Ricardo Pinto

• Research Assistant at University of Aveiro

Current research in cancer therapy focuses on personalized therapies, through nanotechnology‐based targeted drug delivery systems. Particularly, controlled drug release with nanoparticles (NPs) can be designed to safely transport various active agents, optimizing delivery to specific organs and tumors, minimizing side effects. The use of microfluid...

The presence of plastic particles in oceans has been recognized as a major environmental concern. The decrease in particle size increases their ability to directly interact with biota, with particles in the nanometer size range (nanoplastics—NPs) displaying a higher ability to penetrate biological membranes, which increases with the decrease in par...

Biopolymeric nanoparticles (NPs) have gained significant attention in several areas as an alternative to synthetic polymeric NPs due to growing environmental and immunological concerns. Among the most promising biopolymers is poly(lactic acid) (PLA), with a reported high degree of biocompatibility and biodegradability. In this work, PLA NPs were sy...

This work aimed at studying the self‐assembly of lignin macromolecules towards lignin nanoparticles (LNPs) with green solvents and shedding light on a tailor‐made production of LNPs through a meticulous study of different variables. The methodology (antisolvent to lignin solution – method A; or lignin solution to antisolvent – method B), the lignin...

Biopolymeric injectable hydrogels are promising biomaterials for myocardial regeneration applications. Besides being biocompatible, they adjust themselves, perfectly fitting the surrounding tissue. However, due to their nature, biopolymeric hydrogels usually lack desirable functionalities, such as antioxidant activity and electrical conductivity, a...

Nowadays, packaging applications require the use of advanced materials as well as production methods that have a low environmental impact. In this study, a solvent-free photopoly-merizable paper coating was developed using two acrylic monomers (2-ethylhexyl acrylate and isobornyl methacrylate). A copolymer, with a molar ratio of 2-ethylhexyl acryla...

Nowadays, the dependence on synthetic plastic-based materials for the preservation and transport of different types of products is very high, leading to major environmental and human health concerns, which highlights the importance of investigating sustainable options. Paper is a widely used bio-based material for packaging however , the developmen...

The development of suitable bioinks is an important research topic in the field of three-dimensional (3D) bioprinting. Herein, novel hydrogel-based bioinks composed of nanofibrillated cellulose (NFC) and gellan gum (GG) in different NFC/GG mass proportions (90:10, 80:20, 70:30, and 60:40) were developed and characterized. The increase in the conten...

Hazardous leachate/effluent from fluorescent lamps contains potentially toxic elements such as Hg and Pb and critical raw materials such as rare earth elements (REEs). This work evaluated the ability of the live macroalgae Ulva sp. to remediate a simulated lamp industry wastewater consisting of a complex mixture of elements (Y, Eu, La, Ce, Tb, Gd,...

Highly thermally stable Er³⁺/Tm³⁺/Yb³⁺ tri-doped bismuth lanthanum tungstate phosphors were prepared by high temperature solid-state reaction method. The structural and morphological properties of the prepared phosphors were analysed by X-ray diffraction (XRD), Raman spectroscopy and Scanning electron microscopy (SEM) coupled with energy dispersion...

Magnetically frustrated lattices even at low temperatures are well-known for not minimizing interaction energies. In a magnetically frustrated structure like strontium gadolinium oxide (SrGd2O4), there exists more than one suitable site for rare-earth doping due to availability of two low Gd³⁺ site symmetries. In the present work SrGd2O4 doped with...

Photothermal Materials In article number 2007761, Shiqi Wang, Hélder Santos, and co-workers introduce a polyoxometalate {Mo154}-incorporating, dual-crosslinked dynamic hydrogel (Mo154Gel) formed by Schiff base and electrostatic interactions. Mo154Gel shows exceptional photothermal conversion, and pH- and near-infrared-laser-triggered drug release....

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...

Polyoxometalates are an emerging class of molecular clusters, with well-defined structures and chemical compositions that are produced through simple, low-cost, and highly reproducible methods. In particular, the wheel-shaped cluster {Mo154} is a promising photothermal agent due to its intervalence charge transfer transitions. However, its toxicity...

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...

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...

Pseudomonas syringae pv. actinidiae (Psa) is a phytopathogen responsible for bacterial canker in kiwifruit plants and can be disseminated through pollen. This study aimed to evaluate the effectiveness of antimicrobial photodynamic therapy (aPDT) in the inactivation of Psa on kiwifruit pollen using New Methylene Blue (NMB) and Methylene Blue (MB) in...

