Development of capacitive-type sensors by electrochemical anodization: Humidity and touch sensing applications

This work describes the development of a capacitive-type sensor created from nanoporous anodic aluminium oxide (NP-AAO) prepared by the one-step anodization method conducted in potentiostatic mode and performed in a low-cost homemade system. A series of samples were prepared via an anodization campaign carried out on different acid electrolytes, in which the anodization parameters were adjusted to investigate the effect of pore size and porosity on the capacitive sensing performance. Two sensor test cases are investigated. The first case explores the use of highly uniform NP-AAO structures for humidity sensing applications while the second analyses the use of NP-AAO as a capacitive touch sensor for biological applications, namely, to detect the presence of small "objects " such as bacterial colonies of Escherichia Coli. A mathematical model based on equivalent electrical circuits was developed to evaluate the effect of humidity condensation (inside the pores) on the sensor capacitance and also to estimate the capacitance change of the sensor due to pore blocking by the presence of a certain number of bacterial microorganisms. Regarding the humidity sensing test cases, it was found that the sensitivity of the sensor fabricated in a phosphoric acid solution reaches up to 39 (pF/RH%), which is almost three times higher than the sensor fabricated in oxalic acid and about eight times higher than the sensor fabricated in sulfuric acid. Its improved sensitivity is explained in terms of the pore size effect on the mean free path and the loss of Brownian energy of the water vapour molecules. Concerning the touch sensing test case, it is demonstrated that the NP-AAO structures can be used as capacitive touch sensors because the magnitude of the capacitance change directly depends on the number of bacteria that cover the nanopores; the fraction of the electrode area activated by bacterial pore blocking is about 4.4% and 30.2% for B1 (E. Coli OD600nm = 0.1) and B2 (E. Coli OD600nm = 1) sensors, respectively.This research was funded by: the Portuguese Foundation for Science and Technology (FCT) under the strategic funding grants UIDB/04029/2020, UIDB/04650/2020 and UIDB/04469/2020 units; and, the European Regional Development Fund under the scope of Norte2020 program grant NORTE-01-0145-FEDER-000004, BioTecNorte

Development of capacitive-type sensors by electrochemical anodization: humidity and touch sensing applications

This work describes the development of a capacitive-type sensor created from nanoporous anodic aluminium oxide (NP-AAO) prepared by the one-step anodization method conducted in potentiostatic mode and performed in a low-cost homemade system. A series of samples were prepared via an anodization campaign carried out on different acid electrolytes, in which the anodization parameters were adjusted to investigate the effect of pore size and porosity on the capacitive sensing performance. Two sensor test cases are investigated. The first case explores the use of highly uniform NP-AAO structures for humidity sensing applications while the second analyses the use of NP-AAO as a capacitive touch sensor for biological applications, namely, to detect the presence of small objects such as bacterial colonies of Escherichia Coli. A mathematical model based on equivalent electrical circuits was developed to evaluate the effect of humidity condensation (inside the pores) on the sensor capacitance and also to estimate the capacitance change of the sensor due to pore blocking by the presence of a certain number of bacterial microorganisms. Regarding the humidity sensing test cases, it was found that the sensitivity of the sensor fabricated in a phosphoric acid solution reaches up to 39 (pF/RH%), which is almost three times higher than the sensor fabricated in oxalic acid and about eight times higher than the sensor fabricated in sulfuric acid. Its improved sensitivity is explained in terms of the pore size effect on the mean free path and the loss of Brownian energy of the water vapour molecules. Concerning the touch sensing test case, it is demonstrated that the NP-AAO structures can be used as capacitive touch sensors because the magnitude of the capacitance change directly depends on the number of bacteria that cover the nanopores; the fraction of the electrode area activated by bacterial pore blocking is about 4.4% and 30.2% for B1 (E. Coli OD600nm=0.1) and B2 (E. Coli OD600nm=1) sensors, respectively.This research was funded by: the Portuguese Foundation for Science and Technology (FCT) under the strategic funding grants UIDB/04029/2020, UIDB/04650/2020 and UIDB/04469/20 units; and, the European Regional Development Fund under the scope of Norte2020 program grant NORTE-01-0145-FEDER-000004, BioTecNorte.info:eu-repo/semantics/publishedVersio

