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1.
J Colloid Interface Sci ; 678(Pt A): 1052-1059, 2025 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-39236434

RESUMO

Here we demonstrate for the first time that an antibody-gold nanoparticles (AuNPs)-polymer conjugate thin-film biosensor can easily be fabricated to selectively capture Tau protein. Gold nanoparticles (AuNPs) are employed as sensing elements, thus capitalizing on their propensity to undergo assembly or disassembly in response to the adsorption or conjugation of various biomolecules on their surface, thereby forming robust interactions with the target analyte. We show that the Tau protein in its different aggregation phases can be detected, by restricting the reaction area on the solid thin polymer film and thus reducing the diffusion effects usually encountered in immunosensors. A limit of detection (LOD) of 460 pg/mL was reached, demonstrating a great potential for detecting Tau in aggregation states. This sensor based on thin polymer film could open new routes for sensing and monitoring Tau protein in biological assays and biomedical diagnosis.


Assuntos
Técnicas Biossensoriais , Colorimetria , Ouro , Nanopartículas Metálicas , Polímeros , Proteínas tau , Ouro/química , Proteínas tau/análise , Nanopartículas Metálicas/química , Polímeros/química , Imunoensaio/métodos , Limite de Detecção , Humanos , Agregados Proteicos , Propriedades de Superfície , Anticorpos Imobilizados/química , Anticorpos Imobilizados/imunologia
2.
Anal Chim Acta ; 1329: 343178, 2024 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-39396275

RESUMO

BACKGROUND: Pyro-electrohydrodynamic jetting (p-jet) has emerged recently as a promising technique for biosensing applications, through the concentration of highly diluted biomolecules in fluorescent spots at microscale. However, a great challenge still remains in optimizing the binding strategy for the sensing interface, enabling the detection of low abundance proteins through immunofluorescence protocols. Indeed, the surface of reaction can be functionalized with different chemical groups able to bind the target molecule with a strong interaction, prior to the p-jet spots decreasing the possibility to lose sensitivity after the common rinsing steps. RESULTS: Here, we characterize the immobilization of a model protein, specifically the bovine serum albumin (BSA), in the concentrated p-jet spots to demonstrate the reliability of the technique for highly sensitive immunodetection assays. We first performed spectroscopic measurements on BSA deposited through pipette spots at relatively high concentrations and we achieved a higher efficiency in case of the covalent bond by using the carbonate buffer and the epoxy-based slides. We then tested the covalent setting in case of the p-jet spots with highly diluted samples of pre-labelled BSA. A significant concentration-dependent behavior of the signal was obtained down to picogram levels. Finally, an immunofluorescent protocol was settled with the p-jet spots and a Limit of the Detection (LOD) of 0. 27 pg/mL was reached. SIGNIFICANCE: The demonstration here that the p-jet spots are compatible with immunodetection procedures and provide a LOD down to 0.27 pg/mL, launches the p-jet technique towards the development in future of a point-of-care (POC) diagnostic tool. This would become a major force in analytical chemical laboratories. The identification of highly diluted biomarkers from peripheral body fluids would help clinicians performing early diagnosis, overcoming the limitations of the traditional immunochemistry tests, such as the enzyme-linked immunosorbent assay (ELISA).


Assuntos
Vidro , Soroalbumina Bovina , Propriedades de Superfície , Soroalbumina Bovina/química , Animais , Bovinos , Vidro/química , Técnicas Biossensoriais/métodos , Proteínas Imobilizadas/química
3.
R Soc Open Sci ; 11(7): 240465, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39086831

