Tidal changes in estuarine systems induced by local geomorphologic modifications

Although rising global sea levels will affect the estuarine flooded areas over the coming decades, the local and regional-scale processes will also induce important changes in these coastal systems. The main aim of this work is to investigate possible tidal changes in estuarine systems induced by local geomorphologic modifications, analysing the particular case of Ria de Aveiro which is in risk of inundation. Located in the Portuguese west coast, this tidally driven lagoon has a large area of mostly abandoned salt pans, which are in progressive degradation caused by the lack of maintenance and by the strong currents which erode their protective walls. To explore possible tidal changes the hydrodynamic model ELCIRC was applied to Ria de Aveiro to simulate and analyse the impact in the lagoon hydrodynamics of this degradation which results in the enlargement of the lagoon flooded area. A high-resolution grid (grid spacing of the order of 1 m) was developed in order to represent the narrow channels adjacent to the salt pans. The hydrodynamic model was then successfully calibrated and assessed for skill for the Aveiro lagoon through comparison between measurements and model results and quantification of the numerical accuracy. The model was subsequently used to investigate the effect of the flooded lagoon area enlargement on tidal propagation in Ria de Aveiro. Simulations were performed for three geomorphologic configurations, representing the reference or present situation and two flooded scenarios. Results were compared through the analysis of tidal currents, tidal asymmetry and tidal prism. The increase of the lagoon flooded area results in an intensification of the tidal currents, tidal prism and tidal asymmetry. Results also indicate that the tidal prism further increases when the flooding depth increases. Otherwise, changes in tidal currents and in tidal asymmetry pattern are negligible with the increase of the flooded area depth. These results indicate that modifications of the flooded area of estuarine systems will result in tidal changes, with an intensification of the actual tidal patterns induced by the enlargement of inundation areas

Toward a Microencapsulated 3D hiPSC-Derived in vitro Cardiac Microtissue for Recapitulation of Human Heart Microenvironment Features

SAICTPAC/0047/2015 PTDC/BTMSAL/32566/ 2017 PTDC/MEC-CAR/29590/2017 UIDB/04462/2020 UIDP/04462/2020 H2020, ID:874827 SFRH/BD/52475/2013 SFRH/BPD/120595/2016The combination of cardiomyocytes (CM) and non-myocyte cardiac populations, such as endothelial cells (EC), and mesenchymal cells (MC), has been shown to be critical for recapitulation of the human heart tissue for in vitro cell-based modeling. However, most of the current engineered cardiac microtissues still rely on either (i) murine/human limited primary cell sources, (ii) animal-derived and undefined hydrogels/matrices with batch-to-batch variability, or (iii) culture systems with low compliance with pharmacological high-throughput screenings. In this work, we explored a culture platform based on alginate microencapsulation and suspension culture systems to develop three-dimensional (3D) human cardiac microtissues, which entails the co-culture of human induced pluripotent stem cell (hiPSC) cardiac derivatives including aggregates of hiPSC–CM and single cells of hiPSC–derived EC and MC (hiPSC–EC+MC). We demonstrate that the 3D human cardiac microtissues can be cultured for 15 days in dynamic conditions while maintaining the viability and phenotype of all cell populations. Noteworthy, we show that hiPSC–EC+MC survival was promoted by the co-culture with hiPSC–CM as compared to the control single-cell culture. Additionally, the presence of the hiPSC–EC+MC induced changes in the physical properties of the biomaterial, as observed by an increase in the elastic modulus of the cardiac microtissue when compared to the hiPSC–CM control culture. Detailed characterization of the 3D cardiac microtissues revealed that the crosstalk between hiPSC–CM, hiPSC–EC+MC, and extracellular matrix induced the maturation of hiPSC–CM. The cardiac microtissues displayed functional calcium signaling and respond to known cardiotoxins in a dose-dependent manner. This study is a step forward on the development of novel 3D cardiac microtissues that recapitulate features of the human cardiac microenvironment and is compliant with the larger numbers needed in preclinical research for toxicity assessment and disease modeling.publishersversionpublishe

Interindividual heterogeneity affects the outcome of human cardiac tissue decellularization

