Mariana Agostini de Moraes

• PhD
• Professor at State University of Campinas (UNICAMP)

This work investigated the production and characterization of a silk fibroin (SF) hydrogel incorporated with an Aloe vera (AV) extract. Four extraction methods, ultrasound-assisted extraction with bath and probe, stirring, and Soxhlet, were tested, while the hydrogel was produced by a one-step freeze–thaw method. Besides the extraction yield, the a...

Immunoglobulin G (IgG) is an antibody used in numerous therapeutic indications. For this reason, high-purity IgG is required, which implies the use of selective adsorption chromatographic purification techniques. Although, before using chromatography, it is highly important to study the interaction between IgG and the adsorbent. Due to its characte...

Mucin, a glycoprotein with viscoelastic properties, and silk fibroin, a protein excreted from silkworms with properties of thermal and mechanical resistance, have been probed as building blocks in the design of biomaterials. Aiming to evaluate the interaction and miscibility between mucin and fibroin, we synthesized silk fibroin and mucin (SF/MU) b...

Active packaging (AP) is an innovative type of food packaging from which active compounds, such as antimicrobials or antioxidants, may be released in order to enhance food quality and safety and extend its shelf-life. The efficiency of the AP system depends on the release rate, since too high rates may lead to a premature loss of the AP activity, w...

Silk fibroin (SF) and sodium alginate (SA) are natural polymers with interesting properties to produce biomaterials. Blends of these polymers form a complex protein–polysaccharide system where phase separation can be observed. Therefore, the thermodynamic analysis of this system is important to understand the interaction between the polymers and pr...

Biopolymers appear as a great candidate for plastic substitution in a wide array of industries, attracting interest for its non-toxicity and biodegradability. Among the biopolymers, starch can be highlighted due to its abundance and capability to undergo diverse chemical and physical modifications. Therefore, the aim of this work is to produce film...

Barbatimão (Stryphnodendron adstringens) is a Brazilian medicinal plant known for its pharmacological properties, including healing activity related to its phenolic composition, which is chiefly given by tannins. In order to preserve its stability and bioactivity, barbatimão extracts can be incorporated into (bio-)polymeric matrixes, of which silk...

The aim of this work was to prepare silk fibroin (SF) membranes incorporated with cationic and anionic dyes, in order to analyze the behavior of SF matrix loaded with charged compounds. For that, the combinatorial effect of pH and ionic strength on the release kinetics was assessed, showing that cationic dye has poor interaction with SF and high re...

Due to its abundance in nature and low cost, starch is one of the most relevant raw materials for replacing synthetic polymers in a number of applications. It is generally regarded as non-toxic, biocompatible, and biodegradable and, therefore, a safe option for biomedical, food, and packaging applications. In this review, we focused on studies that...

Background: COVID-19 is caused by the SARS-CoV-2 virus, an emerging respiratory pathogen. The work environment represents a high-risk factor for health professionals. Given the scarcity of protective personal equipment due to global demand, decontamination and reuse studies should be carried out. Thus, the aim of this study was to evaluate the saf...

Chitosan films have been extensively studied as dressings in formulations for the treatment of chronic wounds. The incorporation of aloe vera (Aloe barbadensis Miller) into chitosan dressings could potentialize the healing process since aloe vera shows several pharmacological activities. This work aimed to evaluate the effect of aloe vera and chito...

Silk fibroin (SF) is a promising and versatile biodegradable protein for biomedical applications. This study aimed to develop a prolonged release device by incorporating SF microparticles containing dyes into SF hydrogels. The influence of dyes on incorporation and release kinetics in SF based devices were evaluated regarding their hydrophilicity,...

In recent years, orally disintegrating films (ODFs) have been studied as alternative ways for drug administration. They can easily be applied into the mouth and quickly disintegrate, releasing the drug with no need of water ingestion and enabling absorption through the oral mucosa. The ODFs matrices are typically composed of hydrophilic polymers, i...

