A delivery system containing polymeric (Eudragit) nanoparticles has been developed for encapsulat... more A delivery system containing polymeric (Eudragit) nanoparticles has been developed for encapsulation and controlled release of bioactive flavonoids (quercetin). Nanoparticles were fabricated using a solvent displacement method. Particle size, morphology, and charge were measured by light scattering, electron microscopy and ζ-potential. Encapsulation efficiency (EE) and release profiles were determined using electrochemical methods. Molecular interactions within the particle matrix were characterized by X-ray diffraction, differential scanning calorimetry, and infrared spectroscopy. Antioxidant properties of free and encapsulated quercetin were analyzed by TBARS and fluorescence spectroscopy. Bioaccessibility of quercetin was evaluated using an in vitro digestion model. Relatively small (d≈370 nm) anionic polymeric nanoparticles were formed containing quercetin in a non-crystalline form (EE≈67 %). The main interaction between quercetin and Eudragit was hydrogen bonding. Encapsulated quercetin remained stable during 6 months storage and maintained its antioxidant activity. Quercetin bioaccessibility within simulated small intestinal conditions was improved by encapsulation. The knowledge obtained from this study will facilitate the rational design and fabrication of polymeric nanoparticles as oral delivery systems for encapsulation, protection, and release of bioactive compounds.
Background: The need to combat and reduce the incidence, virulence, and drug resistance of specie... more Background: The need to combat and reduce the incidence, virulence, and drug resistance of species belonging to Candida genus, has led to the development of new strategies. Nanotechnology, through the implementation of nanomaterials, has emerged as an infallible tool to treat various diseases caused by pathogens, where its mechanisms of action prevent the development of undesirable pharmacological resistance. Objective: The antifungal activity and adjuvant properties of biogenic silver nanoparticles in different Candida species (C. parapsilosis, C. glabrata, and C. albicans) are evaluated. Methods: The biogenic metallic nanoparticles were developed by quercetin-mediated biological synthesis. The physicochemical properties were studied by light scattering, electrophoretic mobility, UV-vis and infrared spectroscopy, and transmission electron microscopy. The elucidation of mechanisms of antifungal action was carried out under stress conditions in Candida species at the cell wall and re...
Sargassum spp. affects the Caribbean shores; thus, its remotion or valorization is a priority. Th... more Sargassum spp. affects the Caribbean shores; thus, its remotion or valorization is a priority. This work aimed to synthesize a low-cost magnetically retrievable Hg+2 adsorbent functionalized with ethylenediaminetetraacetic acid (EDTA) based on Sargassum. The Sargassum was solubilized to synthesize by co-precipitation a magnetic composite. A central composite design was assessed to maximize the adsorption of Hg+2. The solids yield magnetically attracted mass, and the saturation magnetizations of the functionalized composite were 60.1 ± 17.2%, 75.9 ± 6.6%, and 1.4 emu g−1. The functionalized magnetic composite yielded 29.8 ± 0.75 mg Hg+2 g−1 of chemisorption after 12 h, pH 5, and 25 °C achieving 75% Hg+2 adsorption after four reuse cycles. Crosslinking and functionalization with Fe3O4 and EDTA created differences in surface roughness as well as the thermal events of the composites. The Fe3O4@Sargassum@EDTA composite was a magnetically recovered biosorbent of Hg2+.
O conteúdo deste livro está licenciado sob uma Licença de Atribuição Creative Commons Atribuição-... more O conteúdo deste livro está licenciado sob uma Licença de Atribuição Creative Commons Atribuição-Não-Comercial NãoDerivativos 4.0 Internacional (CC BY-NC-ND 4.0). Direitos para esta edição cedidos à Editora Artemis pelos autores. Permitido o download da obra e o compartilhamento, desde que sejam atribuídos créditos aos autores, e sem a possibilidade de alterá-la de nenhuma forma ou utilizá-la para fins comerciais. A responsabilidade pelo conteúdo dos artigos e seus dados, em sua forma, correção e confiabilidade é exclusiva dos autores. A Editora Artemis, em seu compromisso de manter e aperfeiçoar a qualidade e confiabilidade dos trabalhos que publica, conduz a avaliação cega pelos pares de todos manuscritos publicados, com base em critérios de neutralidade e imparcialidade acadêmica.
