3D-printed alginate-hydroxyapatite aerogel scaffolds for bone tissue engineering

3D-printing technology allows the automated and reproducible manufacturing of functional structures for tissue engineering with customized geometries and compositions by depositing materials layer-by-layer with high precision. For these purposes, the production of bioactive gel-based 3D-scaffolds made of biocompatible materials with well-defined internal structure comprising a dual (mesoporous and macroporous) and highly interconnected porosity is essential. In this work, aerogel scaffolds for bone regeneration purposes were obtained by an innovative strategy that combines the 3D-printing of alginate-hydroxyapatite (HA) hydrogels and the supercritical CO2 drying of the gels. BET and SEM analyses were performed to assess the textural parameters of the obtained aerogel scaffolds and the dimensional accuracy to the original computer-aided design (CAD) design was also evaluated. The biological characterization of the aerogel scaffolds was also carried out regarding cell viability, adhesion and migration capacity. The obtained alginate-HA aerogel scaffolds were highly porous, biocompatible, with high fidelity to the CAD-pattern and also allowed the attachment and proliferation of mesenchymal stem cells (MSCs). An enhancement of the fibroblast migration toward the damaged area was observed in the presence of the aerogel formulations tested, which is positive in terms of bone regenerationThis work was supported by Xunta de Galicia [ED431C 2020/17], MICINN [PID2020-120010RB-I00], Agencia Estatal de Investigación [AEI] and FEDER funds. Work carried out in the framework of the COST Action CA18125 “Advanced Engineering and Research of aeroGels for Environment and Life Sciences” (AERoGELS) and funded by the European Commission. A.I.-M. acknowledges to Xunta de Galicia for her predoctoral research fellowship [ED481A- 2020/104]. A. Alonso is commended for his technical contribution to this workS

100 años investigando el mar. El IEO en su centenario (1914-2014).

Se trata de un libro que pretende divulgar a la sociedad las principales investigaciones multidisciplinares llevadas a cabo por el Instituto Español de Oceanografía durante su primer siglo de vida, y dar a conocer la historia del organismo, de su Sede Central y de los nueve centros oceanográficos repartidos por los litorales mediterráneo y atlántico, en la península y archipiélagos.Kongsberg 20

Estudios de marcado y recaptura de especies marinas

Los resultados obtenidos del marcado y posterior recaptura de los ejemplares son una herramienta muy valiosa para contribuir a mejorar el conocimiento de la biología y ecología de una especie, examinando ciertos aspectos como son: el crecimiento, los movimientos o migraciones, la mortalidad o supervivencia, la abundancia y distribución de la especie, el hábitat y diferenciación de poblaciones o stocks. Actualmente la técnica de marcado se aplica a muchas especies, tanto terrestres como marinas, pertenecientes a diversos grupos zoológicos: peces, crustáceos, reptiles, moluscos y mamíferos. Este libro repasa algunos ejemplos de marcado de especies marinas de interés comercial. No todas las especies pueden ser marcadas, porque es necesario cumplir una serie de requisitos para poder llevar a cabo con éxito un experimento de marcado. En uno de los apartados de esta guía, se describen los distintos aspectos a tener en cuenta para obtener buenos resultados. Se describen los principales proyectos de marcado actualmente en ejecución o en marcha llevados a cabo por el Instituto Español de Oceanografía (IEO). En primer lugar, se describe brevemente la especie, su distribución, crecimiento, reproducción, alimentación, etc. A continuación, se presenta la información del marcado, es decir, campañas realizadas, número de ejemplares marcados y algunos de los resultados obtenidos hasta la fecha a partir de las recapturas disponibles. En algunas especies, los programas de marcado se llevan realizando desde hace más de 20 años, como es el caso del atún rojo, por lo que la información disponible es bastante amplia. En otros casos por el contrario como la merluza, los proyectos son relativamente recientes, no obstante los resultados son bastante interesantes y prometedores.Nowadays many different marine animals are being tagged. This book summarizes recent tagging programs carried out by the Spanish Institute of Oceanography (IEO). Although the objectives of these various studies mainly depend on the species and each project in particular, the general aim is to better understand the biology and ecology of these animals the structure and dynamics of their populations and their capacity to respond to human activities. This book provides an overview of different aspects of this technique such as a brief history of tagging, the types of tags currently used, including both conventional and electronic tags, where and how to put them on the marine animals, some recommendations regarding how to perform a tagging survey and where to go or what to do if anyone recovers a tagged fish or marine animal. The book then summarizes the main species tagged by the IEO, making a short description of their biology followed by some of the results obtained from tagging studies undertaken until now. Other applications are to know the spatial distribution (spawning or feeding areas), estimate growth parameters, mortality and survival rates, longevity, the size of the population or identifying stocks. Nowadays the advances in electronics have also open new fields such us the possibility of tracking an animal and knowing its habitat preferences and behaviour. Besides some of these tags have the capacity of recording this information during long periods and sending the data from long distances even without the need to recover the animal. Tagging activities constitute a very useful tool to improve the knowledge of many species and contribute to their management and conservation. For that reason this methodology is included in many IEO projects in which other activities like the monitoring of the fishery (landings, fishing effort, fleet characteristics, fishing areas, biological sampling, etc.) are carried out. Some projects are related with coastal pelagic fisheries including anchovy, sardine and mackerel or oceanic pelagic fisheries like tuna and billfish species and pelagic sharks. Others are focused on benthic and demersal species such as hake, black spot seabream, anglerfish, flatfish, etc. Nevertheless not all species can be tagged, as they have to survive being caught and handled before being release. For this reason, tagging techniques may not easily be applied to some species

