Mara G Freire

Mara G Freire
University of Aveiro | UA · CICECO - Aveiro Institute of Materials

PhD

About

371
Publications
89,036
Reads
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17,507
Citations
Introduction
Mara G. Freire is a Coordinator Researcher at CICECO - Aveiro Institute of Materials, Chemistry Department, University of Aveiro. She is the Coordinator of Group 5 of CICECO and Deputy Chair of the Scientific Council of University of Aveiro. She is member of the Young Scientists Seminar of the Lisbon Academy of Sciences. Freire published +220 scientific manuscripts (+10,000 citations; h-index 61) and participated in 22 R&D projects, including two Grants from the European Research Council (ERC).
Additional affiliations
February 2014 - present
University of Aveiro
Position
  • Coordinator Researcher
June 2013 - January 2014
University of Aveiro
Position
  • Research Assistant
January 2008 - May 2013
Universidade NOVA de Lisboa
Position
  • PostDoc Position

Publications

Publications (371)
Article
Full-text available
Currently, the use of alternative solvents is increasing, namely ionic liquids (ILs) and deep eutectic solvents (DESs) in diverse fields of knowledge, such as biochemistry, chemistry, chemical engineering, biotechnology and biomedicine. Particularly, when compared to traditional solvents, these alternative solvents have great importance for biomole...
Article
Although their high potential as alternative biopharmaceuticals, less than 2% of the total polyclonal antibodies produced worldwide correspond to immunoglobulin Y (IgY) due to the difficulties in isolating them from egg yolk that is a complex biological matrix. In this work, the proteins water soluble fraction (WSPF) of egg yolk was first obtained...
Article
Artemisinin is an antimalarial substance very sparingly soluble in water. In the attempt to identify environmental-friendly and non-toxic aqueous-based solvents to extract it from Artemisia annua L., the solubility of artemisinin in aqueous solutions of different hydrotropes was measured at 303.2 K, for hydrotrope concentrations up to 5 M. The abil...
Article
Full-text available
Compartmentalized structures obtained in all‐aqueous settings have shown promising properties as cell encapsulation devices, as well as reactors for trans‐membrane chemical reactions. While most approaches focus on the preparation of spherical devices, advances on the production of complex architectures have been enabled by the interfacial stabilit...
Article
Full-text available
L-asparaginase (ASNase) is an aminohydrolase currently used in the pharmaceutical and food industries. Enzyme immobilization is an exciting option for both applications, allowing for a more straightforward recovery and increased stability. High surface area and customizable porosity make carbon xerogels (CXs) promising materials for ASNase immobili...
Article
Full-text available
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...
Preprint
L-asparaginase (ASNase) is an aminohydrolase currently used in the pharmaceutical and food industries. Enzyme immobilization is an exciting option for both applications, allowing a more straightforward recovery and increased stability. High surface area and customizable porosity make carbon xerogels (CXs) promising materials for ASNase immobilizati...
Article
Full-text available
Neonicotinoids are systemic insecticides commonly used for pest control in agriculture and veterinary applications. Due to their widespread use, neonicotinoid insecticides (neonics) are found in different environmental compartments, including water, soils, and biota, in which their high toxicity towards non-target organisms is a matter of great con...
Article
Full-text available
Proteins are one the most widely studied biomolecules with diverse functions and applications. Aiming at overcoming the current drawbacks of purification processes of proteins, the introduction of ionic liquids (ILs) has been a hot topic of research. ILs have been applied in the creation of aqueous biphasic systems (IL-based ABS), solid-phase extra...
Article
In the past years large efforts have been placed in the development of novel separation techniques with improved resolution, simplicity, speed and easy to scale-up. Among these, ionic-liquid-based (IL-based) aqueous biphasic systems (ABS) have been broadly proposed for the separation of high-value compounds, allowing improved extraction performance...
Article
Full-text available
Liquid chromatography plays a central role in biomanufacturing, and, apart from its use as a preparative purification strategy, either in biopharmaceuticals or in fine chemicals industries, it is also very useful as an analytical tool for monitoring, assessing, and characterizing diverse samples. The present review gives an overview of the progress...
Article
Full-text available
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...
