66 research outputs found

    A review on flexible electrochemical biosensors to monitor alcohol in sweat

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    The continued focus on improving the quality of human life has encouraged the development of increasingly efficient, durable, and cost-effective products in healthcare. Over the last decade, there has been substantial development in the field of technical and interactive textiles that combine expertise in electronics, biology, chemistry, and physics. Most recently, the creation of textile biosensors capable of quantifying biometric data in biological fluids is being studied, to detect a specific disease or the physical condition of an individual. The ultimate goal is to provide access to medical diagnosis anytime and anywhere. Presently, alcohol is considered the most commonly used addictive substance worldwide, being one of the main causes of death in road accidents. Thus, it is important to think of solutions capable of minimizing this public health problem. Alcohol biosensors constitute an excellent tool to aid at improving road safety. Hence, this review explores concepts about alcohol biomarkers, the composition of human sweat and the correlation between alcohol and blood. Different components and requirements of a biosensor are reviewed, along with the electrochemical techniques to evaluate its performance, in addition to construction techniques of textile-based biosensors. Special attention is given to the determination of biomarkers that must be low cost and fast, so the use of biomimetic materials to recognize and detect the target analyte is turning into an attractive option to improve electrochemical behavior.Authors acknowledge the Portuguese Foundation for Science and Technology (FCT), FEDER funds by means of Portugal 2020 Competitive Factors Operational Program (POCI) and the Portuguese Government (OE) for funding the project PluriProtech—“Desenvolvimentos de soluções multicamada para proteção ativa contra ameaças NBQR”, ref. POCI-01-0247-FEDER-047012. Authors also acknowledge strategic funding of UID/CTM/00264/2020 of 2C2T and by the “plurianual” 2020–2023 Project UIDB/00264/2020

    Antimicrobial activity of a bacterial nanocellulose film functionalized with nisin Z for prospective burn wounds treatment

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    Supplementary Materials: The following are available online at https://www.mdpi.com/article/10 .3390/eca2022-12708/s1Burn wounds can lead to numerous severe complications including bacterial infections causing patient morbidity and mortality, mostly in low- and middle-income countries. The considerable increase in microbial resistance against traditional antibiotics is leading towards alternative strategies to treat bacterial infections. Nisin Z is an antimicrobial peptide which exhibits a significant antibacterial activity against Gram-positive bacteria. Its efficacy against Gram-negative bacteria is limited, nonetheless it can be improved with the addition of surfactants, such as ethylenediaminetetraacetic acid (EDTA). The incorporation of peptide and other biomolecules within a biopolymer matrix provides protection maintaining their antimicrobial potential. Bacterial nanocellulose (BNC) has been widely used as wound dressings. Its impressive water retention capacity (>99%) and porosity are beneficial to manage wounds due to its potential to absorb exudates, providing a breathable and humid environment. In this work, the functionalization of BNC with Nisin Z (BNC-NZ) via vacuum filtration is reported. The entrapment of the peptide inside the BNC films was confirmed through morphological characterization using attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrometry. Typical absorbance peaks of Nisin Z are easily identifiable at 1647 cm−1 (amide group) and 1520 cm−1 (bending of primary amines). Thermal gravimetric analysis (TGA) suggested that Nisin Z did not interfere with the BNC matrix. The antimicrobial activity of Nisin Z against five of the most common bacteria found in burn wounds was verified by minimum bactericidal concentration (MBC) ranging 8.0–256.0 µg/mL. Agar diffusion and shake flask methods revealed the potential of BNC-NZ for prospective applications in burn wound dressings.This research was funded by FEDER funds through COMPETE and by national funds through FCT via the projects POCI-01-0145-FEDER-028074 and UID/CTM/00264/2020. L.M. and T.D.T. also acknowledge FCT for their Ph.D. scholarships with references 2020.04919.BD and 2020.06046.BD.info:eu-repo/semantics/publishedVersio

    Physical, thermal, and antibacterial effects of active essential oils with potential for biomedical applications loaded onto cellulose acetate/polycaprolactone wet-spun microfibers

