Helena Oliveira

Helena Oliveira
University of Aveiro | UA · Centre for Environmental and Marine Studies (CESAM)

PhD

About

168
Publications
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2,339
Citations

Publications

Publications (168)
Article
Full-text available
In this study, alginate nanocomposite hydrogel bioinks reinforced with lysozyme nanofibers (LNFs) were developed. Alginate-LNF (A-LNF) suspensions with different LNF contents (1, 5 and 10 wt.%) were prepared and pre-crosslinked with 0.5% (w/v) CaCl2 to formulate A-LNF inks. These inks exhibit proper shear-thinning behavior and good recovery propert...
Article
Full-text available
The unique physicochemical properties of silver nanoparticles (AgNPs) make them useful in a wide range of sectors, increasing their propensity for human exposure, as well as the need for thorough toxicological assessment. The biodistribution of silver, hematological parameters and GSH/GSSG levels in the lung and liver were studied in mice that were...
Article
Particulate matter emissions (PM10) from the combustion, in a residential stove, of two commercial brands of certified (ENplus A1) pellets, a non-certified brand and laboratory made pellets of acacia were tested for their ability to induce ecotoxic, cytotoxic, and mutagenic responses in unicellular organisms and a human cell line. Ecotoxicity was e...
Article
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Graphene-related two-dimensional nanomaterials possess very technically promising characteristics, but gaps exist regarding their potential adverse health effects. Based on their nano-thickness and lateral micron dimensions, nanoplates exhibit particular aerodynamic properties, including respirability. To develop a lung-focused, in vitro/in vivo sc...
Article
Nanoparticles (NP) are potentially reprotoxic, which may compromise the success of populations. However, the reprotoxicity of NP is still scarcely addressed in marine fish. Therefore, we evaluated the impacts of environmentally relevant and supra environmental concentrations of titanium dioxide (TiO2: 10 to 10,000 μg·L⁻¹) and silver NP (Ag: 0.25 to...
Article
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Melanoma is a drug-resistant cancer, representing a serious challenge in cancer treatment. Dacarbazine (DTIC) is the standard drug in metastatic melanoma treatment, despite the poor results. Hyperthermia has been proven to potentiate chemotherapy. Hence, this work analyzed the combined action of hyperthermia and DTIC on A375 and MNT-1 cell lines. F...
Article
Full-text available
Upconversion nanoparticles (UCNPs) have attracted considerable attention owing to their unique photophysical properties. Their utilization in biomedical applications depends on the understanding of their transformations under physiological conditions and their potential toxicity. In this study, NaYF4:Yb,Er UCNPs, widely used for luminescence and ph...
Article
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Burning vegetative debris is a worldwide long-standing practice. The current study was designed to examine the cytotoxicity and mutagenicity of particulate matter with an aerodynamic diameter below 10 µm (PM10) released from the burning of pruning residues common in Portugal and other countries of the Mediterranean region. Field measurements were c...
Article
The critical scenario of antimicrobial resistance to antibiotics highlights the need for improved therapeutics and/or formulations. Herein, we demonstrate that deep eutectic solvents (DES) formulations are very promising to remarkably improve the solubility, stability and therapeutic efficacy of antibiotics, such as ciprofloxacin. DES aqueous solut...
Article
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Melanoma is the deadliest form of skin cancer, and its incidence has alarmingly increased in the last few decades, creating a need for novel treatment approaches. Thus, we evaluated the combinatorial effect of doxorubicin (DOX) and hyperthermia on A375 and MNT-1 human melanoma cell lines. Cells were treated with DOX for 24, 48, and 72 h and their v...
Article
Fridericia chica (Bonpl.) L.G. Lohmann (synonym Arrabidaea chica Verlot) is widely used in Brazilian folk medicine. Considering overcoming pitfalls of scaling up production of plant extracts, herein the effects of N2 atmosphere for extract spray-drying process is reported. Samples were monitored by in vitro antioxidant activity and microbiological...
Article
BACKGROUND Natural products are under the spotlight due to the increasing awareness of consumers. Among these products is phycocyanin (C-PC), a blue colorant that can be extracted from cyanobacteria - a poorly explored feedstock - and applied in several fields, due to its argued health benefits. Arthropira (previously called Spirulina) is nowadays...
Article
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Lead (Pb) soil contamination remains a major ecological challenge. Zygophyllum fabago is a candidate for the Pb phytostabilisation of mining tailings; nevertheless, the cytogenotoxic effects of low doses of Pb on this species are still unknown. Therefore, Z. fabago seeds collected from non-mining (NM) and mining (M) areas were exposed to 0, 5 and 2...
