The influence of surface modified poly(L-lactic acid) films on the differentiation of human monocytes into macrophages

Macrophages play a crucial role in the biological performance of biomaterials, as key factors in defining the optimal inflammation-healing balance towards tissue regeneration and implant integration. Here, we investigate how different surface modifications performed on poly(L-lactic acid) (PLLA) films would influence the differentiation of human monocytes into macrophages. We tested PLLA films without modification, surface-modified by plasma treatment (pPLLA) or by combining plasma treatment with different coating materials, namely poly(L-lysine) and a series of proteins from the extracellular matrix: collagen I, fibronectin, vitronectin, laminin and albumin. While all the tested films are non-cytotoxic, differences in cell adhesion and morphology are observed. Monocyte-derived macrophages (MDM) present a more rounded shape in non-modified films, while a more elongated phenotype is observed containing filopodia-like and podosome-like structures in all modified films. No major differences are found for the expression of HLA-DR+/CD80(+) and CD206(+)/CD163(+) surface markers, as well as for the ability of MDM to phagocytize. Interestingly, MDM differentiated on pPLLA present the highest expression of MMP9. Upon differentiation, MDM in all surface modified films present lower amounts of IL-6 and IL-10 compared to non-modified films. After stimulating MDM with the potent pro-inflammatory agent LPS, pPLLA and poly(L-lysine) and fibronectin-modified films reveal a significant reduction in IL-6 secretion, while the opposite effect is observed with IL-10. Of note, in comparison to non-modified films, all surface modified films induce a significant reduction of the IL-6/IL-10 ratio, a valuable prognosticator of the pro-versus anti-inflammatory balance. These findings provide important insights into MDM-biomaterial interactions, while strengthening the need for designing immune-informed biomaterials.project NORTE-01-0145-FEDER-000023, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement through the European Regional Development Fund (FEDER). C. R. Correia and J. F. Mano acknowledge the funding from the European Research Council for project ATLAS with the grant agreement number ERC-2014-ADG-669858. J. Gaifem, M.B. Oliveira and R. Silvestre acknowledge the Portuguese Foundation for Science and Technology (FCT) for the doctoral (PD/BD/106053/2015), post-doctoral (SFRH/BPD/111354/2015) and FCT Investigator (IF/00021/2014) grants, respectively. The authors also acknowledge Hospital de Braga for providing the buffy coatsThis work was developed under the scope of the project NORTE-01-0145-FEDER-000023, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement through the European Regional Development Fund (FEDER). C. R. Correia and J. F. Mano acknowledge the funding from the European Research Council for project ATLAS with the grant agreement number ERC-2014-ADG-669858. J. Gaifem, M.B. Oliveira and R. Silvestre acknowledge the Portuguese Foundation for Science and Technology (FCT) for the doctoral (PD/BD/106053/2015), post-doctoral (SFRH/BPD/111354/2015) and FCT Investigator (IF/00021/2014) grants, respectively. The authors also acknowledge Hospital de Braga for providing the buffy coats.info:eu-repo/semantics/publishedVersio

Paper-based laser-induced graphene for sustainable and flexible microsupercapacitor applications

