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A sensor device based on doped-carbon quantum dots is proposed herein for detection of nitrite in meat products by fluorescence quenching. For the sensing platform, carbon quantum dots doped with boron and functionalized with nitrogen (B,N-Cdot) were synthesized with an excellent 44.3% quantum yield via a one-step hydrothermal route using citric acid, boric acid, and branched polyethylenimine as carbon, boron, and nitrogen sources, respectively. After investigation of their chemical structure and fluorescent properties, the B,N-Cdot at aqueous suspensions showed high selectivity for NO

The use of nanotechnological products is increasing steadily. In this scenario, the application of nanotechnology in food science and as a technological platform is a reality. Among the several applications, the main use of this technology is for the development of foods and nutraceuticals with higher bioavailability, lower toxicity, and better sustainability. In the health field, nano-nutraceuticals are being used as supplementary products to treat an increasing number of diseases. This review summarizes the main concepts and applications of nano-nutraceuticals for health, with special focus on treating cancer and inflammation.The online version contains supplementary material available at 10.1007/s43450-022-00338-7.

Micelles have aroused interest due to their ability to assist in the transport of poorly soluble drugs. In this study the mixture of copolymers F127/E45S8 in different proportions (F/ES 30/70, 50/50 and 70/30) was performed to improve the bioavailability of griseofulvin and quercetin. The results of cytotoxicity (MTT assay) revealed that the copolymers F127 and E45S8 had considerable biocompatibility and did not affect the metabolism of human neutrophils. The binary systems were also evaluated by critical micellar concentration (CMC) and thermoresponsive behavior. The CMC values were intermediate to those of the isolated copolymers. The systems maintained the thermoresponsive properties present in F127 making the systems interesting for subcutaneous administration. The systems presented small size, an average range in size from 17 to 38 nm, and the samples prepared with higher hydrophobic proportion presented more uniform sizes. Results suggest stability and the increasing of the nanosystems circulation time. The F/ES 30/70 system has polydispersity smaller than 0.1 and showed an increase of 129 times for quercetin solubility. Thus, it is possible to consider F127/E45S8 micelles as potential nanosystems for poorly soluble drug delivery.

Yttrium iron garnet and calcium titanate (Y3Fe5O12-CaTiO3, YIG-CTO) ceramic composite were obtained according to the well-established solid-state route. This system was studied by complex impedance spectroscopy as a function of temperature. All samples showed a thermo-activated relaxation with energy activation between 1.10 and 1.70 eV. The CaTi0.6Fe0.4O2.8 phase is formed during sintering process, which influences in the electrical behavior of the samples. Nyquist diagrams were adjusted by two equivalent circuits in series to represent electric response. The YIG-CTO system was also used to design a dielectric resonator antenna (DRA) for microwave applications. The results indicate that DRA YIG-CTO-based presented an operation frequency range around 1–7 GHz, and reflection coefficient below −38 dB. From obtained results, the YIG-CTO composite is a great candidate for usage in electronic devices, operating in the C-band, such as WiFi and ISM band applications.

Magnetic nanocomposites were synthesized for the targeted delivery of hydrophilic bioactives through guidance generated by a magnetic field. Superparamagnetic iron oxide nanoparticles (SPIONs) were used to generate hydroxyethyl starch magnetic nanocapsules (HES MNCs). This synthesis allowed the co-encapsulation of oncocalyxone A (onco A) and surface-modified magnetite nanoparticles (Fe3O4@citrate) into the same nanostructure. The synthesized nanocapsules exhibited a core-shell morphology, with an average diameter of 143 nm. This nanocomposite showed potential anticancer activity (IC50) against four human tumor cell lines: glioblastoma SNB-19 (1.010 μgmL−1), colon carcinoma HCT-116 (2.675 μgmL−1), prostate PC3 (4.868 μgmL−1), and leukemia HL-60 (2.166 μgmL−1). Additionally, in vivo toxicity and locomotor activity were evaluated in a zebrafish (Danio rerio) model. The nanocomposite exhibited in vitro cytotoxicity, prolonged drug release profile and also responded to an applied magnetic field, representing a versatile compound with perspectives for highest concentration of different hydrophilic bioactives in a target tissue through magnetic vectorization.