Abstract In this work, gold nanomaterials were obtained using aqueous extracts of black carrots v... more Abstract In this work, gold nanomaterials were obtained using aqueous extracts of black carrots varying the molar ratio between the extract and the gold precursor salt (1:10, 1:5 and 2:5). Additionally, Au nanoparticles were obtained by the Turkevich method as reference material (Au Turkevich). Transmission electron micrographs indicated that a 1:5 ratio allowed to obtain a mixture of gold shapes like triangular, plate, rod, wire, and hemispherical shapes. The electrocatalytic evaluation for 0.5 M glycerol electro-oxidation indicated that Au (1:5) displayed higher current density (298.26 vs. 230.25 mA mg−1), and a more negative onset potential (ΔE = 150 mV) than Au Turkevich. In addition, Au (1:5) displayed higher current density during the electro-oxidation of 1 M crude glycerol (466.91 vs. 244.73 mA mg−1) with a similar potential difference. The improvement in activity and durability presented by Au (1:5) was attributed to the abundance of {1 0 0} facets as was determined by X-ray diffraction and HR-TEM.
Journal of Environmental Science and Health, Part A, 2021
Abstract There is currently controversy over the use of quantum dots (QDs) in biological applicat... more Abstract There is currently controversy over the use of quantum dots (QDs) in biological applications due to their toxic effects. Therefore, the purpose of the present study was to evaluate the toxic effect of chemical and biogenic (synthesized by Fusarium oxysporum f. sp. lycopersici) cadmium sulfide quantum dots (CdSQDs) using a bacterial model of Escherichia coli and sprouts of Lactuca sativa L. with the aim to foresee its use in the near future in biological systems. Physicochemical properties of both types of CdSQDs were determined by TEM, XRD, zeta potential and fluorescence spectroscopy. Both biogenic and chemical CdSQDs showed agglomerates of spherical CdSQDs with diameters of 4.14 nm and 3.2 nm, respectively. The fluorescence analysis showed a band around 361 nm in both CdSQDs, the zeta potential was −1.81 mV for the biogenic CdSQDs and −5.85 mv for the chemical CdSQDs. Results showed that chemical CdSQDs, presented inhibition in the proliferation of E. coli cell in a dose-dependent manner, unlike biogenic CdSQDs, that only at its highest concentration showed an antibacterial activity. Also, it was observed that after incubation with chemical and biogenic CdSQDs of L. sativa L. seeds, only the biogenic CdSQDs showed no inhibition on seed germination. In summary, our results suggest that the production route has a significant effect on the toxicity of QDs; in addition, it seems that the biological coating of the CdSQDs from F. oxysporum f. sp. lycopersici inhibit their toxic effect on bacterial strains and plant seeds.
Polymeric nanoparticles (PLGA) have been developed for the encapsulation and controlled release o... more Polymeric nanoparticles (PLGA) have been developed for the encapsulation and controlled release of quercetin and catechin. Nanoparticles were fabricated using a solvent displacement method. Physicochemical properties were measured by light scattering, scanning electron microscopy andζ-potential, X-ray diffraction, infrared spectroscopy and differential scanning calorimetry. Encapsulation efficiency andin vitrorelease profiles were obtained from differential pulse voltammetry experiments. Antioxidant properties of free and encapsulated flavonoids were determined by TBARS, fluorescence spectroscopy and standard chelating activity methods. Relatively small (d≈ 400 nm) polymeric nanoparticles were obtained containing quercetin or catechin in a non-crystalline form (EE≈79%) and the main interactions between the polymer and each flavonoid were found to consist of hydrogen bonds.In vitrorelease profiles were pH-dependant, the more acidic pH, the faster release of each flavonoid from the po...
