Colonización bacteriana en películas de ácido poliláctico enriquecidas con magnesio y bromuro de hexadeciltrietilamonio. Consideraciones en entorno diabético

Programa de Doctorado en Modelización y Experimentación en Ciencia y TecnologíaEl aumento de la esperanza de vida ha generado el incremento de problemas de salud que precisan del uso de implantes en prácticas clínicas. Sin embargo, estos implantes pueden convertirse en focos de infección debido a la colonización de microorganismos y otras patologías como la diabetes. La creciente incidencia de infecciones requiere medidas urgentes para prevenir no solo su aparición, sino también su propagación. Esta Tesis investiga las causas por las que las bacterias alteran su proceso de colonización de biomateriales poliméricos, cuando éstos se enriquecen con compuestos activos o cuando se suplementa el entorno bacteriano con componentes diabéticos. Así, se podrán diseñar estrategias más eficaces para combatir las infecciones asociadas a implantes. El material escogido ha sido el ácido poliláctico (PLA), un polimérico degradable con gran potencial en biomedicina, enriquecido con Mg y bromuro de hexadeciltrimetilamonio (CTAB). El entorno diabético se ha simulado con glucosa y cuerpos cetónicos, y se han utilizado bacterias típicas en las infecciones protésicas, como las del género Staphylococci. El estudio combina la caracterización física superficial de bacterias y materiales con los ensayos in vitro de colonización que incluyen adhesión inicial, viabilidad y formación de biocapas. Los resultados muestran que el enriquecimiento con Mg y CTAB genera respuestas bactericidas del PLA y mejora su humectabilidad. Además, la patología diabética con hiperglucemia y cetoacidosis representa el peor escenario de colonización ya que las bacterias encuentran en este entorno un impulso en su actividad metabólica que potencia su afinidad bacteria-superficie y maximiza la formación de biocapas.Increased life expectancy has led to an increase in the number of health problems requiring implants in clinical practices. However, these implants can become shotspot of infection due to microorganism's colonisation and other pathologies such as diabetes. The increasing incidence of infections requires urgent measures to prevent not only their occurrence, but also their spread. This thesis studies the causes by which bacteria alter their colonisation process on polymeric biomaterials, when these are enriched with active compounds, or when their environment is supplemented with diabetic components. In this way, more effective strategies can be designed to combat implant-associated infections. The material chosen was polylactic acid (PLA), a degradable polymer with great potential in biomedicine, enriched with Mg and hexadecyltrimethylammonium bromide (CTAB). The diabetic environment was simulated with glucose and ketone bodies, and bacteria typical of prosthetic infections, such as Staphylococci, were used. The study combines surface physical characterisation of bacteria and materials with in vitro colonisation assays including initial adhesion, viability and biofilm formation. The results show that enrichment with Mg and CTAB generate bactericidal responses of PLA and improve its wettability. Moreover, diabetic pathology with hyperglycaemia and ketoacidosis represents the worst case scenario for colonisation as bacteria find in this environment a boost in their metabolic activity that enhances their bacteria-surface affinity and maximises biofilm formation.La realización de esta tesis doctoral ha sido posible gracias a las siguientes ayudas de financiación: • Junta de Extremadura. Consejería de Economía e Infraestructuras. Ayudas para la financiación de contratos predoctorales para la formación de doctores en los centros públicos de I+D pertenecientes al Sistema Extremeño de Ciencia, Tecnología e Innovación en el ejercicio 2017. Decreto 45/2016, de 12 de abril. DOE 95 de 19 de mayo de 2017. Cofinanciado por el Fondo Social Europeo, “Una manera de hacer Europa” : PD16055. • Junta de Extremadura. Ayuda a Grupos de Investigación. Consejería de Economía, Competitividad e Innovación. Decreto 56/2021, de 4 de junio. DOE 55, de 21 de marzo de 2022. Cofinanciado por el Fondo Europeo de Desarrollo Regional. GR21119 – Grupo de Investigación FQM006 (ANAYCO). • Esta tesis doctoral es parte del proyecto de I+D+i RTI2018-096862-B-I00, financiado por Ministerio de Ciencia e Innovación/ Agencia Estatal de Investigación /10.13039/501100011033/ FEDER “Una manera de hacer Europa” • Junta de Extremadura. Proyecto de investigación. Consejería de Economía e Infraestructuras. Decreto 68/2016, de 31 de mayo de 2016. DOE 114, de 16 de junio de 2021. Cofinanciado por el Fondo Europeo de Desarrollo Regional. IB20092

