Three-dimensional printed polycaprolactone-microcrystalline cellulose scaffolds

Microcrystalline cellulose (MCC) is proposed in this study as an additive in polycaprolactone (PCL) matrices to obtain three-dimensional (3D) printed scaffolds with improved mechanical and biological properties. Improving the mechanical behavior and the biological performance of polycaprolactone-based scaffolds allows to increase the potential of these structures for bone tissue engineering. Different groups of samples were evaluated in order to analyze the effect of the additive in the properties of the PCL matrix. The concentrations of MCC in the groups of samples were 0, 2, 5, and 10% (w/w). These combinations were subjected to a thermogravimetric analysis in order to evaluate the influence of the additive in the thermal properties of the composites. 3D printed scaffolds were manufactured with a commercial 3D printer based on fused deposition modelling. The operation conditions have been established in order to obtain scaffolds with a 0/90° pattern with pore sizes between 450 and 500 µm and porosity values between 50 and 60%. The mechanical properties of these structures were measured in the compression and flexural modes. The scaffolds containing 2 and 5% MCC have higher flexural and compression elastic modulus, although those containing 10% do not show this reinforcement effect. On the other hand, the proliferation of sheep bone marrow cells on the proposed scaffolds was evaluated over 8 days. The results show that the proliferation is significantly better (p < 0.05) on the group of samples containing 2% MCC. Therefore, these scaffolds (PCL:MCC 98:2) have suitable properties to be further evaluated for bone tissue engineering applications

Study Nanostruc-ture of a Biomaterial with

Abstract In Mexico, the medicinal plants have been for used since ancient times and still continue to use by rural populations to treat conditions such as infectious diseases (skin, gastrointestinal or respiratory), metabolics, inflammatory problems, among others. This work includes a proposal that initiates the study and development of new biomaterials or vehicles with therapeutic application. . The biomaterial shows that higher anti-inflammatory activity is to be generated through the combination of EOV-gel, the nanostructure interaction SEM shows integrated particles agglome-rated form and porous due to the presence of EOV and some flat areas indicated the gel preponderance situation generated by the low interaction between materials of organic type and polar type (gel)

Evaluation of Aloe Vera Coated Polylactic Acid Scaffolds for Bone Tissue Engineering

3D-printed polylactic acid (PLA) scaffolds have been demonstrated as being a promising tool for the development of tissue-engineered replacements of bone. However, this material lacks a suitable surface chemistry to efficiently interact with extracellular proteins and, consequently, to integrate into the surrounding tissue when implanted in vivo. In this study, aloe vera coatings have been proposed as a strategy to improve the bioaffinity of this type of structures. Aloe vera coatings were applied at three different values of pH (3, 4 and 5), after treating the surface of the PLA scaffolds with oxygen plasma. The surface modification of the material has been assessed through X-ray photoelectron spectroscopy (XPS) analysis and water contact angle measurements. In addition, the evaluation of the enzymatic degradation of the structures showed that the pH of the aloe vera extracts used as coating influences the degradation rate of the PLA-based scaffolds. Finally, the cell metabolic activity of an in vitro culture of human fetal osteoblastic cells on the samples revealed an improvement of this parameter on aloe vera coated samples, especially for those treated at pH 3. Hence, these structures showed potential for being applied for bone tissue regeneration

Microcrystalline cellulose as filler in polycaprolactone matrices

Polycaprolactone is a biomaterial widely used for tissue engineering applications. However, its hydrophobicity hinders cell attachment and proliferation on its surface. In this study microcrystalline cellulose has been proposed as a functional filler for polycaprolactone matrices expected to improve these properties. Composite material samples containing 0, 2, 5, 10 and 20% w/w of microcrystalline cellulose have been manufactured by compression molding and evaluated in terms of their mechanical properties, swelling behavior, water contact angle values and sheep mesenchymal cells viability. The results confirm that the presence of the additive is able to increase the swelling ability of the material (the samples containing 20% w/w of additive are able to absorb an amount of water 6 times higher than the value for polycaprolactone ones), the Young’s modulus (from 224±14 MPa for polycaprolactone to 388±30 MPa for the composites containing 20% of microcrystalline cellulose) and the bioaffinity of polycaprolactone based composite materials

