FE - DCTT | Documentos por Auto-Depósito
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- Advances in the Production of Biomaterials through Kombucha Using Food Waste: Concepts, Challenges, and PotentialPublication . Cubas, Anelise Leal Vieira; Provin, A. P.; Dutra, Ana; Mouro, Cláudia; Gouveia, I.C.In recent years, several researchers have focused their studies on the development of sustainable biomaterials using renewable sources, including the incorporation of living biological systems. One of the best biomaterials is bacterial cellulose (BC). There are several ways to produce BC, from using a pure strain to producing the fermented drink kombucha, which has a symbiotic culture of bacteria and yeasts (SCOBY). Studies have shown that the use of agricultural waste can be a low-cost and sustainable way to create BC. This article conducts a literature review to analyze issues related to the creation of BC through kombucha production. The databases used were ScienceDirect, Scopus, Web of Science, and SpringerLink. A total of 42 articles, dated from 2018 to 2022, were referenced to write this review. The findings contributed to the discussion of three topics: (1) The production of BC through food waste (including patents in addition to the scientific literature); (2) Areas of research, sectors, and products that use BC (including research that did not use the kombucha drink, but used food waste as a source of carbon and nitrogen); and (3) Production, sustainability, and circular economy: perspectives, challenges, and trends in the use of BC (including some advantages and disadvantages of BC production through the kombucha drink).
- Amino Acid-Based Material for the Complementary Therapy of Decubitus UlcersPublication . Nogueira, Frederico; Gouveia, Isabel C.Chronic wounds, pressure sores, lesions, and infections of microbial origin in bedridden, paralyzed, or malnutrition patients remain the object of study of many researchers. A variety of factors behind the development of these disorders are related to the patient's immune system, making it unable to respond effectively to the treatment of the wound. These factors can be properly controlled, giving particular importance to the ethiology and stage of the wound, as well as the time periods corresponding to the replacement of the dressings. The present research reports a novel foam/soft material, L-Cys-g-PCL, with an application for decubitus/pressure ulcers, especially for wounds with a difficult healing process due to infections and constant oxidation of the soft tissues. During this work, the interactions between S. aureus and L-Cys-g-PCL foam were studied under conditions that simulate decubitus ulcers; namely, pH and exudate. The effects of duration of grafting (1 or 8 h) and pH (7.0 and 8.9) on wettability, surface energy, swelling, and porosity were also evaluated. Results showed an effective microbicidal activity exhibiting an inhibition ratio of 99.73% against S. aureus. This new L-Cys-g-PCL soft material showed saftey to contact skin, ability to be shaped to fill in sunken holes (craters) - pressure ulcers stage III - and to act as a smart material responsive to pH, which can be tailored to develop better swelling properties at alkaline pH where exudates are normally higher, so as to address exudate self-cleaning and prevention of desiccation..
- Anti-microbial coating innovations to prevent infectious diseases (AMiCI): Cost action ca15114Publication . Dunne, Colum; Keinanen-Toivola, Minna; Kahru, Anne; Teunissen, Birgit; Ölmez, Hülya; Gouveia, Isabel C.; Melo, Luis F.; Murzyn, Kazimierz; Modic, Martina; Ahonen, Merja; Askew, Pete; Papadopoulos, Theofilos; Adlhart, Christian; Crijns, FrancyWorldwide, millions of patients are affected annually by healthcare-associated infection (HCAI), impacting up to 80,000 patients in European Hospitals on any given day. This represents not only public health risk, but also an economic burden. Complementing routine hand hygiene practices, cleaning and disinfection, antimicrobial coatings hold promise based, in essence, on the application of materials and chemicals with persistent bactericidal or -static properties onto surfaces or in textiles used in healthcare environments. The focus of considerable commercial investment and academic research energies, such antimicrobial coating-based approaches are widely believed to have potential in reduction of microbial numbers on surfaces in clinical settings. This belief exists despite definitive evidence as to their efficacy and is based somewhat on positive studies involving, for example, copper, silver or gold ions, titanium or organosilane, albeit under laboratory conditions. The literature describes successful delay and/or prevention of recontamination following conventional cleaning and disinfection by problematic microbes such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin resistant enterococci (VRE), among others. However, there is a scarcity of studies assessing antimicrobial surfaces other than copper in the clinical environment, and a complete lack of published data regarding the successful implementation of these materials on clinically significant outcomes (including HCAI). Through its Cooperation in Science and Technology program (COST), the European Commission has funded a 4-year initiative to establish a network of stakeholders involved in development, regulation and use of novel anti-microbial coatings for prevention of HCAI. The network (AMiCI) comprises participants of more than 60 universities, research institutes and companies across 29 European countries and, to-date, represents the most comprehensive consortium targeting use of these emergent technologies in healthcare settings. More specifically, the network will prioritise coordinated research on the effects (both positive and negative) of antimicrobial coatings in healthcare sectors; know-how regarding availability and mechanisms of action of (nano)-coatings; possible adverse effects of such materials (e.g., potential emergence of microbial resistance or emission of toxic agents into the environment); standardised performance assessments for antimicrobial coatings; identification and dissemination of best practices by hospitals, other clinical facilities, regulators and manufacturers.