Graphic abstract Over the past few years, there has been a growing potential use of graphene and its derivatives in several biomedical areas, such as drug delivery systems, biosensors, and imaging systems, especially for having excellent optical, electronic, thermal, and mechanical properties. Therefore, nanomaterials in the graphene family have shown promising results in several areas of science. The different physicochemical properties of graphene and its derivatives guide its biocompatibility and toxicity. Hence, further studies to explain the interactions of these nanomaterials with biological systems are fundamental. This review has shown the applicability of the graphene family in several biomedical modalities, with particular attention for cancer therapy and diagnosis, as a potent theranostic. This ability is derivative from the considerable number of forms that the graphene family can assume. The graphene-based materials biodistribution profile, clearance, toxicity, and cytotoxicity, interacting with biological systems, are discussed here, focusing on its synthesis methodology, physicochemical properties, and production quality. Despite the growing increase in the bioavailability and toxicity studies of graphene and its derivatives, there is still much to be unveiled to develop safe and effective formulations.

Ultrasonic irradiation has become a versatile tool in a variety of synthetic pathways of organic, inorganic and composite materials at “nanorange”. Basically, the ultrasonic waves in a medium, generally, a liquid, provide the phenomenon called acoustic cavitation, which can result in an energy gain by heating reactional system. In this chapter, it is reported that the ultrasound-driven chemical reactions to generate a wide broad of nanoparticle types, specifically by co-precipitation and interface reactions. Herein, a deeply literature review is provided, describing the synthesis of nanomaterials, from metal oxides to polymer-based particles, under ultrasound irradiation, and “how” the chosen of the sonochemistry strategy can tailor the size and shape of these nanomaterials and, consequently, their unique properties.

Magneto-dielectric composites are interesting advanced materials principally due to their potential applications in electronic fields, such as in microstrip antennas substrates. In this work, we developed superparamagnetic polymer-based films using the biopolymeric matrices chitosan (Ch), cellulose (BC) and collagen (Col). For this proposal, we synthesized superparamagnetic iron oxide nanoparticles (SPIONs) functionalized with polyethyleneimine with a cheap method using sonochemistry. Further, the SPIONs were dispersed into polymer matrices and the composites were evaluated regarding morphology, thermal, dielectric and magnetic properties and their application as microstrip antennas substrates. Microscopically, all tested films presented a uniform dispersion profile, principally due to polyethyleneimine coating. Under an operating frequency (fo) of 4.45 GHz, Ch, BC and Col-based SPION substrates showed moderate dielectric constant (&epsilon, &prime, ) values in the range of 5.2&ndash, 8.3, 6.7&ndash, 8.4 and 5.9&ndash, 9.1, respectively. Furthermore, the prepared films showed no hysteresis loop, thereby providing evidence of superparamagnetism. The microstrip antennas showed considerable bandwidths (3.37&ndash, 6.34%) and a return loss lower than &minus, 10 dB. Besides, the fo were modulated according to the addition of SPIONs, varying in the range of 4.69&ndash, 5.55, 4.63&ndash, 5.18 and 4.93&ndash, 5.44 GHz, for Ch, BC and Col-based substrates, respectively. Moreover, considering best modulation of &epsilon, and fo, the Ch-based SPION film showed the most suitable profile as a microstrip antenna substrate.

In this work, chitosan/magnetite nanoparticles (ChM) were quickly synthesized according to our previous report based on co-precipitation reaction under ultrasound (US) irradiation. Besides ChM was in-depth structurally characterized, showing a crystalline phase corresponding to magnetite and presenting a spheric morphology, a &ldquo, nanorod&rdquo, type morphology was also obtained after increasing reaction time for eight minutes. Successfully, both morphologies presented a nanoscale range with an average particle size of approximately 5&ndash, 30 nm, providing a superparamagnetic behavior with saturation magnetization ranging from 44 to 57 emu&middot, g&minus, 1. As ChM nanocomposites have shown great versatility considering their properties, we proposed a comparative study using three different amine-based nanoparticles, non-surface-modified and surface-modified, for removal of azo dyes from aqueous solutions. From nitrogen adsorption&ndash, desorption isotherm results, the surface-modified ChMs increased the specific surface area and pore size. Additionally, the adsorption of anionic azo dyes (reactive black 5 (RB5) and methyl orange (MO)) on nanocomposites surface was pH-dependent, where surface-modified samples presented a better response under pH 4 and non-modified one under pH 8. Indeed, adsorption capacity results also showed different adsorption mechanisms, molecular size effect and electrostatic attraction, for unmodified and modified ChMs, respectively. Herein, considering all results and nanocomposite-type structure, ChM nanoparticles seem to be a suitable potential alternative for conventional anionic dyes adsorbents, as well as both primary materials source, chitosan and magnetite, are costless and easily supplied.