To investigate polymeric nanoparticles as an oral delivery system for protein biocontrol agents f... more To investigate polymeric nanoparticles as an oral delivery system for protein biocontrol agents for control of the brushtail possum, Trichosurus vulpecula. Insulin-loaded poly(ethyl 2-cyanoacrylate) (PECA) nanoparticles were prepared using interfacial polymerisation, and characterised for size, zeta potential, and efficiency of encapsulation of insulin. In-vitro release of insulin-loaded PECA nanoparticles was quantified using reverse-phase high-pressure liquid chromatography (HPLC). The in-vivo pharmacokinetics of insulin in PECA nanoparticles was investigated following I/V administration, and when injected directly into the caecum alone or in conjunction with the permeation enhancer EDTA. Blood samples were collected at intervals from -5 to 180 minutes, and the concentration of insulin in plasma was quantified using a radioimmunoassay (RIA) validated for possum plasma. Poly(ethyl 2-cyanoacrylate) nanoparticles were produced with a uniform particle size of 200-300 nm, and the mean entrapment of insulin was 78%. In-vitro release of insulin from the PECA nanoparticles was controlled, although incomplete, and approximately 30% of the insulin remained entrapped. The bioavailability of insulin when administered in a PECA nanoparticulate formulation injected directly into the caecum was <1%, and was not increased by addition of the permeation enhancer. The nanoparticulate formulations investigated as part of this study resulted in low bioavailability of the peptide insulin in the brushtail possum.
Abstract This work aims to encapsulate Bacillus licheniformis, a marine probiotic, in alginate mi... more Abstract This work aims to encapsulate Bacillus licheniformis, a marine probiotic, in alginate microparticles (AMPs), and the evaluation of its controlled and targeted release within a simulated shrimp digestive tract (DT). The encapsulation process was carried out using the ionic gelation technique. Both free and bacteria-loaded AMPs were physicochemically characterized by size, morphology, surface electrical charge, the survival, and the number of encapsulated bacteria after the encapsulation process, and the bacterial survival after 40-days of storage (at 4 °C and 25 °C). The in vitro release and survival studies of the bacteria were carried out using a protocol developed in our laboratory by implementing buffers of dissected organs from shrimp's DT. Results indicated that microparticles with an average size of 172–185 μm and negatively charged (−16.77 and − 17.66 mV, respectively) were obtained after using the ionic gelation method. The bacterial survival and encapsulation efficiency showed high cell viability and yield above 99%. Stability studies showed that the best storage temperature was 4 °C, in which it remained almost 100% of the bacteria viable for 15 days; however, cell viability declined to 55% survival after 30 days of storage at this temperature. Regardless of the cell viability reduction after 30 days, there are enough viable bacteria cells to be considered as a probiotic product. Release and survival studies showed that alginate particles had a protective effect on bacteria by keeping ca. 51.29% of viable probiotic within the shrimp intestine; in contrast, free bacteria only reached the shrimp intestine ca. 27.16% viable. Our results suggest that microparticles can be produced by a low-cost method that could ultimately benefit shrimp farming in a near future.
Journal of colloid and interface science, Jan 8, 2015
The aim of this work is to formulate biofunctional hybrid materials (HMs) with quercetin (QC) and... more The aim of this work is to formulate biofunctional hybrid materials (HMs) with quercetin (QC) and silica particles (SiPs) by simple methods such as sol-gel and QC conjugation. Physicochemical characterization included particle size, zeta potential (ζ), FTIR and SEM imaging. Spherical particles with ca. 115nm in diameter were produced, ζ and FTIR demonstrated that QC conjugation was successfully achieved. Electrochemical analyses performed by cyclic voltammetry (CV) suggested that potential binding sites between QC and SiPs may be at functional groups from A ring or C ring, affecting the transfer electron of resorcinol moiety. Iron chelating activity and lipid peroxidation assays showed that after conjugation to SiPs, QC decreased its metal chelating activity, but anti-radical properties is maintained. Our results demonstrated that our proposed method is simple and effective to obtain bio-functional HMs. Our findings prove to be useful in the design of protective approaches against l...