RESUMO

The asymmetry between the left and right sides seems to be a general principle of organization of the nervous systems in Bilateria, providing the foundations for a plethora of leftward and rightward biases in behaviour as documented in species ranging from Caenorhabditis elegans nematodes to humans. Several theories have been put forward to account for the existence and maintenance in the evolution of the asymmetric organization of the brain at both individual and population levels. However, what is missing in theorizing about the evolution of brain asymmetry is an overarching general hypothesis that may subsume all different aspects of current models. Here, we tried to provide an overarching general framework based on the energy and free-energy minimization principle, which proved so valuable in other areas of neuroscience. We found that at the individual level the antisymmetric singlet configuration realizes the lowest energy state of the system, whereas at the group level, the spontaneous emergence of directional asymmetry arises as a consequence of the minimization of the free energy of the system, which guarantees its stability and equilibrium. We thus argue that the various phenomenological aspects of brain asymmetry that have been captured in biology-e.g. sparing of neural tissue, control of unitary motor responses and, at the population level, evolutionarily stable strategies described by mathematical games theory-may be thought of as the manifestation of a more general principle of energy minimization generating, among others, asymmetry of the brains.

4.
Int J Biol Macromol ; 266(Pt 1): 131022, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38522688

RESUMO

In this work, the adsorption of Candida antarctica B (CALB) and Rhizomucor miehei (RML) lipases into hydrophobic wrinkled silica nanoparticles (WSNs) is investigated. WSNs are hydrophobized by chemical vapor deposition. Both proteins are homogeneously distributed inside the pores of the nanoparticles, as confirmed by Transmission Electron Microscopy and Energy Dispersive X-ray measurements. The maximum enzyme load of CALB is twice that obtained for RML. Fourier Transform Infrared Spectroscopy confirms the preservation of the enzyme secondary structure after immobilization for both enzymes. Adsorption isotherms fit to a Langmuir model, resulting in a binding constant (KL) for RML 4.5-fold higher than that for CALB, indicating stronger binding for the former. Kinetic analysis reveals a positive correlation between enzyme load and RML activity unlike CALB where activity decreases along the enzyme load increases. Immobilization allows for enhancing the thermal stability of both lipases. Finally, CALB outperforms RML in the hydrolysis of ethyl-3-hydroxybutyrate. However, immobilized CALB yielded 20 % less 3-HBA than free lipase, while immobilized RML increases 3-fold the 3-HBA yield when compared with the free enzyme. The improved performance of immobilized RML can be explained due to the interfacial hyperactivation undergone by this lipase when immobilized on the superhydrophobic surface of WSNs.


Assuntos
Estabilidade Enzimática , Enzimas Imobilizadas , Interações Hidrofóbicas e Hidrofílicas , Lipase , Nanopartículas , Dióxido de Silício , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Lipase/química , Lipase/metabolismo , Dióxido de Silício/química , Nanopartículas/química , Adsorção , Cinética , Rhizomucor/enzimologia , Proteínas Fúngicas/química , Hidrólise , Temperatura
5.
Biosens Bioelectron ; 254: 116234, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38522234

RESUMO

It is largely documented that neurodegenerative diseases can be effectively treated only if early diagnosed. In this context, the structural changes of some biomolecules such as Tau, seem to play a key role in neurodegeneration mechanism becoming eligible targets for an early diagnosis. Post-translational modifications are responsible to drive the Tau protein towards a transition phase from a native disorder conformation into a preaggregation state, which then straight recruits the final fibrillization process. Here, we show for the first time the detection of pre-aggregated Tau in artificial urine at femto-molar level, through the concentration effect of the pyro-electrohydrodynamic jet (p-jet) technique. An excellent linear calibration curve is demonstrated at the femto-molar level with a limit of detection (LOD) of 130 fM. Moreover, for the first time we show here the structure stability of the protein after p-jet application through a deep spectroscopic investigation. Thanks to the small volumes required and the relatively compact and cost-effective characteristics, this technique represents an innovative breakthrough in monitoring the early stage associated to neurodegeneration syndromes in different scenarios of point of care (POC) and such as for example in long-term human space exploration missions.