Folate-target nanodevices to activated macrophages for rheumatoid arthritis

6th Iberian Meeting on Colloids and InterfaceMethotrexate is the first line of treatment of rheumatoid arthritis. Since many patients become unresponsive to methotrexate treatment, only very expensive biological therapies are effective and increased methotrexate tolerance strategies need to be identified. In a previous European project NANOFOL, we performed the encapsulation of methotrexate in a new liposomal formulation using a hydrophobic fragment of surfactant protein conjugated to a linker and folate to enhance their tolerance and efficacy. We evaluate the efficiency of this system to treat rheumatoid arthritis, by targeting folate receptor present at the surface of activated macrophages, key effector cells in this pathology. The specificity of our liposomal formulation to target folate receptor was investigated both in vitro as in vivo using a mouse model of arthritis (collagen-induced arthritis in DBA/1J mice strain). In both systems, the liposomal constructs were shown to be highly specific and efficient in targeting folate receptor . These liposomal formulations also significantly increase the clinical benefit of the encapsulated methotrexate in vivo in arthritic mice. A new project, called FOLSMART, will perform the preclinical development and the phase I clinical trials of this new liposomal formulation.info:eu-repo/semantics/publishedVersio

Discovery of thiazolo [5,4-c] isoquinoline based compounds as acetylcholinesterase inhibitors through computational target prediction, molecular docking and bioassay

We thank Nathalie Reichmann and Leendert Hamoen (University of Amsterdam) for critical reading of the manuscript, Ana Velic (Proteome Center Tübingen) for help with proteome analysis and Mike VanNieuwenhze (Indiana University) for the generous gift of HADA. This study was funded by the European Research Council through grant ERC‐2017‐CoG‐771709 (to MGP), by national funds through FCT– Fundação para a Ciência e a Tecnologia, PTDC/BIA‐MIC/6982/2020 (to HV); PTDC/BIA‐PLA/3432/2012 (to SRF); FCT through MOSTMICRO‐ITQB R&D Unit (UIDB/04612/2020, UIDP/04612/2020) and LS4FUTURE Associated Laboratory (LA/P/0087/2020) and FCT fellowship SFRH/BD/147052/2019 (to BMS); by the Swiss National National Foundation through P300P3_155346 (to AJ); by the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska‐Curie grant agreement No 839596 (to SS) and by the European Molecular Biology Organization through award ALTF 673‐2018 (to SS). Figure 6D and Appendix Fig S7 were created with Biorender.com .A computer-aided drug design (CADD) approach was developed for a focused chemical library comprising a series of sixteen thiazolo[5,4-c]isoquinoline derivatives. Little is known about this group of heteroaromatic compounds, both from the point of view of their synthesis and their biological properties. First, our CADD approach included target prediction by Mondrian conformal prediction with the ChEMBL database. The acetylcholinesterase (AChE) was identified as having a high probability of thiazolo[5,4-c]isoquinolines being active against it. Secondly, the molecular docking predictions revealed four promising thiazoloisoquinolines (2, 7, 13 and 14) according to their prominent ligand-protein energy scores and relevant binding affinities with the AChE pocket residues. The subsequent in vitro evaluation of promising hits and related ones revealed a set of novel AChE inhibitors. Therefore, the findings reported herein may provide a new strategy for discovering novel AChE inhibitors.publishersversionpublishe

Studies of stabilization of native catalase using additives

Native catalase preparations isolated from Bacillus Sp were formulated with different additives for storage stabilization and better performance at high temperature and pH. The additives studied were: polyethylene glycol, glycerol, BSA, casein, glutaraldehyde, n-butylamine, ethylenediamine, 1.6-diaminohexane, BSA/glutaraldehyde and casein/glutaraldehyde. The glycerol and glutaraldehyde showed the best performance for long-term storage at 30degreesC and neutral pH. No stabilization additives were effective at pH 12, but below that pH the polyethylene glycol and glycerol appeared to be the most appropriate. Amines, polyethylene glycol and glycerol shifted the pH activity maximum of the native catalase toward more alkaline region, while glycerol were the only additive to improve the temperature profile of the enzyme. (C) 2002 Elsevier Science Inc. All rights reserved

