Vera Alejandra Alvarez

• National University of Mar del Plata

This study presents the pilot-scale development of environmentally friendly agro-inputs based on natural bentonite functionalized with chitosan (Q) and salicylic acid (SA), based on successful previous laboratory-scale formulations. Comprehensive physicochemical, morphological, and thermal characterization tests were carried out in order to evaluat...

A novel bio‐based and biodegradable plastic based on poly(lactic acid) (PLA) and corn starch (CS) was developed as a single‐use rigid packaging material. Chitosan (Q) and eucalyptus essential oil (EEO) were incorporated as antimicrobial and antioxidant agents. The effects of these additives were evaluated using a three‐factor, two‐level factorial d...

Viral infections remain a major concern, as existing treatments often yield inadequate responses or lead to the development of antiviral resistance in some cases. Fucoidan extracted from Undaria pinnatifida (F) is a natural sulphated polysaccharide that exhibits antiviral action. Despite its potential, the biomedical application of F is limited due...

Chitosan and pectin form biocompatible polyelectrolyte complex hydrogels. This study investigates the impact of cellulose nanowhiskers (CNW) and NaCl on hydrogel’s properties, particularly in mechanical behavior. Swelling tests revealed deswelling under physiological conditions. Thermal analysis indicated enhanced crosslinking with CNW, correlating...

Fucose‐rich sulfated polysaccharides such as fucoidans are primarily found in brown algae. These compounds possess interesting pharmacological perspectives for antiviral and antioxidant drug development. The brown alga Myriogloea major (Chordariaceae, Ectocarpales) is an endemic brown alga from Argentine Patagonia similar to other members of the Ch...

Chitosan and pectin are employed here in the formation of biodegradable hydrogels. The addition of cellulose nanowhiskers (CNW) into the hydrogels was accomplished through two methods: a) By swelling, after the polymeric network formation, and b) inclusion in polymer solutions before gelation, with varying CNW content. Comprehensive physico‐chemica...

Nitrogen (N) deficiency is one of the most prevalent nutrient deficiencies in plants, and has a significant impact on crop yields. In this work we aimed to develop and evaluate innovative strategies to mitigate N deficiency. We studied the effect of supplementing tomato plants grown under suboptimal N nutrition with chitosan microparticles (CS-MPs)...

In this research, hydrogels based on chitosan, pectin, and salt (NaCl) were synthesized through the formation of polyelectrolyte complexes (PECs). The synthesis parameters, including pH, salinity, and polymer concentration, were varied to explore their influence. Weight and texture analysis revealed differences in hydrogel morphology. Swelling beha...

The use of fishing industry waste residues for biotechnological developments is blossoming in the last decade to improve the management of marine resources while reducing the environmental impact of the fisheries sector. Chitosan (CS), is a natural and nontoxic biopolymer that exerts great antimicrobial properties and is being considered as GRAS by...

In the global context of excessive and indiscriminate application of synthetic agrochemicals, this work combined natural compounds and nanotechnology to develop eco-friendly and sustainable agricultural systems with antifungal action. Cannabis (C) is composed of a large number of phytocannabinoids and terpenes and exhibit important biological prope...

Chagas disease is a neglected endemic disease prevalent in Latin American countries, affecting around 8 million people. The first-line treatment, benznidazole (BNZ), is effective in the acute stage of the disease but has limited efficacy in the chronic stage, possibly because current treatment regimens do not eradicate transiently dormant Trypanoso...

Fucoidans are fucose-rich sulfated polysaccharides that display a wide array of biological properties and are found mainly in brown seaweeds. These compounds possess interesting pharmacological perspectives for antiviral and antioxidant drug development. Myriogloea major Asensi (Chordariaceae; Ectocarpales) is an endemic brown seaweed from Argentin...

Oral candidiasis is an opportunistic infection that affects mainly individuals with weakened immune system. Devices used in the oral area to treat this condition include buccal films, which present advantages over both oral tablets and gels. Since candidiasis causes pain, burning, and itching, the purpose of this work was to develop buccal films lo...

