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1.
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
2.
Macromol Biosci ; : e2400013, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38509742

RESUMO

The development of biosafe theranostic nanoplatforms has attracted great attention due to their multifunctional behavior, reduced potential toxicity, and improved long-term safety. When considering photoacoustic contrast agents and photothermal conversion tools, melanin and constructs like melanin are highly appealing due to their ability to absorb optical energy and convert it into heat. Following a sustainable approach, in this study, silver-melanin like-silica nanoplatforms are synthesized exploiting different bio-available and inexpensive phenolic acids as potential melanogenic precursors and exploring their role in tuning the final systems architecture. The UV-Vis combined with X-Ray Diffraction investigation proves metallic silver formation, while Transmission Electron Microscopy analysis reveals that different morphologies can be obtained by properly selecting the phenolic precursors. By looking at the characterization results, a tentative formation mechanism is proposed to explain how phenolic precursors' redox behavior may affect the nanoplatforms' structure. The antibacterial activity experiments showed that all synthesized systems have a strong inhibitory effect on Escherichia coli, even at low concentrations. Furthermore, very sensitive Photoacoustic Imaging capabilities and significant photothermal behavior under laser irradiation are exhibited. Finally, a marked influence of phenol nature on the final system architecture is revealed resulting in a significant effect on both biological and photoacoustic features of the obtained systems. These melanin-based hybrid systems exhibit excellent potential as triggerable nanoplatforms for various biomedical applications.

3.
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
4.
ACS Omega ; 9(7): 7793-7805, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38405468

RESUMO

Hydrogen is expected to largely contribute to the near-future circular economy. Today, most hydrogen is still produced from fossil fuels or renewable pathways with low efficiency and high cost. Herein, a proof of concept for a novel hydrogen production process is proposed, here named cyan hydrogen, inspired by a combination of the green and blue processes, due to the key role played by water and the low carbon content in the gas phase, respectively. The developed novel process, recently patented and demonstrated at the lab scale, is based on successive steps in which ethanol (5.0 mL) and water (10.0 mL) are alternately fed, with a fixed initial amount of sodium metaborate (2.0 g), in a batch reactor at 300 °C. Preliminary results showed the simultaneous production of a 95% v/v hydrogen stream, a polymeric byproduct with a repetitive carbon pattern -CH2-CH2-, and a liquid phase rich in oxygenated chemicals at temperatures lower than conventional hydrogen production processes.

5.
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
6.
Int J Mol Sci ; 24(24)2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38139203

RESUMO

Bioinspired nanoparticles have recently been gaining attention as promising multifunctional nanoplatforms for therapeutic applications in cancer, including breast cancer. Here, the efficiency of the chemo-photothermal and photoacoustic properties of hybrid albumin-modified nanoparticles (HSA-NPs) loaded with doxorubicin was evaluated in a three-dimensional breast cancer cell model. The HSA-NPs showed a higher uptake and deeper penetration into breast cancer spheroids than healthy breast cell 3D cultures. Confocal microscopy revealed that, in tumour spheroids incubated with doxorubicin-loaded NPs for 16 h, doxorubicin was mainly localised in the cytoplasm, while a strong signal was detectable at the nuclear level after 24 h, suggesting a time-dependent uptake. To evaluate the cytotoxicity of doxorubicin-loaded NPs, tumour spheroids were treated for up to 96 h with increasing concentrations of NPs, showing marked toxicity only at the highest concentration of doxorubicin. When doxorubicin administration was combined with laser photothermal irradiation, enhanced cytotoxicity was observed at lower concentrations and incubation times. Finally, the photoacoustic properties of doxorubicin-loaded NPs were evaluated in tumour spheroids, showing a detectable signal increasing with NP concentration. Overall, our data show that the combined effect of chemo-photothermal therapy results in a shorter exposure time to doxorubicin and a lower drug dose. Furthermore, owing to the photoacoustic properties of the NPs, this nanoplatform may represent a good candidate for theranostic applications.


