Armando J. D. Silvestre

University of Aveiro | UA · CICECO Aveiro Institute of Materials

Melanoma is one of the most aggressive types of skin cancer, and the need for advanced platforms to study this disease and to develop new treatments is rising. 3D bioprinted tumor models are emerging as advanced tools to tackle these needs, with the design of adequate bioinks being a fundamental step to address this challenging process. Thus, this...

Poly(trimethylene 2,5-furandicarboxylate) (PTF) is an emergent biobased polymer potentially able to outperform the fossil-based poly(ethylene terephthalate) counterpart. In this work, computational chemistry and vibrational spectroscopy tools are combined to elucidate the conformational preferences of PTF in both crystalline and amorphous regions....

State-of-the-art delivery systems currently rely on chemical synthesis routes for drug encapsulation. However, these methods have inherent drawbacks concerning toxicity, selectivity, and the potential for burst release. To overcome these limitations, the enzymatic synthesis of polymer-drug conjugates emerges as a promising alternative to promote ec...

This study focuses on the preparation of layered bacterial nanocellulose (BNC) patches for drug delivery and wound healing in the context of herpes labialis. Nanostructured patches were prepared by selective aqueous diffusion of acyclovir (ACV, antiviral drug), hyaluronic acid (HA, skin healing promoter), and glycerol (GLY, plasticizer and humectan...

The design of eco‐friendly active food packaging systems based on biobased polymeric materials is a growing field of research because of the pressing concern for sustainable development. Herein, monolayer ternary thermoplastic films composed of poly(lactic acid) (PLA), gallic acid (GA, 2.5% w/w relative to PLA), and a plasticizer (poly(ethylene gly...

This study delves into the potential advantage of utilizing crab shells as sustainable solid adsorbents for CO2 capture, offering an environmentally friendly alternative to conventional porous adsorbents such as zeolites, silicas, MOFs, and porous carbons. The investigation focuses on crab shell waste, which exhibit inherent natural porosity and N-...

The bioaccessibility and bioavailability of phenolic compounds (PC) influence directly their role in disease prevention/control. Studies have evaluated this ability through complex plant and food matrices, which may reflect more a synergistic effect of the matrix than the ability of the PCs, hindering their individual exploitation in nutraceutical...

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...

Poly(trimethylene 2,5-furandicarboxylate) (PTF) is an emergent biobased polymer potentially able to outperform the fossil-based poly(ethylene terephthalate) counterpart. In this study computational chemistry and vibrational spectroscopy tools are combined to elucidate...

Polymers have played a pivotal role in shaping modern society, owing to their exceptional properties such as low density, flexibility, transparency, impermeability, mechanical strength, and durability [1]. However, these properties which make polymers advantageous also raise significant challenges, as most used polymers are neither biodegradable no...

Polymers have played a significant role in shaping modern society, thanks to their exceptional attributes like low density, flexibility, transparency, impermeability, mechanical strength, and durability [1]. However, most polymers are neither biodegradable nor easily recyclable, leading to accumulation in landfills and natural environments. Therefo...

The present work presents a highly efficient and greener alternative route for recycling one of the most consumed polymers today-poly(ethylene terephthalate) (PET). The process consists in the hydrolytic depolymerization of PET into terephthalic acid (TPA) using terpenoid-based eutectic solvents (ES) under alkaline conditions. It was demonstrated t...

3D bioprinting is a versatile technique that allows the fabrication of living tissue analogs through the layer-by-layer deposition of cell-laden biomaterials, viz. bioinks. In this work, composite alginate hydrogel-based bioinks reinforced with curcumin-loaded particles of cellulose esters (CEpCUR) and laden with human keratinocytes (HaCaT) are dev...

Polymers based on furans have received much attention in recent years due to their renewable origin and high-performance properties; nevertheless, the important class of polyesteramides still remains overlooked. Thus, here we introduced a new series of polyesteramides based on 2,5-furandicarboxylic acid (FDCA), 5,5′-isopropylidene bis(2-furfurylami...