Assuntos
Técnicas Biossensoriais , Doenças Neurodegenerativas , Humanos , Proteínas tau/química , Doenças Neurodegenerativas/diagnóstico , Biomarcadores
6.
Int J Biol Macromol ; 263(Pt 1): 130210, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38365144

RESUMO

Sustainable active food packaging is essential to reduce the use of plastics, preserve food quality and minimize the environmental impact. Humic substances (HS) are rich in redox-active compounds, such as quinones, phenols, carboxyl, and hydroxyl moieties, making them functional additives for biopolymeric matrices, such as poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). Herein, composites made by incorporating different amounts of HS into PHBV were developed using the electrospinning technology and converted into homogeneous and continuous films by a thermal post-treatment to obtain a bioactive and biodegradable layer which could be part of a multilayer food packaging solution. The morphology, thermal, optical, mechanical, antioxidant and barrier properties of the resulting PHBV-based films have been evaluated, as well as the antifungal activity against Aspergillus flavus and Candida albicans and the antimicrobial properties against both Gram (+) and Gram (-) bacterial strains. HS show great potential as natural additives for biopolymer matrices, since they confer antioxidant, antimicrobial, and antifungal properties to the resulting materials. In addition, barrier, optical and mechanical properties highlighted that the obtained films are suitable for sustainable active packaging. Therefore, the electrospinning methodology is a promising and sustainable approach to give biowaste a new life through the development of multifunctional materials suitable in the active bio-packaging.


Assuntos
Embalagem de Alimentos , Substâncias Húmicas , Ácidos Pentanoicos , Antifúngicos/farmacologia , Antioxidantes/farmacologia , Poliésteres
7.
J Colloid Interface Sci ; 659: 926-935, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38219311

RESUMO

Achieving a controlled preparation of nanoparticle superstructures with spatially periodic arrangement, also called superlattices, is one of the most intriguing and open questions in soft matter science. The interest in such regular superlattices originates from the potentialities in tailoring the physicochemical properties of the individual constituent nanoparticles, eventually leading to emerging behaviors and/or functionalities that are not exhibited by the initial building blocks. Despite progress, it is currently difficult to obtain such ordered structures; the influence of parameters, such as size, softness, interaction potentials, and entropy, are neither fully understood yet and not sufficiently studied for 3D systems. In this work, we describe the synthesis and characterization of spatially ordered hierarchical structures of coated cerium oxide nanoparticles in water suspension prepared by a bottom-up approach. Covering the CeO2 surface with amphiphilic molecules having chains of appropriate length makes it possible to form ordered structures in which the particles occupy well-defined positions. In the present case superlattice arrangement is accompanied by an improvement in photoluminescence (PL) efficiency, as an increase in PL intensity of the superlattice structure of up to 400 % compared with that of randomly dispersed nanoparticles was observed. To the best of our knowledge, this is one of the first works in the literature in which the coexistence of 3D structures in solution, such as face-centered cubic (FCC) and Frank-Kasper (FK) phases, of semiconductor nanoparticles have been related to their optical properties.

8.
Colloids Surf B Biointerfaces ; 235: 113756, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38278033

RESUMO

Melanin is a multifunctional biological pigment that recently emerged as endowed with anti-inflammatory, antioxidant, and antimicrobial properties and with high potentialities in skin protection and regenerative medicine. Here, a biomimetic magnesium-doped nano-hydroxyapatite (MgHA) was synthesized and decorated with melanin molecules starting from two different monomeric precursors, i.e. 5,6-dihydroxyindole-2-carboxylic acid (DHICA) and dopamine (DA), demonstrating to be able to polymerize on the surface of MgHA nanostructures, thus leading to a melanin coating. This functionalization was realized by a simple and green preparation method requiring mild conditions in an aqueous medium and room temperature. Complementary spectroscopy and electron imaging analyses were carried out to define the effective formation of a stable coating, the percentage of the organic compounds, and the structural properties of resulting melanin-coated nanostructures, which showed good antioxidant activity. The in vitro interaction with a cell model, i.e. mouse fibroblasts, was investigated. The excellent biocompatibility of all bioinspired nanostructures was confirmed from a suitable cell proliferation. Finally, the enhanced biological performances of the nanostructures coated with melanin from DHICA were confirmed by scratch assays. Jointly our findings indicated that low crystalline MgHA and melanin pigments can be efficiently combined, and the resulting nanostructures are promising candidates as multifunctional platforms for a more efficient approach for skin regeneration and protection.