A delivery system containing polymeric (Eudragit) nanoparticles has been developed for encapsulat... more A delivery system containing polymeric (Eudragit) nanoparticles has been developed for encapsulation and controlled release of bioactive flavonoids (quercetin). Nanoparticles were fabricated using a solvent displacement method. Particle size, morphology, and charge were measured by light scattering, electron microscopy and ζ-potential. Encapsulation efficiency (EE) and release profiles were determined using electrochemical methods. Molecular interactions within the particle matrix were characterized by X-ray diffraction, differential scanning calorimetry, and infrared spectroscopy. Antioxidant properties of free and encapsulated quercetin were analyzed by TBARS and fluorescence spectroscopy. Bioaccessibility of quercetin was evaluated using an in vitro digestion model. Relatively small (d≈370 nm) anionic polymeric nanoparticles were formed containing quercetin in a non-crystalline form (EE≈67 %). The main interaction between quercetin and Eudragit was hydrogen bonding. Encapsulated quercetin remained stable during 6 months storage and maintained its antioxidant activity. Quercetin bioaccessibility within simulated small intestinal conditions was improved by encapsulation. The knowledge obtained from this study will facilitate the rational design and fabrication of polymeric nanoparticles as oral delivery systems for encapsulation, protection, and release of bioactive compounds.
The ability of four extracellular filtrates (FE), obtained from A. alternata biomass grown in fou... more The ability of four extracellular filtrates (FE), obtained from A. alternata biomass grown in four different culture media; malt dextrose broth (MDB), potato dextrose broth (PDB), sucrose (S) and Czapek (C), were evaluated to biosynthesize iron nanoparticles (FeNPs), at the end of the assay a brown color was revealed in all the samples. To evidence biosynthesis of nanoparticles, absorption spectra were made from 200 to 600 nm for all the samples and, analyzed by transmission electronic microscopy (TEM). The morphology and size of the synthesized FeNPs were studied using the SPIP 6.2.0 software. From the four extracellular filtrates assays, the nanoparticles biosynthesis was possible only in the EF-PDB and EF-C, showing their presence in the UV-vis spectrum when forming an absorption band at 226 and 225 respectively, and plateau around at 270 nm to EF-PDB, and 290 nm to EF-C. The synthesized nanoparticles presented spherical and polydisperse form, those synthesized with EF-PDB showed a size of 20-40 nm, while those synthesized with EF-C had a size of 10-80 nm. Six months after their production, the FeNPs biosynthesized by EF-C were analyzed by microscopy showing an
The anticancer use of genistein (Gen) has been severely limited due to its low water solubility, ... more The anticancer use of genistein (Gen) has been severely limited due to its low water solubility, low bioavailability, and instability under experimental conditions. To overcome these limitations, we propose a formulation of a hybrid nanomaterial (HNM) based upon the incorporation of Gen into PEGylated silica nanoparticles (PEG-SiNPs) (Gen-PEG-SiHNM), where their physicochemical and biological effects on HT29 cells were evaluated. Genistein-loaded PEGylated silica hybrid nanomaterials were obtained by a simple end effective aqueous dispersion method. Physicochemical properties were determined by its mean particle size, surface charge, amount of cargo, spectroscopic properties, release profiles and aqueous solubility. biological performance was carried out by evaluating its antioxidant capacity and elucidating its antiproliferative mechanistic. Results showed that small (ca. 33 nm) and spherical particles were obtained with positive surface charge (+9.54 mV). Infrared analyses determi...
The recent fermentable fiber revolution has emerged on the prospect of providing digestive health... more The recent fermentable fiber revolution has emerged on the prospect of providing digestive health benefits such as enhanced immune system, mineral adsorption, and general colonic health. These benefits accrue from dietary component, primarily ‘non-digestible’ (ND) dietary carbohydrates that reach the colon intact or partially digested by the stomach or small intestine. The fructo-, galacto-, and xylooligosaccharides, as well as fermentable carbohydrates such as pectin, arabinoxylans, and resistant starch form part of this diverse group of compounds also commonly referred to as ‘prebiotic’. These prebiotic modulate the composition and metabolism of the gut microbiota thereby improving long-term human health status. Numerous studies have shown that gut microbiota is significantly influenced by the type and quantity of nondigestible carbohydrate in the diet, hence the increased awareness of food industries and consumers in incorporating a wide range of pre- and pro-biotics in the daily...