Antimicrobial photodynamic therapy (aPDT) is a potent tool to surpass the global rise of antimicrobial resistance; still, the effective topical administration of photosensitizers remains a challenge. Biopolymer-based adhesive films can safely extend the residence time of photosensitizers. However, their wide application is narrowed by their limited...

The manufacture of sustainable functional fibers with low environmental footprint and superior properties is a pressing research issue under the auspices of more sustainable industrial textile processes. In the present study, regenerated cellulose fibers (CellReg) with flame retardancy properties are manufactured by functionalizing regenerated wood...

Polymers have a unique set of properties (such as lightweight and durability) which explains why they quickly become irreplaceable materials in our daily life. However, polymers' fossil origin and related geopolitical instability of the places where these sources are located, as well as polymers' non-circular fate after use, have encouraged a vigor...

In this study the viability of the integrated exploitation of E. globulus leaf essential oil and triterpenic acids was evaluated through the development of a novel extraction process that can be implemented sequentially in a biorefinery context. Thus, essential oil (EO) collected by hydrodistillation was used for the first time as a bio-based solve...

The use of active packaging technologies and biopolymeric materials are among the emerging trends for implementation of sustainability in the food packaging industry. Thus, herein, bioactive transparent nanocomposite films of thermoplastic starch (TPS) reinforced with bacterial nanocellulose (BNC) (1%, 5% and 10% w/w, relative to starch) and enrich...

The continuous search for novel biobased polymers with high-performance properties has highlighted the role of monofuranic-based polyesters as some of the most promising for future plastic industry but has neglected the huge potential for the polymers' innovation, relatively low cost, and synthesis easiness of 5,5-isopropylidene bis-(ethyl 2-furoat...

E. globulus leaves have been mainly exploited for essential oil recovery or for energy generation in industrial pulp mills, neglecting the abundance of valuable families of extractives, namely, triterpenic acids, that might open new ways for the integrated valorization of this biomass. Therefore, this study highlights the lipophilic characterizatio...

The rise of antibiotic resistant strains, as methicillin‐resistant Staphylococcus aureus (MRSA), challenges the current treatment of infections. In the case of ocular infections, antibiotic eye drops are commonly prescribed. However, their efficacy is usually compromised by the low viscosity of these formulations and the eye drainage. To overcome t...

Polysaccharides and proteins are extensively used for the design of advanced sustainable materials. Owing to the high aspect ratio and specific surface area, ease of modification, high mechanical strength and thermal stability, renewability, and biodegradability, biopolymeric nanofibrils are gaining growing popularity amongst the catalog of nanostr...

This work explores the conformational preferences and the structure-property correlations of poly(butylene 2,5-furandicarboxylate) (PBF), a longer chain analogue of the most well-known biobased polyester from the furan family, poly(ethylene 2,5-furandicarboxylate) (PEF). A thorough computational spectroscopic study–including infrared, Raman and ine...

The accumulation of advanced glycation end-products (AGEs) in the body is implicated in numerous diseases, being methylglyoxal (MGO) one of the main precursors. One of the strategies to reduce AGEs accumulation might be acting in an early stage of glycation by trapping MGO. Thus, this work aimed to evaluate, for the first time, the potential of eld...

Pretreatment processes — recognized as critical steps for efficient biomass refining — have received much attention over the last two decades. In this context, deep eutectic solvents (DES) have emerged as a novel alternative to conventional solvents representing a step forward in achieving more sustainable processes with both environmental and econ...

Given the current environmental crisis caused by polymers, we have seen that it is mandatory to make changes in the way we produce, consume, and, at the downstream, dispose, and manage polymeric materials after use. For applications where recycling might not be the adequate answer, or landfilling is highly likely to occur, (bio)degradable polymers...

The aim of this study is to prepare dissolvable biopolymeric microneedle (MN) patches comprised solely of sodium carboxymethylcellulose (CMC), a water‐soluble cellulose derivative with good film‐forming ability, by micromoulding technology for the transdermal delivery of diclofenac sodium salt (DCF). The microneedles with ca. 456 μm in height displ...

The chemical composition, investigated by gas chromatography-mass spectrometry, and antibacterial activity of lipophilic extractives of three varieties of Opuntia ficus-indica roots from Algeria are reported in this paper for the first time. The results obtained revealed a total of 55 compounds, including fatty acids, sterols, monoglycerides and lo...