Assuntos
Indóis , Melaninas , Animais , Camundongos , Melaninas/química , Indóis/farmacologia , Indóis/química , Antioxidantes/farmacologia , Antioxidantes/química , Cicatrização , Hidroxiapatitas , Regeneração
9.
Chemosphere ; 346: 140605, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37931713

RESUMO

As a result of the accumulation of plastic in the environment, microplastics have become part of the food chain, boosting the resistance of fungi and bacteria which can frequently encounter human beings. Employing photocatalytic degradation is a possible route towards the removal of chemical and biological pollutants, such as plastics and microplastic wastes as well as microorganisms. Using biowaste materials to design hybrid nanoparticles with enhanced photocatalytic and antimicrobial features would uphold the principles of the circular bioeconomy. Here, two unexpensive semiconductors-namely titanium dioxide (TiO2) and zinc oxide (ZnO) - were synthetized through solvothermal synthesis and combined with humic substances deriving from agrifood biomass. The preparation led to hybrid nanoparticles exhibiting enhanced ROS-generating properties for simultaneous applications as antimicrobial agents against different bacterial and fungal strains and as photoactive catalysts to degrade polylactic acid (PLA) microplastics under UVA and solar irradiation. In comparison to bare nanoparticles, hybrid nanoparticles demonstrated higher antibacterial and antimycotic capabilities toward various pathogenic microorganisms as well as advanced photocatalytic activity in the degradation of PLA with a carbonyl index reduction in the range of 15-23%, thus confirming a noteworthy ability in microplastics photodegradation under UVA and solar irradiation.


Assuntos
Antibacterianos , Nanopartículas Multifuncionais , Humanos , Antibacterianos/farmacologia , Microplásticos , Plásticos , Substâncias Húmicas , Óxidos , Poliésteres/farmacologia , Titânio/farmacologia , Titânio/química
10.
Biomed Pharmacother ; 169: 115894, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37988850

RESUMO

Based on a growing body of evidence that a dysregulated innate immune response mediated by monocytes/macrophages plays a key role in the pathogenesis of COVID-19, a clinical trial was conducted to investigate the therapeutic potential and safety of oral macrophage activating factor (MAF) plus standard of care (SoC) in the treatment of hospitalized patients with COVID-19 pneumonia. Ninety-seven hospitalized patients with confirmed COVID-19 pneumonia were treated with oral MAF and a vitamin D3 supplement, in combination with SoC, in a single-arm, open label, multicentre, phase II clinical trial. The primary outcome measure was a reduction in an intensive care unit transfer rate below 13% after MAF administration. At the end of the study, an additional propensity score matching (PSM) analysis was performed to compare the MAF group with a control group treated with SoC alone. Out of 97 patients treated with MAF, none needed care in the ICU and/or intubation with mechanical ventilation or died during hospitalization. Oxygen therapy was discontinued after a median of nine days of MAF treatment. The median length of viral shedding and hospital stay was 14 days and 18 days, respectively. After PSM, statistically significant differences were found in all of the in-hospital outcomes between the two groups. No mild to serious adverse events were recorded during the study. Notwithstanding the limitations of a single-arm study, which prevented definitive conclusions, a 21-day course of MAF treatment plus SoC was found to be safe and promising in the treatment of hospitalized adult patients with COVID-19 pneumonia. Further research will be needed to confirm these preliminary findings.