The use of polymers capable of being degraded by the action of microorganisms and/or enzymes without causing harmful effects is a strategy in waste management and environmental care. In this work, bio-nanocomposites based on thermoplastic starch (TPS) were synthesized by reactive extrusion using a twin-screw extruder. Two strategies were evaluated...

The main objective of this research was to develop biobased superabsorbent materials (SAM) able to control humidity in soils. For this purpose, two abundant biopolymers (alginate and chitosan) were studied. Concentration of both polysaccharides, cross-linking time, CaCl2 and acetic acid concentrations were evaluated through Taguchi design. Then, tw...

The excessive use of pesticides in modern agriculture as a result of the increasing demand for crops for the world's growing population has caused harmful effects not only to human health but also to the environment. In this context, great efforts have been recently made to develop novel low-cost and eco-friendly technologies for the removal of pes...

3D bioprinting allows creative ideas for 3D scaffold development. Therefore, it enhances the creation of customized dressings for tissue regeneration and the wound healing process. A relevant requirement when employing hydrogels in extrusion-based bioprinting (EBB), is to maintain design fidelity and shape of printed structures. In this work, three...

Novel formulations based on corn starch (CS), thermoplastic starch (TPS), poly (lactic acid) (PLA) and poly (ε-caprolactone) (PCL) were developed in order to evaluate their performance as agricultural mulch films. Neat PLA and PCL samples, binary and ternary films were prepared using a Brabender type mixer. In order to determine the impact of the P...

This work is aimed to develop antifungal films from nanocomplexes based on egg white protein nanogels (EWPn) and phenolic compounds (PC), carvacrol (CAR) and thymol (THY). EWPn-PC nanocomplexes were characterized by intrinsic fluorescence spectroscopy, particle size (DLS), ζ potential, encapsulation efficiency (EE), and antifungal properties. Nanoc...

Polymeric anthocyanins are biologically active, pH-sensitive natural compounds and pigments with beneficial functional, pharmacological and therapeutic properties for consumer health. More recently, they have been used for the manufacture of active and pH-sensitive (“intelligent”) food nanopackaging, due to their bathochromic effect. Nevertheless,...

In recent years, constant innovations have led to the applications of textile biotech, biomaterials, biotechnologies, and environmentally friendly processes. Biofunctional textiles are specific textiles which demonstrate new properties; their main purpose is to protect or heal the skin. Nanotechnology plays a fundamental role in developing them, by...

The excessive use of pesticides in modern agriculture as a result of the increasing demand for crops for the world's growing population has caused harmful effects not only on human health but also on the environment. In this context, great efforts have been recently made to develop novel low-cost and eco-friendly technologies for the removal of pes...

Vitamin E (VitE) is one of the most important antioxidants and plays a key role in decreasing the inflammatory effects of oxidative stress caused by recurrent doses of iron administration in anemia treatment. However, VitE is poorly soluble in aqueous environments. Here, VitE encapsulation into solid lipid nanoparticles (SLN) composed of myristil m...

The extraordinary occurrence of COVID‐19 by the fast expansion of viral infections has propelled particular interest in developing novel antiviral and virucidal agents to guarantee personal security. The main objective of this work is to propose novel formulations able to optimize the use of personal protection elements. In recent years, chitosan (...

This work is aimed to develop antifungal films from nanocomplexes based on egg white protein nanogels (EWPn) and phenolic compounds (PC), carvacrol (CAR) and thymol (THY). EWPn-PC nanocomplexes were characterized by intrinsic fluorescence spectroscopy, particle size (DLS), ζ potential, encapsulation efficiency (EE), and antifungal properties. Nanoc...

Introducción: Durante la actual pandemia de COVID-19 han surgido muchas controversias e interrogantes respecto de la persistencia de la actividad viral en distintas superficies. Para el área de salud, ha sido un gran desafío lograr optimizar los usos de equipos de protección personal (EPP), teniendo en cuenta la incertidumbre acerca de la estabilid...