Poly(2,5-furananedicarboxylate)s incorporating aliphatic moieties represents a promising family of polyesters, typically entirely based on renewable resources and with tailored properties, notably degradability. This study aims to go beyond by developing poly(isosorbide 2,5-furandicarboxylate-co-dodecanedioate) copolyesters derived from isosorbide...

The global demand for sustainable textile fibers is growing and has led to an increasing research interest from both academia and industry to find effective solutions. In this research, regenerated wood pulp fibers were functionalized with glycidyltrimethylammonium chloride (GTAC) to produce modified regenerated cellulose with cationic pending grou...

Proanthocyanidin’s molecular characteristics, especially mean degree of polymerization (mDP), have a high impact on their anti-inflammatory and antioxidant activities. Nevertheless, the mDP of proanthocyanidin’s extracts obtained from the same plant species can change due to the use of different plant varieties or by using plant material grown in d...

Green composites made of bioplastics reinforced with natural fibers have gained considerable attention over recent years. However, the use of natural fibers in composites usually compromise some key properties, such as the impact strength and the processability of the final materials. In the present study, two distinct additives, namely an epoxidiz...

Enzymatic synthesis of polymeric materials is a powerful approach to make these processes greener, more economical, and safer for scale-up. Herein, we characterized new variants of the hyperthermophilic carboxylesterase from the archaeon Archaeoglobus fulgidus with quantum mechanics/molecular mechanics molecular dynamics simulations. The designed v...

Betulinic acid (BA) was used as starting building block to create a library of novel BA-derived compounds containing O- and N-heterocycles. Firstly, BA was converted into methyl betulonate (BoOMe), which was used as intermediate in the developed methodologies. 1,2-Oxazine-fused BoOMe compounds were obtained in 12–25% global yields through a Michael...

Passiflora is a highly diverse genus where taxonomic lack of consensus remains. This may be the reason why numerous studies do not specify to the infraspecific level the plant material used or lack consistency in the nomenclature of botanical formae of Passiflora edulis. Ultimately, this may contribute to inaccurate chemical composition and health...

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...

Three-dimensional (3D) bioprinting is an innovative technology in the biomedical field, allowing the fabrication of living constructs through an approach of layer-by-layer deposition of cell-laden inks, the so-called bioinks. An ideal bioink should possess proper mechanical, rheological, chemical, and biological characteristics to ensure high cell...

In this study we report a series of partially biobased new (hetero)aromatic copolyesters, namely poly(ethylene-bis(ethyl 2-furoate)-co-ethylene 5-nitroisophthalate)s synthesised via the two-step melt polycondensation process, by combining commercially available dimethyl 5-nitroisophthalate and a biobased bisfuranic diester derivative (DEF), and eth...

The transdermal administration of nonsteroidal anti-inflammatory drugs (NSAIDs) is a valuable and safer alternative to their oral intake. However, most of these drugs display low water solubility, which makes their incorporation into hydrophilic biopolymeric drug-delivery systems difficult. To overcome this drawback, aqueous solutions of bio-based...

Bacterial nanocellulose (BNC) membranes, with remarkable physical and mechanical properties, emerged as a versatile biopolymeric carrier of bioactive compounds for skin care applications. In this study, BNC membranes were loaded with glycerol (as plasticizer and humectant agent) and different doses (1–3 μg cm−2) of an aqueous extract obtained from...

The development of novel separation technologies has been highly tackled in the last years not only to address scientific challenges but also to overcome technological hurdles essential to trigger and to implement more sustainable processes. In this context, the selection of solvents applied in multiple extraction, separation, and purification proc...

Hydroxymethylfurfural (5-HMF) is a key platform chemical, essential for the production of other chemicals, as well as fuels. Despite its importance, the production methods applied so far still lack in sustainability. In this work, acidic deep eutectic solvents (DES), acting both as solvent and catalyst, were studied for the conversion of fructose i...

