445 research outputs found
Recovering and Exploiting Aragonite and Calcite Single Crystals with Biologically Controlled Shapes from Mussel Shells
This research was performed under the Bluebio ERANET project CASEAWA (grant no.: 161B0949). This study represents partial fulfillment of the requirements for the International FishMed-PhD thesis of C.T. J.G.M acknowledges the CASEAWA project, grant no. PCI2020-112108 funded by MCIN/AEI/10.13039/501100011033 (Spain) and the EU “NextGenerationEU”/PRTR”. PCI2020-112108 is part of the ERANET Cofund BlueBio Programme supported by the European Union.Control over the shape and morphology of single crystals is a theme of great interest in fundamental science and for technological application. Many synthetic strategies to achieve this goal are inspired by biomineralization processes. Indeed, organisms are able to produce crystals with high fidelity in shape and morphology utilizing macromolecules that act as modifiers. An alternative strategy can be the recovery of crystals from biomineralization products, in this case, seashells. In particular, waste mussel shells from aquaculture are considered. They are mainly built up of single crystals of calcite fibers and aragonite tablets forming an outer and an inner layer, respectively. A simple mechanochemical treatment has been developed to separate and recover these two typologies of single crystals. The characterization of these single crystals showed peculiar properties with respect to the calcium carbonate from quarry or synthesis. We exploited these biomaterials in the water remediation field using them as substrate adsorbing dyes. We found that these substrates show a high capability of adsorption for anionic dye, such as Eosin Y, but a low capability of adsorption for cationic dyes, such as Blue Methylene. The adsorption was reversible at pH 5.6. This application represents just an example of the potential use of these biogenic single crystals. We also envision potential applications as reinforcing fillers and optical devices.Bluebio ERANET: CASEAWA 161B0949MCIN/AEI/10.13039/501100011033 (Spain) PCI2020-112108EU “NextGenerationEU”/PRTR”European Unio
Análisis discriminante de algunas variables que influyen en la contaminación acústica debida al tráfico urbano en una gran ciudad
El ruido producido por el tráfico es función de un gran número de variables, unas propias de las características de la calzada y del entorno por el que discurre, y otras propias de los vehículos. De todas las variables que pueden influir, solo unas pocas están estudiadas en profundidad para ver su relación real con la contamina- ción acústica. El nivel de presión sonora, Leq, es el índice utilizado para evaluar la contaminación acústica, y la unidad de medida es el decibelio.
Esta investigación consiste en la medición de todas las variables presentes en una gran ciudad que pudieran tener alguna influencia en la contaminación acústica, así como el nivel de ruido en la ciudad de Madrid. Todo ello mediante un trabajo de campo en el que se han medido 519 puntos de forma aleatoria, en los que se iban registrando todos estos datos
Progress on the preparation of nanocrystalline apatites and surface characterization: Overview of fundamental and applied aspects
Nanocrystalline calcium phosphate apatites constitute the main inorganic part of hard tissues, and a growing focus is devoted to prepare synthetic analogs, so-called “biomimetic”, able to precisely mimic the morphological and physico-chemical features of biological apatite compounds. Both from fundamental and applied viewpoints, an accurate characterization of nanocrystalline apatites, including their peculiar surface features, and a deep knowledge of crystallization aspects are prerequisites to attempt understanding mineralization phenomena in vivo as well as for designing innovative bioactive materials that may then find applications in bone tissue engineering, either as self-supported scaffolds and fillers or in the form of coatings, but also in other domains such as drug delivery or else medical imaging. Also,interfacial phenomena are of prime importance for getting a better insight of biomineralization and for following the behavior of biomaterials in or close to their final conditions of use. In this view,both adsorption and ion exchange represent essential processes involving the surface of apatite nanocrystals, possibly doped with foreign elements or functionalized with organic molecules of interest. In this review paper, we will address these various points in details based on a large literature survey. We will also underline the fundamental physico-chemical and behavioral differences that exist between nanocrystalline apatites (whether of biological origin or their synthetic biomimetic analogs) and stoichiometric hydroxyapatite
Hydrothermal Transformation of Eggshell Calcium Carbonate into Apatite Micro-Nanoparticles: Cytocompatibility and Osteoinductive Properties
This research was funded by Spanish Agencia Estatal de Investigación of the Ministerio de Ciencia e Innovación y Universidades (MCIU), Bioscaffold project, ref. PGC2018-102047-B-I00 (MCIU/AEI/FEDER, UE). The Ministry of Science, Technology, and Innovation of Colombia provided support for A.T-M´s participation. P.Á.-L. acknowledge support from MCIN project PCI2019–111931-2 and the European Regional Development Fund–ERDF)—Next Generation/EU program. J.G.-M. acknowledges PCI2020-112108 funded by MCI/AEI/10.13039/501100011033 (Spain) and the European Union “NextGeneration/PRTR”. PCI2020-112108 is part of the CASEAWA project of the ERA-NET Cofund BlueBio Programme, supported by the European Union (H2020).