Funding Information: The work here presented was funded by Fundação para a Ciência e Tecnologia (FCT) projects NETDIAMOND (SAICTPAC/0047/2015), financially supported by FEEI-Lisboa2020 and FCT/POCI-01-0145-FEDER-016385, and MetaCardio (PTDC/BTM-SAL/32566/2017); iNOVA4Health-UIDB/04462/2020 and UIDP/04462/2020, a program financially supported by FCT/Ministério da Ciência, Tecnologia e Ensino Superior, through national funds; and EU-funded projects BRAV3 (H2020, ID:874827), ERAatUC (ID: 669088) and Twinning RESETageing (ID: 952266). HVA was financed by FCT Grant SFRH/BPD/120595/2016.The extracellular matrix (ECM) of engineered human cardiac tissues corresponds to simplistic biomaterials that allow tissue assembly, or animal derived off-the-shelf non-cardiac specific matrices. Decellularized ECM from human cardiac tissue could provide a means to improve the mimicry of engineered human cardiac tissues. Decellularization of cardiac tissue samples using immersion-based methods can produce acceptable cardiac ECM scaffolds; however, these protocols are mostly described for animal tissue preparations. We have tested four methods to decellularize human cardiac tissue and evaluated their efficiency in terms of cell removal and preservation of key ECM components, such as collagens and sulfated glycosaminoglycans. Extended exposure to decellularization agents, namely sodium dodecyl sulfate and Triton-X-100, was needed to significantly remove DNA content by approximately 93% in all human donors. However, the biochemical composition of decellularized tissue is affected, and the preservation of ECM architecture is donor dependent. Our results indicate that standardization of decellularization protocols for human tissue is likely unfeasible, and a compromise between cell removal and ECM preservation must be established in accordance with the scaffold’s intended application. Notwithstanding, decellularized human cardiac ECM supported human induced pluripotent-derived cardiomyocyte (hiPSC-CM) attachment and retention for up to 2 weeks of culture, and promoted cell alignment and contraction, providing evidence it could be a valuable tool for cardiac tissue engineering.publishersversionpublishe

Hydrophobic modification of bacterial cellulose using oxygen plasma treatment and chemical vapor deposition

A new strategy for the surface modification of bacterial cellulose (BC) through the combination of oxygen plasma deposition and silanization with trichloromethyl silane (TCMS) is described. The combined use of the two techniques modifies both the surface roughness and energy and therefore maximizes the obtained hydrophobic effect. These modified membranes were characterized by Scanning Electron Microscopy (SEM), water contact angle measurements, Fourier-transform infrared spectroscopy (FTIR-ATR) and X-ray photoelectron spectroscopy (XPS), and its cytotoxic potential was investigated using both indirect and direct contact in vitro studies. The obtained results suggest an effective conjugation of TCMS to the surface of BC, leading to a highly hydrophobic surface, with a water contact angle of approximately 130º. It is also demonstrated that this is a stable and durable surface modification strategy, since BC remained hydrophobic even after 6 months, in dry conditions or after being submerged in distilled water for about a month. Importantly, this surface modification revealed no short-term cytotoxic effects on L929 and hDNFs cells. Altogether, these data indicate the successful development of a surface modification method that can be applied to BC, enabling the production of a biodegradable and hydrophobic platform that can be applied to different areas of research and industry.This work was supported by the Fundação para a Ciência e a Tecnologia (FCT), under the project ‘‘SkinChip: Disruptive cellulose-based microfluidic device for 3D skin modelling’’ (PTDC/BBB-BIO/1889/2014, SFRH/BPD/121526/2016), co-financed by the Lisboa 2020, COMPETE 2020, Portugal 2020 and the BioTecNorte operation (NORTE01-0145-FEDER-000004) with funding by the European Regional Development Fund under the scope of Norte2020— Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

Human Extracellular-Matrix Functionalization of 3D hiPSC-Based Cardiac Tissues Improves Cardiomyocyte Maturation