Assuntos
COVID-19 , Adulto , Humanos , Progressão da Doença , Hospitalização , Tempo de Internação , Estudos Prospectivos , SARS-CoV-2 , Resultado do Tratamento
11.
ACS Appl Mater Interfaces ; 15(40): 46756-46764, 2023 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-37774145

RESUMO

Photoacoustics (PA) is gaining increasing credit among biomolecular imaging methodologies by virtue of its poor invasiveness, deep penetration, high spatial resolution, and excellent endogenous contrast, without the use of any ionizing radiation. Recently, we disclosed the excellent PA response of a self-structured biocompatible nanoprobe, consisting of ternary hybrid nanoparticles with a silver core and a melanin component embedded into a silica matrix. Although preliminary evidence suggested a crucial role of the Ag sonophore and the melanin-containing nanoenvironment, whether and in what manner the PA response is controlled and affected by the self-structured hybrid nanosystems remained unclear. Because of their potential as multifunctional platforms for biomedical applications, a detailed investigation of the metal-polymer-matrix interplay underlying the PA response was undertaken to understand the physical and chemical factors determining the enhanced response and to optimize the architecture, composition, and performance of the nanoparticles for efficient imaging applications. Herein, we provide the evidence for a strong synergistic interaction between eumelanin and Ag which suggests an important role in the in situ-generated metal-organic interface. In particular, we show that a strict ratio between melanin and silver precursors and an accurate choice of metal nanoparticle dimension and the kind of metal are essential for achieving strong enhancements of the PA response. Systematic variation of the metal/melanin component is thus shown to offer the means of tuning the stability and intensity of the photoacoustic response for various biomedical and theranostic applications.


Assuntos
Nanopartículas Metálicas , Nanopartículas , Técnicas Fotoacústicas , Melaninas/química , Prata/química , Dióxido de Silício , Nanopartículas/química , Nanopartículas Metálicas/química , Polímeros , Técnicas Fotoacústicas/métodos
12.
Biomater Adv ; 153: 213558, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37467646

RESUMO

Redox-active nano-biointerfaces are gaining weight in the field of regenerative medicine since they can act as enzymes in regulating physiological processes and enabling cell homeostasis, as well as the defense against pathogen aggression. In particular, cerium oxide nanoparticles (CeO2 NPs) stand as intriguing enzyme-mimicking nanoplatforms, owing to the reversible Ce+3/Ce+4 surface oxidation state. Moreover, surface functionalization leads to higher catalytic activity and selectivity, as well as more tunable enzyme-mimicking performances. Conjugation with melanin is an adequate strategy to boost and enrich CeO2 NPs biological features, because of melanin redox properties accounting for intrinsic antioxidant, antimicrobial and anti-inflammatory power. Herein, hybrid Melanin/CeO2 nanostructures were designed by simply coating the metal-oxide nanoparticles with melanin chains, obtained in-situ through ligand-to-metal charge transfer mechanism, according to a bioinspired approach. Obtained hybrid nanostructures underwent detailed physico-chemical characterization. Morphological and textural features were investigated through TEM, XRD and N2 physisorption. The nature of nanoparticle-melanin interaction was analyzed through FTIR, UV-vis and EPR spectroscopy. Melanin-coated hybrid nanostructures exhibited a relevant antioxidant activity, confirmed by a powerful quenching effect for DPPH radical, reaching 81 % inhibition at 33 µg/mL. A promising anti-inflammatory efficacy of the melanin-coated hybrid nanostructures was validated through a significant inhibition of BSA denaturation after 3 h. Meanwhile, the enzyme-mimicking activity was corroborated by a prolonged peroxidase activity after 8 h at 100 µg/mL and a relevant catalase-like action, by halving the H2O2 level in 30 min at 50 µg/mL. Antimicrobial assays attested that conjugation with melanin dramatically boosted CeO2 biocide activity against both Gram (-) and Gram (+) strains. Cytocompatibility tests demonstrated that the melanin coating not only enhanced the CeO2 nanostructures biomimicry, resulting in improved cell viability for human dermal fibroblast cells (HDFs), but mostly they proved that Melanin-CeO2 NPs were able to control the oxidative stress, modulating the production of nitrite and reactive oxygen species (ROS) levels in HDFs, under physiological conditions. Such remarkable outcomes make hybrid melanin-CeO2 nanozymes, promising redox-active interfaces for regenerative medicine.