Estudios de marcado y recaptura de especies marinas

Los resultados obtenidos del marcado y posterior recaptura de los ejemplares son una herramienta muy valiosa para contribuir a mejorar el conocimiento de la biología y ecología de una especie, examinando ciertos aspectos como son: el crecimiento, los movimientos o migraciones, la mortalidad o supervivencia, la abundancia y distribución de la especie, el hábitat y diferenciación de poblaciones o stocks. Actualmente la técnica de marcado se aplica a muchas especies, tanto terrestres como marinas, pertenecientes a diversos grupos zoológicos: peces, crustáceos, reptiles, moluscos y mamíferos. Este libro repasa algunos ejemplos de marcado de especies marinas de interés comercial. No todas las especies pueden ser marcadas, porque es necesario cumplir una serie de requisitos para poder llevar a cabo con éxito un experimento de marcado. En uno de los apartados de esta guía, se describen los distintos aspectos a tener en cuenta para obtener buenos resultados. Se describen los principales proyectos de marcado actualmente en ejecución o en marcha llevados a cabo por el Instituto Español de Oceanografía (IEO). En primer lugar, se describe brevemente la especie, su distribución, crecimiento, reproducción, alimentación, etc. A continuación, se presenta la información del marcado, es decir, campañas realizadas, número de ejemplares marcados y algunos de los resultados obtenidos hasta la fecha a partir de las recapturas disponibles. En algunas especies, los programas de marcado se llevan realizando desde hace más de 20 años, como es el caso del atún rojo, por lo que la información disponible es bastante amplia. En otros casos por el contrario como la merluza, los proyectos son relativamente recientes, no obstante los resultados son bastante interesantes y prometedores.Nowadays many different marine animals are being tagged. This book summarizes recent tagging programs carried out by the Spanish Institute of Oceanography (IEO). Although the objectives of these various studies mainly depend on the species and each project in particular, the general aim is to better understand the biology and ecology of these animals the structure and dynamics of their populations and their capacity to respond to human activities. This book provides an overview of different aspects of this technique such as a brief history of tagging, the types of tags currently used, including both conventional and electronic tags, where and how to put them on the marine animals, some recommendations regarding how to perform a tagging survey and where to go or what to do if anyone recovers a tagged fish or marine animal. The book then summarizes the main species tagged by the IEO, making a short description of their biology followed by some of the results obtained from tagging studies undertaken until now. Other applications are to know the spatial distribution (spawning or feeding areas), estimate growth parameters, mortality and survival rates, longevity, the size of the population or identifying stocks. Nowadays the advances in electronics have also open new fields such us the possibility of tracking an animal and knowing its habitat preferences and behaviour. Besides some of these tags have the capacity of recording this information during long periods and sending the data from long distances even without the need to recover the animal. Tagging activities constitute a very useful tool to improve the knowledge of many species and contribute to their management and conservation. For that reason this methodology is included in many IEO projects in which other activities like the monitoring of the fishery (landings, fishing effort, fleet characteristics, fishing areas, biological sampling, etc.) are carried out. Some projects are related with coastal pelagic fisheries including anchovy, sardine and mackerel or oceanic pelagic fisheries like tuna and billfish species and pelagic sharks. Others are focused on benthic and demersal species such as hake, black spot seabream, anglerfish, flatfish, etc. Nevertheless not all species can be tagged, as they have to survive being caught and handled before being release. For this reason, tagging techniques may not easily be applied to some species.Versión del edito

3D-Printed, Dual Crosslinked and Sterile Aerogel Scaffolds for Bone Tissue Engineering