Article
Full-text available
Despite the progress achieved by aqueous biphasic systems (ABSs) comprising ionic liquids (ILs) in extracting valuable proteins, the quest for bio-based and protein-friendly ILs continues. To address this need, this work uses natural organic acids as precursors in the synthesis of four ILs, namely tetrabutylammonium formate ([N4444][HCOO]), tetrabu...
Article
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...
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
Full-text available
Immunoglobulin Y (IgY) represents an important class of antibodies, being present in egg yolk, with relevant medical applications and involving non-invasive methods of extraction. However, due to the complexity of egg yolk, the purification levels required for use in most medical applications demands the application of multi-step and cost-intensive...
Article
Full-text available
L-asparaginase (ASNase) is an amidohydrolase that can be used as a biopharmaceutical, as an agent for acrylamide reduction, and as an active molecule for L-asparagine detection. However, its free form displays some limitations, such as the enzyme’s single use and low stability. Hence, immobilization is one of the most effective tools for enzyme rec...
Article
Full-text available
In this work, the extraction and separation of bovine serum albumin (BSA) from its original matrix, i.e., bovine serum, was performed using a novel ionic-liquid-based aqueous biphasic system (IL-based ABS). To this end, imidazolium-, phosphonium-, and ammonium-based ILs, combined with the anions’ acetate, arginate and derived from Good Buffers, wer...
Chapter
Following the advent of Green Analytical Chemistry, several strategies have been proposed to reduce environmental, health and economic burdens of analytical chemistry methods. Among these, the use of alternative solvents such as deep eutectic solvents (DES) represents a viable option. The present chapter provides important insights on the design an...
Chapter
Environmental pollution is nowadays a serious concern, requiring an adequate monitoring of hazardous compounds, such as heavy metals, pesticides, and other organic compounds, and pharmaceutical drugs. However, due to the low concentration of some of these pollutants in environmental aqueous samples and the complexity of these samples, the major cha...
Chapter
The monitoring of pollutants plays a crucial role in environmental analysis, in which the development of more efficient and greener analytical methods is in high demand. To meet these requirements, the application of ionic liquids (ILs) as high-performance and selective solvents and based materials in new (ideally miniaturized) preparation techniqu...
Chapter
Microbial biosurfactants have been emerging as promising compounds for drug-delivery systems (DDS) advances. They can be formed using diverse classes of microorganisms, being versatile biocompounds with specific surface characteristics. When compared to chemical surfactants, good biodegradability, small toxicity, and potential biological activity a...
Article
Full-text available
Ribulose-1,5-biphosphate carboxylase/oxygenase (RuBisCO) is the most abundant protein on the planet, being present in plants, algae and various species of bacteria, with application in the pharmaceutical, chemical, cosmetic and food industries. However, current extraction methods of RuBisCO do not allow high yields of extraction. Therefore, the dev...
Article
Full-text available
Chlorophylls and their derivatives have been extensively studied due to their unique and valuable properties, including their anti-mutagenic and anti-carcinogenic features. Nevertheless, high-purity-level chlorophylls extracted from natural sources are quite expensive because the methods used for their extraction have low selectivity and result in...
Article
Full-text available
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...
Chapter
Biocatalysis is an important area in the context of green chemistry and sustainable development, competing with traditional chemical catalytic processes. However, to be a sustainable bioprocess, the proper choice of the reaction medium plays a significant role, combined with better performance and reduced costs. Volatile organic solvents are common...
Article
Aqueous biphasic systems (ABS) are promising for proteins purification; however, when dealing with samples comprising several proteins, the selectivity towards a target protein is difficult to achieve. In this work, the addition of ionic liquids (ILs) as adjuvants (5 and 10 wt%) in ABS composed of polyethyleneglycol (PEG) and Dextran was investigat...
Article
In an attempt to elucidate the aggregation behaviour of bovine serum albumin and its modulation by salt ions, size-exclusion high-performance liquid chromatography was used and complemented by dynamic light scattering. The influence of the protein concentration, and type and concentration of inorganic salt on the aggregation of albumin in solution...
Article
Full-text available
l-asparaginase (ASNase, EC 3.5.1.1) is an enzyme that catalyzes the l-asparagine hydrolysis into l-aspartic acid and ammonia, being mainly applied in pharmaceutical and food industries. However, some disadvantages are associated with its free form, such as the ASNase short half-life, which may be overcome by enzyme immobilization. In this work, the...