In this communication, it was evaluated the production of fatty acid ethyl ester (FAAE) from the free fatty acids of babassu oil catalyzed by lipase from Rhizomucor miehei (RML) immobilized on magnetic nanoparticles (MNP) coated with 3-aminopropyltriethoxysilane (APTES), Fe3O4@APTES-RML or RML-MNP for short. MNPs were prepared by co-precipitation coated with 3-aminopropyltriethoxysilane and used as a support to immobilize RML (immobilization yield: 94.7 ± 1.0%; biocatalyst activity: 341.3 ± 1.2 U p-NPB/g), which were also activated with glutaraldehyde and then used to immobilize RML (immobilization yield: 91.9 ± 0.2%; biocatalyst activity: 199.6 ± 3.5 U p-NPB/g). RML-MNP was characterized by X-Ray Powder Diffraction (XRPD), Fourier Transform-Infrared (FTIR) spectroscopy and Scanning Electron Microscope (SEM), proving the incorporation and immobilization of RML on the APTES matrix. In addition, the immobilized biocatalyst presented at 60°C a half-life 16-19 times greater than that of the soluble lipase in the pH range 5-10. RML and RML-MNP showed higher activity at pH 7; the immobilized enzyme was more active than the free enzyme in the pH range (5-10) analyzed. For the production of fatty acid ethyl ester, under optimal conditions [40°C, 6 h, 1:1 (FFAs/alcohol)] determined by the Taguchi method, it was possible to obtain conversion of 81.7 ± 0.7% using 5% of RML-MNP.

This work proposes the development of a starch-based drug carrier for fluoxetine (FLX) delivery and evaluate the improvement of the drug antibacterial activity. The starch nanocapsules were prepared via interfacial polyaddition reaction presenting a core-shell morphology, based on polyurethane linkage, with a particle size in the range 250–300 nm. Furthermore, FLX-loaded nanocapsules were evaluated regarding antibacterial potential against Staphylococcus aureus (ATCC® 6538P ™) and its clinical strains of methicillin-resistant. As expected, the FLX-loaded presented lower minimum inhibitory concentration (MIC) values, in the range of 190–95 μg mL−1, against all isolated microorganisms in comparison to FLX, 255 μg mL−1. According to results, the FLX-loaded starch nanocapsules have successfully improved drug antibacterial activity, generating promising perspectives on the field of the hydrophilic drug delivery systems.

TiO2 is a common inorganic filter used in sunscreens due to its photoprotective effect on the skin against UV radiation. However, the use of this kind of material in cosmetics is limited by its inherent photocatalytic activity. It is known that coating on TiO2 surface can improve some features. Although, many of the methodologies used for this purpose are still laborious and time-consuming. Thus, this work reports a novel, easy, cheap and fast strategy to coat TiO2 particles by using a sonochemistry approach, aiming to decrease photocatalytic activity and to enhance colloidal stability. For this proposal, SiO2, Al2O3, ZrO2 and sodium polyacrylate (PAANa) were used to tune the surface of commercial TiO2 particles and they were applied in a sunscreen formulation. The samples were characterized by XRPD, FT-IR, DLS, EDS, SEM and TEM. The photocatalytic activity and UV-shielding ability were also evaluated. The sunscreen formulations were prepared and characterized by zeta potential, DLS, and Sun Protection Factor (SPF). FT-IR, EDS, and charge surface of the particles confirmed the success of the sonochemistry coating. Additionally, TiO2@Al2O3, TiO2@SiO2 and TiO2@PAANa show a lower photocatalytic activity than original TiO2 with similar UV-shielding ability. The sunscreens produced with the coated TiO2 have similar SPF to the one with commercial TiO2. Specifically, the sunscreen with TiO2@PAANa shows an increase in colloidal stability. Herein, the incorporation of the sonochemical-coated TiO2 particles in sunscreen formulations may produce sunscreens with better aesthetic appearance and a greater health security due to its lower free radicals production.

Nowadays, around 40% of the lubricant market is dominated by petroleum-derived products, resulting in a negative impact on environment. Herein, it was aimed to develop a biodegradable lubricant-grade ester using Tilapia oil as primary feedstock. The synthetic route was carried out in three steps: (1) transesterification, (2) epoxidation and (3) ring-opening reaction with different long chain alcohols, where the final esters were characterised regarding their physicochemical properties. The lubricant-grade esters showed superior biodegradability and viscosity index (>117) compared to commercial petroleum-based oils. The ester synthesized with 2-ethyl hexanol showed highest thermal stability (Tonset = 230 °C) compared to other long chain alcohols. Therefore, as mainly proposed, this study shows that esters from Tilapia oil have a great potential to obtain lubricants with high biodegradability and better physicochemical properties.

