Cell behaviour in new poly(l-lactic acid) films with crystallinity gradients

We report a new facile method for the development of crystallinity gradients in poly(l-lactic acid) films, based on the gradual dipping of amorphous PLLA samples in a hot bath. Isothermal cold crystallization studies were performed using DSC and optical microscopy in order to find adequate conditions to generate crystallinity gradients in the PLLA films. Cellular response along PLLA samples with graded spherulitic developments was tested: cell adhesion is higher in more crystalline zones due to highly flattened appearance of the cells in regions densely populated with spherulites, but cell density was found to be higher in the more amorphous side.This work was financially supported by the Portuguese Foundation for Science and Technology (FCT)-Project PTDC/FIS/115048/2009

Wettable arrays onto superhydrophobic surfaces for bioactivity testing of inorganic nanoparticles

Poly(l-lactic acid) superhydrophobic surfaces prepared by a phase-separation methodology were treated with 30 min exposition of UV/O3 irradiation using hollowed masks in order to obtain patterned superhydrophilic squared-shaped areas. These wettable areas successfully confined bioactive glass nanoparticles (BG-NPs), by dispensing and drying individual droplets of BG-NPs suspensions. The obtained biomimetic chips were used to test the in vitro bioactivity of binary (SiO2–CaO) and ternary (SiO2–CaO–P2O5) nanoparticles produced using sol–gel chemistry by immersing such substrate in simulated body fluid (SBF). From SEM and EDX it was possible to conclude that the ternary system promoted an enhanced apatite deposition. This work shows the potential of using such flat disposable matrices in combinatory essays to easily evaluate the osteoconductive potential of biomaterials using small amounts of different samples.Fundação para a Ciência e a Tecnologia (FCT) - PTDC/QUI/69263/2006

Novel antibacterial bioactive glass nanocomposite functionalized with tetracycline hydrochloride

To prevent the high frequency of wound infections, anti-bacterial agents can be loaded onto composites. In the present study, the antibiotic tetracycline hydrochloride (TC)was incorporated, for the first time, in collagen type I membranes coated with nano-sized SiO2-CaOP2O5 bioactive glass (n-BG) obtained by a sol-gel chemical route. Collagen membranes coated with n-BG were immersed in simulated body fluid (SBF) containing 0.25, 0.75 or 1.25 mg mL−1 of TC for 48 h at 37∘C following a coprecipitation method. The antibiotic was released in distilledwater at 37∘C for up to 72 h. The antibacterial activity of the composites was evaluated in vitro by the inhibition zone test and plate count method. Two different Staphylococcus aureus strains, S. aureus ATCC29213 and S. aureus ATCC25923, were exposed to the biomaterials. The results showed that the incorporation but not the release of TC was dependent on the initial concentration of TC in SBF. The biomaterials inhibited S. aureus growth, although the efficacy was similar for all the concentrations. The results allow us to conclude that the new composite could have potential in the prevention of wound infections.Fil: Rivadeneira, Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; ArgentinaFil: Luz, Gisela M.. Universidade Do Minho; PortugalFil: Audisio, Marcela Carina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones Para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones Para la Industria Química; ArgentinaFil: Mano, Joao F.. Universidade Do Minho; PortugalFil: Gorustovich Alonso, Alejandro Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; Argentin

Adhesive bioactive coatings inspired by sea life

Inspired by nature, in particular by the marine mussels adhesive proteins (MAPs) and by the tough brick-and-mortar nacre-like structure, novel multilayered films are prepared in the present work. Organic-inorganic multilayered films, with an architecture similar to nacre based on bioactive glass nanoparticles (BG), chitosan and hyaluronic acid modified with catechol groups, which are the main responsible for the outstanding adhesion in MAPs, are developed for the first time. The biomimetic conjugate is prepared by carbodiimide chemistry and analyzed by ultraviolet-visible spectrophotometry. The build-up of the multilayered films is monitored with a quartz crystal microbalance with dissipation monitoring and their topography is characterized by atomic force microscopy. The mechanical properties reveal that the films containing catechol groups and BG present an enhanced adhesion. Moreover, the bioactivity of the films upon immersion in a simulated body fluid solution for 7 days is evaluated by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy and X-ray diffraction. It was found that the constructed films promote the formation of bone-like apatite in vitro. Such multifunctional mussel inspired LbL films, which combine enhanced adhesion and bioactivity, could be potentially used as coatings of a variety of implants for orthopedic applications.The authors want to acknowledge the Portuguese Foundation for Science and Technology (FCT) and the European program FEDER/COMPETE for the financial support through project BioSeaGlue: EXPL/CTM-BIO/0646/2013 (FCOMP-01-0124- FEDER-041105)