Article
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Magnetic nanoparticles (NP), such as magnetite, have been the subject of research for application in the biomedical field, especially in Magnetic Hyperthermia Therapy (MHT), a promising technique for cancer therapy. NP are often coated with different compounds such as natural or synthetic polymers to protect them from oxidation and enhance their co...
Article
Hyperspectral microscopy is an intriguing technique combining spectroscopy with optical microscopy that can be used to simultaneously obtain spectral and spatial information. The relevance of hyperspectral imaging in biomedical applications such as the monitoring of bioimaging agents, the identification of pathogens and cancerous cells, and the cel...
Article
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3D printing emerged as a potential game-changer in the field of biomedical engineering. Robocasting in particular has shown excellent capability to produce custom-sized porous scaffolds from pastes with suitable viscoelastic properties. The materials and respective processing methods developed so far still need further improvements in order to obta...
Article
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Cellulose nanocrystals (CNCs) are elongated biobased nanostructures with unique characteristics that can be explored as nanosystems in cancer treatment. Herein, the synthesis, characterization, and cellular uptake on folate receptor (FR)-positive breast cancer cells of nanosystems based on CNCs and a chitosan (CS) derivative are investigated. The p...
Article
The emergence of multi-drug resistant bacteria and limitations on cancer treatment represent two important challenges in modern medicine. Biological compounds have been explored with particular focus on venoms. Although they can be lethal or cause considerable damage to humans, venom is also a source rich in components with high therapeutic potenti...
Article
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New agents are demanded to increase the therapeutic options for osteosarcoma (OS). Although OS is the most common bone cancer in children and adolescents, it is considered a rare disorder. Therefore, finding adjuvant drugs has potential to advance therapy for this disease. In this study, 3′,4′-dihydroxyflavonol (DiOHF) was investigated to assess th...
Article
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Copper chrome arsenate (CCA) water-borne solution used to be widely used to make timber highly resistant to pests and fungi, in particular, wood products designed for outdoor use. Nowadays, CCA is a restricted chemical product in most countries, since potential environmental and health risks were reported due to dermal contact with CCA residues fro...
Article
Wildfires are a complex environmental problem worldwide. The ashes produced during the fire bear metals and PAHs with high toxicity and environmental persistence. These are mobilized into downhill waterbodies, where they can impair water quality and human health. In this context, the present study aimed at assessing the toxicity of mimicked wildfir...
Preprint
Full-text available
Nanographene oxide (nGO)-mediated hyperthermia has been increasingly investigated as a localised, minimally invasive anticancer therapeutic approach. Near InfraRed (NIR) light irradiation for inducing hyperthermia is particularly attractive, because biological systems mostly lack chromophores that absorb in this spectral window, facilitating the se...
Article
Full-text available
Chemotherapy has limited success in the treatment of malignant melanoma due to fast development of drug resistance and the low bioavailability of chemotherapeutic drugs. Resveratrol (RES) is a natural polyphenol with recognized preventive and therapeutic anti-cancer properties. However, poor RES solubility hampers its bioactivity, thus creating a d...
Research Proposal
Full-text available
Nanotechnology has gained growing importance in diverse fields of science, medicine, economy and industry. Nevertheless, the generalized use of nanomaterials (NM) lead to their release (direct or indirect) to the environment and consequent interaction with natural systems. Several studies have highlighted the potential toxicity of nanomaterials for...
Article
Particulate matter with aerodynamic diameter < 10 μm (PM10) was collected, indoors and outdoors, when wood burning appliances (open fireplace and woodstove) were in operation. The PM10 ecotoxicity was assessed with the Vibrio fischeri bioluminescence inhibition assay, while the cytotoxicity was evaluated by the WST-8 and lactate dehydrogenase (LDH)...
Article
Full-text available
Upconversion nanoparticles (UCNPs), consisting of NaYF 4 doped with 18% Yb and 2% Er, were coated with microporous silica shells with thickness values of 7 ± 2 and 21 ± 3 nm. Subsequently, the negatively charged particles were functionalized with N -(6-aminohexyl)-3-aminopropyltrimethoxysilane (AHAPS), which provide a positive charge to the nanopar...
Article
Full-text available
The respiratory tract is the route of entry for accidentally inhaled AgNPs, which can reach the lungs and redistribute to other main organs through systemic circulation. In the present work, we aimed to evaluate silver biodistribution and biological effects after 1 or 2 intratracheal instillations (IT) of two differently sized PVP-coated AgNPs (5 a...
Article
Full-text available
Antibacterial multi-layered patches composed of an oxidized bacterial cellulose (OBC) membrane loaded with dexpanthenol (DEX) and coated with several chitosan (CH) and alginate (ALG) layers were fabricated by spin-assisted layer-by-layer (LbL) assembly. Four patches with a distinct number of layers (5, 11, 17, and 21) were prepared. These nanostruc...