A delivery system containing polymeric (Eudragit) nanoparticles has been developed for encapsulat... more A delivery system containing polymeric (Eudragit) nanoparticles has been developed for encapsulation and controlled release of bioactive flavonoids (quercetin). Nanoparticles were fabricated using a solvent displacement method. Particle size, morphology, and charge were measured by light scattering, electron microscopy and ζ-potential. Encapsulation efficiency (EE) and release profiles were determined using electrochemical methods. Molecular interactions within the particle matrix were characterized by X-ray diffraction, differential scanning calorimetry, and infrared spectroscopy. Antioxidant properties of free and encapsulated quercetin were analyzed by TBARS and fluorescence spectroscopy. Bioaccessibility of quercetin was evaluated using an in vitro digestion model. Relatively small (d≈370 nm) anionic polymeric nanoparticles were formed containing quercetin in a non-crystalline form (EE≈67 %). The main interaction between quercetin and Eudragit was hydrogen bonding. Encapsulated quercetin remained stable during 6 months storage and maintained its antioxidant activity. Quercetin bioaccessibility within simulated small intestinal conditions was improved by encapsulation. The knowledge obtained from this study will facilitate the rational design and fabrication of polymeric nanoparticles as oral delivery systems for encapsulation, protection, and release of bioactive compounds.
Background: The need to combat and reduce the incidence, virulence, and drug resistance of specie... more Background: The need to combat and reduce the incidence, virulence, and drug resistance of species belonging to Candida genus, has led to the development of new strategies. Nanotechnology, through the implementation of nanomaterials, has emerged as an infallible tool to treat various diseases caused by pathogens, where its mechanisms of action prevent the development of undesirable pharmacological resistance. Objective: The antifungal activity and adjuvant properties of biogenic silver nanoparticles in different Candida species (C. parapsilosis, C. glabrata, and C. albicans) are evaluated. Methods: The biogenic metallic nanoparticles were developed by quercetin-mediated biological synthesis. The physicochemical properties were studied by light scattering, electrophoretic mobility, UV-vis and infrared spectroscopy, and transmission electron microscopy. The elucidation of mechanisms of antifungal action was carried out under stress conditions in Candida species at the cell wall and re...
Sargassum spp. affects the Caribbean shores; thus, its remotion or valorization is a priority. Th... more Sargassum spp. affects the Caribbean shores; thus, its remotion or valorization is a priority. This work aimed to synthesize a low-cost magnetically retrievable Hg+2 adsorbent functionalized with ethylenediaminetetraacetic acid (EDTA) based on Sargassum. The Sargassum was solubilized to synthesize by co-precipitation a magnetic composite. A central composite design was assessed to maximize the adsorption of Hg+2. The solids yield magnetically attracted mass, and the saturation magnetizations of the functionalized composite were 60.1 ± 17.2%, 75.9 ± 6.6%, and 1.4 emu g−1. The functionalized magnetic composite yielded 29.8 ± 0.75 mg Hg+2 g−1 of chemisorption after 12 h, pH 5, and 25 °C achieving 75% Hg+2 adsorption after four reuse cycles. Crosslinking and functionalization with Fe3O4 and EDTA created differences in surface roughness as well as the thermal events of the composites. The Fe3O4@Sargassum@EDTA composite was a magnetically recovered biosorbent of Hg2+.
O conteúdo deste livro está licenciado sob uma Licença de Atribuição Creative Commons Atribuição-... more O conteúdo deste livro está licenciado sob uma Licença de Atribuição Creative Commons Atribuição-Não-Comercial NãoDerivativos 4.0 Internacional (CC BY-NC-ND 4.0). Direitos para esta edição cedidos à Editora Artemis pelos autores. Permitido o download da obra e o compartilhamento, desde que sejam atribuídos créditos aos autores, e sem a possibilidade de alterá-la de nenhuma forma ou utilizá-la para fins comerciais. A responsabilidade pelo conteúdo dos artigos e seus dados, em sua forma, correção e confiabilidade é exclusiva dos autores. A Editora Artemis, em seu compromisso de manter e aperfeiçoar a qualidade e confiabilidade dos trabalhos que publica, conduz a avaliação cega pelos pares de todos manuscritos publicados, com base em critérios de neutralidade e imparcialidade acadêmica.