Silk fibroin (SF) and sodium alginate (SA) are natural polymers used to produce biomaterials. One of the strategies to improve the properties of these products is to prepare blends with them, which are partially miscible. Phase separation is observed, therefore, the thermodynamic analysis of this system is important to predict the final state and c...

In this study, we proposed the use of the biopolymer alginate to produce membranes with diclofenac sodium incorporated as model-drug aiming at wound dressing application with drug delivery. The membranes were prepared by casting and the drug was incorporated directly into alginate solution, being retained within the membrane. Morphological, chemica...

In this study, we proposed the use of the biopolymers silk fibroin, chitosan and alginate, which are recognized for their biocompatibility and biodegradability, for the preparation of multilayer membranes aiming at high performance wound dressings with controlled drug delivery. The rationale was to combine in one material the mechanical properties...

In this chapter, a full overview of the main characterization techniques of biopolymer membranes and films is presented, focusing on the fundamentals and methods of analysis of each technique applied to biopolymers. First, a complete publications search on the main characterizations of biopolymer films and membranes is reported, specifying the numb...

Chitosan is a semisynthetic biopolymer made from chitin which is the second most abundant biopolymer on Earth. In addition to being abundant, chitosan exhibits properties such as biodegradability and nontoxicity that make it very attractive for applications in diverse fields. However, the mechanical properties of chitosan devices represent one of t...

In this paper, we have evaluated the incorporation of a drug model and its release from silk fibroin (SF) membranes, analyzing the morphological, chemical, barrier, and biological properties. SF self‐assembled into stable globular structures, encapsulating the drug, when diclofenac sodium (DS) was incorporated into SF solution prior to membranes pr...

Glucomannan asymmetric membranes for wound dressing–Erratum - Giovana Maria Genevro, Reginaldo Jose Gomes Neto, Letícia de Almeida Paulo, Patrícia Santos Lopes, Mariana Agostini de Moraes, Marisa Masumi Beppu

The novelty of this study was to investigate for the first time in literature the influence of Bombyx mori silkworm cocoon's age on the properties of silk fibroin-based materials, during all stages of cocoon processing to obtain the fibroin film. The study started with the premise that the cocoon age could cause modifications on fibroin properties...

Freezing is an interesting technique to modify the mechanical properties and morphology of hydrogels. Konjac glucomannan (KGM) is a polysaccharide that has potential use in cutting-edge areas as biomaterials and tissue engineering. In this work, we deeply investigated the influence of freezing on KGM. For that, KGM hydrogels were frozen at several...

A novel bilayer film of chitosan and konjac glucomannan were prepared by the two-step casting technique. Blend films were also prepared to investigate the interactions between the two polymers in the interfacial region of the bilayer structure. Scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction analysis sho...

Asymmetric membranes present promising characteristics for wound dressing applications. A porous structure uptakes the wound exudate, whereas an occlusive layer (upper film) inhibits the microbial penetration and prevents an excessive loss of water. Konjac glucomannan (KGM) is a natural polysaccharide that has been investigated as wound dressings i...

Silk fibroin (SF) and sodium alginate (SA) are natural polymers with many applications as biomaterials. It is possible to make blends with them in order to improve their properties. Those blends are partially miscible; therefore, understanding the mechanism and phase equilibrium of this system is important to better understand the interaction betwe...

Miscibility is an important issue in biopolymer blends for analysis of the behavior of polymer pairs through the detection of phase separation and improvement of the mechanical and physical properties of the blend. This study presents the formulation of a stable and one-phase mixture of collagen and regenerated silk fibroin (RSF), with the highest...

The use of natural resources, especially processing wastes, as low cost and environmentally friendly alternative aiming high value-added applications is a subject of broad interest. Since the Brazilian silk production annually generates a large amount of waste during the silk fibers processing, this work explores the preparation and characterizatio...

The layer-by-layer technique has been used as a powerful method to produce multilayer thin films with tunable properties. When natural polymers are employed, complicated phenomena such as self-aggregation and fibrilogenesis can occur, making characterization and the obtainment of high quality films more difficult. The weak acid and base character o...