The fabrication of bioactive three-dimensional (3D) hydrogel scaffolds from biocompatible materials with a complex inner structure (mesoporous and macroporous) and highly interconnected porosity is crucial for bone tissue engineering (BTE). 3D-printing technology combined with aerogel processing allows the fabrication of functional nanostructured scaffolds from polysaccharides for BTE with personalized geometry, porosity and composition. However, these aerogels are usually fragile, with fast biodegradation rates in biological aqueous fluids, and they lack the sterility required for clinical practice. In this work, reinforced alginate-hydroxyapatite (HA) aerogel scaffolds for BTE applications were obtained by a dual strategy that combines extrusion-based 3D-printing and supercritical CO2 gel drying with an extra crosslinking step. Gel ageing in CaCl2 solutions and glutaraldehyde (GA) chemical crosslinking of aerogels were performed as intermediate and post-processing reinforcement strategies to achieve highly crosslinked aerogel scaffolds. Nitrogen adsorption–desorption (BET) and SEM analyses were performed to assess the textural parameters of the resulting alginate-HA aerogel scaffolds. The biological evaluation of the aerogel scaffolds was performed regarding cell viability, hemolytic activity and bioactivity for BTE. The impact of scCO2-based post-sterilization treatment on scaffold properties was also assessed. The obtained aerogels were dual porous, bio- and hemocompatible, as well as endowed with high bioactivity that is dependent on the HA content. This work is a step forward towards the optimization of the physicochemical performance of advanced biomaterials and their sterilization

Nanomolar resveratrol reduces early alterations of pancreatitis and pancreatic cancer in pancreatic acinar cells

Resveratrol is a natural phytoalexin present in human diet with a potential beneficial effect in many diseases including chronic and acute pancreatitis, a potentially fatal disease with significant morbimortality accompanied with obscure pathogenesis and without effective treatments. Resveratrol has also been shown to be a promising anti-tumor molecule on the millimolar scale. In this study, the protective effects of nanomolar concentrations of resveratrol against early events common to pancreatic cancer and pancreatitis induced by supra-physiological concentrations of cholecystokinin (CCK, 100 nM) were evaluated. Resveratrol (200, 500 nM) reduced CCK-induced intracellular trypsin activation and cell injury in isolated rat pancreatic acinar cells (PAC). The damage induced by high CCK and the protective effect of resveratrol was also measured in pancreatic tissue explants by analyzing histological changes. Finally, the effect of resveratrol on the CCK-enhanced nuclear factor κB (NF-κB) expression was studied by Western blot experiments in the AR42J pancreatic acinar cell line. Our results show, for the first time, the ability of resveratrol to reduce premature intracellular activation of trypsin and necrosis in PAC. It is suggested that resveratrol counteracts CCK-induced pancreatic tissue breakdown by downregulation of NF-κB in the nuclear fraction. Since these effects occur at nanomolar concentrations that can be achieved by oral intake, our results suggest that dietary consumption of resveratrol could have a preventive effect and delay the evolution of pancreatitis and pancreatic cancer.</p

Preparation of Vancomycin-Loaded Aerogels Implementing Inkjet Printing and Superhydrophobic Surfaces

Chronic wounds are physical traumas that significantly impair the quality of life of over 40 million patients worldwide. Aerogels are nanostructured dry porous materials that can act as carriers for the local delivery of bioactive compounds at the wound site. However, aerogels are usually obtained with low drug loading yields and poor particle size reproducibility and urges the implementation of novel and high-performance processing strategies. In this work, alginate aerogel particles loaded with vancomycin, an antibiotic used for the treatment of Staphylococcus aureus infections, were obtained through aerogel technology combined with gel inkjet printing and water-repellent surfaces. Alginate aerogel particles showed high porosity, large surface area, a well-defined spherical shape and a reproducible size (609 &plusmn; 37 &mu;m). Aerogel formulation with vancomycin loadings of up to 33.01 &plusmn; 0.47 &mu;g drug/mg of particle were obtained with sustained-release profiles from alginate aerogels for more than 7 days (PBS pH 7.4 medium). Overall, this novel green aerogel processing strategy allowed us to obtain nanostructured drug delivery systems with improved drug loading yields that can enhance the current antibacterial treatments for chronic wounds