Abstract In this work, gold nanomaterials were obtained using aqueous extracts of black carrots v... more Abstract In this work, gold nanomaterials were obtained using aqueous extracts of black carrots varying the molar ratio between the extract and the gold precursor salt (1:10, 1:5 and 2:5). Additionally, Au nanoparticles were obtained by the Turkevich method as reference material (Au Turkevich). Transmission electron micrographs indicated that a 1:5 ratio allowed to obtain a mixture of gold shapes like triangular, plate, rod, wire, and hemispherical shapes. The electrocatalytic evaluation for 0.5 M glycerol electro-oxidation indicated that Au (1:5) displayed higher current density (298.26 vs. 230.25 mA mg−1), and a more negative onset potential (ΔE = 150 mV) than Au Turkevich. In addition, Au (1:5) displayed higher current density during the electro-oxidation of 1 M crude glycerol (466.91 vs. 244.73 mA mg−1) with a similar potential difference. The improvement in activity and durability presented by Au (1:5) was attributed to the abundance of {1 0 0} facets as was determined by X-ray diffraction and HR-TEM.
Journal of Environmental Science and Health, Part A, 2021
Abstract There is currently controversy over the use of quantum dots (QDs) in biological applicat... more Abstract There is currently controversy over the use of quantum dots (QDs) in biological applications due to their toxic effects. Therefore, the purpose of the present study was to evaluate the toxic effect of chemical and biogenic (synthesized by Fusarium oxysporum f. sp. lycopersici) cadmium sulfide quantum dots (CdSQDs) using a bacterial model of Escherichia coli and sprouts of Lactuca sativa L. with the aim to foresee its use in the near future in biological systems. Physicochemical properties of both types of CdSQDs were determined by TEM, XRD, zeta potential and fluorescence spectroscopy. Both biogenic and chemical CdSQDs showed agglomerates of spherical CdSQDs with diameters of 4.14 nm and 3.2 nm, respectively. The fluorescence analysis showed a band around 361 nm in both CdSQDs, the zeta potential was −1.81 mV for the biogenic CdSQDs and −5.85 mv for the chemical CdSQDs. Results showed that chemical CdSQDs, presented inhibition in the proliferation of E. coli cell in a dose-dependent manner, unlike biogenic CdSQDs, that only at its highest concentration showed an antibacterial activity. Also, it was observed that after incubation with chemical and biogenic CdSQDs of L. sativa L. seeds, only the biogenic CdSQDs showed no inhibition on seed germination. In summary, our results suggest that the production route has a significant effect on the toxicity of QDs; in addition, it seems that the biological coating of the CdSQDs from F. oxysporum f. sp. lycopersici inhibit their toxic effect on bacterial strains and plant seeds.
Polymeric nanoparticles (PLGA) have been developed for the encapsulation and controlled release o... more Polymeric nanoparticles (PLGA) have been developed for the encapsulation and controlled release of quercetin and catechin. Nanoparticles were fabricated using a solvent displacement method. Physicochemical properties were measured by light scattering, scanning electron microscopy andζ-potential, X-ray diffraction, infrared spectroscopy and differential scanning calorimetry. Encapsulation efficiency andin vitrorelease profiles were obtained from differential pulse voltammetry experiments. Antioxidant properties of free and encapsulated flavonoids were determined by TBARS, fluorescence spectroscopy and standard chelating activity methods. Relatively small (d≈ 400 nm) polymeric nanoparticles were obtained containing quercetin or catechin in a non-crystalline form (EE≈79%) and the main interactions between the polymer and each flavonoid were found to consist of hydrogen bonds.In vitrorelease profiles were pH-dependant, the more acidic pH, the faster release of each flavonoid from the po...