Assuntos
Neoplasias da Mama , Hipertermia Induzida , Nanopartículas , Técnicas Fotoacústicas , Humanos , Feminino , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/terapia , Terapia Fototérmica , Técnicas Fotoacústicas/métodos , Doxorrubicina/farmacologia , Fototerapia/métodos , Linhagem Celular Tumoral , Hipertermia Induzida/métodos
7.
Chemosphere ; 344: 140430, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37832885

RESUMO

Humic acids (HA) consist in a multitude of heterogeneous organic molecules surviving the biological and chemical degradation of both vegetal and animal biomasses. The great abundance and chemical richness of these residues make their valorisation one of the most promising approaches to move towards a circular economy. However, the heterogeneity of the biomass from which HA are extracted, as well as the production process, significantly affects the nature and the relative content of functional groups (i.e. quinones, phenols and carboxylic and hydroxyl moieties), eventually changing HA reactivity and ultimately determining their application field. Indeed, depending on their properties, these substances can be used as flame retardants in the case of pronounced resilience degree (i.e., absent or low reactivity), or as antioxidant or antimicrobial agents in the case of pronounced reactivity, thanks to their redox behaviour. In this work we investigated the flammable, the thermal and the physico-chemical features of HA extracted from different composted biomasses to identify the reactivity or the resiliency of these moieties. Several techniques, including flammability characterization (LIT and MIE), laser diffraction granulometry, TG, XRD analyses, FTIR spectroscopy on both solid and gaseous phases, and Raman spectroscopy were integrated to investigate the correlation among the safety parameters, the distributions of particle sizes, as well as the thermal, the chemical properties of HA powders and the influence of post-extraction processes on HA final properties.


Assuntos
Recuperação e Remediação Ambiental , Substâncias Húmicas , Substâncias Húmicas/análise , Solo/química , Fenóis/análise , Espectroscopia de Infravermelho com Transformada de Fourier/métodos
8.
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
9.
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
10.
Polymers (Basel) ; 15(14)2023 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-37514377

RESUMO

This review focuses on the opportunities provided by sol-gel chemistry for the production of silica/epoxy nanocomposites, with significant representative examples of the "extra situ" approach and an updated description of the "in situ" strategy. The "extra situ" strategy enables the creation of nanocomposites containing highly engineered nanoparticles. The "in situ" approach is a very promising synthesis route that allows us to produce, in a much easier and eco-friendly manner, properly flame-retarded silica/epoxy nanocomposites endowed with very interesting properties. The review highlights the recently proposed mechanism of nanoparticles formation, which is expected to help to design the synthesis strategies of nanocomposites, changing their composition (both for the nanoparticle and matrix nature) and with in situ-generated nanoparticles possibly more complex than the ones obtained, until today, through this route.

11.
Biomacromolecules ; 24(6): 2691-2705, 2023 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-37167573

RESUMO

Exploring opportunities for biowaste valorization, herein, humic substances (HS) were combined with gelatin, a hydrophilic biocompatible and bioavailable polymer, to obtain 3D hydrogels. Hybrid gels (Gel HS) were prepared at different HS contents, exploiting physical or chemical cross-linking, through 1-ethyl-(3-3-dimethylaminopropyl)carbodiimide (EDC) chemistry, between HS and gelatin. Physicochemical features were assessed through rheological measurements, X-ray diffraction, attenuated total reflectance (ATR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and scanning electron microscopy (SEM). ATR and NMR spectroscopies suggested the formation of an amide bond between HS and Gel via EDC chemistry. In addition, antioxidant and antimicrobial features toward both Gram(-) and Gram(+) strains were evaluated. HS confers great antioxidant and widespread antibiotic performance to the whole gel. Furthermore, the chemical cross-linking affects the viscoelastic behavior, crystalline structures, water uptake, and functional performance and produces a marked improvement of biocide action.