A robust fluorescence-based sensing strategy was designed considering relevance of analyzing chemical additives in industrialized food. In this study, a sensing approach was developed using fluorescent carbon quantum dots (CQDs) as a chemometric tool. CQDs were synthesized by a simple one-step hydrothermal route using the American natural seed Caelsalpinia pulcherrima, and further characterized regarding their chemical structure. Five food additives were identified, citric acid, lactic acid, ascorbic acid, sodium benzoate and potassium sorbate, which showed a highly sensitive response with a limit of detection (LOD) as low as 252 ng mL−1. The sensing platform was designed using the supervised method for recognizing patterns of linear discriminant analysis (LDA), where we could identify different concentrations of additives, after optimization of experimental parameters. Furthermore, the sensing strategy successfully identified all tested additives in a pickled olives sample with 95 % of confidence, where 100 % of combinations were correctly identified based on classification matrix. Overall, the obtained results evidence the accuracy and potential of CQDs-based fluorescence sensing in the identification of food additives.

The great performance of functionalized Fe3O4 nanoparticles (NPs) as contrast agent for magnetic resonance imaging (MRI) is related to the functionalizing agents, once can tune colloidal properties, chemical stability, hydrophilicity, overall toxicity, as well as, dipole interparticle interactions. Phosphonate derivatives have proven to be excellent capping agents due to their ability to control the above parameters. However, the available functionalizing agents do not provide enough both attached and free-form phosphoric acid groups on NPs surface. Herein, we report the use of a commercially available amino-phosphonate compound, diethylenetriaminepenta (methylene phosphonic acid, DTPMP), to functionalize Fe3O4 NPs to be potentially applied as MRI contrast agent. For the synthesis of DTPMP-coated Fe3O4 NPs, two methodologies were applied, hydrothermal and sonochemical approaches. Several characterization techniques were performed, confirming the success of surface functionalization, which allowed a deep chemical discussion involving the interactions between DTPMP and Fe3O4 NPs. Furthermore, relaxivity and cytotoxicity analyses confirmed the MRI contrast agent potential of the DTPMP-coated Fe3O4 NPs, presenting non-cytotoxicity profile and high values of transverse relaxivity (357–417 mM−1 s−1). Therefore, this work presents a novel and excellent alternative magnetic material for biological and technological application, mainly considering MRI contrast agent.

Preconcentration of Pb(II) in grape-based beverages using organophosphate-functionalized halloysite nanotubes was investigated by flame atomic absorption spectroscopy (FAAS). For this proposal, a central composition design (CCD) was performed for an optimum experimental condition on Pb(II) preconcentration procedure, pH 7.5, preconcentration time of 7.5 min and adsorbent mass of 40 mg. The detection and quantification limit values were calculated as 12 and 40 μg kg−1, respectively. Additionally, considering Pb(II) tolerable recovery, the nanotubes could be reuse for six cycles. The preconcentration method was applied to wine and grape juice samples and concentrations below LOD were found for all samples. The proposed methodology presented great accuracy and limits compatible with current legislation, since spike/recovery tests were performed, and quantitative recoveries were obtained.

In the present work, an alternative to synthesized nanocapsules in which the lipophilic core was a multiple nanoemulsification forming a complex system constituted of various phases was studied. A primary emulsion (O/W) was poured into another lipophilic solvent, forming a multiple nanoemulsion (O/W/O) able to provide the encapsulation of lapachol, a lipophilic drug. The synthesized nanocapsules were well characterized and the results demonstrate a core-shell morphology, based on the polyurethane formation that exists in the cross-linked starch shell. Furthermore, these systems have moderate stability, with particle size measuring up to 274 nm. The nanocapsules containing lapachol encapsulated 73% of the drug initially added. This demonstrates success in the synthetic route adopted, evidenced by the efficiency of incorporation of the lapachol, in addition of providing a controlled release, reaching 51.4% in 24 h. This behavior shows that the polymeric shell influences the drug release profile and it is in accordance with the kinetic model proposed by Peppas.

Mangiferin-loaded F127/PEG micellar systems were evaluated regarding the effect of PEG addition at different molecular weights, where the system with best mangiferin solubility response (0.5 wt% of PEG in 1 wt% F127 aqueous solution) was chosen to be a potential drug delivery system (DDS), which solubilized 7.92 mg dL−1 of mangiferin. Subsequently, the chosen mangiferin-loaded DDS was evaluated in regard the inhibition of enzyme α-glucosidase, which showed a more effective inhibition, around 95.42%, when compared to the standard acarbose (92.59%) and to the free-form mangiferin (90.42%). The same micellar system was also evaluated for its cytotoxicity, where no significative values of LDH activity was observed. No study has been done yet with both mangiferin and DDSs regarding in vitro α-glucosidase inhibitory activity. This work proposes a “new” alternative towards diabetes treatment.