To investigate polymeric nanoparticles as an oral delivery system for protein biocontrol agents f... more To investigate polymeric nanoparticles as an oral delivery system for protein biocontrol agents for control of the brushtail possum, Trichosurus vulpecula. Insulin-loaded poly(ethyl 2-cyanoacrylate) (PECA) nanoparticles were prepared using interfacial polymerisation, and characterised for size, zeta potential, and efficiency of encapsulation of insulin. In-vitro release of insulin-loaded PECA nanoparticles was quantified using reverse-phase high-pressure liquid chromatography (HPLC). The in-vivo pharmacokinetics of insulin in PECA nanoparticles was investigated following I/V administration, and when injected directly into the caecum alone or in conjunction with the permeation enhancer EDTA. Blood samples were collected at intervals from -5 to 180 minutes, and the concentration of insulin in plasma was quantified using a radioimmunoassay (RIA) validated for possum plasma. Poly(ethyl 2-cyanoacrylate) nanoparticles were produced with a uniform particle size of 200-300 nm, and the mean entrapment of insulin was 78%. In-vitro release of insulin from the PECA nanoparticles was controlled, although incomplete, and approximately 30% of the insulin remained entrapped. The bioavailability of insulin when administered in a PECA nanoparticulate formulation injected directly into the caecum was <1%, and was not increased by addition of the permeation enhancer. The nanoparticulate formulations investigated as part of this study resulted in low bioavailability of the peptide insulin in the brushtail possum.
Abstract This work aims to encapsulate Bacillus licheniformis, a marine probiotic, in alginate mi... more Abstract This work aims to encapsulate Bacillus licheniformis, a marine probiotic, in alginate microparticles (AMPs), and the evaluation of its controlled and targeted release within a simulated shrimp digestive tract (DT). The encapsulation process was carried out using the ionic gelation technique. Both free and bacteria-loaded AMPs were physicochemically characterized by size, morphology, surface electrical charge, the survival, and the number of encapsulated bacteria after the encapsulation process, and the bacterial survival after 40-days of storage (at 4 °C and 25 °C). The in vitro release and survival studies of the bacteria were carried out using a protocol developed in our laboratory by implementing buffers of dissected organs from shrimp's DT. Results indicated that microparticles with an average size of 172–185 μm and negatively charged (−16.77 and − 17.66 mV, respectively) were obtained after using the ionic gelation method. The bacterial survival and encapsulation efficiency showed high cell viability and yield above 99%. Stability studies showed that the best storage temperature was 4 °C, in which it remained almost 100% of the bacteria viable for 15 days; however, cell viability declined to 55% survival after 30 days of storage at this temperature. Regardless of the cell viability reduction after 30 days, there are enough viable bacteria cells to be considered as a probiotic product. Release and survival studies showed that alginate particles had a protective effect on bacteria by keeping ca. 51.29% of viable probiotic within the shrimp intestine; in contrast, free bacteria only reached the shrimp intestine ca. 27.16% viable. Our results suggest that microparticles can be produced by a low-cost method that could ultimately benefit shrimp farming in a near future.
Journal of colloid and interface science, Jan 8, 2015
The aim of this work is to formulate biofunctional hybrid materials (HMs) with quercetin (QC) and... more The aim of this work is to formulate biofunctional hybrid materials (HMs) with quercetin (QC) and silica particles (SiPs) by simple methods such as sol-gel and QC conjugation. Physicochemical characterization included particle size, zeta potential (ζ), FTIR and SEM imaging. Spherical particles with ca. 115nm in diameter were produced, ζ and FTIR demonstrated that QC conjugation was successfully achieved. Electrochemical analyses performed by cyclic voltammetry (CV) suggested that potential binding sites between QC and SiPs may be at functional groups from A ring or C ring, affecting the transfer electron of resorcinol moiety. Iron chelating activity and lipid peroxidation assays showed that after conjugation to SiPs, QC decreased its metal chelating activity, but anti-radical properties is maintained. Our results demonstrated that our proposed method is simple and effective to obtain bio-functional HMs. Our findings prove to be useful in the design of protective approaches against l...