Cellulose-in-cellulose 3D-printed bioaerogels for bone tissue engineering

Nanostructured scaffolds based on cellulose with advanced performances and personalized morphologies for bone tissue engineering are under technological development. 3D-printing and supercritical carbon dioxide (scCO2) technologies are innovative processing strategies that, when combined, allow the precise fabrication of highly porous aerogel scaffolds. Novel sterile cellulose-in-cellulose aerogels decorated with superparamagnetic iron oxide nanoparticles (SPIONs) are synthesized in this work by an integrated technological platform based on 3D-printing and scCO2. Methylcellulose (MC) and bacterial nanocellulose (BC) are two versatile cellulosic polysaccharides with remarkable physicochemical and biological performances, whereas SPIONs are commonly used to functionalize biomaterials aimed at tissue engineering. Aerogels with hierarchical porosity and high structural resolution were obtained according to nitrogen adsorption–desorption analysis, confocal, scanning and transmission microscopies (SEM and TEM). The magnetic properties of SPIONs-doped aerogels confirmed the correct functionalization of the nanostructures. Finally, NIH/3T3 fibroblast cell viability, hemocompatibility with human blood and safety tests (in ovo with HET-CAM and in vivo with Artemia salina) indicate the biocompatibility of the cellulose-in-cellulose aerogels. Graphical abstract: [Figure not available: see fulltext.].This work was supported by Xunta de Galicia [ED431C 2020/17], MICINN [PID2020-120010RB-I00; PDC2022-133526-I00; PID2021-122645OB-I00], Agencia Estatal de Investigación [AEI], FEDER funds, 'Severo Ochoa' Programme for Center of Excellence in R&D (CEX2019-000917), and Generalitat de Catalunya (2021SGR00446 Grant). Work carried out in the framework of the COST Action IG18125 “Technical, commercial and societal innovations on aerogels towards circular economy” (ECO-AERoGELS) and funded by the European Commission. This work was also supported by Fundação para a Ciência e Tecnologia (FCT), Portugal, under the project references UIDB/00645/2020, UIDB/04138/2020 and UIDP/04138/2020. A.I.-M. acknowledges to Xunta de Galicia [ED481A-2020/104], N.M. to MICINN (PRE2019-089754, enrolled at the Biotechnology PhD program of the UABand), and T.F.-G. to Fundação para a Ciência e a Tecnologia, I.P. (FCT) [SFRH/BD/147306/2019] for their predoctoral research fellowships. N.M., A.L., and A.R. participate in the Spanish National Research Council (CSIC) interdisciplinary platform for sustainable plastics towards a circular economy (SusPlast), Nanomed Hub, Conexion Nanomedicina, Red Nanocare 2.0, and EPNOE network.With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).Peer reviewe

Nanomolar resveratrol reduces early alterations of pancreatitis and pancreatic cancer in pancreatic acinar cells

Resveratrol is a natural phytoalexin present in human diet with a potential beneficial effect in many diseases including chronic and acute pancreatitis, a potentially fatal disease with significant morbimortality accompanied with obscure pathogenesis and without effective treatments. Resveratrol has also been shown to be a promising anti-tumor molecule on the millimolar scale. In this study, the protective effects of nanomolar concentrations of resveratrol against early events common to pancreatic cancer and pancreatitis induced by supra-physiological concentrations of cholecystokinin (CCK, 100 nM) were evaluated. Resveratrol (200, 500 nM) reduced CCK-induced intracellular trypsin activation and cell injury in isolated rat pancreatic acinar cells (PAC). The damage induced by high CCK and the protective effect of resveratrol was also measured in pancreatic tissue explants by analyzing histological changes. Finally, the effect of resveratrol on the CCK-enhanced nuclear factor κB (NF-κB) expression was studied by Western blot experiments in the AR42J pancreatic acinar cell line. Our results show, for the first time, the ability of resveratrol to reduce premature intracellular activation of trypsin and necrosis in PAC. It is suggested that resveratrol counteracts CCK-induced pancreatic tissue breakdown by downregulation of NF-κB in the nuclear fraction. Since these effects occur at nanomolar concentrations that can be achieved by oral intake, our results suggest that dietary consumption of resveratrol could have a preventive effect and delay the evolution of pancreatitis and pancreatic cancer

Biological Thermal Performance of Organic and Inorganic Aerogels as Patches for Photothermal Therapy

Aerogels are materials with unique properties, among which are low density and thermal conductivity. They are also known for their exquisite biocompatibility and biodegradability. All these features make them attractive for biomedical applications, such as their potential use in photothermal therapy (PTT). This technique is, yet, still associated with undesirable effects on surrounding tissues which emphasizes the need to minimize the exposure of healthy regions. One way to do so relies on the use of materials able to block the radiation and the heat generated. Aerogels might be potentially useful for this purpose by acting as insulators. Silica- and pectin-based aerogels are reported as the best inorganic and organic thermal insulators, respectively; thus, the aim of this work relies on assessing the possibility of using these materials as light and thermal insulators and delimiters for PTT. Silica- and pectin-based aerogels were prepared and fully characterized. The thermal protection efficacy of the aerogels when irradiated with a near-infrared laser was assessed using phantoms and ex vivo grafts. Lastly, safety was assessed in human volunteers. Both types presented good textural properties and safe profiles. Moreover, thermal activation unveils the better performance of silica-based aerogels, confirming the potential of this material for PTT