- Antimicrobial and antioxidant surface modification toward a new silk-fibroin (SF)-l-Cysteine material for skin disease managementPublication . Nogueira, Frederico; Granadeiro, Luiza Breitenfeld ; Mouro, Cláudia; Gouveia, Isabel C.A novel dressing material – silk fibroin fabric (SF)-l-Cysteine (l-Cys) – is here developed to be used asstandard treatment for atopic dermatitis (AD), which combines comfort, thermic, and tensile strengthproperties of silk materials with antioxidant and antimicrobial effects of l-Cys. A careful understand-ing about the linking strategies is needed in order not to compromise the bioavailability of l-Cys anddeplenish its bioactivity. Durability was also addressed through washing cycles and compared with hos-pital requirements, according to international Standard EN ISO 105-C06:2010. The present research alsoanalyze the interactions between Staphylococcus aureus and SF-l-Cys under simulating conditions of ADand demonstrated the effectiveness of a double covalent grafting, with the importance of SF tyrosine(Tyr) covalent linkage with l-Cys (SF-g-l-Cys/Tyr-g-l-Cys) even after several washing cycles, twenty five,whereas for a disposable application a single covalent mechanism of grafting l-Cys proved to be suffi-cient (SF-g-l-Cys). Results showed effective antimicrobial activities exhibiting higher inhibition ratios of98.65% for SF-g-l-Cys after 5 washing cycles, whereas 97.55% for SF-g-l-Cys/Tyr-g-l-Cys after 25 washingcycles, both at pH 9.5 grafting strategy. Furthermore, it is also reported a non-protumoral effect of l-Cys. Anew advance is herein achieved at the world of medical antimicrobial textiles tailored to address woundmoisture environment and exudate self-cleaning, which may open novel applications as complementarytherapy for AD disease.
- Antimicrobial functionalization of wool: assessment of the effect of Cecropin-B and [Ala5]-Tritrp7 antimicrobial peptidesPublication . Mouro, Cláudia; Gouveia, Isabel C.This investigation provides a new strategy to impart antimicrobial properties into wool-based materials using Cecropin-B and [Ala5]-Tritrp7 antimicrobial peptides (AMPs). The process was conducted using exhaustion method at 40 °C for 1–3 h. The presence of the AMPs in the modified-wool samples was confirmed by colorimetric assay of Bradford reagent and possible changes in the morphology of the fibers and damage to its surface were analyzed by scanning electron microscopy. Results showed that 1 h were long enough for the functionalization to occur effectively and that the morphology of the fibers was not influenced by the functionalization process. Furthermore, the antimicrobial activity of the AMPs applied on wool was assessment by JIS L 1902-2002 against Staphylococcus aureus (ATCC 6538) and Klebsiella pneumoniae (ATCC 4352). The results showed that both AMPs have a high reduction in bacterial growth (Cecropin-B resulting in 71.67% reduction against S. aureus and 85.95% against K. pneumoniae. While [Ala5]-Tritrp7 resulting in 66.74% reduction against S. aureus and 88.65% against K. pneumoniae).
- Biofunctionalization of cellulosic fibres with l-cysteine: Assessment of antibacterial properties and mechanism of action against Staphylococcus aureus and Klebsiella pneumoniaePublication . Caldeira, Estela; Piskin, Erhan; Granadeiro, Luiza Breitenfeld ; Silva, Filomena; Gouveia, Isabel C.The main purpose of this work is to obtain a cotton-based textile material functionalized with l-cysteine (l-cys) to achieve an antimicrobial effect with potential application in biomedical, geriatric or pediatric textiles. The binding capacity of l-cys to cotton fibres was assessed through different functionalization strategies—surface activation and exhaustion processes. A subsequent analysis of the possible antibacterial action against Staphylococcus aureus and Klebsiella pneumoniae was performed according with the Japanese International standard (JISL, 2008). To determine the mechanism of action of l-cys on the selected strains, flow cytometry was used. The results revealed that the exhaustion process was performed with success to confer bioactivity to the treated fabric, as assessed by an effective antibacterial effect against both Gram-positive and Gram-negative bacteria, and successfully linkage of l-cys was observed via FTIR with a durable effect demonstrated after the washing tests (fastness to washing). It was also observed that l-cys exerts a bacteriostatic effect against both bacterial strains, since there were alterations in the metabolic activity ofthe microorganisms after the application of the bioactive textile which was shown by the CTC (cyanoditolyl tetrazolium chloride) staining used in flow cytometry. This study shows a new and successful biotechnological process to develop antibacterial textiles through the functionalization of cotton fibres with l-cys which presents a broad range of applications in healthcare, since l-cys is a natural antibacterial compound, non-toxic and affects pathogenic bacteria related to hospital infections.