Sheep condyle model evaluation of bone marrow cell concentrate combined with a scaffold for repair of large osteochondral defects

AIMS: Minimally manipulated cells, such as autologous bone marrow concentrates (BMC), have been investigated in orthopaedics as both a primary therapeutic and augmentation to existing restoration procedures. However, the efficacy of BMC in combination with tissue engineering is still unclear. In this study, we aimed to determine whether the addition of BMC to an osteochondral scaffold is safe and can improve the repair of large osteochondral defects when compared to the scaffold alone. METHODS: The ovine femoral condyle model was used. Bone marrow was aspirated, concentrated, and used intraoperatively with a collagen/hydroxyapatite scaffold to fill the osteochondral defects (n = 6). Tissue regeneration was then assessed versus the scaffold-only group (n = 6). Histological staining of cartilage with alcian blue and safranin-O, changes in chondrogenic gene expression, microCT, peripheral quantitative CT (pQCT), and force-plate gait analyses were performed. Lymph nodes and blood were analyzed for safety. RESULTS: The results six months postoperatively showed that there were no significant differences in bone regrowth and mineral density between BMC-treated animals and controls. A significant upregulation of messenger RNA (mRNA) for types I and II collagens in the BMC group was observed, but there were no differences in the formation of hyaline-like cartilage between the groups. A trend towards reduced sulphated glycosaminoglycans (sGAG) breakdown was detected in the BMC group but this was not statistically significant. Functional weightbearing was not affected by the inclusion of BMC. CONCLUSION: Our results indicated that the addition of BMC to scaffold is safe and has some potentially beneficial effects on osteochondral-tissue regeneration, but not on the functional endpoint of orthopaedic interest. Cite this article: Bone Joint Res 2021;10(10):677-689

Tropical Cyclones and Climate Change

Trabajo presentado en: 10th International Worskshop Cyclones Tropicales, celebrado del 5 al 9 de diciembre de 2022 en Bali, Indonesia.A substantial number of studies have been published since the IWTC-9 in 2018, improving our understanding of the effect of climate change on tropical cyclones (TCs) and associated hazards and risks. They reinforced the robustness of increases in TC intensity and associated TC hazards and risks due to anthropogenic climate change. New modeling and observational studies suggested the potential influence of anthropogenic climate forcings, including greenhouse gases and aerosols, on global and regional TC activity at the decadal and century time scale. However, there is still substantial uncertainty owing to model uncertainty in simulating historical TC decadal variability in the Atlantic and owing to limitations of observed TC records. The projected future change in the global number of TCs has become more uncertain since IWTC-9 due to projected increases in TC frequency by a few climate models. A new paradigm, TC seeds, has been proposed, and there is currently a debate on whether seeds can help explain the physical mechanism behind the projected changes in global TC frequency. New studies also highlighted the importance of large-scale environmental fields on TC activity, such as snow cover and air-sea interactions. Future projections on TC translation speed and Medicanes are new additional focus topics in our report. Recommendations and future research are proposed relevant to the remaining scientific questions and assisting policymakers

At the beginnings of the funerary Megalithism in Iberia at Campo de Hockey necropolis

The excavations undertaken at the Campo de Hockey site in 2008 led to the identification of a major Neolithic necropolis in the former Island of San Fernando (Bay of Cádiz). This work presents the results of the latest studies, which indicate that the site stands as one of the oldest megalithic necropolises in the Iberian Peninsula. The main aim of this work is to present with precision the chronology of this necropolis through a Bayesian statistical model that confirms that the necropolis was in use from c. 4300 to 3800 cal BC. The presence of prestige grave goods in the earliest and most monumental graves suggest that the Megalithism phenomenon emerged in relation to maritime routes linked to the distribution of exotic products. We also aim to examine funerary practices in these early megalithic communities, and especially their way of life and the social reproduction system. As such, in addition to the chronological information and the Bayesian statistics, we provide the results of a comprehensive interdisciplinary study, including anthropological, archaeometric and genetic data.Archaeological background: the Campo de Hockey settlement Methods - Tomb typology - Radiocarbon dates and Bayesian analysis. - Bioarchaeology. - DNA - Grave goods Results - Tomb typology - Radiocarbon dating: Bayesian analysis - Bioarchaeology. - DNA - Grave goods. Discussion and conclusions