Assuntos
Gelatina , Hidrogéis , Gelatina/química , Hidrogéis/farmacologia , Hidrogéis/química , Substâncias Húmicas , Antioxidantes/farmacologia , Reagentes de Ligações Cruzadas/química , Antibacterianos/farmacologia
12.
Nanomaterials (Basel) ; 13(7)2023 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-37049262

RESUMO

Stimulated Raman scattering in transparent glass-ceramics (TGCs) based on bulk nucleating phase Ba2NaNb5O15 were investigated with the aim to explore the influence of micro- and nanoscale structural transformations on Raman gain. Nanostructured TGCs were synthesized, starting with 8BaO·15Na2O·27Nb2O5·50SiO2 (BaNaNS) glass, by proper nucleation and crystallization heat treatments. TGCs are composed of nanocrystals that are 10-15 nm in size, uniformly distributed in the residual glass matrix, with a crystallinity degree ranging from 30 up to 50% for samples subjected to different heat treatments. A significant Raman gain improvement for both BaNaNS glass and TGCs with respect to SiO2 glass is demonstrated, which can be clearly related to the nanostructuring process. These findings show that the nonlinear optical functionalities of TGC materials can be modulated by controlling the structural transformations at the nanoscale rather than microscale.

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.
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.

15.
FEMS Microbiol Ecol ; 99(2)2023 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-36478021

RESUMO

Polyethylene (PE) is high molecular weight synthetic polymer, very hydrofobic and hardly biodegradable. To increase polyethylene bio-degradability it is very important to find microorganisms that improve the PE hydrophilic level and/or reduce the length of its polymeric chain by oxidation. In this study, we isolated Cladosporium halotolerans, a fungal species, from the gastric system of Galleria mellonella larvae. Here, we show that C. halotolerans grows in the presence of PE polymer, it is able to interact with plastic material through its hyphae and secretes enzymes involved in PE degradation.


Assuntos
Plásticos , Polietileno , Animais , Polietileno/metabolismo , Cladosporium/metabolismo , Polímeros , Biodegradação Ambiental
16.
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.

17.
RSC Adv ; 12(23): 14645-14654, 2022 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-35702191

RESUMO

CeO2 slow redox kinetics as well as low oxygen exchange ability limit its application as a catalyst in solar thermochemical two-step cycles. In this study, Ce0.75Zr0.25O2 catalysts doped with potassium or transition metals (Cu, Mn, Fe), as well as co-doped materials were synthesized. Samples were investigated by X-ray diffraction (XRD), N2 sorption (BET), as well as by electron paramagnetic resonance (EPR) and X-ray photoelectron spectroscopy (XPS) to gain insight into surface and bulk features, which were connected to redox properties assessed both in a thermogravimetric (TG) balance and in a fixed bed reactor. Obtained results revealed that doping as well as co-doping with non-reducible K cations promoted the increase of both surface and bulk oxygen vacancies. Accordingly, K-doped and Fe-K co-doped materials show the best redox performances evidencing the highest reduction degree, the largest H2 amounts and the fastest kinetics, thus emerging as very interesting materials for solar thermochemical splitting cycles.

18.
Chemosphere ; 287(Pt 1): 131985, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34454229

RESUMO

Humic acids (HA) are considered a promising and inexpensive source for novel multifunctional materials for a huge range of applications. However, aggregation and degradation phenomena in aqueous environment prevent from their full exploitation. A valid strategy to address these issues relies on combining HA moieties at the molecular scale with an inorganic nanostructured component, leading to more stable hybrid nanomaterials with tunable functionalities. Indeed, chemical composition of HA can determine their interactions with the inorganic constituent in the hybrid nanoparticles and consequently affect their overall physico-chemical properties, including their stability and functional properties in aqueous environment. As a fundamental contribution to HA materials-based technology, this study aims at unveiling this aspect. To this purpose, SiO2 nanoparticles have been chosen as a model platform and three different HAs extracted from composted biomasses, manure (HA_Man), artichoke residues (HA_Art) and coffee grounds (HA_Cof), were employed to synthetize hybrid HA-SiO2 nanoparticles through in-situ sol-gel synthesis. Prepared samples were submitted to aging in water to assess their stability. Furthermore, antioxidant properties and physico-chemical properties of both as prepared and aged samples in aqueous environment were assessed through Scanning Electron Microscopy (SEM), N2 physisorption, Simultaneous Thermogravimetric (TGA) and Differential Scanning Calorimetric (DSC) Analysis, Fourier Transform Infrared (FT-IR), Nuclear Magnetic Resonance (NMR), Electron Paramagnetic Resonance (EPR) spectroscopies. The experimental results highlighted that hybrid HA-SiO2 nanostructures acted as dynamic systems which exhibit structural supramolecular reorganization during aging in aqueous environment with marked effects on physico-chemical and functional properties, including improved antioxidant activity. Obtained results enlighten a unique aspect of interactions between HA and inorganic nanoparticles that could be useful to predict their behavior in aqueous environment. Furthermore, the proposed approach traces a technological route for the exploitation of organic biowaste in the design of hybrid nanomaterials, providing a significant contribution to the development of waste to wealth strategies based on humic substances.