The work here presented was funded by Fundacao para a Ciencia e Tecnologia (FCT) projects NETDIAMOND (SAICTPAC/0047/2015), financially supported by FEEI-Lisboa2020 and FCT/POCI-01-0145-FEDER-016385, and MetaCardio (PTDC/BTM-SAL/32566/2017); iNOVA4-Health -UIDB/04462/2020 and UIDP/04462/2020, a program financially supported by FCT/Ministerio da Ciencia, Tecnologia e Ensino Superior, through national funds is acknowledged; Funding from INTERFACE Programme, through the Innovation, Technology and Circular Economy Fund (FITEC), is gratefully acknowledged; and EU-funded projects BRAV3 (H2020, ID:874827) and ERAatUC (ref. 669088). HVA, AFL, and DS were financed by FCT Grants SFRH/BPD/120595/2016 and PD/BD/139078/2018 and PD/BD/106051/2015, respectively.Human induced pluripotent stem cells (hiPSC) possess significant therapeutic potential due to their high self-renewal capability and potential to differentiate into specialized cells such as cardiomyocytes. However, generated hiPSC-derived cardiomyocytes (hiPSC-CM) are still immature, with phenotypic and functional features resembling the fetal rather than their adult counterparts, which limits their application in cell-based therapies, in vitro cardiac disease modeling, and drug cardiotoxicity screening. Recent discoveries have demonstrated the potential of the extracellular matrix (ECM) as a critical regulator in development, homeostasis, and injury of the cardiac microenvironment. Within this context, this work aimed to assess the impact of human cardiac ECM in the phenotype and maturation features of hiPSC-CM. Human ECM was isolated from myocardium tissue through a physical decellularization approach. The cardiac tissue decellularization process reduced DNA content significantly while maintaining ECM composition in terms of sulfated glycosaminoglycans (s-GAG) and collagen content. These ECM particles were successfully incorporated in three-dimensional (3D) hiPSC-CM aggregates (CM+ECM) with no impact on viability and metabolic activity throughout 20 days in 3D culture conditions. Also, CM+ECM aggregates displayed organized and longer sarcomeres, with improved calcium handling when compared to hiPSC-CM aggregates. This study shows that human cardiac ECM functionalization of hiPSC-based cardiac tissues improves cardiomyocyte maturation. The knowledge generated herein provides essential insights to streamline the application of ECM in the development of hiPSC-based therapies targeting cardiac diseases.publishersversionpublishe

Characterisation of Films Based on Exopolysaccharides from Alteromonas Strains Isolated from French Polynesia Marine Environments

LA/P/0140/202019 UID/AGR/04129/2020 LA/P/0037/2020This work assessed the film-forming capacity of exopolysaccharides (EPS) produced by six Alteromonas strains recently isolated from different marine environments in French Polynesia atolls. The films were transparent and resulted in small colour alterations when applied over a coloured surface (ΔEab below 12.6 in the five different colours tested). Moreover, scanning electron microscopy showed that the EPS films were dense and compact, with a smooth surface. High water vapour permeabilities were observed (2.7–6.1 × 10−11 mol m−1 s−1 Pa−1), which are characteristic of hydrophilic polysaccharide films. The films were also characterised in terms of barrier properties to oxygen and carbon dioxide. Interestingly, different behaviours in terms of their mechanical properties under tensile tests were observed: three of the EPS films were ductile with high elongation at break (ε) (35.6–47.0%), low tensile strength at break (Ꞇ) (4.55–11.7 MPa) and low Young’s modulus (εm) (10–93 MPa), whereas the other three were stiffer and more resistant with a higher Ꞇ (16.6–23.6 MPa), lower ε (2.80–5.58%), and higher εm (597–1100 MPa). These properties demonstrate the potential of Alteromonas sp. EPS films to be applied in different areas such as biomedicine, pharmaceuticals, or food packaging.publishersversionpublishe

An ultra-sensitive electrochemical biosensor using the Spike protein for capturing antibodies against SARS-CoV-2 in point-of-care