Preprint
Full-text available
Upconversion nanoparticles (UCNP) consisting of NaYF₄ doped with 18% Yb and 2% Er were coated with microporous silica shells of 7±2 nm and 21±3 nm thickness. Subsequently, the initially negatively charged particles were optionally functionalized with N-(6-aminohexyl)-aminopropyltrimethoxysilane (AHAPS), providing a positive charge onto the nanopart...
Article
Full-text available
Urea, the main nitrogenous waste product of protein metabolism, is eliminated almost exclusively by the kidney, and hence, displays considerable clinical significance in the assessment of kidney disorders. The aim of this study is to prepare and investigate the potential of swellable cross‐linked gelatin methacryloyl (c‐GelMA) microneedles (MNs) as...
Article
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Plant-derived pentacyclic triterpenic acids (TAs) have gained increasing attention due to their multiple biological activities. Betulinic acid (BA) and ursolic acid (UA) modulate diverse pathways in carcinogenesis, offering increased changes of success in refractory cancers, such as triple negative breast cancer (TNBC). The present work aimed to as...
Article
The aim of the present study was to develop innovative patches for dermo-cosmetic applications based on dissolvable hyaluronic acid (HA) microneedles (MNs) combined with bacterial nanocellulose (BC) as the back layer. HA was employed as an active biomacromolecule, with hydrating and regenerative properties and volumizing effect, whereas BC was used...
Article
This study employed NMR metabolomics to characterize macrophage responses to subtoxic concentrations of silver nanoparticles (AgNPs ca. 30 nm) and ionic silver (Ag + ), with a view to further elucidate their immunomodulatory activity at the cell metabolism level. Exposure to AgNPs caused RAW 264.7 macrophages to decrease intracellular glucose utili...
Article
The present study reports the fabrication of dissolvable microneedle (MN) patches using pullulan (PL), a water-soluble polysaccharide with excellent film-forming ability, for the transdermal administration of insulin, envisioning the non-invasive treatment of diabetes. PL MNs patches were successfully prepared by micromolding and revealed good ther...
Article
Full-text available
Nanostructured patches composed of bacterial nanocellulose (BNC), hyaluronic acid (HA) and diclofenac (DCF) were developed, envisioning the treatment of aphthous stomatitis. Freestanding patches were prepared via diffusion of aqueous solutions of HA and DCF, with different concentrations of DCF, into the wet BNC three-dimensional porous network. Th...
Article
Full-text available
Gold nanoparticles (AuNPs) are one of the most studied nanosystems with great potential for biomedical applications, including cancer therapy. Although some gold-based systems have been described, the use of green and faster methods that allow the control of their properties is of prime importance. Thus, the present study reports a one-minute micro...
Article
Sustainably made, flexible and biocompatible composites, having environmentally friendly compositions and multifunctional capabilities, are promising materials for several emerging biomedical applications. Here, the development of flexible and multifunctional chitosan-based bionanocomposites with a mixed reduced graphene oxide-iron oxide (rGO-Fe3-x...
Article
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Non-contact, self-referenced and near-infrared luminescent nanothermometers have been recognized as emerging tools in the fields of nanomedicine and nanotechnology due to their great capability of precise temperature readout at the nanoscale and real-time deep-tissue imaging. However, the development of multifunctional and biocompatible luminescent...
Article
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Excessive exposure to ultraviolet (UV) radiation is the main risk factor to develop skin pathologies or cancer because it encourages oxidative condition and skin inflammation. In this sense, strategies for its prevention are currently being evaluated. Natural products such as carotenoids or polyphenols, which are abundant in the marine environment,...
Article
Metal contamination, as well as pesticides, organic matter and nutrient input are main factors leading to freshwater ecosystems degradation. The Water Framework Directive (WFD) was implemented within the European Union with the ultimate goal of promoting a good ecological status in all European waterbodies. However, the broad implementation of the...
Article
The design of functional materials capable of fighting fungal infections is of paramount importance given the intricate problem of multidrug-resistant pathogenic fungi. Herein, nanocomposites consisting of cross-linked poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) (PMETAC) and bacterial nanocellulose (BNC) were prepared, characterized...
Article
Anthropogenic activities such as agriculture, industry and climate change have been creating an enormous pressure on freshwater ecosystems leading to its degradation. Because the Water Framework Directive (WFD; main EU instrument for ecological water quality assessment) is costly and time-consuming, the main goal of this study was to use the scorin...