Modification of physico-chemical surface properties and growth of Staphylococcus aureus under hyperglycemia and ketoacidosis conditions

Diabetes is a widely spread disease affecting the quality of life of millions of people around the world and is associated to a higher risk of developing infections in different parts of the body. The reasons why diabetes enhances infection episodes are not entirely clear; in this study our aim was to explore the changes that one of the most frequently pathogenic bacteria undergoes when exposed to hyperglycemia and ketoacidosis conditions. Physical surface properties such as hydrophobicity and surface electrical charge are related to bacterial growth behavior and the ability of Staphylococcus aureus to form biofilms. The addition of glucose made bacteria more negatively charged and with moderate-intermediate hydrophobicity. Ketone bodies increased hydrophobicity to approximately 75% and pathological concentrations hindered some of the bacterial surface charge by decreasing the negative zeta potential of cells. When both components were present, the bacterial physical surface changes were more similar to those observed in ketone bodies, suggesting a preferential adsorption of ketone bodies over glucose because of the more favorable solubility of glucose in water. Glucose diabetic concentrations gave the highest number of bacteria in the stationary phase of growth and provoked an increase in the biofilm slime index of around 400% in relation to the control state. Also, this situation is related with an increase of bacterial coverage. The combination of a high concentration of glucose and ketone bodies, which corresponds to a poorly controlled diabetic situation, appears associated with an early infection phase; increased hydrophobic attractive force and reduced electrostatic repulsion between cells results in better packing of cells within the biofilm and more efficient retention to the host surface. Knowledge of bacterial response in high amount of glucose and ketoacidosis environments can serve as a basis for designing strategies to prevent bacterial adhesion, biofilm formation and, consequently, the development of infections.Authors are grateful to Junta de Extremadura and FEDER (grant numbers GR18153, GR18096 and IB20092), project RTI2018-096862- B-I00, supported by FEDER (European Regional Development Fund " Una Manera de hacer Europa”), Ministry of Science and Innovation of the Government of Spain, Spanish Research Agency, respectively. Also, MFG, would like to thank the Junta de Extremadura and the European Social Fund for its grant PD16055.peerReviewe

Bacterial Response to the Surface Aging of PLA Matrices Loaded with Active Compounds

The use of active components in biomaterials improves the properties of existing ones and makes it possible to obtain new devices with antibacterial properties that prevent infections after implantation, thus guaranteeing the success of the implant. In this work, cetyltrimethylammonium bromide (CTAB) and magnesium particles were incorporated into polylactic acid (PLA) films to assess the extent to which progressive aging of the new surfaces resists bacterial colonization processes. For this purpose, the films’ surface was characterized by contact angle measurements, ToF-SIMS and AFM, and adhesion, viability and biofilm growth of Staphylococcus epidermidis bacteria on these films were also evaluated. The results show that the inclusion of Mg and CTAB in PLA films changes their surface properties both before and after aging and also modifies bacterial adhesion on the polymer. Complete bactericidal activity is exhibited on non-degraded films and films with CTAB. This antibacterial behavior is maintained after degradation for three months in the case of films containing a higher amount of CTAB

Aging of Solvent-Casting PLA-Mg Hydrophobic Films: Impact on Bacterial Adhesion and Viability

Biomaterials used for the manufacture of biomedical devices must have suitable surface properties avoiding bacterial colonization and/or proliferation. Most biomaterial-related infections start during the surgery. Bacteria can begin colonization of the surface of a device right after implantation or in the next few hours. This time may also be sufficient to begin the deterioration of a biodegradable implant. This work explores the surface changes that hydrophobic films of poly(lactic) acid reinforced with Mg particles, prepared by solving-casting, undergone after in vitro degradation at different times. Hydrophobicity, surface tension, zeta potential, topography, and elemental composition were obtained from new and aged films. The initial degradation for 4 h was combined with unspecific bacterial adhesion and viability tests to check if degraded films are more or less susceptible to be contaminated. The degradation of the films decreases their hydrophobicity and causes the appearance of a biocompatible layer, composed mainly of magnesium phosphate. The release of Mg2+ is very acute at the beginning of the degradation process, and such positive charges may favor the electrostatic approach and attachment of Staphylococci. However, all bacteria attached on the films containing Mg particles appeared damaged, ensuring the bacteriostatic effect of these films, even after the first hours of their degradation