Sometidos a esclavitud: los africanos y sus descendientes en el Caribe Hispano

Con autorización de la editorial para este libro. La edición estuvo a cargo de Consuelo Naranjo Orovio.Sometidos a esclavitud: los africanos y sus descendientes en el Caribe hispano contribuye al estudio de la historia Atlántica en la que la esclavización de millones de africanos fue uno de principales factores que generaron e impulsaron el desarrollo del mundo moderno. La formación de redes comerciales, compañías mercantiles y negocios particulares contribuyeron a conectar mundos y a hacerlos interdependientes. Junto a las mercancías, individuos y productos, viajaron ideas y tradiciones que fueron tejiendo la historia atlántica. En ella, la esclavización, los esclavizados y los afrodescendientes fueron y son partes destacadas, como muestra su legado presente de las culturas americanas. Estos estudios de la obra se suman a investigaciones que, desde distintos países, proyectos, grupos de investigación y enfoques, se están realizando sobre un tema tan rico, diverso y complejo como es la esclavitud atlántica. El espacio temporal que recorren los capítulos se prolonga en el tiempo como lo hizo la trata y el sistema esclavista. Lo mismo ocurre con los territorios afectados por este fenómeno. Su cartografía es una larga sombra que se expande por el mundo atlántico desde el siglo XVI hasta las últimas décadas del siglo XIX. Distintos actores y puntos de África, Europa y América emergen como protagonistas del sometimiento, el comercio y la esclavización de más de doce millones y medio de africanos.Este libro se inserta en el proyecto europeo Connected Worlds: The Caribbean, Origin of Modern World. This project has received funding from the European Union´s Horizon 2020 research and innovation programme under the Marie Sklodowska Curie grant agreement Nº 823846. This project is directed by professor Consuelo Naranjo Orovio, Institute of History-CSIC.Peer reviewe

VIII Encuentro de Docentes e Investigadores en Historia del Diseño, la Arquitectura y la Ciudad

Acta de congresoLa conmemoración de los cien años de la Reforma Universitaria de 1918 se presentó como una ocasión propicia para debatir el rol de la historia, la teoría y la crítica en la formación y en la práctica profesional de diseñadores, arquitectos y urbanistas. En ese marco el VIII Encuentro de Docentes e Investigadores en Historia del Diseño, la Arquitectura y la Ciudad constituyó un espacio de intercambio y reflexión cuya realización ha sido posible gracias a la colaboración entre Facultades de Arquitectura, Urbanismo y Diseño de la Universidad Nacional y la Facultad de Arquitectura de la Universidad Católica de Córdoba, contando además con la activa participación de mayoría de las Facultades, Centros e Institutos de Historia de la Arquitectura del país y la región. Orientado en su convocatoria tanto a docentes como a estudiantes de Arquitectura y Diseño Industrial de todos los niveles de la FAUD-UNC promovió el debate de ideas a partir de experiencias concretas en instancias tales como mesas temáticas de carácter interdisciplinario, que adoptaron la modalidad de presentación de ponencias, entre otras actividades. En el ámbito de VIII Encuentro, desarrollado en la sede Ciudad Universitaria de Córdoba, se desplegaron numerosas posiciones sobre la enseñanza, la investigación y la formación en historia, teoría y crítica del diseño, la arquitectura y la ciudad; sumándose el aporte realizado a través de sus respectivas conferencias de Ana Clarisa Agüero, Bibiana Cicutti, Fernando Aliata y Alberto Petrina. El conjunto de ponencias que se publican en este Repositorio de la UNC son el resultado de dos intensas jornadas de exposiciones, cuyos contenidos han posibilitado actualizar viejos dilemas y promover nuevos debates. El evento recibió el apoyo de las autoridades de la FAUD-UNC, en especial de la Secretaría de Investigación y de la Biblioteca de nuestra casa, como así también de la Facultad de Arquitectura de la UCC; va para todos ellos un especial agradecimiento