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    New approaches to deal with the growing concern associated with antibiotic-resistant bacteria are emerging daily. Essential oils (EOs) are natural antimicrobial substances with great potential to mitigate this situation. However, their volatile nature, in their liquid-free form, has restricted their generalized application in biomedicine. Here, we propose the use of cellulose acetate (CA)/polycaprolactone (PCL) wet-spun fibers as potential delivery platforms of selected EOs to fight infections caused by Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Twenty EOs were selected and screened for their minimal inhibitory concentration (MIC), using the antibiotic ampicillin as positive control. The cinnamon leaf oil (CLO), cajeput oil (CJO), and the clove oil (CO) were the most effective EOs, against the Gram-positive (MIC < 22.38 mg/mL) and the Gram-negative (MIC < 11.19 mg/mL) bacteria. Uniform microfibers were successfully wet-spun from CA/PCL with an averaged diameter of 53.9 ± 4.5 µm, and then modified by immersion with CLO, CJO and CO at 2 × MIC value. EOs incorporation was confirmed by UV-visible spectroscopy, Fourier-transformed infrared spectroscopy, and thermal gravimetric analysis. However, while microfibers contained ampicillin at MIC (control) after the 72 h modification, the CLO, CO and CJO-loaded fibers registered ≈ 14%, 66%, and 76% of their MIC value, respectively. Data showed that even at small amounts the EO-modified microfibers were effective against the tested bacteria, both by killing bacteria more quickly or by disrupting more easily their cytoplasmic membrane than ampicillin. Considering the amount immobilized, CLO-modified fibers were deemed the most effective from the EOs group. These results indicate that CA/PCL microfibers loaded with EOs can be easily produced with increased antibacterial action, envisioning their use as scaffolding materials for the treatment of infections.Authors acknowledge the Portuguese Foundation for Science and Technology (FCT), FEDER funds by means of Portugal 2020 Competitive Factors Operational Program (POCI) and the Portuguese Government(OE) for funding the project PEPTEX with reference PTDC/CTM-TEX/28074/2017 (POCI-01-0145-FEDER-028074).Authors also acknowledge project UID/CTM/00264/2020 of Centre for Textile Science and Technology (2C2T),funded by national funds through FCT/MCTES. SEM studies were performed at the Materials CharacterizationServices of the University of Minho (SEMAT/UM)

    Multifunctional coated textiles for active biological protection

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    The rising threats to the worldwide security (military and civilian) attest the need to develop efficient and versatile technological solutions to protect the human being [...]info:eu-repo/semantics/publishedVersio

    Comparison of zinc oxide nanoparticle integration into non-woven fabrics using different functionalisation methods for prospective application as active facemasks

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    The development of advanced facemasks stands out as a paramount priority in enhancing healthcare preparedness. In this work, different polypropylene non-woven fabrics (NWF) were characterised regarding their structural, physicochemical and comfort-related properties. The selected NWF for the intermediate layer was functionalised with zinc oxide nanoparticles (ZnO NPs) 0.3 and 1.2wt% using three different methods: electrospinning, dip-pad-dry and exhaustion. After the confirmation of ZnO NP content and distribution within the textile fibres by morphological and chemical analysis, the samples were evaluated regarding their antimicrobial properties. The functionalised fabrics obtained via dip-pad-dry unveiled the most promising data, with 0.017 ± 0.013wt% ZnO NPs being mostly located at the fibre’s surface and capable of total eradication of Staphylococcus aureus and Escherichia coli colonies within the tested 24 h (ISO 22196 standard), as well as significantly contributing (**** p < 0.0001) to the growth inhibition of the bacteriophage MS2, a surrogate of the SARS-CoV-2 virus (ISO 18184 standard). A three-layered structure was assembled and thermoformed to obtain facemasks combining the previously chosen NWF, and its resulting antimicrobial capacity, filtration efficiency and breathability (NP EN ISO 149) were assessed. The developed three-layered and multiscaled fibrous structures with antimicrobial capacities hold immense potential as active individual protection facemasks.FCT -Fundação para a Ciência e a Tecnologia(LA/P/0029/2020)info:eu-repo/semantics/publishedVersio