MALT LYMPHOMA OF PALATE AND ORBIT

TITLE: Malt palate and orbit lymphoma/n /n /nAuthors: CIFUENTES NAVAS-Viviana Andrea; MARTÍN PASCUAL- María Consolación; FERNÁNDEZ RODRÍGUEZ- Ana; ALONSO MESONERO- Marta; CHAVIANO GRAHJERA-Juan; MORAIS PÉREZ-Darío./n /nINTRODUCTION/nMALT-type lymphomas are lymphoid proliferations originated in the glandular epithelium of organs like the stomach, the salivary and lacrimal glands, and even, we can find lymphoid neoformations of non-epithelial localization, like in the orbital soft tissue. The lymphomas of the mucosal-associated lymphatic tissue (MALT) represent only 0.2-0.3% and constitute a well-defined group of non-Hodgkin lymphomas of B origin. In the field of oral pathology, the salivary glands, tonsils and palate are mainly affected, it is more rare to find it in jugal mucosa./nWe present a rare case of MALT lymphoma with involvement of the palate and orbit./n /nMATERIAL AND METHODS/n84-year-old patient with multiple pathologies. Derived from his primary care physician due to pharyngeal complaints of 4 to 5 days of evolution, associated with a painful palate lesion./nHe presented in right hemipaladar a tumoration of elastic consistency in submucosa, ulcerated in the center, with normal neck. Also left orbital tumor that limits the visual field./n /nRESULTSCT and MRI of the neck report mass of 4x4 x2.5 cm in right hemipaladar, noninfiltrating concordant with possible lymphoma. The orbital MRI describes an intra and extra nasal left nasal lesion of 2.3x1.2x2 cm with characteristics consistent with lymphoma. CT of the neck: It demostrates a great mass of right hemipaladar, with lobulated contours and homogeneous enhancement of 40x32x25 mm, in intimate contact with medial pterygoid muscle, although there were no signs of infiltration, the rest of the edges being well delimited. Images characteristics look like a lymphoma, without being able to rule out other etiologies. MRI of the neck: It demostrates a diffuse thickening of right side of the soft palate that acquires a tumour morphology of 4x4x2.2 cm, well defined that does not infiltrate adjacent tissues. It enhances intensely and homogeneously with contrast.  There are bilateral laterocervical ganglionic images ,with predominance in right side, nonspecific.Orbit MRI: It demostrates mixed orbital mass intra and extraconal on the left side, oval morfology, Its limits are partially well-defined, with transverse diameters 2.3x1.1 cm and craniocaudal 2cm approximately, it show a  moderate and diffuse enhance after endovenous contrast. The result of the biopsy of both lesions indicated infiltration of "B" lymphoma type MALT lymphoma. The patient was referred to the service of hematology, found no adenopathies or visceromegalies.  It was cataloged like a lymphoma NO HODGKIN B malt type STAGE IV-A (two extranodal sites, orbit and palate), He is currently with chemotherapy treatment, and he is followed up by this department.  CONCLUSIONS MALT lymphoma affects adults older than 60 years mainly, showing a slight female predominance, and more probably for gastric locations. The clinical characteristics and the presentation of the symptoms are mainly related to the primary location of the tomour. Approximately 6% of the non-hodgkin lymphomas that affect Waldeyer's ring are MALT lymphomas, affecting most of them to the palatine amygdala. However, according to the reviewed bibliography, the affectation of the palate is rare, being more frequent the orbital location MALT lymphomas follow a relatively indolent clinical course and generally remain localized in their primary extranodal site. Tumors are sensitive to radiation therapy and local treatment. However, dissemination at multiple sites is not infrequent, it may involve extra-ganglionic sites, such as bone marrow, spleen and liver.  Early diagnosis is the basis of a better prognosis, this allows a more adequate treatment. The role of the in-depth clinical study is emphasized and confirmed by a biopsy. It is important the multidisciplinary treatment of the patient from the departments of oncology, hematology with radio and chemotherapy, etc. The follow-up of the patient has to be long.We have reviewed the literature,and we found that MALT lymphomas with palate involvement in association with the orbit are extremely rare; It is because we think is important to publish this case. /nLos linfomas de tipo MALT son proliferaciones linfoides originadas en el epitelio glandular de órganos como el estómago o las glándulas salivales y lagrimales, e incluso neoformaciones linfoides de localización no epitelial, como las que asientan sobre el tejido blando orbitario. Los linfomas del tejido linfoide asociado a mucosas (MALT) representan solamente el 0,2-0,3% y constituyen un grupo bien definido de linfomas no hodgkinianos de origen B. En el campo de la patología oral se afectan principalmente las glándulas salivales, amígdalas y paladar, siendo la localización en mucosa yugal excepcional./nPresentamos un raro caso de linfoma MALT con afectación de paladar y órbita./n