Magnetic-responsive hydrogels for cartilage tissue engineering

Publicado em "Journal of Tissue Engineering and Regenerative Medicine", vol. 7, supp. 1 (2013)The use of magnetic nanoparticles (MNPs) has been explored as an alternative approach to overcome current limitations of regenerative medicine strategies. Cell engineering approaches where MNPs are incorporated within three-dimensional constructs, such as scaffolds or hydrogels may constitute a novel and attractive approach towards the development of a magnetically-responsive system. These systems would enable remote controlled actions over tissue engineered constructs in vitro and in vivo. Moreover, growing evidence suggests that the application of a magnetic field may enhance biological performance over commonly used static culture conditions providing stimulation for cell proliferation, migration and differentiation. In this work we analyze the role of magnetic stimulation on the behavior of human adipose derived stem cells (hASCs) laden in k-carrageenan hydrogels aiming at cartilage tissue engineering approaches. Thermo-responsive natural-based κ-carrageenan hydrogels were used as 3D templates since previous studies(1) report the adequate environment provided by these materials to support the viability and chondrogenic differentiation of several types of cells

Clinical course of sepsis, severe sepsis, and septic shock in a cohort of infected patients from ten Colombian hospitals

ABSTARCT: Sepsis has several clinical stages, and mortality rates are different for each stage. Our goal was to establish the evolution and the determinants of the progression of clinical stages, from infection to septic shock, over the first week, as well as their relationship to 7-day and 28-day mortality

In vivo efficacy and toxicity of curcumin nanoparticles in breast cancer treatment : a systematic review

Breast cancer is one of the most prevalent types of malignant tumors in the world, resulting in a high incidence of death. The development of new molecules and technologies aiming to apply more effective and safer therapy strategies has been intensively explored to overcome this situation. The association of nanoparticles with known antitumor compounds (including plant-derived molecules such as curcumin) has been considered an effective approach to enhance tumor growth suppression and reduce adverse effects. Therefore, the objective of this systematic review was to summarize published data regarding evaluations about efficacy and toxicity of curcumin nanoparticles (Cur-NPs) in in vivo models of breast cancer. The search was carried out in the databases: CINAHL, Cochrane, LILACS, Embase, FSTA, MEDLINE, ProQuest, BSV regional portal, PubMed, ScienceDirect, Scopus, and Web of Science. Studies that evaluated tumor growth in in vivo models of breast cancer and showed outcomes related to Cur-NP treatment (without association with other antitumor molecules) were included. Of the 528 initially gathered studies, 26 met the inclusion criteria. These studies showed that a wide variety of NP platforms have been used to deliver curcumin (e.g., micelles, polymeric, lipid-based, metallic). Attachment of poly(ethylene glycol) chains (PEG) and active targeting moieties were also evaluated. Cur-NPs significantly reduced tumor volume/weight, inhibited cancer cell proliferation, and increased tumor apoptosis and necrosis. Decreases in cancer stem cell population and angiogenesis were also reported. All the studies that evaluated toxicity considered Cur-NP treatment to be safe regarding hematological/biochemical markers, damage to major organs, and/or weight loss. These effects were observed in different in vivo models of breast cancer (e.g., estrogen receptor-positive, triple-negative, chemically induced) showing better outcomes when compared to treatments with free curcumin or negative controls. This systematic review supports the proposal that Cur-NP is an effective and safe therapeutic approach in in vivo models of breast cancer, reinforcing the currently available evidence that it should be further analyzed in clinical trials for breast cancer treatments