Article
Occupational environments are major exposure routes to Cr(VI). However, Cr(VI) may also establish in bone tissues by ingestion or through Cr containing orthopaedic prostheses that, due to wear and corrosion, may release metal particles and ions potentially affecting bone tissue. The aim of this work was to evaluate the effects of clinically relevan...
Article
Full-text available
The tailor-made character of deep eutectic solvents (DES) turns them very attractive to be used in several applications, including in health-related areas such as pharmaceutical, nutraceutical, and cosmetic industries. However, although DES has been touted as “green” solvents, several works proved that their potential toxicity should not be neglect...
Article
Two-dimensional transition metal dichalcogenides (TMDCs), such as MoS 2 and WS 2 , have recently emerged as nanomaterials with potential use in biomedicine. An attractive means to favor their interaction with biological media is the use of proper biomolecules as exfoliating/dispersing agents. Here, MoS 2 flakes were stabilized with different small...
Article
Full-text available
The unique photoluminescent properties of upconversion nanoparticles (UCNPs) have attracted worldwide research interest and inspired many bioanalytical applications. The anti‐Stokes emission with long luminescence lifetimes, narrow and multiple absorption and emission bands, and excellent photostability enable background‐free and multiplexed detect...
Article
Full-text available
The occurrence of protein synthesis errors (mistranslation) above the typical mean mistranslation level of 10⁻⁴ is mostly deleterious to yeast, zebrafish and mammal cells. Previous yeast studies have shown that mistranslation affects fitness and deregulates genes related to lipid metabolism, but there is no experimental proof that such errors alter...
Data
LC-MS analysis of PL molecular species in positive (as [M+H]+ ions) and negative mode (as [M-H]- ions) from post-diauxic shift phase. Relative abundances of PA, PE, PC and LPC molecular species in post-diauxic shift phase are altered. Data is normalized against the sum of the reconstructed areas considered for each class and presented as mean ± sta...
Data
LC-MS analysis of TG molecular species in positive mode (as [M+NH4]+ ions) from logarithmic and post-diauxic shift phases. Relative abundances of triacylglycerol molecular species in logarithmic (A) and post-diauxic shift phase (B) were altered. Data is normalized against the sum of the reconstructed areas considered for each phase and presented as...
Data
Phospholipid-to-protein ratios are only altered in PDS phase. Total PL were quantified after lipid extraction and normalized to the previously determined protein concentration for both logarithmic (A) and post-diauxic shift (B) phases. Data were normalized against the averaged values of the control strain and presented as mean ± standard deviation...
Data
Peptides with Ala→Ser (A) and Gly→Ser (B) misincorporations detected by LC-MS/MS. (DOCX)
Data
Mistranslation decreases protein stability. E. coli β-galactosidase (β-gal) was co-expressed in yeast cells with pRS315, pUA268 and pUA269. β-gal expression (A, B) was verified by western blot with an anti-β-gal antibody. Alcohol dehydrogenase (ADH) was used as loading control. The blot image of 1n represents the observations made for the set of bi...
Data
LC-MS analysis of PL molecular species in positive (as [M+H]+ ions) and negative mode (as [M-H]- ions) from logarithmic phase. Relative abundances of PA, PE, PS, LPC and PI molecular species in logarithmic phase are altered. Data is normalized against the sum of the reconstructed areas considered for each class and presented as mean ± standard devi...
Data
Quantification of lipid hydroperoxides. Lipid extracts from logarithmic phase were assayed with the FOX II assay. Data were normalized against the averaged values of the control strain and are presented as mean ± standard deviation of duplicates of three biological replicates. Statistical significance in all experiments was determined by one-way an...
Data
Examples of spectra obtained for each misincorporating strain. The identified ions and corresponding amino acids are displayed in the tables below each spectrum. The spectra on the left represent the peptide with misincorporation, whereas on the right side, the same peptide is shown unaltered. (PPTX)
Data
Lipid species identified in the LC-MS analysis of the total lipid extracts in positive and negative modes. The complete list of TG, PC and LPC molecular species identified in positive mode, and PS, PG, PE, LPE, PI, IPC, MIPC and PA molecular species identified in the negative mode, in MS and MS/MS spectra, are annotated. Data are presented as m/z v...
Data
Determination of β-galactosidase activity and quantity. (PDF)
Data
Detection of tRNA by northern blot. (PDF)
Data
The mutant tRNACGASer is expressed in the host strains. 25 μg of total RNA were fractionated on polyacrylamide gel. The mutated tRNACGASer was detected using a ɣ-32P-ATP-tRNACGASer probe. Ca corresponds to total RNA purified from C. albicans; EV, empty vector; Ser, native C. albicans tRNACGASer transformed into S. cerevisiae. Membranes were exposed...