Assuntos
Substâncias Húmicas , Nanoestruturas , Idoso , Humanos , Substâncias Húmicas/análise , Masculino , Dióxido de Silício , Espectroscopia de Infravermelho com Transformada de Fourier , Água
19.
Biomacromolecules ; 23(1): 443-453, 2022 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-34936338

RESUMO

Exploring the chance to convert biowaste into a valuable resource, this study tests the potential role of humic acids (HA), a class of multifunctional compounds obtained by oxidative decomposition of biomass, as physical agents to improve gelatin's mechanical and thermal properties. To this purpose, gelatin-HA aqueous samples were prepared at increasing HA content. HA/gelatin concentrations changed in the range 2.67-26.67 (wt/wt)%. Multiple techniques were employed to assess the influence of HA content on the gel properties and to unveil the underlying mechanisms. HAs increased gel strength up to a concentration of 13.33 (wt/wt)% and led to a weaker gel at higher concentrations. FT-IR and DSC results proved that HAs can establish noncovalent interactions through H-bonding with gelatin. Coagulation phenomena occur because of HA-gelatin interactions, and at concentrations greater than 13.33 (wt/wt)%, HAs established preferential bonds with water molecules, preventing them from coordinating with gelatin chains. These features were accompanied by a change in the secondary structure of gelatin, which lost the triple helix structure and exhibited an increase in the random coil conformation. Besides, higher HA weight content caused swelling phenomena due to HA water absorption, contributing to a weaker gel. The current findings may be useful to enable a better control of gelatin structures modified with composted biowaste, extending their exploitation for a large set of technological applications.


Assuntos
Gelatina , Hidrogéis , Gelatina/química , Substâncias Húmicas , Hidrogéis/química , Espectroscopia de Infravermelho com Transformada de Fourier , Água
20.
Int J Mol Sci ; 22(20)2021 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-34681890

RESUMO

Hybrid nanomaterials have attracted research interest owing to their intriguing properties, which may offer new diagnostic options with triggering features, able to realize a new kind of tunable nanotherapeutics. Hybrid silica/melanin nanoparticles (NPs) containing silver seeds (Me-laSil_Ag-HSA NPs) disclosed relevant photoacoustic contrast for molecular imaging. In this study we explored therapeutic function in the same nanoplatform. For this purpose, MelaSil_Ag-HSA were loaded with doxorubicin (DOX) (MelaSil_Ag-HSA@DOX) and tested to assess the efficiency of drug delivery combined with concurrent photothermal treatment. The excellent photothermal properties allowed enhanced cytotoxic activity at significantly lower doses than neat chemotherapeutic treatment. The results revealed that MelaSil_Ag-HSA@DOX is a promising platform for an integrated photothermal (PT) chemotherapy approach, reducing the efficacy concentration of the DOX and, thus, potentially limiting the several adverse side effects of the drug in in vivo treatments.


Assuntos
Albuminas/química , Neoplasias da Mama/terapia , Doxorrubicina/farmacologia , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Nanopartículas/administração & dosagem , Terapia Fototérmica/métodos , Antibióticos Antineoplásicos/farmacologia , Apoptose , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Proliferação de Células , Terapia Combinada , Liberação Controlada de Fármacos , Feminino , Humanos , Raios Infravermelhos , Nanopartículas/química , Células Tumorais Cultivadas
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