Pharmacological treatments of central nervous system diseases are always challenging due to the restrictions imposed by the blood–brain barrier: while some drugs can effectively cross it, many others, some antiepileptic drugs among them, display permeability issues to reach the site of action and exert their pharmacological effects. The development...

One of the major agricultural concerns is enhance plant productivity linked with the minimum environmental damage. In this work, we studied the action of chitosan microparticles (CS-MP) in tomato plantlets grown under nutritional nitrogen (N) deficiency. For that, plantlets were grown in deficient medium (DM), supplemented or not with CS-MP. We dem...

Violacein (Viol) is a bacterial purple water-insoluble pigment synthesized by Chromobacterium violaceum and other microorganisms that display many beneficial therapeutic properties including anticancer activity. Viol was produced, purified in our laboratory, and encapsulated in a nanostructured lipid carrier (NLC). The NLC is composed of the solid...

In order to evaluate the influence of corn starch (CS) storage in controlled-chambers at different relative humidities on thermoplastic starch (TPS) film properties, CS films were prepared by extrusion using glycerol and water as plasticizers. Four TPS formulations were compared with low-density polyethylene (LDPE) film, which is the most commonly...

Extrusion-based bioprinting (EBB) is a biofabrication technique that has been widely used by researchers in the last two decades, mainly due to its versatility, ease to use, and low cost. EBB can deposit many materials, different cell types, and biomolecules in a predetermined position to generate 3D complex architectures for its usage in tissue en...

Novel antiviral cotton fabrics impregnated with different formulations based on Chitosan (CH), citric acid (CA), and Copper (Cu) were developed. CA was selected as a CH crosslinker agent and Cu salts as enhancers of the polymer antimicrobial activity. The characterization of the polymeric-inorganic formulations was assessed by using atomic absorpti...

Nanocrystalline cellulose (NCC) is usually obtained by the acid hydrolysis of microcrystalline cellulose for its use as polymer reinforcement. An ecological alternative to this process, avoiding the use of acids, is a mechanical method. High intensity ultrasonication (HIU) in optimal conditions (time, wave amplitude, volume ratio fiber/solution, ce...

Sprayable agricultural mulch suspensions were prepared from the combination of sodium alginate (Alg) and three different concentrations of the seaweed Undaria pinnatifida (A) microparticles: 0.5, 1, and 2 wt%. Growth parameters were measured in tomato plants cultivated under each type of mulches, including polyethylene (PE) as a control treatment....

The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) is widely used due to it selective action, and preferential control of dicotyledonous weeds affecting cereal crops. Physiological responses of sensitive dicotyledonous plants to 2,4-D include growth retardation, senescence, and cell death. Due to soil and water contamination by agricultural pract...

La mayoría de los hidrogeles comercialmente disponibles están basados en acrilatos, es decir no son biodegradables y presentan cierto grado de toxicidad. Particularmente, en este trabajo se propone el desarrollo de hidrogeles biodegradables a partir de la gelación iónica de alginato de sodio (Alg) con cloruro de calcio como una alternativa sustenta...

A new tioconazole (TCZ) mucoadhesive film, based on a biodegradable chitosan/ hydroxypropyl methylcellulose (CH/HPMC) blend, was developed for treatment of vaginal candidiasis. The formulation was optimized through an I-optimal design (minimizing the integral of the prediction variance across the factor space), where the impact of the proportion of...

BACKGROUND Recycling food wastes into high‐value‐added products not only impacts beneficially on the environment but also on local economies. Mango wastes represent more than 92 000 tons per year in Peru. Bioconversion of mango waste into bacterial cellulose (BC) can provide valuable products in biomedicine. RESULTS Screening of BC producers in ko...

Plants constitute the world's primary food source. Thus, due to demographic growth in recent years there has been a tendency to maximize agricultural yields. Active molecules are useful to improve different aspects related with their plants production and yield. Immobilization, encapsulation and vehiculization of active principles, as amino-acids,...