- Circular economy for fashion industry: Use of waste from the food industry for the production of biotextilesPublication . Provin, A. P.; Dutra, Ana; Gouveia, Isabel C.; Leal Vieira Cubas, AneliseIn the context of current environmental, social and economic issues, it is imperative to perform more in-depth studies on waste management and the life cycle of a product. Thus, the concept of circular economy, aimed at transforming traditional patterns of production and economic growth, is extremely important. One way to mitigate negative environmental impacts that is consistent with a circular economic system is to encourage interdisciplinarity between sectors, that is, one production sector can provide a function for waste from another. In this context, this article gathers scientific information on two sectors relevant to the global economy (textiles and food), with the aim of reusing waste from the food industry to manufacture a new textile product with added value. Specifically, the focus is on the use of bacterial cellulose from the probiotic drinks from kombucha, for the manufacture of biotextiles for fashion industry. A discussion is also presented, relating the circular economy concept to the UN Sustainable Development Goals, in order to understand which goals can be achieved with this approach.
- Electrospinning polypropylene with an amino acid as a strategy to bind the antimicrobial peptide Cys-LC-LL-37Publication . Nogueira, Frederico; Teixeira, Pilar; Gouveia, Isabel C.Hospital isolation gowns are increasingly competitive, with brands and manufacturers contesting consumer preferences. The textile materials in contact with the skin can acquire secretions and multiresistant microorganisms, causing discomfort and health risks, respectively. A new nanofibrous substrate— polypropylene grafted with L-Cys—was developed with an increased crystallinity, providing its surface with –SH hooks necessary to efficiently cross-link the antimicrobial peptide Cys-LC-LL-37 in order to protect against nosocomial pathogens and their spread to community. Furthermore, this application does not require environmental control of humidity, and it is not susceptible to enzyme and microorganism degradation.
- Emulsion Electrospun Fiber Mats of PCL/PVA/Chitosan and Eugenol for Wound Dressing ApplicationsPublication . Mouro, Cláudia; Simões, Manuel; Gouveia, Isabel C.In recent years, the damaging e ects of antimicrobial resistance relating to wound management and infections have driven the ongoing development of composite wound dressing mats containing natural compounds, such as plant extracts and their derivatives. e present research reports the fabrication of novel electrospun Polycaprolactone (PCL)/Polyvinyl Alcohol (PVA)/Chitosan (CS) ber mats loaded with Eugenol (EUG), an essential oil, known for its therapeutic properties. e electrospun ber mats were prepared via electrospinning from either water-in-oil (W/O) or oil-in-water (O/W) emulsions and characterized using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), total porosity measurements, and water contact angle. e in vitro EUG release pro le and antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa were also evaluated. e obtained results proved that the EUG was loaded e ciently into electrospun PCL/PVA/CS ber mats and the two W/O and O/W emulsions prepared from the PCL/PVA/CS (7 : 3 : 1) and PCL/PVA/CS (3 : 7 : 1) revealed porosity within the ideal range of 60–90%, even when EUG was loaded. e measured contact angle values showed that the O/W emulsion exhibited a more hydrophilic character and the wettability noticeably decreased a¢er adding EUG in both emulsion blends. Furthermore, the electrospun PCL/PVA/CS ber mats demonstrated a rapid release of EUG during the rst 8 hours, which enhanced gradually a¢erward (up to 120 hours). Moreover, an e cient antibacterial activity against S. aureus (inhibition ratios of 92.43% and 83.08%) and P. aeruginosa (inhibition ratios of 94.68% and 87.85%) was displayed and the in vitro cytotoxic assay demonstrated that the normal human dermal broblasts (NHDF) remained viable for at least 7 days, a¢er direct contact with the produced electrospun ber mats. erefore, such ndings support the biocompatibility and suitability of using these EUG-loaded electrospun PCL/PVA/CS ber mats as a new innovative wound dressing material with potential for preventing and treating microbial wound infections.
- Enzymatic removal of plant residues from wool: Application of experimental design techniques for optimization parametersPublication . Gouveia, Isabel C.; Fiadeiro, José; Queiroz, JoãoThis study was undertaken to find the optimum conditions of a new enzymatic process to remove plant residues from wool. Commercial enzymatic preparations of Celluclast 1.5 L and Pectinex Ultra SP-L were selected in order to hydrolyze the polysaccharides in primary plant cell walls and middle lamella, resulting into more fragile residues easier to be removed. Since it was intended to define the optimal conditions for enzyme application, a four-factor central composite design was selected to study the effects of pH, temperature, enzyme concentration and wetting agent concentration, on the two selected responses, i.e., soluble reducing sugars (RS) and alkali solubility (AS) of wool to detect plant degradation and to evaluate wool quality, respectively. Results demonstrated that enzyme concentration was the most significant effect in plant residues degradation. A total enzyme concentration loading of 20 mL of both diluted enzymatic preparations in equal parts per 1 L of incubation solution (42.970 U/L of Celluclast preparation and PG 29.3 nkat/L + PME 2.537 nkat/L of Pectinex preparation), yielded an equivalent amount of 240.127 mg of glucose per 1.0 g of plant residue, at the optimal conditions: 40.56 ◦C, pH 4.0 and 1 mL Plurafac/L. SEM analysis has indicated an identical and important degradation of the plant residues, when compared to the conventional carbonization process, and wool quality has been preserved.
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