    Blunt traumatic injuries of thoracic aorta and supra-aortic trunks - a narrative review

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    INTRODUCTION: Blunt thoracic aortic injuries (BTAI) are defined as a tear in the thoracic aorta caused by a high energy blunt trauma. The most common reported mechanism of injury is motor vehicle accidents, and it can be potentially lethal. The Society for Vascular Surgery (SVS) and the European Society for Vascular Surgery (ESVS) guidelines recommend thoracic endovascular aortic repair (TEVAR) as the first line treatment for BTAI. Other controversies regarding BTAI management were reported in the literature, such as the best treatment for minimal aortic injuries with intimal tear, ideal stent graft oversizing, best timing for treatment and necessity to cover the left subclavian artery (LSA). The purpose of this review is to identify and analyze appropriate studies published so far about the management of BTAI. METHODS: We performed a thorough electronic search of the literature using PubMed and Embase databases. We used the following combination of key words in our search strategy ((aortic injury) AND (blunt thoracic trauma)) AND (vascular surgery* OR treatment* OR TEVAR*). Articles not in English were excluded. The primary subject was results of endovascular treatment. Secondary subjects were indications and results of OSR, best timing for intervention, ideal graft oversizing, need for left subclavian artery (LSA) coverage, and management of BTAI grade I (intimal tear). RESULTS: Data related to our primary and secondary subjects were extracted from the selected articles. TEVAR is considered the primary treatment for BTAI, if the patient has suitable anatomy, with good short and mid-term outcomes, with lower mortality and paraplegia rates at short and mid-term follow-up, compared to OSR. Despite good term results at short-term follow-up after TEVAR, long-term outcomes are still a concern. OSR is still a valid option in selected cases, and it should be considered for patients whose injury location is unsuitable for the endovascular approach. In most patients with BTAI, it is recommended around 10% of graft oversizing. However, a more aggressive approach with oversizing between 10-20% should be considered for patients with considerable hypotension and even >20% for patients presenting with severe hypotensive hemorrhagic shock. A necessity of LSA coverage has been reported in 30% of TEVAR for urgent treatment of BTAI, and it seems to be well tolerated. We should considered expectant approach with serial follow-up CT scans in patients with BTAI grade I injuries with asymptomatic intimal aortic tear. CONCLUSIONS: This literature review reports and synthetizes published data about the management strategies for BTAI. TEVAR seems to be effective in the treatment of BTAI, with few complications and good outcomes at short and mid-term follow-up, and it should be the first-line treatment for these patients. OSR should be an option when a patient’s injury is not suitable for endovascular approach

    OLIVESIM: Gestão dos serviços de ecossistema no olival utilizando modelos espaciais avançados

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    Poster apresentado no Congresso Politécnico Setúbal - 40 anos a construir o futuro, 3-4 outubro 2019, Setúbal, PortugalN/

    A fibrin coating method of polypropylene meshes enables the adhesion of menstrual blood-derived mesenchymal stromal cells: a new delivery strategy for stem cell-based therapies