Funding Information: Open access funding provided by FCT|FCCN (b-on). This work was financed by national funds from Fundação para a Ciência e a Tecnologia (FCT), I.P., in the scope of the projects LA/P/0037/2020, UIDP/50025/2020, and UIDB/50025/2020 of the Associate Laboratory Institute of Nanostructures, Nanomodelling and Nanofabrication–i3N and by FEDER funds through the COMPETE 2020 Program and National Funds through Portuguese Foundation for Science and Technology under projects POCI-01–0145-FEDER-007688, UID/CTM/50025 and by ERC AdG grant from the project DIGISMART (ERC-AdG-2017, GA 787410). J.C. would like to acknowledge FCT/MCTES for his present research contract with reference CEECIND/00880/2018. R.C. acknowledges funding from i3N-FCT I.P. through the PhD Grant UI/BD/151295/2021. S. S. and T. P. also acknowledge the funding from National Foundation for Science and Technology, through the PhD Grants SFRH/BD/149751/2019 and 2020.08606.BD, respectively. Publisher Copyright: © 2022, The Author(s).Laser-induced graphene (LIG) is as a promising material for flexible microsupercapacitors (MSCs) due to its simple and cost-effective processing. However, LIG-MSC research and production has been centered on non-sustainable polymeric substrates, such as polyimide. In this work, it is presented a cost-effective, reproducible, and robust approach for the preparation of LIG structures via a one-step laser direct writing on chromatography paper. The developed strategy relies on soaking the paper in a 0.1 M sodium tetraborate solution (borax) prior to the laser processing. Borax acts as a fire-retardant agent, thus allowing the laser processing of sensitive substrates that other way would be easily destroyed under the high-energy beam. LIG on paper exhibiting low sheet resistance (30 Ω sq−1) and improved electrode/electrolyte interface was obtained by the proposed method. When used as microsupercapacitor electrodes, this laser-induced graphene resulted in specific capacitances of 4.6 mF cm−2 (0.015 mA cm−2). Furthermore, the devices exhibit excellent cycling stability (> 10,000 cycles at 0.5 mA cm−2) and good mechanical properties. By connecting the devices in series and parallel, it was also possible to control the voltage and energy delivered by the system. Thus, paper-based LIG-MSC can be used as energy storage devices for flexible, low-cost, and portable electronics. Additionally, due to their flexible design and architecture, they can be easily adapted to other circuits and applications with different power requirements. Graphical Abstract: [Figure not available: see fulltext.]publishersversionpublishe

Extraction of bioactive compounds from vine pruning residues by using ohmic heating and conventional heating techniques

Vine pruning residue (VPR), a waste from the wine production, has attracted the interest of chemical and food industries thanks to its great potential as a raw material to obtain bioactive compounds. Due to the high market price of these compounds, different technologies have been studied to improve the economic profitability of their obtaining process. Therefore, the objective of this work was to evaluate an emerging technology named ohmic heating (OH) against conventional heating (CH) to extract bioactive compounds from VPR with significant antioxidant and antimicrobial activities. Extractions were carried out using a 45% hydroalcoholic solution, a solid/liquid ratio of 1/40 (g VPR/mL solvent) at 80°C for 60 min and under constant stirring. Total phenolic compounds (TPC) of the extractes were evaluated and the bioactive compounds identified and quantified by HPLC. Moreover, the antioxidant potential of the recovered compounds was estimated by the methods of DPPH, FRAP and ABTS, and the antimicrobial activity through MIC assay was tested against five food pathogenic fungi. The OH extract showed higher TPC concentration (196.2 mg GAE/kg), being identified 12 polyphenolic compounds, twice the number of compounds found in the CH extract and revealing quercetin and apigenin (2867.8 and 1574.9 mg/kg, respectively) as the main compounds in OH extract. Moreover, OH extract showed higher antioxidant activity (432.7 mg FE/kg, 370.2, 207.4 mg TE/kg for FRAP, DPPH and ABTS, respectively) and better inhibitory effects against P. expansum, Alternaria sp., Phoma violacea, and C. cladosporioides (54.5, 45.4, 33.9, 59.9%, respectively) when 1000 g/mL of extract was used. These findings demonstrated the potential of VPR extracts as a probable source of bioactive compounds with relevant functional characteristics, as well as the efficiency of OH in the extraction of polyphenolic compounds from VPR, proposing a reduction in energy consumption and making the process more environmentally friendly.Project of UID/BIO/04469/2013 CEBinfo:eu-repo/semantics/publishedVersio

Effects of moderate electric fields on the post-harvest preservation of chestnuts