Funding Information: The authors acknowledge funding through project TecniCov ( POCI-01-02B7-FEDER-069745 ), co-funded by FEDER through COMPETE2020 and Lisboa2020 and CY-Sensors ( POCI-01-0145-FEDER-032359 ) through Fundação para a Ciência e a Tecnologia (FCT) , Portugal. ARC acknowledge funding to National Foundation for Science and Technology , I.P., Portugal ( FCT ) through the PhD. Grant, reference SFRH/BD/130107/2017 . Publisher Copyright: © 2022 The AuthorsThis work presents an innovative ultra-sensitive biosensor having the Spike protein on carbon-based screen-printed electrodes (SPEs), for monitoring in point-of-care antibodies against SARS-CoV-2, a very important tool for epidemiological monitoring of COVID-19 infection and establishing vaccination schemes. In an innovative and simple approach, a highly conductive support is combined with the direct adsorption of Spike protein to enable an extensive antibody capture. The high conductivity was ensured by using carboxylated carbon nanotubes on the carbon electrode, by means of a simple and quick approach, which also increased the surface area. These were then modified with EDC/NHS chemistry to produce an amine layer and undergo Spike protein adsorption, to generate a stable layer capable of capturing the antibodies against SARS-CoV-2 in serum with great sensitivity. Electrochemical impedance spectroscopy was used to evaluate the analytical performance of this biosensor in serum. It displayed a linear response between 1.0 ​pg/mL and 10 ​ng/mL, with a detection limit of ∼0.7 ​pg/mL. The analysis of human positive sera containing antibody in a wide range of concentrations yielded accurate data, correlating well with the reference method. It also offered the unique ability of discriminating antibody concentrations in sera below 2.3 ​μg/mL, the lowest value detected by the commercial method. In addition, a proof-of-concept study was performed by labelling anti-IgG antibodies with quantum dots to explore a new electrochemical readout based on the signal generated upon binding to the anti-S protein antibodies recognised on the surface of the biosensor. Overall, the alternative serologic assay presented is a promising tool for assessing protective immunity to SARS-CoV-2 and a potential guide for revaccination.publishersversionpublishe

Electrochromic device composed of a Di-Urethanesil electrolyte incorporating lithium triflate and 1-Butyl-3-Methylimidazolium chloride

A di-urethane cross-linked poly(oxyethylene)/silica hybrid matrix [di-urethanesil, d-Ut(600)], synthesized by the sol-gel process, was doped with lithium triflate (LiCF3SO3) and the 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) ionic liquid. The as-produced xerogel film is amorphous, transparent, flexible, homogeneous, hydrophilic, and has low nanoscale surface roughness. It exhibits an ionic conductivity of 3.64 x 10(-6) and 5.00 x 10(-4) S cm(-1) at 21 and 100 degrees C, respectively. This material was successfully tested as electrolyte in an electrochromic device (ECD) with the glass/ITO/a-WO3/d-Ut(600)(10)LiCF3SO3[Bmim]Cl/c-NiO/ITO/glass configuration, where a-WO3 and c-NiO stand for amorphous tungsten oxide and crystalline nickel oxide, respectively. The device demonstrated attractive electro-optical performance: fast response times (1-2 s for coloring and 50 s for bleaching), good optical memory [loss of transmittance (T) of only 41% after 3 months, at 555 nm], four mode modulation [bright mode (+3.0 V, T = 77% at 555 nm), semi-bright mode (-1.0 V, T = 60% at 555 nm), dark mode (-1.5 V, T = 38 % at 555 nm), and very dark mode (-2.0 V, T = 11% and -2.5 V, T = 7% at 555 nm)], excellent cycling stability denoting improvement with time, and high coloration efficiency [CEin = -6727 cm(2) C-1 (32th cycle) and CEout = +2794 cm(2) C-1 (480th cycle), at 555 nm].The authors are grateful to Fundacao para a Ciencia e a Tecnologia (FCT) and when applicable by FEDER under the PT2020 Partnership Agreement for financial support under contracts PEst-OE/SAU/UI0709/2014, UID/Multi/00709/2013, UID/QUI/00686/2016, UID/QUI/00686/2018, UID/QUI/00686/2019, PEst-OE/QUI/UI0616/2016, FCOMP-01-0124-FEDER037271, UID/CTM/50011/2013, LUMECD project (POCI01-0145-FEDER-016884 and PTDC/CTM-NAN/0956/2014), UniRCell project (SAICTPAC/0032/2015 and POCI-01-0145FEDER-016422). RP and SN acknowledge FCT-MCTES for grants (SFRH/BPD/87759/2012 and LUMECD, respectively). RP thanks FCT-UM for the contracts in the scope of Decreto-Lei 57/2016 and 57/2017. MF acknowledges FCTUTAD for the contract in the scope of Decreto-Lei 57/2016 -Lei 57/2017. HG acknowledges projects POCI-010145-FEDER-030858 and PTDC/BTM-MAT/30858/2017 for financial support

Advancing manufacture of hiPSC-derived hepatocytes with improved functionality: A nature-inspired protocol

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