Assuntos
Anti-Infecciosos , Nanopartículas Metálicas , Nanoestruturas , Humanos , Melaninas/farmacologia , Peróxido de Hidrogênio , Nanoestruturas/química , Antibacterianos/farmacologia , Antibacterianos/química , Nanopartículas Metálicas/química , Antioxidantes/farmacologia , Antioxidantes/química , Homeostase
13.
Microorganisms ; 11(3)2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36985196

RESUMO

Microbial colonization of surfaces is a sanitary and industrial issue for many applications, leading to product contamination and human infections. When microorganisms closely interact with a surface, they start to produce an exo-polysaccaridic matrix to adhere to and protect themselves from adverse environmental conditions. This type of structure is called a biofilm. The aim of our work is to investigate novel technologies able to prevent biofilm formation by surface coatings. We coated glass surfaces with melanin-ZnO2, melanin-TiO2, and TiO2 hybrid nanoparticles. The functionalization was performed using cold plasma to activate glass-substrate-coated surfaces, that were characterized by performing water and soybean oil wetting tests. A quantitative characterization of the antibiofilm properties was done using Pseudomonas fluorescens AR 11 as a model organism. Biofilm morphologies were observed using confocal laser scanning microscopy and image analysis techniques were used to obtain quantitative morphological parameters. The results highlight the efficacy of the proposed surface coating to prevent biofilm formation. Melanin-TiO2 proved to be the most efficient among the particles investigated. Our results can be a valuable support for future implementation of the technique proposed here in an extended range of applications that may include further testing on other strains and other support materials.

14.
Biomimetics (Basel) ; 8(1)2023 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-36975352

RESUMO

The in situ measurement of the bioelectric potential in xilematic and floematic superior plants reveals valuable insights into the biological activity of these organisms, including their responses to lunar and solar cycles and collective behaviour. This paper reports on the "Cyberforest Experiment" conducted in the open-air Paneveggio forest in Valle di Fiemme, Trento, Italy, where spruce (i.e., Picea abies) is cultivated. Our analysis of the bioelectric potentials reveals a strong correlation between higher-order complexity measurements and thermodynamic entropy and suggests that bioelectrical signals can reflect the metabolic activity of plants. Additionally, temporal correlations of bioelectric signals from different trees may be precisely synchronized or may lag behind. These correlations are further explored through the lens of quantum field theory, suggesting that the forest can be viewed as a collective array of in-phase elements whose correlation is naturally tuned depending on the environmental conditions. These results provide compelling evidence for the potential of living plant ecosystems as environmental sensors.

15.
Int J Mol Sci ; 24(3)2023 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-36768327

RESUMO

The existing literature survey reports rare and conflicting studies on the effect of the preparation method of metal-based semiconductor photocatalysts on structural/morphological features, electronic properties, and kinetics regulating the photocatalytic H2 generation reaction. In this investigation, we compare the different copper/titania-based photocatalysts for H2 generation synthesized via distinct methods (i.e., photodeposition and impregnation). Our study aims to establish a stringent correlation between physicochemical/electronic properties and photocatalytic performances for H2 generation based on material characterization and kinetic modeling of the experimental outcomes. Estimating unknown kinetic parameters, such as charge recombination rate and quantum yield, suggests a mechanism regulating charge carrier lifetime depending on copper distribution on the TiO2 surface. We demonstrate that H2 generation photoefficiency recorded over impregnated CuxOy/TiO2 is related to an even distribution of Cu(0)/Cu(I) on TiO2, and the formation of an Ohmic junction concertedly extended charge carrier lifetime and separation. The outcomes of the kinetic analysis and the related modeling investigation underpin photocatalyst physicochemical and electronic properties. Overall, the present study lays the groundwork for the future design of metal-based semiconductor photocatalysts with high photoefficiencies for H2 evolution.