Background Parkinson’s disease (PD) is a neurodegenerative movement disorder affecting 1–5% of the general population for which neither effective cure nor early diagnostic tools are available that could tackle the pathology in the early phase. Here we report a multi-stage procedure to identify candidate genes likely involved in the etiopathogenesis...

Agriculture represents one of the most important human activities in the world. Currently, the agricultural system deals with multiple challenges, including population growth, dietary choices, technological progress, climate change, and sustainability. In order to overcome these challenges, many agricultural applications have emerged to enhance pro...

Soil salinity is one of the most critical environmental stresses that affects crop productivity. In a context in which world demand for food is growing continuously, this problem requires urgent attention. Actions that go beyond traditional agricultural practices are needed. The objective of the current study was to develop a bioactive, economic, a...

Contamination of water with arsenic is a major global health problem. The use of adsorbent materials for the removal of As from aqueous systems is a plausible solution to this problem. In this work, the use of commercial bentonites (purified and modified with iron (III)) for the removal of As from water was studied. The samples were characterized b...

In this work, biodegradable nanocomposites based on polycaprolactone reinforced with pristine and organo‐modified bentonites are prepared by melt extrusion. Bentonite is exchanged with benzalkonium chloride (CBK) in a pilot plant scale reactor. The influence of clay type and loading on morphology, rheology, mechanical properties, and creep performa...

OBJECTIVE: Parkinson's disease (PD) is a complex neurodegenerative disorder. Males are on average ~ 1.5 times more likely to develop PD compared to females with European ancestry. Over the years genome-wide association studies (GWAS) have identified numerous genetic risk factors for PD, however it is unclear whether genetics contribute to disease e...

Nanotechnology application in agriculture has been increasing over recent years and constitutes a valuable tool to reach the goal of sustainable food production worldwide. A wide array of nanomaterials has been used to develop strategies of delivery of bioactive compounds aimed to boost the production and protection of crops. The controlled deliver...

The excessive and indiscriminate use of synthetic agrochemicals and toxic fumigants has become essential in the maximization of agricultural production worldwide. Despite their beneficial roles in the field and during storage, they produce environmental pollution, increasing pesticide/herbicide resistance and destruction of beneficial insects, and...

Since the 1940s, the introduction of plastic technology caused a true revolution in agriculture. Among the uses of plastics, mulch films have been used to improve yields and crop traits. They are useful to increase air and soil temperatures, protect plants from several agents, improve water management, reduce the growth of weeds, and consequently,...

Polycaprolactone (PCL)-based nanocomposites reinforced with different clay loadings (1.5, 3 and 5 wt%) of neat and organo-modified bentonites were successfully fabricated using twin-screw melt extrusion followed by melt compression. The whole processing of the materials, including the organic modification of bentonite with benzalkonium chloride (CB...

The development of versatile carriers to deliver chemotherapeutic agents to specific targets with establishing drug release kinetics and minimum undesirable side effects is becoming a promising relevant tool in the medical field. Magnetic hybrid nanostructured lipid carriers (NLC) were prepared by incorporation of 1,8-cineole (CN, a monoterpene wit...

Long runs of homozygosity (ROH) are contiguous stretches of homozygous genotypes, which are a footprint of inbreeding and recessive inheritance. The presence of recessive loci is suggested for Alzheimer’s disease (AD); however, their search has been poorly assessed to date. To investigate homozygosity in AD, here we performed a fine-scale ROH analy...

Otro estilo científico y tecnológico es posible Resumen: En junio de 2020 fue creada la Red de Pensamiento Latinoamericano en Ciencia, Tecnología y Sociedad (Red PLACTS). Conformada por integrantes del sector científico, tecnológico y universitario, impulsa una agenda que ponga el conocimiento, los recursos y el complejo CyT en proyectos destinados...