A delivery system containing polymeric (Eudragit) nanoparticles has been developed for encapsulat... more A delivery system containing polymeric (Eudragit) nanoparticles has been developed for encapsulation and controlled release of bioactive flavonoids (quercetin). Nanoparticles were fabricated using a solvent displacement method. Particle size, morphology, and charge were measured by light scattering, electron microscopy and ζ-potential. Encapsulation efficiency (EE) and release profiles were determined using electrochemical methods. Molecular interactions within the particle matrix were characterized by X-ray diffraction, differential scanning calorimetry, and infrared spectroscopy. Antioxidant properties of free and encapsulated quercetin were analyzed by TBARS and fluorescence spectroscopy. Bioaccessibility of quercetin was evaluated using an in vitro digestion model. Relatively small (d≈370 nm) anionic polymeric nanoparticles were formed containing quercetin in a non-crystalline form (EE≈67 %). The main interaction between quercetin and Eudragit was hydrogen bonding. Encapsulated quercetin remained stable during 6 months storage and maintained its antioxidant activity. Quercetin bioaccessibility within simulated small intestinal conditions was improved by encapsulation. The knowledge obtained from this study will facilitate the rational design and fabrication of polymeric nanoparticles as oral delivery systems for encapsulation, protection, and release of bioactive compounds.
The ability of four extracellular filtrates (FE), obtained from A. alternata biomass grown in fou... more The ability of four extracellular filtrates (FE), obtained from A. alternata biomass grown in four different culture media; malt dextrose broth (MDB), potato dextrose broth (PDB), sucrose (S) and Czapek (C), were evaluated to biosynthesize iron nanoparticles (FeNPs), at the end of the assay a brown color was revealed in all the samples. To evidence biosynthesis of nanoparticles, absorption spectra were made from 200 to 600 nm for all the samples and, analyzed by transmission electronic microscopy (TEM). The morphology and size of the synthesized FeNPs were studied using the SPIP 6.2.0 software. From the four extracellular filtrates assays, the nanoparticles biosynthesis was possible only in the EF-PDB and EF-C, showing their presence in the UV-vis spectrum when forming an absorption band at 226 and 225 respectively, and plateau around at 270 nm to EF-PDB, and 290 nm to EF-C. The synthesized nanoparticles presented spherical and polydisperse form, those synthesized with EF-PDB showed a size of 20-40 nm, while those synthesized with EF-C had a size of 10-80 nm. Six months after their production, the FeNPs biosynthesized by EF-C were analyzed by microscopy showing an
The anticancer use of genistein (Gen) has been severely limited due to its low water solubility, ... more The anticancer use of genistein (Gen) has been severely limited due to its low water solubility, low bioavailability, and instability under experimental conditions. To overcome these limitations, we propose a formulation of a hybrid nanomaterial (HNM) based upon the incorporation of Gen into PEGylated silica nanoparticles (PEG-SiNPs) (Gen-PEG-SiHNM), where their physicochemical and biological effects on HT29 cells were evaluated. Genistein-loaded PEGylated silica hybrid nanomaterials were obtained by a simple end effective aqueous dispersion method. Physicochemical properties were determined by its mean particle size, surface charge, amount of cargo, spectroscopic properties, release profiles and aqueous solubility. biological performance was carried out by evaluating its antioxidant capacity and elucidating its antiproliferative mechanistic. Results showed that small (ca. 33 nm) and spherical particles were obtained with positive surface charge (+9.54 mV). Infrared analyses determi...
The recent fermentable fiber revolution has emerged on the prospect of providing digestive health... more The recent fermentable fiber revolution has emerged on the prospect of providing digestive health benefits such as enhanced immune system, mineral adsorption, and general colonic health. These benefits accrue from dietary component, primarily ‘non-digestible’ (ND) dietary carbohydrates that reach the colon intact or partially digested by the stomach or small intestine. The fructo-, galacto-, and xylooligosaccharides, as well as fermentable carbohydrates such as pectin, arabinoxylans, and resistant starch form part of this diverse group of compounds also commonly referred to as ‘prebiotic’. These prebiotic modulate the composition and metabolism of the gut microbiota thereby improving long-term human health status. Numerous studies have shown that gut microbiota is significantly influenced by the type and quantity of nondigestible carbohydrate in the diet, hence the increased awareness of food industries and consumers in incorporating a wide range of pre- and pro-biotics in the daily...
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