16.
Langmuir ; 39(4): 1482-1494, 2023 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-36651862

RESUMO

ß-Glucosidase (BG) catalyzes the hydrolysis of cellobiose to glucose, a substrate for fermentation to produce the carbon-neutral fuel bioethanol. Enzyme thermal stability and reusability can be improved through immobilization onto insoluble supports. Moreover, nanoscaled matrixes allow for preserving high reaction rates. In this work, BG was physically immobilized onto wrinkled SiO2 nanoparticles (WSNs). The adsorption procedure was tuned by varying the BG:WSNs weight ratio to achieve the maximum controllability and maximize the yield of immobilization, while different times of immobilization were monitored. Results show that a BG:WSNs ratio equal to 1:6 wt/wt provides for the highest colloidal stability, whereas an immobilization time of 24 h results in the highest enzyme loading (135 mg/g of support) corresponding to 80% yield of immobilization. An enzyme corona is formed in 2 h, which gradually disappears as the protein diffuses within the pores. The adsorption into the silica structure causes little change in the protein secondary structure. Furthermore, supported enzyme exhibits a remarkable gain in thermal stability, retaining complete folding up to 90 °C. Catalytic tests assessed that immobilized BG achieves 100% cellobiose conversion. The improved adsorption protocol provides simultaneously high glucose production, enhanced yield of immobilization, and good reusability, resulting in considerable reduction of enzyme waste in the immobilization stage.


Assuntos
Enzimas Imobilizadas , Nanopartículas , Adsorção , beta-Glucosidase/metabolismo , Celobiose , Estabilidade Enzimática , Enzimas Imobilizadas/química , Glucose , Concentração de Íons de Hidrogênio , Dióxido de Silício/química , Temperatura , Biocatálise
17.
Microorganisms ; 10(10)2022 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-36296161

RESUMO

The biogenic synthesis of nanomaterials, i.e., synthesis carried out by means of living organisms, is an emerging technique in nanotechnology since it represents a greener and more eco-friendly method for the production of nanomaterials. In this line, in order to find new biological entities capable of biogenic synthesis, we tested the ability of some extremophilic microorganisms to carry out the biogenic production of AgNPs and SeNPs. Silver NPs were produced extracellularly by means of the thermophilic Thermus thermophilus strain SAMU; the haloalkaliphilic Halomonas campaniensis strain 5AG was instead found to be useful for the synthesis of SeNPs. The structural characterization of the biogenic nanoparticles showed that both the Ag and Se NPs possessed a protein coating on their surface and that they were organized in aggregates. Moreover, both types of NPs were found be able to exert an interesting antibacterial effect against either Gram-positive or Gram-negative species. This study confirmed that extremophilic microorganisms can be considered valuable producers of biologically active nanoparticles; nevertheless, further experiments must be performed to improve the synthesis protocols in addition to the downstream processes.

18.
Polymers (Basel) ; 14(17)2022 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-36080642

RESUMO

Heparin plays multiple biological roles depending on the availability of active sites strongly influenced by the conformation and the structure of polysaccharide chains. Combining different components at the molecular scale offers an extraordinary chance to easily tune the structural organization of heparin required for exploring new potential applications. In fact, the combination of different material types leads to challenges that cannot be achieved by each single component. In this study, hybrid heparin/silica nanoparticles were synthesized, and the role of silica as a templating agent for heparin supramolecular organization was investigated. The effect of synthesis parameters on particles compositions was deeply investigated by Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TGA). Transmission Electron Microscopy (TEM) reveals a different supramolecular organization of both components, leading to amazing organic-inorganic nanoparticles with different behavior in drug encapsulation and release. Furthermore, favorable biocompatibility for healthy human dermal fibroblasts (HDF) and tumor HS578T cells has been assessed, and a different biological behavior was observed, ascribed to different surface charge and morphology of synthesized nanoparticles.