Importance Substantial genome-wide association study (GWAS) work in Parkinson disease (PD) has led to the discovery of an increasing number of loci shown reliably to be associated with increased risk of disease. Improved understanding of the underlying genes and mechanisms at these loci will be key to understanding the pathogenesis of PD. / Objecti...

This work describes a setup to characterize the effective diffusivity of barrier membranes to mass transport. Membranes with controlled and well‐defined barrier microstructures are produced from an elastomeric polydimethylsiloxane (PDMS) matrix. Physical obstacles to mass transport are generated by carving in the matrix microscopic holes with well‐...

While there are many existing technologies for treating water, many of them are expensive, inefficient, or not environmentally friendly. The application of green materials in water and wastewater treatment and pollution cleanup is promising, as demonstrated by an increasing number of investigations. However, although many of them show great potenti...

The incidence of cancer and the death rate increases every year in the world. The drug 8-hydroxyquinoline platinum(II) [PtCl(8-O-quinoline)(dmso)] (8HQ-Pt) has been identified as a promising antitumor complex. Nanostructured lipid carriers (NLC) are the second-generation drug nanocarrier systems that present superior advantages over other kinds of...

In the global context of emerging pathogens associated with respiratory diseases, novel nanostructured lipid carriers (NLCs) having both antioxidant and antimicrobial properties produced by α-tocopherol (αT) and levofloxacin (LV) respectively, were developed. Hybrid NLCs were made of solid lipid esters and liquid αT as central core, plus chitosan (...

Pectin is a biopolymer extracted from the cell walls of higher plants; it has high molecular weight, nontoxic, and biocompatible characteristics. Pectin is a highly complex polymer, an heteropolysaccharide, and is mainly formed by D-galacturonic acid (D-GalA), which is present in different polymeric forms, that is, homogalacturonan (HG), rhamnogala...

Fungal green biosynthesis of nanoparticles (NPs) is a promising eco-friendly method for mass-scale production. In the present study Ag, CuO and ZnO nanoparticles were biogenically synthetized using a cell filtrate of a strain of Trichoderma harzianum as a reducer and stabilizer agent. The structure, morphology and physicochemical properties of the...

Magnetic beads composed by polyvinyl alcohol and iron oxides were developed and fully characterized. The materials were not only cross‐linked by a physical treatment but also the magnetic nanoparticles (MNPs) are acting as cross‐linking dots. Interestingly, the analysis of scanning electron micrographs revealed that, in the case of hydrated samples...

In order to meet the cost-effective sustainable agriculture and the global increasing food demand, novel green materials are being developed. The need to increase safety-food production while reducing inputs, represents a significant challenge to be faced by researchers in the current century. The use of biomaterials in agriculture, particularly po...

People with weakened immune systems are at risk of developing candidiasis which is a fungal infection caused by several species of Candida genus. In this work, polymeric nanoparticles containing miconazole nitrate and the anesthetic lidocaine clorhydrate were developed. Miconazole was chosen as a typical drug to treat buccopharyngeal candidiasis wh...

Objective Kidney markers are some of the most frequently used laboratory tests in patient care, and correct clinical decision making depends upon knowledge and correct application of biological variation (BV) data. The aim of this study was to review available BV data and to provide updated BV estimates for the following kidney markers in serum and...

Gelatin based hydrogels were synthesized by the thawing-freezing method employing gum Arabic as crosslinking agent. The incorporation of cellulose nanowhiskers (NC) was analysed aiming to reach a control over the solubility/degradation rate, swelling properties and their ability to load anaesthetic drugs. Three concentrations of NC were explored, i...

Composites based on bentonite and chitin were prepared and its application for trimethoprim (TMP) adsorption from aqueous solution was investigated. Composites were characterized by ATR-FTIR, XRD, DSC and TGA. Characterization data revealed the intercalation of the chitin macromolecules into the bentonite interlayer. Several important parameters of...