The authors acknowledge the staff of Scientific Instrumentation Centre (CIC) of the University of Granada for HRSEM and TGA characterizations and Scientific and Technical Services of the University of Oviedo for XRD analyses.Supplementary Materials: The following supporting information can be downloaded at:
https://www.mdpi.com/article/10.3390/nano13162299/s1The eggshell is a biomineral consisting of CaCO3 in the form of calcite phase and a pervading organic matrix (1-3.5 wt.%). Transforming eggshell calcite particles into calcium phosphate (apatite) micro-nanoparticles opens the door to repurposing the eggshell waste as materials with potential biomedical applications, fulfilling the principles of the circular economy. Previous methods to obtain these particles consisted mainly of two steps, the first one involving the calcination of the eggshell. In this research, direct transformation by a one-pot hydrothermal method ranging from 100-200 C-circle was studied, using suspensions with a stoichiometric P/CaCO3 ratio, K2HPO4 as P reagent, and eggshells particles (phi < 50 mu m) both untreated and treated with NaClO to remove surface organic matter. In the untreated group, the complete conversion was achieved at 160 C-circle, and most particles displayed a hexagonal plate morphology, eventually with a central hole. In the treated group, this replacement occurred at 180 C-circle, yielding granular (spherulitic) apatite nanoparticles. The eggshell particles and apatite micro-nanoparticles were cytocompatible when incubated with MG-63 human osteosarcoma cells and m17.ASC murine mesenchymal stem cells and promoted the osteogenic differentiation of m17.ASC cells. The study results are useful for designing and fabricating biocompatible microstructured materials with osteoinductive properties for applications in bone tissue engineering and dentistry.Spanish Agencia Estatal de Investigación of the Ministerio de Ciencia e Innovación y Universidades (MCIU)Bioscaffold project PGC2018-102047-B-I00 (MCIU/AEI/FEDER, UE)Ministry of Science, Technology, and Innovation of ColombiaMCIN project PCI2019–111931-2European Regional Development Fund–ERDF—Next Generation/EU programMCI/AEI/10.13039/501100011033 (Spain) PCI2020-112108European Union “NextGeneration/PRTR”European Union (H2020), CASEAWA of ERA-NET, PCI2020-112108University of Granada, Scientific Instrumentation Centre (CIC)University of Oviedo, Scientific and Technical Service
Análisis discriminante de algunas variables que influyen en la contaminación acústica debida al tráfico urbano en una gran ciudad.
El ruido producido por el tráfico es función de un gran número de variables, unas propias de las características de la calzada y del entorno por el que discurre, y otras propias de los vehículos. De todas las variables que pueden influir, solo unas pocas están estudiadas en profundidad para ver su relación real con la contaminación acústica. El nivel de presión sonora, Leq, es el índice utilizado para evaluar la contaminación acústica, y la unidad de medida es el decibelio. Esta investigación consiste en la medición de todas las variables presentes en una gran ciudad que pudieran tener alguna influencia en la contaminación acústica, así como el nivel de ruido en la ciudad de Madrid. Todo ello mediante un trabajo de campo en el que se han medido 519 puntos de forma aleatoria, en los que se iban registrando todos estos datos
Chikungunya, a Global Threat Currently Circulating in Latin America
Chikungunya fever (CHIK) is a highly important arbovirosis currently established in Latin America and the Caribbean (LAC); its acute and chronic burden is an overlooked issue for policy makers. Disease spread control and proper management of chronic-derived sequelae do not seem like a realistic goal in short- and mid-term. The CHIKV circulating in the Western Hemisphere is closely related to strains from Philippines, China, and Yap (Federated States of Micronesia), and vertical and horizontal transmission of infection has been reported. Pathogenesis is still not well understood, and vaccines are under development yet. Here, we provide a summary of information regarding LAC spread of the disease from a public health, clinical and molecular perspective, particularly from the experience in Colombia
Biomimetic Citrate-Coated Luminescent Apatite Nanoplatforms for Diclofenac Delivery in Inflammatory Environments