19.
Diagnostics (Basel) ; 12(8)2022 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-36010207

RESUMO

Purpose: We aimed to assess the role of lung ultrasound (LUS) in the diagnosis and prognosis of SARS-CoV-2 pneumonia, by comparing it with High Resolution Computed Tomography (HRCT). Patients and methods: All consecutive patients with laboratory-confirmed SARS-CoV-2 infection and hospitalized in COVID Centers were enrolled. LUS and HRCT were carried out on all patients by expert operators within 48−72 h of admission. A four-level scoring system computed in 12 regions of the chest was used to categorize the ultrasound imaging, from 0 (absence of visible alterations with ultrasound) to 3 (large consolidation and cobbled pleural line). Likewise, a semi-quantitative scoring system was used for HRCT to estimate pulmonary involvement, from 0 (no involvement) to 5 (>75% involvement for each lobe). The total CT score was the sum of the individual lobar scores and ranged from 0 to 25. LUS scans were evaluated according to a dedicated scoring system. CT scans were assessed for typical findings of COVID-19 pneumonia (bilateral, multi-lobar lung infiltration, posterior peripheral ground glass opacities). Oxygen requirement and mortality were also recorded. Results: Ninety-nine patients were included in the study (male 68.7%, median age 71). 40.4% of patients required a Venturi mask and 25.3% required non-invasive ventilation (C-PAP/Bi-level). The overall mortality rate was 21.2% (median hospitalization 30 days). The median ultrasound thoracic score was 28 (IQR 20−36). For the CT evaluation, the mean score was 12.63 (SD 5.72), with most of the patients having LUS scores of 2 (59.6%). The bivariate correlation analysis displayed statistically significant and high positive correlations between both the CT and composite LUS scores and ventilation, lactates, COVID-19 phenotype, tachycardia, dyspnea, and mortality. Moreover, the most relevant and clinically important inverse proportionality in terms of P/F, i.e., a decrease in P/F levels, was indicative of higher LUS/CT scores. Inverse proportionality P/F levels and LUS and TC scores were evaluated by univariate analysis, with a P/F−TC score correlation coefficient of −0.762, p < 0.001, and a P/F−LUS score correlation coefficient of −0.689, p < 0.001. Conclusions: LUS and HRCT show a synergistic role in the diagnosis and disease severity evaluation of COVID-19.

20.
Nutrients ; 14(12)2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35745216

RESUMO

Mediterranean Diet (Med Diet) is one of the healthiest dietary patterns. We aimed to verify the effects of weaning (i.e., the introduction of solid foods in infants previously fed only with milk) using adult foods typical of Med Diet on children eating habits, and on the microbiota composition. A randomized controlled clinical trial on 394 healthy infants randomized in a 1:1 ratio in a Med Diet group weaned with fresh; seasonal and tasty foods of Med Diet and control group predominantly weaned with industrial baby foods. The primary end point was the percentage of children showing a good adherence to Med Diet at 36 months. Secondary end points were mother's changes in adherence to Med Diet and differences in children gut microbiota. At 36 months, children showing a good adherence to Med Diet were 59.3% in the Med Diet group and 34.3% in the control group (p < 0.001). An increase in adherence to the Med Diet was observed in the mothers of the Med Diet group children (p < 0.001). At 4 years of age children in the Med Diet group had a higher gut microbial diversity and a higher abundance of beneficial taxa. A Mediterranean weaning with adult food may become a strategy for early nutritional education, to develop a healthy microbiota, to prevent inflammatory chronic diseases and to ameliorate eating habits in children and their families.


Assuntos
Dieta Mediterrânea , Adulto , Criança , Comportamento Alimentar , Feminino , Humanos , Lactente , Alimentos Infantis , Paladar , Desmame
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