Ohmic heating (OH) was evaluated as a post-harvest technology to improve chestnuts shelf-life (Castanea sativa Mill.) by controlling molds and insect larvae proliferation. Chestnuts were processed by OH at 35, 45, and 55 °C and compared with untreated fruits and the conventional hydrothermal technology (HT - 50 °C for 45 min), which is the process currently used by the chestnut industry. Shelf-life studies were carried out at different atmospheric conditions for 60 days: (i) 25 °C and 40% relative humidity (RH); (ii) 5 °C and 70% RH. The results show that the OH conducted at 55 °C (OH-55 °C), combined with storage at 5 °C, was more effective in controlling molds and larvae growth than the other treatments. Moreover, under these conditions, chestnuts shelf-life could be extended for 60 days without substantial changes in the fruits color and texture. After the OH-55 °C treatment, lower losses of some nutrients and vitamin C were registered compared to HT. This study demonstrates for the first time that OH has the potential to be used by the chestnut industry for the post-harvest disinfestation of this fruit.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. Enrique Pino-Hernández is a recipient of a fellowship supported by an advanced doctoral training program (call NORTE-69-2015-15), funded by the European Social Fund under the scope of Norte2020 – Programa Operacional Regional do Norte (NORTE-08-5369-FSE 000036). Ricardo N. Pereira and Luís Abrunhosa acknowledge FCT for their Assistant Research contract obtained under CEEC Individual 2017: reference CEECIND/02903/2017 and CEECIND/00728/2017, respectively.info:eu-repo/semantics/publishedVersio

Water Peel-Off Transfer of Electronically Enhanced, Paper-Based Laser-Induced Graphene for Wearable Electronics

Funding Information: This work is funded by National Funds through FCT I.P., under the scope of the project UIDB/50025/2020-2023. The authors acknowledge the ERC AdG project DIGISMART ref 787410, EC project SYNERGY H2020-WIDESPREAF-2020-5, CSA, proposal number 952169, EC project EMERGE, No. 101008701, and project BEST - ALT20-03-0247-FEDER-113469 | LISBOA-01-0247-FEDER-113469. T.P. and R.C. acknowledge funding from FCT I.P. through the Ph.D. Grants DFA/BD/8606/2020 and UI/BD/151295/2021. The authors also want to thank Jonas Deuermeier for the help with XPS measurements and analysis. Publisher Copyright: © 2022 American Chemical Society.Laser-induced graphene (LIG) has gained preponderance in recent years, as a very attractive material for the fabrication and patterning of graphitic structures and electrodes, for multiple applications in electronics. Typically, polymeric substrates, such as polyimide, have been used as precursor materials, but other organic, more sustainable, and accessible precursor materials have emerged as viable alternatives, including cellulose substrates. However, these substrates have lacked the conductive and chemical properties achieved by conventional LIG precursor substrates and have not been translated into fully flexible, wearable scenarios. In this work, we expand the conductive properties of paper-based LIG, by boosting the graphitization potential of paper, through the introduction of external aromatic moieties and meticulous control of laser fluence. Colored wax printing over the paper substrates introduces aromatic chemical structures, allowing for the synthesis of LIG chemical structures with sheet resistances as low as 5 ω·sq-1, translating to an apparent conductivity as high as 28.2 S·cm-1. Regarding chemical properties, ID/IG ratios of 0.28 showcase low defect densities of LIG chemical structures and improve on previous reports on paper-based LIG, where sheet resistance has been limited to values around 30 ω·sq-1, with more defect dense and less crystalline chemical structures. With these improved properties, a simple transfer methodology was developed, based on a water-induced peel-off process that efficiently separates patterned LIG structures from the native paper substrates to conformable, flexible substrates, harnessing the multifunctional capabilities of LIG toward multiple applications in wearable electronics. Proof-of concept electrodes for electrochemical sensors, strain sensors, and in-plane microsupercapacitors were patterned, transferred, and characterized, using paper as a high-value LIG precursor for multiples scenarios in wearable technologies, for improved sustainability and accessibility of such applications.publishersversionpublishe

Taxonomic bias in amphibian research : Are researchers responding to conservation need?