Article
Beer corresponds to a fermented alcoholic beverage composed of several components, including purine compounds. These molecules, when ingested by humans, can be catabolized into uric acid, contributing to uric acid's level increase in serum, which may lead to hyperuricemia and gout. To assure a proper management of this disease, physicians recommend...
Article
Full-text available
The negligible volatility and high tunable nature of ionic liquids (ILs) have been the main drivers of their investigation in a wide diversity of fields, among which is their application in areas involving pharmaceuticals. Although most literature dealing with ILs is still majorly devoted to hydrophobic ILs, evidence on the potential of hydrophilic...
Article
Full-text available
High quality nucleic acids (with high integrity, purity, and biological activity) have become indispensable products of modern society, both in molecular diagnosis and to be used as biopharmaceuticals. As the current methods available for the extraction and purification of nucleic acids are laborious, time-consuming, and usually rely on the use of...
Article
Full-text available
Ionic liquids (ILs) have been applied in several fields in which enzymes and proteins play a noteworthy role, for instance in biorefinery, biotechnology, and pharmaceutical sciences, among others. Despite their use as solvents and co-solvents, their combination with materials for protein- and enzyme-based applications has raised significant attenti...
Article
Full-text available
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...
Article
With the goal of finding sustainable solvents, novel ionic liquids (ILs) with low ecotoxicity features have been a target of research. Among these, ILs with surface-active characteristics play a significant role in the food, cosmetic, pharmaceutical, household cleaning and other detergent industries. Most surface-active ILs reported up to date are...
Chapter
The low solubility, permeation, and bioavailability of active pharmaceutical ingredients are the main factors affecting their delivery and therapeutic efficiency. Intensive research has pursuit new possibilities to overcome these drawbacks, in which polymers have played a major role in advances brought by drug delivery systems. Furthermore, the res...
Article
Full-text available
L-asparaginase (ASNase) is an aminohydrolase enzyme widely used in the pharmaceutical and food industries. Although currently its main applications are focused on the treatment of lymphoproliferative disorders such as acute lymphoblastic leukemia (ALL) and acrylamide reduction in starch-rich foods cooked at temperatures above 100 °C, its use as a b...
Article
Egg white proteins (ovalbumin, ovotransferrin, lysozyme, ovoinhibitor and ovomucin) are used in a wide range of applications, thus requiring the development of cost-effective purification platforms for their isolation and recovery. In this work, aqueous biphasic systems (ABS) and three phase partitioning (TPP) were investigated as combined approach...
Article
Full-text available
Spent coffee grounds (SCGs) are a waste product with no relevant commercial value. However, SCGs are rich in extractable compounds with biological activity. To add value to this coffee byproduct, water and aqueous solutions of cholinium-based ionic liquids (ILs) were studied to extract caffeine from SCGs. In general, all IL aqueous solutions lead t...
Article
Full-text available
Green Chemistry has been defined by the EPA as the design of chemical products and processes that reduce or eliminate the use or generation of hazardous substances [...]
Article
Full-text available
In the past decades, the production of biopharmaceuticals has gained high interest due to its great sensitivity, specificity, and lower risk of negative effects to patients. Biopharmaceuticals are mostly therapeutic recombinant proteins produced through biotechnological processes. In this context, L-asparaginase (L-asparagine amidohydrolase, L-ASNa...
Article
Levodopa is an amino acid commonly used in the treatment of Parkinson’s disease found in several plants, such as Mucuna pruriens. The extraction of levodopa from biomass has been achieved using methanol, ethanol:water mixtures in presence of ascorbic acid, chloroform in alkaline media, and acetonitrile. Aiming at finding more sustainable solvents a...
Chapter
Full-text available
Immunoglobulin Y (IgY) is an antibody present in the yolk of the egg and to obtain it at high purity levels, while retaining its biological activity, multi-step processes are required. The initial step is removal of the lipid fraction from the yolk. The delipidation methods routinely used are water dilution or precipitation by either polyethylene g...
Article
Full-text available
Ionic liquids (ILs) are molten salts composed of a large organic cation and an organic/inorganic anion. Due to their ionic character, most ILs present advantageous properties over conventional solvents, such as negligible volatility at atmospheric conditions and high thermal and chemical stabilities. The wide variety of IL anion–cation combinations...