Development of an ex vivo assay for the characterization of a new elastin-like polymer with antimicrobial properties

[Excerpt] New treatment formulations for skin regeneration and wound infectionshaverecentlybeenthefocusofresearchinthebiomedical field,as they are one of the most common healthcare-associated infections. Antimicrobial peptides (AMPs) are a class of small molecules that can be used in the treatment of skin and wound infections as they occur as part of the innate defense mechanism in many organisms, even in microbes and virus, displaying immunomodulatory effects. With advances in protein engineering and recombinant DNA technology, it is now possible to reengineer protein-based materials with added functionality.Indeed,recombinantDNAtechnologyallows combining in the same molecule distinct functionalities, leading to the production of a chimeric protein displaying the properties of each blockof amino acids. With the aim of developing novel advanced materials and ultimately, the fabrication of advanced medical devices, hereby we describe the development, processing and characterization of a new recombinant protein-based-polymer (rPBP) with antimicrobial activity. The functionalrPBPcomprisesafunctionaldomainbasedonasyntheticcationic AMP, fused in frame with an elastin-like-polymer consisting of 200 repeatsofVPAVG(A200),asstructural unit.Acknowledgments: This work was financially supported Portuguese funding from FEDER through POFC – COMPETE and PEst project C/ BIA/UI4050/2011 (Portugal). AC and RM acknowledge FCT for SFRH/BD/75882/2011 and SFRH/BPD/86470/2012 grants, respectively

Overview of phlorotannins’ constituents in Fucales

Fucales are an order within the Phaeophyceae that include most of the common littoral seaweeds in temperate and subtropical coastal regions. Many species of this order have long been a part of human culture with applications as food, feedand remedies in folk medicine. Apart from their high nutritional value, these seaweeds are also a well-known reservoir of multiple bioactive compounds with great industrial interest. Among them, phlorotannins, a unique and diverse class of brown algae-exclusive phenolics, have gathered much attention during the last few years due to their numerous potential health benefits. However, due to their complex structural features, combined with the scarcity of standards, it poses a great challenge to the identification and characterization of these compounds, at least with the technology currently available. Nevertheless, much effort has been taken towards the elucidation of the structural features of phlorotannins, which have resulted in relevant insights into the chemistry of these compounds. In this context, this review addresses the major contributions and technological advances in the field of phlorotannins extraction and characterization, with a particular focus on Fucales.This work received financial support from PT national funds (FCT/MCTES, Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior) through the projects UIDB/50006/2020 and UIDP/50006/2020. Thanks to PTDC/BAA-AGR/31015/2017, “Algaphlor—Brown algae phlorotannins: From bioavailability to the development of new functional foods”, co-financed by the Operational Programme for Competitiveness and Internationalization— POCI, within the European Regional Development Fund (FEDER), and the Science and Technology Foundation (FCT), through national funds. Silva S. thanks FCT for funding through program DL 57/2016–Norma transitória (Ref. SFRH/BPD/74299/2010)

Time-dependent effect of tamoxifen on melanogenesis in normal human melanocytes

In medical literature, occasional case reports describe gray hair re-pigmentation in patients after administration of certain drugs, such as tamoxifen, supporting the possibility of reversing pigmentation loss associated with ageing. This work aimed to study, in vitro, the effect on melanin production in primary human melanocytes of tamoxifen, an antagonist of the estrogen receptor in breast tissue, and of its most bioactive derivative, 4-hydroxy-tamoxifen. Adult normal human epidermal melanocytes (NHEM) were exposed to physiological concentrations of tamoxifen and 4-hydroxy-tamoxifen for 72 hours. The results showed that tamoxifen and 4HO-tamoxifen treatments promoted melanin extrusion. The transcript levels of genes coding for premelanosome protein and melan- A, directly related to skin and hair pigmentation, showed an increased tendency upon tamoxifen and 4-hydroxy-tamoxifen treatment. Induction of catalase gene expression in NHEM points towards a promelanogenic effect mediated by reactive oxygen species. According to the results, these compounds seem to act as melanogenesis stimulators at a molecular level. Our data suggests that SERMs might be a new tool for increasing melanogenesis and might be of great interest for topical formulations in cosmetic industry