Nowadays, the development of sustainable high-performance functional nanomaterials is on the spotlight. In this work, we report the preparation of a new generation of flexible and high electro-conductive nanopapers based on nanofibrillated cellulose (NFC) and copper nanowires (CuNWs). Homogeneous red-brick nanopapers (thickness: 30.2–36.4 μm) were...

The present study explores the preparation of dual nanofibrillar-based bio-sorbent films composed of cellulose nanofibrils (CNFs) and lysozyme nanofibrils (LNFs) for application in the removal of Hg(II) from aqueous solutions. The free-standing films were fabricated via simple vacuum filtration of water suspensions of CNFs and LNFs and disclose goo...

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...

In this study, brewers' spent grain (BSG) arabinoxylans-based nanocomposite films were prepared by solvent casting of arabinoxylans (AX) suspensions containing different amounts of nanofibrillated cellulose (NFC, 5, 10, 25, 50 and 75% mass fraction). The obtained nanocomposite films were homogeneous and presented thermal stability up to 230 °C and...

This work focuses on exploring combinations of disintegrated bacterial cellulose nanofibres (BC) with graphene oxide (GO) (reduced and non-reduced) and phase change materials (PCMs) prepared in the form of foam-like structures. The presence of GO remarkable improves the fire-retardancy and provides dimensional stability to the foams while PCMs give...

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...

The brown macroalgae Bifurcaria bifurcata have gained special attention due to their ability to biosynthesize linear diterpenes (rarely found in other species). However, the conventional extraction methods normally used to extract these compounds involve organic solvents and often high temperatures, leading to the degradation of thermo-labile compo...

This brief explores polysaccharides, the most abundant family of naturally occurring polymers, and explains how they have gained considerable attention in recent decades as a source of innovative bio-based materials. The authors present a range of material including an extensive array of polysaccharide hybrid nanomaterials with distinct application...

Carbon nanotubes (CNTs) are nanometric scale sp² carbon bonded materials with a tube-like structure formed by rolling-up graphene sheet(s) in a seamless way into a cylinder with open or closed ends (De Volder et al in Science 339:535–539, 2013 [1]; Kumar et al in Prog Energy Combust Sci 64:219–253 2018 [2]; Chinnappan et al in J Mater Chem A 4:9347...

The evolution of ideas towards the development of environmentally friendly materials derived from renewable resources has spotlighted biopolymers (and polysaccharides in particular) as substrates to engineer multifunctional materials, as corroborated by the extent and diversity of the publications portrayed in the present book.

Metal oxide nanoparticles (NPs), such as titanium dioxide (TiO2), zinc oxide (ZnO), copper oxides (CuO and Cu2O), silica (SiO2) and iron oxides (Fe2O3 and Fe3O4) NPs, are high in request for several high-tech applications, including catalysts, absorbent materials, optoelectronic materials, magnetic composites, luminescent materials, drug delivery s...

Graphene is a single layer of carbon atoms covalently bonded in a hexagonal crystalline structure, isolated for the first time by Geim and Novoselov from the University of Manchester (UK) [1]. Graphene is a flat-like single layer of hybridized sp² carbon atoms, which are densely packed onto each other into an ordered 2D honeycomb network (Fig. 4.1a...

For over a century, metallic nanoparticles (mNPs) have fascinated scientists, however, they have been empirically used by man since the middle ages as decorative pigments for colouring glass, like for example the famous Lycurgus Cup [1]. In this case, its use was due to one of the most interesting aspects of metallic colloids, their optical propert...

Protein nanofibers are gaining much attention due to their unique mechanical strength, thermal stability and functional properties, thus promoting research on new preparation methodologies. Most fibrillation processes developed so far are time consuming, usually taking from 8h to 15h, which represents a major drawback in their use. The use of alter...

The expansion of biomedical and therapeutic applications of silver nanoparticles (AgNPs) raises the need to further understand their biological effects on human cells. In this work, NMR metabolomics has been applied to reveal the metabolic effects of AgNPs towards human hepatoma (HepG2) cells, which are relevant with respect to nanoparticle accumul...