Article
Full-text available
The advent of biopharmaceuticals in modern medicine brought enormous benefits to the treatment of numerous human diseases and improved the well-being of many people worldwide. First introduced in the market in the early 1980s, the number of approved biopharmaceutical products has been steadily increasing, with therapeutic proteins, antibodies, and...
Article
Novel liquid supports for enzyme immobilization and reuse based on aqueous biphasic systems (ABS) constituted by cholinium‐based ionic liquids (ILs) and polymers for the degradation of dyes are here proposed. The biocatalytic reaction for dye decolorization using laccase occurs in the biphasic medium, with the enzyme being “supported” in the IL‐ric...
Article
The therapeutic effectiveness and biological relevance of technologies based on adherent cells depend on platforms that enable long‐term culture in controlled environments. Liquid‐core capsules have been suggested as semipermeable moieties with spatial homogeneity due to the high mobility of all components in their core. The lack of cell‐adhesive s...
Research
Full-text available
l-Asparaginase (ASNase, EC 3.5.1.1) is a tetrameric aminohydrolase enzyme that catalyses the hydrolysis of the amino acid L-Asparagine into ammonia and L-aspartic acid. ASNase is present in different organisms such as bacteria, fungi, plant tissues and algae. ASNase is used in the pharmaceutical field as an anticancer drug for the treatment of acut...
Article
Antibody technologies are the most representative success-case in the biopharmaceutical industry. Widely available purification technologies fail in providing a dedicated universal purification platform that can accommodate antibodies structural diversity, namely antibodies from non-human sources, as chicken IgY, and antigen-binding fragments. In t...
Article
Although aqueous biphasic systems have been largely investigated in the separation and/or purification of biocompounds, their potential as reaction media to design integrated reaction-separation processes has been less explored. In this work aqueous biphasic systems (ABS) composed of polypropylene glycol of molecular weight 400 g.mol-1 (PPG 400) an...
Chapter
Biosurfactants produced by different types of microorganisms are amphiphilic biomolecules with active surface properties. Recently, biosurfactants have emerged as promising agents for cancer therapy since a high diversity of these molecules has shown the ability to induce cytotoxicity against many cancer cell lines, thus regulating cancer progressi...
Article
Artemisinin is a sesquiterpenoid lactone peroxide, known for its potent antimalarial activity that can be extracted from Artemisia annua L. This compound is only sparingly soluble in water, making its extraction using environmental-friendly and non-toxic aqueous solvents difficult. In the attempt to overcome this limitation, hydrotropes, which are...
Article
Cheese whey is an environmental problem as an effluent, but also a source of valuable raw materials, namely proteins and lactose. In this work, Aqueous Two-Phase Systems (ATPS) were studied for the recovery of lactose, BSA, β-lactoglobulin and α-lactalbumin, key components of cheese whey. ATPS formed by PEG (molecular weights: 200–8000 g.mol⁻¹) wit...
Article
The purpose of this work is to integrate the extraction of anthocyanins from grape pomace with a sequential purification process using an aqueous two-phase system (ATPS) and scaled-up in centrifugal partition chromatography (CPC) using as a common solvent the protic ionic liquids based on ethanolammonium and sulfuric acid. The choice of the best op...
Article
Full-text available
l-asparaginase (ASNase, EC 3.5.1.1) is an aminohydrolase enzyme with important uses in the therapeutic/pharmaceutical and food industries. Its main applications are as an anticancer drug, mostly for acute lymphoblastic leukaemia (ALL) treatment, and in acrylamide reduction when starch-rich foods are cooked at temperatures above 100 °C. Its use as a...
Article
The green fluorescent protein (GFP) is a biomolecule used in many biological applications such as biomarkers and biosensors, which require high purity levels. It is usually obtained from recombinant Escherichia coli strains, which also produces other endogenous proteins, demanding multiple purification steps, and consequently, increasing the overal...
Article
A deep analysis upon the chemical modifications of the cellulose and hemicelluloses fractions that take place during biomass delignification with deep eutectic solvents (DES) is lacking in literature, being this a critical issue given the continued research on DES for this purpose. This work intends to fill this gap by disclosing a comprehensive st...
Article
Full-text available
Solubility, bioavailability, permeation, polymorphism, and stability concerns associated to solid-state pharmaceuticals demand for effective solutions. To overcome some of these drawbacks, ionic liquids (ILs) have been investigated as solvents, reagents, and anti-solvents in the synthesis and crystallization of active pharmaceutical ingredients (AP...