Search

Advanced-stage solid primary tumors and metastases often express mucin 16 (MUC16), carrying immature glycans such as the Tn antigen, resulting in specific glycoproteoforms not found in healthy human tissues. This presents a valuable approach for designing targeted therapeutics, including cancer glycovaccines, which could potentially promote antigen recognition and foster the immune response to control disease spread and prevent relapse. In this study, we describe an adjuvant-free poly(lactic- co -glycolic acid) (PLGA)-based nanoglycoantigen delivery approach that outperforms conventional methods by eliminating the need for protein carriers while exhibiting targeted and adjuvant properties. To achieve this, we synthesized a library of MUC16-Tn glycoepitopes through single-pot enzymatic glycosylation, which were then stably engrafted onto the surface of PLGA nanoparticles, generating multivalent constructs that better represent cancer molecular heterogeneity. These glycoconstructs demonstrated affinity for Macrophage Galactose-type Lectin (MGL) receptor, known to be highly expressed by immature antigen-presenting cells, enabling precise targeting of immune cells. Moreover, the glycopeptide-grafted nanovaccine candidate displayed minimal cytotoxicity and induced the activation of dendritic cells in vitro , even in the absence of an adjuvant. In vivo , the formulated nanovaccine candidate was also nontoxic and elicited the production of IgG specifically targeting MUC16 and MUC16-Tn glycoproteoforms in cancer cells and tumors, offering potential for precise cancer targeting, including targeted immunotherapies.

The present work aims to prepare copper-doped MgO nanoparticles via a sol-gel approach and study their antidiabetic alpha-amylase inhibition activity with undoped MgO nanoparticles. The ability of G5 amine-terminated polyamidoamine (PAMAM) dendrimer for the controlled release of copper-doped MgO nanoparticles to exhibit alpha-amylase inhibition activity was also evaluated. The synthesis of MgO nanoparticles via sol-gel approach and optimization of calcination temperature and time has led to the formation of nanoparticles with different shapes (spherical, hexagonal, and rod-shaped) and a polydispersity in size ranging from 10 to 100 nm with periclase crystalline phase. The presence of copper ions in the MgO nanoparticles has altered their crystallite size, eventually modifying their size, morphology, and surface charge. The efficiency of dendrimer to stabilize spherical copper-doped MgO nanoparticles (ca. 30 %) is higher than in other samples, which was confirmed by UV-Visible, DLS, FTIR, and TEM analysis. The amylase inhibition assay emphasized that the dendrimer nanoparticles stabilization has led to the prolonged enzyme inhibition ability of MgO and copper-doped MgO nanoparticles for up to 24 h., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

The nanoprecipitation of hydrogel nanoparticles by complex coacervation is investigated through a systematic study of the popular chitosan-polyphosphate pair of polyelectrolytes with opposite charges at pH 4. Polyphosphates of varying molar masses and electrical charges are investigated as alternatives to the commonly used tripolyphosphate, so as to assess the influence of the strength of electrostatic interactions on the fabrication possibility, the size of hydrogel particles, and their overall charge. Sodium hexametaphosphate and sodium polyphosphate allow the manufacture of such nanoparticles with either a positive or a negative charge, depending on the chitosan/polyphosphate ratio and the order of mixing. The classical way of mixing by pouring the polyphosphate solution into the chitosan solution yields microparticles. Inverting the order of mixing by pouring the chitosan solution into the polyphosphate solution allows the precipitation of negatively charged nanoparticles with diameters in the range 100-200 nm. Such charge inversion of the chitosan into negative is not possible with the common TPP. It was achieved using sodium hexametaphosphate and sodium polyphosphate having a larger negative charge. Charge inversion of chitosan allows an efficient encapsulation of positively charged proteins with an improved encapsulation efficiency than in the usual TPP-based coacervate. The encapsulation of the bovine serum albumin at pH 4 is given as a case study of a positively charged protein., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Aiming to highlight the valorization of the natural products and the green synthesis processes, this work describes the development of a nanoscale system based on the use of alginate to encapsulate a blend of oils (vegetable and essential oils), not previously reported, with antibacterial and antioxidant actions. The study shows the influence of the polymer and surfactant concentrations on the physicochemical properties of the nanoparticles. The formulations were characterized by DLS, zeta potential, efficiency of encapsulation and stability. In addition, the antioxidant and antimicrobial properties of the systems were evaluated using the DPPH method and disk diffusion assays, respectively. The shelf life was studied by coating fruits and seeds. The results showed that the nanostructured system was stable, the efficiency of encapsulation was high and the nanoparticles size range was about 200-400 nm. The coating of fruits and seeds showed that the system was capable of inhibiting the growth of microorganisms and delaying the fruit maturation, indicating its potential for prolonging the shelf-life of fresh food., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