Deep eutectic solvents (DESs), a novel generation of ionic solvents, have recently been described as efficient and timesaving fibrillation agents for proteins. In this context, the present work aims at assessing the effect of the hydrogen bond donor (HBD) of cholinium chloride ([Ch]Cl):carboxylic acid based DESs on the dimensions (length and width)...

Due to their proven efficacy against a variety of pathogens, especially a broad spectrum of bacteria, silver nanoparticles (AgNPs) have been increasingly incorporated into consumer goods and medical products. Furthermore, the recently unveiled antiviral, antiinflammatory, and anticancer activities have attracted great interest and stimulated new de...

Homogeneous, translucent and flexible films of chitosan (CH) and ellagic acid (EA) were prepared by solvent casting. Various concentrations of EA (0.5, 1.0, 2.5 and 5.0% w/w relative to CH) were used in order to evaluate their UV-blocking properties. In addition, the photochemical stability of the films was also studied via artificial solar light i...

Nowadays, the “green synthesis” of different types of nanostructures, e.g. metallic nanoparticles (NPs), using plant extracts, emerged as a powerful, sustainable and economical design tool due to the panoply of plants available. However, the main challenge in this emerging area is still the strict control of the morphology (shapes) and dimensions o...

This study investigates the phytotoxicity of chronic exposure (up to 20 d) of different TiO2 nanoparticles (TiO2-NP) concentrations (5, 50, 150 mg L(-1)) in Triticum aestivum. Germination was not affected by TiO2-NP exposure and seedling shoot length (3 d) was enhanced. Contrarily, plants' shoot growth (20 d) was impaired. Effects on membrane perme...

The present work exploits the combination of a poly(ionic liquid) and nanocellulose for the design of functional nanostructured composites with potential application as bio-based anion-exchange membranes. So, a series of nanocomposite membranes based on a tetraalkylammonium derived polymeric ionic liquid, i.e. poly(methacroylcholine chloride) (PMAC...

This study reports on the development of nanocomposite foams, prepared by Pickering emulsion templating, with promising tailored-properties, simply tunable by their composition. The selected multicomponent monomer mixtures comprise acrylated epoxidized soybean oil (AESO), 1,6-hexanediol diacrylate (HDD) and divinylbenzene (DVB), chosen by their ren...

New materials obtained through the incorporation of meso-tetraarylporphyrins, bearing phenyl or pentafluorophenyl groups at the meso positions with or without acid groups, in chitosan films have been prepared and characterized in detail. The efficiency of these porphyrinic-chitosan films (PS-CF) to prevent Listeria innocua attachment and subsequent...

Amyloid fibrils have recently gained a lot of attention due to their morphology, functionality and mechanical strength, allowing for their application in nanofiber-based materials, biosensors, bioactive membranes and tissue engineering scaffolds. The in vitro production of amyloid fibrils is still a slow process, thus hampering the massive producti...

Brewers spent yeast insoluble residue (BSYIR) is the insoluble material that remains after the exhaustive extraction with strong alkali solutions of brewers spent yeast (BSY). BSYIR contains 57% polysaccharides, composed mainly of glucose residues (98%) and minor amount of mannose residues (1%). The glucans were mainly (1→4)-linked (56.6%); with lo...

The development of inorganic/organic composite materials represents a fast-growing interdisciplinary area in materials science and engineering. In this topic, a key idea is the production of composites comprising biopolymers and functional inorganic phases that could replace conventional materials in several high-technology applications. Following...

Silver nanoparticles (NPs) have received great attention, mainly due to their application as antimicrobial agents in diverse products, including textile- and paper-based materials. In this context, straightforward methodologies to monitor their cationic silver release capacity in diverse environments are required due to the rise of manufactured pro...

Nanobiotechnology has emerged as a fundamental domain in modern science, and metallic nanoparticles (NPs) are one of the largest classes of NPs studied because of their wide spectrum of possible applications in several fields. The use of plant extracts as reducing and stabilizing agents in their synthesis is an interesting and reliable alternative...

The Back Cover picture illustrates the green synthesis of metal nanoparticles using an Eucalyptus globulus bark extract. Santos et al. elucidated, through the use of advanced chromatographic techniques, the precise role of each family of compounds present in the plant extracts used in the bio-based synthesis of gold and silver nanoparticles. Phenol...