Films of silk fibroin (SF) and sodium alginate (SA) blends were prepared by solution casting technique. The miscibility of SF and SA in those blends was evaluated and scanning electron microscopy (SEM) revealed that SF/SA 25/75 wt.% blends underwent microscopic phase separation, resulting in globular structures composed mainly of SF. X-ray diffract...

Silk fibroin has been widely explored for many biomedical applications, due to its biocompatibility and biodegradability. Sterilization is a fundamental step in biomaterials processing and it must not jeopardize the functionality of medical devices. The aim of this study was to analyze the influence of different sterilization methods in the physica...

Silk fibroin has been widely explored for many biomedical applications, due to its biocompatibility and biodegradability. The aim of this work was to study the role of dialysis and freezing on structural conformation, thermal properties and morphology of silk fibroin hydrogels. Hydrogels were prepared after 3 and 7 days of dialysis and the effect o...

Silk hydrogels are interesting materials to be used as matrix in controlled drug delivery devices. However, methods to accelerate fibroin gelation and allow the drug incorporation during the hydrogel preparation are needed in literature. In this article we report the preparation of silk fibroin hydrogels with addition of several contents of ethanol...

Biocomposite membranes from biodegradable and biocompatible natural polymers were prepared from sodium alginate solution reinforced with silk fibroin fibers in several fiber content by casting and solvent evaporation. The properties of these biocomposites were investigated by scanning electron microscopy, swelling test, water vapor transmission, me...

Chitin is a natural copolymer found in crustacean shells and has potential for use in a wide range of faculties. During the chitin obtainment process, effluents with high organic charge are generated. These should be treated before discharge in order to avoid environmental problems. This work aimed to investigate the treatment of effluents from chi...

Silk fibroin (SF) films have been largely studied as biomaterials due to their biocompatibility and biodegradability. Casting a SF aqueous solution at room temperature is a common technique to produce SF films at relative low cost and processing time; however, their brittleness and solubility in water make them unsuitable for certain biomedical app...

Chitosan/alginate multilayer dense membranes, with micrometric thicknesses, were produced by casting the solution of each polymer alternately on a Petri dish. Copper ions were also incorporated into these membranes, which were then characterized with regard to morphology, chemical and crystallographic structures, ions diffusivity, and bacteriostati...

A microstructured composite material made of collagen hydrogel (matrix) and silk fibroin microfibers (randomly oriented reinforcing fibers) is investigated in order to conjugate the mechanical resistance of fibroin with the suitable biological performance of collagen to design new scaffolds for vascular tissue engineering. Results show that fibroin...

Silk fibroin (SF) is a protein that is spun into fibers by arthropods such as silkworms, spiders, scorpions, mites and flies. The process to obtain SF solution consists on fiber dissolution in concentrated saline solutions, followed by dialysis in water. SF aqueous solution (after dialysis) is thermodynamically metastable and may undergo sol-gel tr...

The use of membranes prepared with alginate and chitosan to adsorb paraquat aqueous solution was evaluated as a potential alternative technique for remediation of contaminated water. Production of bilayer membranes was based on the electrostatic interaction between alginate (a polyanion) and chitosan (a polycation). Herbicide adsorption experiments...

Small caliber vascular replacement (<4 mm) still remains a challenge for medical and research teams, as no available vascular substitutes (VS) are suitable for small diameter bypass. Vascular engineering proposes new models of small diameter VS but rare are those that meet the biocompatibility and mechanical criteria. In this study, we developed a...

This chapter describes the use of silk fibroin as fibers, nanofibers and particles in biocomposite materials. Silk fibroin is a material that has the potential to reinforce composites, due to its good mechanical properties, such as high tensile strength, high elongation, good elasticity, and excellent resilience. Silk fibroin microparticles can als...

