmission electron microscopy (TEM) measurements has been applied to go deeper into the uptake and biotransformation of tellurium nanoparticles (TeNPs) in two bacterial model organisms, S. aureus and E. coli. The use of SC-ICP-TQ-MS enabled the individual introduction of bacterial cells where tellurium and phosphorous (as constitutive element) were monitored and detected at concentration levels down to femtogram (fg) per cell. S.aureus uptake of TeNPs was 0.5–1.9 fg Te cell−1 and 7–30 fg Te cell−1 in presence of 0.5 and 15 mg Te L−1 of TeNPs, respectively, whereas for E. coli, the amount of Te ranged from 0.08 to 0.88 fg Te cell−1 and from 2 to 36 fg Te cell−1 in presence of 0.5 and 15 mg Te L−1 of TeNPs, respectively. TEM and XRD analysis confirmed the occurrence of TeNPs biotransformation (from nanospheres to nanorods) as the nanoparticles were incorporated into both bacterial strains. Finally, SP-ICP-MS analysis after cell lysis was applied to determine the number of particles/rods per bacteria cell and to perform the dimensional characterization of the rod-shaped TeNPs. The results obtained clearly confirmed high cell-to-cell variability in terms of Te nanorods dimensions and TeNPs uptake. To the best of our knowledge, this is the first time that SC/SP-ICP-TQ-MS along with TEM and XRD analysis have been applied to investigate, quantitatively, nanoparticle uptake in bacterial cells and to estimate the dimensions of biogenic Te nanorods.Spanish Ministry for Science, Innovation and UniversitiesCommunity of MadridAsturian Foundation for Biosanitary Research and Innovation (FINBA)Depto. de Química AnalíticaCAI Ciencias de la Tierra y ArqueometríaTRUEpu

Quantitative evaluation of cellular uptake, DNA incorporation and adduct formation in cisplatin sensitive and resistant cell lines: Comparison of different Pt-containing drugs

The use of Pt-containing compounds as chemotherapeutic agents facilitates drug monitoring by using highly sensitive elemental techniques like inductively coupled plasma mass spectrometry (ICP-MS). However, methodological problems arise when trying to compare different experiments due to the high variability of biological parameters. In this work we have attempted to identify and correct such variations in order to compare the biological behavior of cisplatin, oxaliplatin and pyrodach-2 (a novel platinum-containing agent). A detailed study to address differential cellular uptake has been conducted in three different cell lines: lung adenocarcinoma (A549); cisplatin-sensitive ovarian carcinoma (A2780); and cisplatin-resistant ovarian carcinoma (A2780cis). The normalization of Pt results to cell mass, after freeze-drying, has been used to minimize the errors associated with cell counting. Similarly, Pt accumulation in DNA has been evaluated by referencing the Pt results to the DNA concentration, as measured by 31P monitoring using flow-injection and ICP-MS detection. These strategies have permitted to address significantly lower Pt levels in the resistant cells when treated with cisplatin or oxaliplatin as well as an independent behaviour from the cell type (sensitive or resistant) for pyrodach-2. Similarly, different levels of incorporation in DNA have been found for the three drugs depending on the cell model revealing a different behavior regarding cell cisplatin resistance. Further speciation experiments (by using complementary HPLC–ICP-MS and HPLC–ESI-Q-TOF MS) have shown that the main target in DNA is still the N7 of the guanine but with different kinetics of the ligand exchange mechanism for each of the compounds under evaluation.Phosplatin Therapeutics Ministerio de Economía (CTQ2013-49032-C2-1-R) FICYT (FC-15-GRUPIN14-010) FICYT (Contrato predoctoral Severo Ochoa BP13114