The use of renewable feedstocks in foam technology is a worldwide demand towards more sustainable materials. Castor oil is a vegetable oil, composed mainly by triricinoglycerol, a natural polyol, suitable for polyurethane foams production. In this study castor oil and a variable amount of microcrystalline cellulose fibers were used in a straightfor...

A series of polysaccharide-based transparent composite films containing lanthanopolyoxometalates (LnPOMs) have been prepared by using a water-soluble cationic chitosan derivative [HTCC = N-(2-hydroxypropyl)-3-trimethylammonium chitosan chloride] and pullulan (PUL). HTCC was more suitable than pure chitosan for this purpose due to its positive charg...

Silver has been mainly investigated as an antibacterial agent and less as a fungicide in which concerns antimicrobial properties. In this research, the antifungal activity of composite films of pullulan and Ag nanoparticles (NP) against Aspergillus niger was evaluated using standard protocols. These new materials were prepared as transparent cast f...

The design of cheap and safe antibacterial materials for widespread use has been a challenge in materials science. The use of copper nanostructures combined with abundant biopolymers such as cellulose offers a potential approach to achieve such materials though this has been less investigated as compared to other composites. Here, nanocomposites co...

Colloidal silver nanoparticles (NPs) were prepared using the citrate and borohydride reduction methods and were then investigated as fillers in three matrices: unmodified chitosan, water-soluble chitosan and a N-alkyl chitosan derivative. The nanocomposites were used to prepare cast thin films (9-19 μm thickness) and characterized for their optical...

The design of paper products based on copper nanoparticles (NPs) is a challenge because of the intrinsic propensity of Cu to oxidize in contact with air. Here, a comparative study on the growth and chemical stability of Cu NPs in vegetable and bacterial cellulose is described for the first time. Furthermore, comparative studies were performed by us...

The preparation of cellulose/metal nanocomposites by the in situ reduction of metal salts in cellulose aqueous suspensions has been extensively investigated. Typically this involves the use of a soluble metal salt as precursor, a reducing agent and a co-stabilizer to avoid agglomeration. However, the in situ method can be employed without addition...

Nanofibrillated cellulose offers new technological solutions for the development of paper products. Here, composites of nanofibrillated cellulose (NFC) and Ag nanoparticles (NP) were prepared for the first time via the electrostatic assembly of Ag NP (aqueous colloids) onto NFC. Distinct polyelectrolytes have been investigated as macromolecular lin...

The preparation and characterization of biocomposite materials with improved properties based on poly(lactic acid) (PLA) and bacterial cellulose, and, for comparative purposes, vegetal cellulose fibers, both in their pristine form or after acetylation, is reported. The composite materials were obtained through the simple and green mechanical compou...

Cellulose/Ag nanocomposites were prepared using two distinct methodologies and two cellulose substrates: vegetable and bacterial cellulose. These nanocomposites were characterized in terms of their morphology and chemical composition. Detailed studies on the antibacterial activity of these materials were carried out for Bacillus subtilis, Staphyloc...

Vegetable cellulose fibres have been surface modified using the hydrolysis of tetraethoxysilane (TEOS), octyltrimethoxysilane (OTMS) or phenyltrimethoxysilane (PTMS), followed by the layer-by-layer deposition of previously synthesized TiO(2) nanoparticles. Raman, FTIR and (29)Si Solid State NMR spectroscopies, and SEM were used to characterize the...

Synthetic Ag-bacterial cellulose nanocomposites are reported here and their performance as surface enhanced Raman scattering (SERS) substrates was investigated using thiosalicylic acid and 2,2'-dithiodipyridine as analytes. These nanocomposite materials act as natural sponges when immersed in aqueous or ethanolic solutions allowing capture and SERS...

SiO2/cellulose nanocomposites were prepared using two distinct methodologies: deposition of morphological well-defined SiO2 nanoparticles at the fibres surfaces via polyelectrolytes assembly (layer-by-layer approach, LbL) and the synthesis of SiO2 nanoparticles via tetraethoxysilane (TEOS) hydrolysis in the presence of cellulose fibres. Although bo...

Synthetic studies of nanocomposites containing gold nanoparticles attached onto wood or bacterial cellulosic fibres have been performed in situ in the presence of the fibres or by polyelectrolyte-assisted deposition. The optical properties of the final nanocomposites could be tailored not only by the starting Au nanoparticles characteristics but al...