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    Polypropylene (PP) mesh is well-known as a gold standard of all prosthetic materials of choice for the reinforcement of soft tissues in case of hernia, organ prolapse, and urinary incontinence. The adverse effects that follow surgical mesh implantation remain an unmet medical challenge. Herein, it is outlined a new approach to allow viability and adhesion of human menstrual blood-derived mesenchymal stromal cells (MenSCs) on PP surgical meshes. A multilayered fibrin coating, based on fibrinogen and thrombin from a commercial fibrin sealant, was optimized to guarantee a homogeneous and stratified film on PP mesh. MenSCs were seeded on the optimized fibrin-coated meshes and their adhesion, viability, phenotype, gene expression, and immunomodulatory capacity were fully evaluated. This coating guaranteed MenSC viability, adhesion and did not trigger any change in their stemness and inflammatory profile. Additionally, MenSCs seeded on fibrin-coated meshes significantly decreased CD4+ and CD8+ T cell proliferation, compared to in vitro stimulated lymphocytes (p < 0.0001). Hence, the proposed fibrin coating for PP surgical meshes may allow the local administration of stromal cells and the reduction of the exacerbated inflammatory response following mesh implantation surgery. Reproducible and easy to adapt to other cell types, this method undoubtedly requires a multidisciplinary and translational approach to be improved for future clinical uses.This work was supported by: SANTANDER BANK: “Convenio de colaboración empresarial en actividades de interés general” to F.M.; FUNDAÇÃO PARA A CIÊNCIA E A TECNOLOGIA (FCT): post-doctoral contract CEECIND/01026/2018 to J.M.S.; INSTITUTO DE SALUD CARLOS III (ISCIII): a “PFIS” contract (FI19/00041) to M.Á.P., a “Sara Borrell” grant (CD19/00048) to E.L.; a “Miguel Servet I” grant (MS17/00021), co-funded by the European Social Fund (ESF) “Investing in your future”, and projects CP17/00021 and PI18/0911, co-funded by the European Regional Development Fund (ERDF) “A way to make Europe” to J.G.C.; a “CIBERCV” grant (CB16/11/00494), co-funded by the ERDF to F.M.S.-M; JUNTA DE EXTREMADURA, CONSEJERÍA DE ECONOMÍA, CIENCIA Y AGENDA DIGITAL: project IB20184 (co-funded by ERDF) to E.L. and M.P.; grant GR18199, co-funded by the ERDF, to F.M.S.-M.; contracts TA18054 to I.J. and TA18011 to J.J.L. (cofinanced by FEDER)

    design, planning and implementation

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    Background: In Health Examination Surveys interview information is complemented with objective information, providing more accurate indicators than self-reported data. We report the study design, planning and implementation of the first Portuguese Health Examination Survey (INSEF). Methods: INSEF was a cross-sectional population-based study representative at regional and national level. Individuals aged between 25 and 74 years old, residing in Portugal were selected from the national health users' registry through multi-stage stratified probabilistic sampling. Sample size was set at 4200 individuals. Data was collected in primary care units and included blood pressure, height, weight, hip and waist measurements, blood collection for lipid profile, HbA1c and blood count and a general health questionnaire. European HES procedures were followed. Results: A total of 4911 individuals agreed to participate (43.9% participation rate). Participation rate varied by region, sex and age group, being lower in Lisbon and Tagus Valley (32.8%), for men (41.8%) and for those aged 25-34 years old (36%). Conclusions: INSEF has set up an experienced national and regional structure for HES implementation. Nationally representative quality epidemiological data is now available for public health monitoring, planning and research.publishe

    TET enzymes and DNA hydroxymethylation in neural development and function : how critical are they?

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    Epigenetic modifications of the genome play important roles in controlling gene transcription thus regulating several molecular and cellular processes. A novel epigenetic modification - 5-hydroxymethylcytosine (5hmC) - has been recently described and attracted a lot of attention due to its possible involvement in the active DNA demethylation mechanism. TET enzymes are dioxygenases capable of oxidizing the methyl group of 5-methylcytosines (5mC) and thus converting 5mC into 5hmC. Although most of the work on TET enzymes and 5hmC has been carried out in embryonic stem (ES) cells, the highest levels of 5hmC occur in the brain and in neurons, pointing to a role for this epigenetic modification in the control of neuronal differentiation, neural plasticity and brain functions. Here we review the most recent advances on the role of TET enzymes and DNA hydroxymethylation in neuronal differentiation and function.We apologize to those researchers whose important work we were not able to cite. We would like to thank all members of the Neurosciences Research Domain (ICVS) for useful discussions, in particular Luisa Pinto and Joao Oliveira for critically reading the manuscript. Our work is funded by the Fundacao para a Ciencia e Tecnologia (FCT, Portugal) and Compete Program with the project reference PTDC/BIA-BCM/121276/2010. C.J. Marques is the recipient of an FCT Investigator Starting Grant
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