This research was funded by Spanish Agencia Estatal de Investigacion (AEI) of the Ministerio de Ciencia e Innovacion (MCI) and co-funded with FEDER, UE, Project No. PGC2018-102047-B-I00 (MCIU/AEI/FEDER, UE). M.P. acknowledges the Progetto di Ricerca Fondi di Ateneo per la Ricerca-FAR 2018 "Development of innovative biological materials for the functional regeneration of cardiac tissue models".Luminescent nanoparticles are innovative tools for medicine, allowing the imaging of cells and tissues, and, at the same time, carrying and releasing different types of molecules. We explored and compared the loading/release ability of diclofenac (COX-2 antagonist), in both undoped- and luminescent Terbium(3+) (Tb3+)-doped citrate-coated carbonated apatite nanoparticles at different temperatures (25, 37, 40 degrees C) and pHs (7.4, 5.2). The cytocompatibility was evaluated on two osteosarcoma cell lines and primary human osteoblasts. Biological effects of diclofenac-loaded-nanoparticles were monitored in an in vitro osteoblast's cytokine-induced inflammation model by evaluating COX-2 mRNA expression and production of PGE(2). Adsorption isotherms fitted the multilayer Langmuir-Freundlich model. The maximum adsorbed amounts at 37 degrees C were higher than at 25 degrees C, and particularly when using the Tb3+ -doped particles. Diclofenac-release efficiencies were higher at pH 5.2, a condition simulating a local inflammation. The luminescence properties of diclofenac-loaded Tb3+ -doped particles were affected by pH, being the relative luminescence intensity higher at pH 5.2 and the luminescence lifetime higher at pH 7.4, but not influenced either by the temperature or by the diclofenac-loaded amount. Both undoped and Tb3+-doped nanoparticles were cytocompatible. In addition, diclofenac release increased COX-2 mRNA expression and decreased PGE(2) production in an in vitro inflammation model. These findings evidence the potential of these nanoparticles for osteo-localized delivery of anti-inflammatory drugs and the possibility to localize the inflammation, characterized by a decrease in pH, by changes in luminescence.Spanish Agencia Estatal de Investigacion (AEI) of the Ministerio de Ciencia e Innovacion (MCI)European Commission PGC2018-102047-B-I0
New injectable two-step forming hydrogel for delivery of bioactive substances in tissue regeneration
The authors would like to thank Dr Alberto Fernández-Medarde (Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, CSIC-USAL) for proofreading the article. Moreover, the help and the advice in the interpretation on FTIR spectra given by Dr Jose Adrián Gavin (Organic Chemistry Department, ULL) and Dr Antonio Manuel Hernández-Daranas (Instituto de Productos Naturales y Agrobiología, CSIC) is appreciated.A hydrogel based on chitosan, collagen, hydroxypropyl-γ-cyclodextrin and polyethylene glycol was developed and characterized. The incorporation of nano-hydroxyapatite and pre-encapsulated hydrophobic/hydrophilic model drugs diminished the porosity of hydrogel from 81.62 ± 2.25% to 69.98 ± 3.07%. Interactions between components of hydrogel, demonstrated by FTIR spectroscopy and rheology, generated a network that was able to trap bioactive components and delay the burst delivery. The thixotropic behavior of hydrogel provided adaptability to facilitate its implantation in a minimally invasive way. Release profiles from microspheres included or not in hydrogel revealed a two-phase behavior with a burst- and a controlled-release period. The same release rate for microspheres included or not in the hydrogel in the controlled-release period demonstrated that mass transfer process was controlled by internal diffusion. Effective diffusion coefficients, Deff, that describe internal diffusion inside microspheres, and mass transfer coefficients, h, i.e. the contribution of hydrogel to mass transfer, were determined using ‘genetic algorithms’, obtaining values between 2.64·10−15 and 6.67·10−15 m2/s for Deff and 8.50·10−10 to 3.04·10−9 m/s for h. The proposed model fits experimental data, obtaining an R2-value ranged between 95.41 and 98.87%. In vitro culture of mesenchymal stem cells in hydrogel showed no manifestations of intolerance or toxicity, observing an intense proliferation of the cells after 7 days, being most of the scaffold surface occupied by living cells.This work was supported by the Ministry of Science and Technology, Spain (MAT2014-55657-R)
Magnetic Bioactive and Biodegradable Hollow Fe-Doped Hydroxyapatite Coated Poly(L‑lactic) Acid Micro-nanospheres
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