Arsenic (As) is a major source of water contamination that has both natural and anthropogenic origins, so that, to remove it from water is a relevant topic. Taking into account the ease of operation, the cost of processing and the required instrumentation, adsorption processes could be considered as very convenient alternative technologies for wate...

The presence of arsenic (As) in water intended for human consumption and wastewater represents a high level of dangerousness for both human health and the environment. Partial or complete removal of this metalloid from water is an important objective for environmental remediation in many parts of the world. Generally, As is present as As(III) and A...

The aim of this study was to develop alginate-based hydrogels for application in horticultural field as bio-based substrate additives to control moisture. For this purpose, a 2-level factorial design was performed to select the appropriate levels of significant variables, i.e. polymer concentration (2-3 % w/v), CaCl2 concentration (0.2-0.4 % w/v),...

Salicylic acid (SA) is a phytohormone with a central role in plant protection against various types of stresses. Exogenous application of SA in plants often requires a fine adjustment of the pH in the applied solution as well as frequent foliar sprays with a rigorous handling of doses. This work investigates the preparation and characterization of...

The use of polymers capable of being degraded by the action of microorganisms and/or enzymes without causing harmful effects is a strategy in the management of waste and environmental care. Agro-polymers have begun to play a significant role among researchers and industry, since it has been found that these materials are Biodegradable and eco-frien...

Thermal degradation of green nanocomposite films prepared from poly (ε-caprolactone) (PCL) and soy lecithin (SL)-modified bentonite (Bent) obtained by melt blending were studied by means of thermal degradation kinetics and molecular weight determinations by gel permeation chromatography (GPC). Kinetic of degradation processes were analyzed by dynam...

The recently published Mean Field Interacting Superparamagnet Model (MFISP model), which introduces the effective demagnetizing factor NE, is tested in specimens having a random-like spatial distribution of magnetic nanoparticles, where different hierarchies of clustering are present. These specimens are ferrogel PVA/iron oxide beads synthesized by...

The use of plastics based on non-renewable petroleum-sources in agriculture represents a growing threat to the environment. Horticultural practices, as well as the growing of plants for landscape, generate great amounts of plastic waste from transplanting pots that are rarely recycled. Nevertheless, there are only few works that deal with biodegrad...

Rising demands of food together with modern practices in agriculture require the inclusion of areas with sub-optimal soil qualities for cultivation and the replacement of contaminant chemical fertilizers. In this work, we evaluated the use of the seaweed Undaria as a soil amendment of organic-matter impoverished soil. We demonstrated that Undaria s...

Natural seaweed microparticles obtained from Undaria pinnatifida waste (A) were used as fillers in thermoplastic starch (TPS)–chitosan (CH) blend in order to obtain microcomposites films for application in sustainable agriculture. The adequate proportion of both polymers was optimized with regards their mechanical, barrier, water interaction and mo...

Polyvinyl alcohol (PVA)/ Bentonite, acid-modified Bentonite, magnetic nanoparticles and mesoporous carbonaceous composite hydrogels were synthesized via an eco-friendly freeze-thawing technique, which is a simple and non-toxic crosslinking methodology. After thorough characterisation using X-Ray Diffraction (XRD), Scanning Electron microscopy (SEM)...

Associated with the growth of the human population and the development of the chemical industry, pesticides have been increasingly used for the control of pests in agriculture. As a result, these chemicals are now frequently found in water bodies and industrial wastewater. Therefore there is an evergrowing need to develop materials capable of remov...

Some inorganic species of arsenic (As) present in drinking waters are highly dangerous for human health. Adsorption technique is considered a promising technology for the selective removal of As from aqueous systems. Iron (Fe), and iron-containing clays are adsorbents commonly used for arsenic elimination from water due to the strong affinity betwe...

Some inorganic species of arsenic (As) present in drinking waters are highly dangerous for human health. Adsorption technique is considered a promising technology for the selective removal of As from aqueous systems. Iron (Fe), and iron-containing clays are adsorbents commonly used for arsenic elimination from water due to the strong affinity betwe...