Amphibians are very diverse, widely distributed, and the most endangered class of vertebrates. As with other taxa, effective conservation of amphibians needs to be supported by detailed scientific knowledge. However, species rich and broadly distributed taxa are typically characterized by high variability in research effort. Our objective was therefore to understand which factors (ecological and cultural) have led some amphibian species to be more researched than others. We used two proxies of research effort: i) the total number of articles on Web of Science (WoS) that mention the scientific name (or synonyms) of each species, and; ii) the number of conservation science articles on WoS that mention the scientific name (or synonyms) of each species. These measures were used as dependent variables in zero hurdle regression models with the aim of identifying the most important factors driving species-level knowledge production. Well researched species (generally, and for conservation) tend to have a longer history of scientific research, come from countries with high scientific capacity, have large body size, and to be present in man-made habitats. Endangered species tend to be less researched, generally and for conservation, possibly because they are often more difficult to study: many endangered amphibians are restricted to small, fragmented and remote habitats in countries with low scientific capacity. We conclude with a discussion of how taxonomic biases in research effort on amphibians can be addressed given the limited funds available for conservation research.Peer reviewe

Effects of pulsed electrical fields on the texture of potato tissue

The application of pulsed electric fields (PEF) to cellular tissue is known to affect permanently or transiently the state of cell membranes, this is reflected in the electric properties of the tissue. Permanent permeabilization is known to affect the texture of the tissue. We have investigated whether low intensities of PEF would give rise to transient or permanent changes in texture. In this study, changes on the viscoelastic properties of potato tissues exposed to PEF during small-amplitude oscillatory dynamic rheological measurements were monitored. Potato tissue was subjected to field strengths ranging from 30 to 500 V/cm, with a single rectangular pulse of 10 µs, 100 µs or 1 ms. The elastic (G) and viscous (G&) moduli were measured every 30 s after the delivery of the pulse and the tan delta change calculated. The results were correlated with measurements of changes on electrical resistance during the delivery of the pulse. Interestingly, there is a drastic increase of tan delta 30 s after the application of the pulse, followed by a decrease 1 min after pulsation. This response is strongly influenced by the intensity and width of the pulse. Moreover, at high field strengths, the observed electroporation of the tissue reached similar levels when pulse widths of 1 ms and 100 µs were applied. Our results, supported by similar measurements on osmotically dehydrated control samples, clearly show that PEF causes a rapid change of the viscoelastic properties of the tissue that could be attributed to a partial loss in turgor pressure. This would be an expected consequence of electroporation. The recovery of the tan delta to values similar to those before pulsation, strongly suggests recovery of plasma membrane properties and turgor. These viscoelastic changes were shown to be independent of the total degree of permeabilization.info:eu-repo/semantics/publishedVersio

Impact of atomic layer deposited TiO2 on the photocatalytic efficiency of TiO2/w-VA-CNT nanocomposite materials

Titanium oxide (TiO2) has been widely investigated as a photocatalytic material, and the fact that its performance depends on its crystalline structure motivates further research on the relationship between preparation methods and material properties. In this work, TiO2 thin films were grown on non- functionalized wave-like patterned vertically aligned carbon nanotubes (w-VA-CNTs) via the atomic layer deposition (ALD) technique. Grazing incidence X-ray diffraction (GIXRD) analysis revealed that the structure of the TiO2/VA-CNT nanocomposites varied from amorphous to a crystalline phase with increasing deposition temperature, suggesting a “critical deposition temperature” for the anatase crystalline phase formation. On the other hand, scanning transmission electron microscopy (STEM) studies revealed that the non-functionalized carbon nanotubes were conformally and homogeneously coated with TiO2, forming a nanocomposite while preserving the morphology of the nanotubes. X-ray photoelectron spectroscopy (XPS) provided information about the surface chemistry and stoichiometry of TiO2. The photodegradation experiments under ultraviolet (UV) light on a model pollutant (Rhodamine B, RhB) revealed that the nanocomposite comprised of anatase crystalline TiO2 grown at 200 ?C (11.2 nm thickness) presented the highest degradation efficiency viz 55% with an illumination time of 240 min. Furthermore, its recyclability was also demonstrated for multiple cycles, showing good recovery and potential for practical applications.publishe