The effect of water on the physicochemical properties of deep eutectic solvents (DES) is a trending research topic. In this work, inelastic neutron scattering (INS) spectroscopy, was used to probe intermolecular interactions in the water-deep eutectic solvent mixtures for the cases of choline chloride (the hydrogen bond acceptor) and three differen...

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...

The production of films derived from renewable resources for food packaging applications is an important research area within the scope of sustainable development. Herein, fully biobased films made from cactus mucilage (CM), extracted from Algerian Opuntia ficus-indica cladodes, and agar (A), extracted from marine red algae, were assembled via solv...

Since the prohibition of diphenylamine, replacement strategies have been needed for long-term disorder prevention, namely superficial scald (SC), in fruit. However, as this disorder only appears after months under cold storage, the assessment of effective strategies to prevent this disorder requires long periods. To tackle this challenge, we report...

Agroforestry by-products have gained rising attention in recent years as they represent inexpensive and abundant raw materials that are a source of added-value chemicals, e.g., for food and pharmaceutical applications, as well as for bioenergy generation. Pinus pinaster Ait. bark extracts are consumed worldwide for their cardiovascular benefits, wh...

Zizyphus lotus L. is a perennial shrub particularly used in Algerian folk medicine, but little is known concerning the lipophilic compounds in the most frequently used parts, namely, root bark, pulp, leaves and seeds, which are associated with health benefits. In this vein, the lipophilic fractions of these morphological parts of Z. lotus from Moro...

Chemically, attempts to recycle bio-based poly(ethyle 2,5-furandicarboxylate) (PEF) were not reported, yet its expected global production, potential accumulation or persistence in the environment call for innovative solutions: here, we report...

The extraction of proanthocyanidins (PACs), despite being an important and limiting aspect of their industrial application, is still largely unexplored. Herein, the possibility of combining eutectic solvents (ESs) with microwave assisted extraction (MAE) in the extraction of PACs from grape pomace (GP) is explored, aiming to improve not only the ex...

Elderberry (Sambucus nigra L.) consumption has been growing in the last years, generating a large number of stalks (~10% of the berries bunch) that are still under-valorized. This study focused on the evaluation of elderberry stalks as a source of high-value phytochemicals. In this vein, the essential mineral content and lipophilic composition were...

Improvement of dietary and ecological biodiversity, namely by exploring autochthonous varieties, is a key point to the construction of a more sustainable food system and planetary health. However, the environmental sustainability continues to face huge challenges, reflecting the importance of achieving a better understanding about the functional ro...

Natural polymers have emerged as promising candidates for the sustainable development of materials in areas ranging from food packaging and biomedicine to energy storage and electronics. In tandem, there is a growing interest in the design of advanced materials devised from naturally abundant and renewable feedstocks, in alignment with the principl...

The addition of alkali metal halide salts to acidic deep eutectic solvents is here reported as an effective way of boosting xylan conversion into furfural. These salts promote an increase in xylose dehydration due to the cation and anion interactions with the solvent being a promising alternative to the use of harsh operational conditions. Several...

Cellulose, the most abundant natural polymer, is a versatile polysaccharide that is being exploited to manufacture innovative blends, composites, and hybrid materials in the form of membranes, films, coatings, hydrogels, and foams, as well as particles at the micro and nano scales. The application fields of cellulose micro and nanoparticles run the...

This appraisal provides an up-to-date overview of the existent renewable, biomass-derived and more sustainable alternatives to conventional oil-based plastics, namely high-market share polyolefins, polyesters or polyamides. Special focus on polymers derived from ubiquitous carbohydrates and vegetable oils is provided. The End-of-Life (EoL) solution...

Green composites, composed of bio-based matrices and natural fibers, are a sustainable alternative for composites based on conventional thermoplastics and glass fibers. In this work, micronized bleached Eucalyptus kraft pulp (BEKP) fibers were used as reinforcement in biopolymeric matrices, namely poly(lactic acid) (PLA) and poly(hydroxybutyrate) (...

Deep eutectic solvents (DES) are eutectic mixtures that present a deviation from the ideal thermodynamic solid–liquid phase behavior, where a significant depression in the melting temperature occurs. If properly designed and chosen, DES may be liquid at room and the human body’s temperatures and display a biocompatible character, thus representing...