Early high-titer plasma therapy to prevent severe Covid-19 in older adults

BACKGROUND: Therapies to interrupt the progression of early coronavirus disease 2019 (Covid-19) remain elusive. Among them, convalescent plasma administered to hospitalized patients has been unsuccessful, perhaps because antibodies should be administered earlier in the course of illness. METHODS We conducted a randomized, double-blind, placebo-controlled trial of convalescent plasma with high IgG titers against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in older adult patients within 72 hours after the onset of mild Covid-19 symptoms. The primary end point was severe respiratory disease, defined as a respiratory rate of 30 breaths per minute or more, an oxygen saturation of less than 93% while the patient was breathing ambient air, or both. The trial was stopped early at 76% of its projected sample size because cases of Covid-19 in the trial region decreased considerably and steady enrollment of trial patients became virtually impossible. RESULTS A total of 160 patients underwent randomization. In the intention-to-treat population, severe respiratory disease developed in 13 of 80 patients (16%) who received convalescent plasma and 25 of 80 patients (31%) who received placebo (relative risk, 0.52; 95% confidence interval [CI], 0.29 to 0.94; P = 0.03), with a relative risk reduction of 48%. A modified intention-to-treat analysis that excluded 6 patients who had a primary end-point event before infusion of convalescent plasma or placebo showed a larger effect size (relative risk, 0.40; 95% CI, 0.20 to 0.81). No solicited adverse events were observed. CONCLUSIONS Early administration of high-titer convalescent plasma against SARS-CoV-2 to mildly ill infected older adults reduced the progression of Covid-19. (Funded by the Bill and Melinda Gates Foundation and the Fundación INFANT Pandemic Fund; Dirección de Sangre y Medicina Transfusional del Ministerio de Salud number, PAEPCC19, Plataforma de Registro Informatizado de Investigaciones en Salud number, 1421, and ClinicalTrials.gov number, NCT04479163.).Fil: Libster, Romina Paula. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Pérez Marc, Gonzalo. Hospital Militar Central, Buenos Aires; ArgentinaFil: Wappner, Diego. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Coviello, Silvina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Bianchi, Alejandra. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Braem, Virginia. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Esteban, Ignacio. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Caballero, Mauricio Tomás. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Wood, Cristian. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Berrueta, Mabel. Hospital Militar Central; ArgentinaFil: Rondan, Aníbal. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Lescano, Gabriela Mariel. Hospital Dr. Carlos Bocalandro; ArgentinaFil: Cruz, Pablo. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Ritou, Yvonne. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Fernández Viña, Valeria Silvina. Hospital Simplemente Evita; ArgentinaFil: Álvarez Paggi, Damián Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Esperante, Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Ferreti, Adrián. Hospital Dr. Carlos Bocalandro; ArgentinaFil: Ofman, Gaston. University of Oklahoma; Estados UnidosFil: Ciganda, Álvaro. Gobierno de la Provincia de Buenos Aires. Hospital Interzonal Especializado de Agudos y Cronicos San Juan de Dios.; ArgentinaFil: Rodriguez, Rocío. Hospital Simplemente Evita; ArgentinaFil: Lantos, Jorge. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Valentini, Ricardo. No especifíca;Fil: Itcovici, Nicolás. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Hintze, Alejandra. No especifíca;Fil: Oyarvide, M. Laura. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Etchegaray, Candela. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Neira, Alejandra. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Name, Ivonne. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Alfonso, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Swiss Medical Group; ArgentinaFil: López Castelo, Rocío. Centro de Educación Médica e Investigaciones Clínicas "Norberto Quirno"; ArgentinaFil: Caruso, Gisela. Hospital Militar Central; ArgentinaFil: Rapelius, Sofía. Hospital Militar Central; ArgentinaFil: Alvez, Fernando. Hospital Militar Central; ArgentinaFil: Etchenique, Federico. Hospital Militar Central; ArgentinaFil: Dimase, Federico. Hospital Militar Central; ArgentinaFil: Alvarez, Darío. Hospital Militar Central; ArgentinaFil: Aranda, Sofía S.. Hospital Militar Central; ArgentinaFil: Sánchez Yanotti, Clara Inés. Hospital Militar Central; ArgentinaFil: De Luca, Julián. Hospital Militar Central; ArgentinaFil: Jares Baglivo, Sofía. Hospital Militar Central; ArgentinaFil: Laudanno, Sofía. Fundación Hematológica Sarmiento; ArgentinaFil: Nowogrodzki, Florencia. Swiss Medical Group; ArgentinaFil: Larrea, Ramiro. Hospital Municipal San Isidro; ArgentinaFil: Silveyra, María. Hospital Militar Central; ArgentinaFil: Leberzstein, Gabriel. No especifíca;Fil: Debonis, Alejandra. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Molinos, Juan. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: González, Miguel. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Perez, Eduardo. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Kreplak, Nicolás. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Pastor Argüello, Susana. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Gibbons, Luz. Hospital Municipal de San Isidro; ArgentinaFil: Althabe, Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Bergel, Eduardo. Sanatorio Sagrado Corazón; ArgentinaFil: Polack, Fernando Pedro. Provincia de Buenos Aires. Ministerio de Salud; Argentin

MAREJADAS RURALES Y LUCHA POR LA VIDA, VOL. I:CONSTRUCCIÓN SOCIOCULTURAL Y ECONÓMICA DEL CAMPO.

Este volumen incluye trabajos que abordan temáticas que demuestran que el campo es una construcción sociocultural, por lo tanto, el medio rural es diferenciado y está en constante cambio y adaptación a los procesos globales y locales. Son 19 trabajos divididos en dos secciones, la primera, denominada Nuevas dinámicas sociales, económicas y culturales en el medio rural, está compuesta por 8 capítulos, en esta sección se incluyen aquellos trabajos que analizan de manera concreta los cambios perceptibles en las relaciones rurales y en las actividades económicas; procesos como desagrarización y nuevas actividades económicas son abordados aquí, así como propuestas metodológicas para el estudio de lo rural considerando los cambios y adaptaciones que se registran en los territorios. La segunda sección, Resistencias y alternativas al modelo neoliberal en la producción agrícola y alimentaria, está integrada por 11 trabajos que abordan las diversas formas en que los campesinos y productores agrícolas resisten y se adaptan a los cambios globales y a las modificaciones de política pública, desde los mercados alternativos hasta la producción de nuevos cultivos que generan un mercado nuevo a su producción, hasta las resistencias y defensa de la milpa, las reflexiones que nos ofrecen dan idea de la diversidad de formas en que la vida campesina se mantiene a pesar de todos los embates.INSTITUTO DE CIENCIAS AGROPECUARIAS Y RURALES (ICAR), UNIVERSIDAD DE GUADALAJARA, EL COLEGIO DE MICHOACÁN A.C., CUCOSTA SUR GRANA, FACULTAD DE ESTUDIOS SUPERIORES ACATLÁN-UNAM, ECOSU