Initial bacterial approach to biodegradable magnesium-doped poly(lactic) acid films prepared by solvent casting

Metallic medical devices have been the first option when good mechanical property is the primary requirement, especially when high strength and excellent toughness is necessary. However, in biological point of view, stable chemical behaviour of typical biometals, mainly made of Ti alloys or stainless steels, allowed negligible effect to wound healing and tissue regeneration. Recently, Park et al. [1] reported a new concept of functionalizing inert biometals based on galvanic corrosion reaction generating reactive oxygen species (ROS). In this report, we report novel material scientific methods to control the ROS generation rate and extend the generation time over a couple of weeks so that the electrochemically functionalized fully metallic devices exhibit delicate cell-selective nature.This work was supported by the Ministry of Health & Welfare, Republic of Korea (the Korea Health Technology R&D Project by KHIDI: grant no. HI17C0471

Leocadia : una mascota transgénero

El trabajo obtuvo una mención honorífica del Premio Tomás García Verdejo a las buenas prácticas educativa en la Comunidad Autónoma de Extremadura para el curso 2020/2021. Modalidad ASe describe un proyecto llevado a cabo desde la biblioteca del CEIP Extremadura (Cáceres) que pretendía modernizar la imagen que se tenía del centro. Se realizaron dos bloques de actividades. En el primer bloque se creó la imagen y leyenda de la biblioteca, 'Leocadia' una mascota transgénero que buscaba su identidad a través de los libros, enseñando valores esenciales para el crecimiento de los alumnos. En el segundo bloque se desarrollaron proyectos articulados desde la biblioteca: 'Y llegaron las científicas' sobre el papel de la mujer en la Ciencia; 'Radio Ciconia' la radio escolar del centro; 'Mi cole con mucho arte' en el que a través de la pintura-escultura y la música se pusieron de manifiesto los valores de respeto, igualdad, etc.ExtremaduraES

Leyendo hasta el confín a lomos del flaco rocín, pero algo despacito que se nos cansa el pollino

El trabajo obtuvo un Premio Tomás García Verdejo a las buenas prácticas educativas en la Comunidad Autónoma de Extremadura para el curso académico 2015/2016. Modalidad BCon motivo de la celebración del 400 aniversario de la edición de la segunda parte de El Quijote (1615-2015) y del cuarto centenario de la muerte de Cervantes (1616-2016) se llevó a cabo en el IES Enrique Díez Canedo de Puebla de la Calzada (Badajoz) un proyecto que pretendía dar a conocer a la comunidad educativa la figura literaria y humana de Miguel de Cervantes, más allá del saber popular de El Quijote. Para ello se realizaron diferentes actividades, entre otras: la creación, a partir de alguna parte de El Quijote, de textos, dibujos, o figuras; lectura de partes de la obra; uso de la biblioteca escolar; difusión de las actividades a través del blog de la biblioteca o de la revista del centro; representación de obras de teatro alusivas a la obra, etc.ExtremaduraES

Rompiendo la barrera de la desigualdad : coeducación para la igualdad efectiva de derechos, oportunidades y libertades entre géneros

Convocatoria Proyectos de innovación de Extremadura 2017/2018Se describe un proyecto llevado a cabo en el IES Tamujal de Arroyo de San Serván (Badajoz) que aborda los contenidos relativos a la promoción de la igualdad de oportunidades, la prevención de la violencia de género y la resolución pacífica de conflictos. Los contenidos son tratados de manera transversal a través de todos los departamentos y las asignaturas. Los objetivos específicos del proyecto fueron: sensibilizar a la comunidad educativa del Centro sobre el problema social que supone el sistema heteropatriarcal que subyace en las estructuras de la sociedad; detectar y corregir las actitudes, los comportamientos, las formas y los contenidos machistas en el entorno educativo y erradicar los comportamientos machistas en el Centro. Las actividades desarrolladas estaban orientadas a fomentar el lenguaje inclusivo; la eliminación y prevención de la violencia de género; el respeto a la orientación sexual; la promoción de la contribución de las mujeres a la ciencia, la historia, el arte, la cultura y el desarrollo de la humanidad; el fomento de la autonomía de las mujeres y la visión crítica de los estereotipos de género en la publicidad y los medios de comunicación; la educación sexual para la prevención de embarazos no deseados y la protección frente a enfermedades de transmisión sexual y para el libre desarrollo de la sexualidadExtremaduraES