Silk fibroin (SF) is a protein fiber spun by Bombyx mori silkworm. SF fibers are about 10-25 μm wide in diameter and a single cocoon may provide over 1000 m of SF fibers. SF can present several conformations regarding protein secondary structure which ultimately define the structural properties of SF-based materials. For this reason, a rigorous con...

Silk fibroin (SF) hydrogels were obtained from the dialysis of a SF metastable solution. Temperature and calcium concentration in SF solution/hydrogel were measured, as critical variables for SF gelation phenomenon. Gelation time of SF solution was increased by decreasing the dialysis temperature, whereas the residual calcium concentration was high...

The aim of this study was to prepare and characterize membranes of silk fibroin (SF) and chitosan (CHI) blends. Moreover, a conformation transition of SF to a more stable form induced by the addition of CHI was verified. Blend membranes were prepared, after pH adjustment, in different ratios, and physical integrity, crystallinity, structural confor...

The moisture equilibrium isotherms of chitosan were determined at 20, 30, 40, 50 and 60°C, using the gravimetric static method. Experimental data were analyzed by the GAB, Oswin, Halsey and Smith equations. Isosteric heat and differential entropy of sorption were determined from the GAB model using the Clausius-Clapeyron and Gibbs-Helmholtz equatio...

Spirulina is the most extensively used microalgae for animal and human nutrition mostly because of its high protein content, 60-65% on a dry weight basis. The drying is the most expensive operation. The aim of the study was to characterize drying of Spirulina platensis in thin layer. A Statistical model was applied to analyze the effects of indepen...

In recent times, the microalgae Spirulina platensis has been used as a functional ingredient in several food applications; its process involving drying and storage steps. Moisture equilibrium data for adsorption isotherms of microalgae Spirulina were investigated at 10, 20 and 30ºC and for desorption, at 40, 50 and 60ºC, using the gravimetric stati...

The moisture equilibrium isotherms of garlic and apple were determined at 50, 60 and 70 °C using the gravimetric static method. The experimental data were analysed using GAB, BET, Henderson–Thompson and Oswin equations. The isosteric heat and the differential entropy of desorption were determined by applying Clausius–Clapeyron and Gibbs–Helmholtz e...

The aim of this work was to study the drying of Spirulina platensis , evaluating the final product characteristics about its phycocyanin content and its protein solubility in water. Two drying techniques were used: the spouted bed and the thin layer. For drying in a spouted bed, the cone‐cylindrical geometry was chosen, namely type conventional spo...

The aim of this study was to analyse the equilibrium isotherms of chitin using several equations from the literature, and to determine the heat of desorption using the Othmer and Clausius-Clapeyron equations. The static method with different concentrations of sulphuric acid solutions was used to determine the isotherms, in a temperature range from...

Silk fibroin (SF) and sodium alginate (SA) offer promising properties for application as biomaterials, especially as artificial skin and wound dressing. By blending SF and SA, it is possible to conjugate their properties, producing a material with suitable mechanical properties and good efficiency for wound healing applications. Degree of swelling...

O objetivo deste trabalho foi preparar e caracterizar membranas de blendas de fibroína de seda e quitosana. Além disso, buscou-se verificar uma possível indução de conformação da fibroína para uma forma mais estável devido à adição de quitosana. Foram preparadas membranas de blendas fibroína/quitosana em diferentes proporções e realizadas análises...

A fibroína de seda tem sido amplamente explorada para aplicações biomédicas, devido à sua biocompatibilidade e biodegradabilidade. A esterilização é uma etapa fundamental no processamento de biomateriais, e não deve alterar de forma negativa as propriedades funcionais dos dispositivos médicos. O objetivo deste trabalho foi analisar a influência de...

A adição de plastificantes visa melhorias nas propriedades mecânicas das membranas densas de fibroína de seda com possíveis interações por pontes de hidrogênio. O objetivo deste trabalho foi estudar e caracterizar membranas densas de fibroína de seda com adição de glicerina em duas concentrações diferentes. A caracterização das membranas foi realiz...