Carbon dots (CDs) and N-carbon dots (N-CDs) loaded with Ru-complex (CDs@RuCN, N-CDs@RuCN, respectively) were investigated as media imposing biochemical changes induced by UV illumination of ovarian cancer, A2780, and osteosarcoma, CAL72, cells. Synchrotron radiation-based Fourier Transform Infrared Spectroscopy was performed, and the spectra were subjected to a Principal Component Analysis. The CDs@RuCN and N-CDs@RuCN effects on cancer cells were analyzed by the theoretical modelling of the stability of the composite systems and a protein database search. Moreover, a detailed evaluation of surface and optical properties of CDs@RuCN and N-CDs@RuCN was carried out. Results demonstrated selective action of the CDs@RuCN and N-CDs@RuCN-based photodynamic therapy, with N-CDs@RuCN being the most active in inducing changes in A2780 and CDs@RuCN in CAL72 cells. We assume that different surface charges of nanoparticles led to direct interactions of N-CDs@RuCN with a Wnt signalling pathway in A2780 and those of CDs@RuCN with PI3-K/Akt in CAL72 cells and that further biochemical changes occurred upon light illumination., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Silica is one of the most abundant minerals in the Earth's crust, and over time it has been introduced first into human life and later into engineering. Silica is present in the food chain and in the human body. As a biomaterial, silica is widely used in dentistry, orthopedics, and dermatology. Recently amorphous sol-gel SiO₂ nanoparticles (NPs) have appeared as nanocarriers in a wide range of medical applications, namely in drug/gene target delivery and imaging diagnosis , where they stand out for their high biocompatibility, hydrophilicity, enormous flexibility for surface modification with a high payload capacity, and prolonged blood circulation time. The sol-gel process is an extremely versatile bottom-up methodology used in the synthesis of silica NPs, offering a great variety of chemical possibilities, such as high homogeneity and purity, along with full scale pH processing. By introducing organic functional groups or surfactants during the sol-gel process, ORMOSIL NPs or mesoporous NPs are produced. Colloidal route, biomimetic synthesis, solution route and template synthesis (the main sol-gel methods to produce monosized silica nanoparticles) are compared and discussed. This short review goes over some of the emerging approaches in the field of non-porous sol-gel silica NPs aiming at medical applications, centered on the syntheses processes used., Competing Interests: The author declares no conflicts of interest.

Gene therapy stays on the cutting edge of biomedical research, being the design of the optimal gene delivery vector one of the key requests. Silica-based nanoparticles (NPs) have emerged as promising non-viral gene delivery vector, due to their high biocompatibility, nontoxicity, non-immunogenicity, biodegradability and enormous bioconjugation versatility. In this work a sol-gel methodology for the synthesis of amino-functionalized silica NPs (NH2-ORMOSIL NPs) was optimized, and NPs were characterized by TEM and FTIR. In a first step NH2-ORMOSIL NPs were bioconjugated with a plasmid DNA, pVAX1-GFP, assembling an ORMOPLEXE, confirmed by agarose gel electrophoresis. In a second step, in vitro studies have been performed with cultured CHO cells, where ORMOPLEXEs transfection was proved by CLSM. In vivo transfection efficiency and bio-distribution were performed in Zebrafish (Danio rerio) embryos, assessed by FM. Finally, NPs ecotoxicity was studied in zebrafish embryos by following the mortality and developmental endpoints., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Despite the wide research done in the field, the development of advanced drug delivery systems with improved drug delivery properties and effective anticancer capability still remains a great challenge. Based on previous work that showed the potentialities of the nanoclay Laponite as a pH-sensitive doxorubicin (Dox) delivery vehicle, herein we report a simple method to modulate its extent of drug release at different pH values. This was achieved by alternate deposition of cationic poly(allylamine) hydrochloride and anionic poly(sodium styrene sulfonate) (PAH/PSS) polyelectrolytes over the surface of Dox-loaded Laponite nanoparticles using the electrostatic layer-by-layer (LbL) self-assembly approach. The successful formation of polyelectrolyte multilayer-coated Dox/Laponite systems was confirmed by Dynamic Light Scattering and zeta potential measurements. Systematic studies were performed to evaluate their drug release profiles and anticancer efficiency. Our results showed that the presence of the polyelectrolyte multilayers improved the sustained release properties of Laponite and allowed a fine tuning of the extension of drug release at neutral and acidic pH values. The cytotoxicity presented by polyelectrolyte multilayer-coated Dox/Laponite systems towards MCF-7 cells was in accordance with the drug delivery profiles. Furthermore, cellular uptake studies revealed that polyelectrolyte multilayer-coated Dox/Laponite nanoparticles can be effectively internalized by cells conducting to Dox accumulation in cell nucleus., (Copyright © 2015 Elsevier B.V. All rights reserved.)

The efficacy of the anticancer drug doxorubicin (Dox) is limited by an insufficient cellular uptake and drug resistance, which is partially due to ion trapping in acidic environments such as the extracellular environment of solid tumors and the interior of endolysosome vesicles. Herein, we describe the preparation and in vitro evaluation of a new type of nanohybrid for anticancer drug delivery which is capable of carrying a high load of the cationic Dox through the cell membrane. In addition, the nanohybrids use the acidic environment of the endolysosomes to release the drug, simultaneously helping to disrupt the endolysosomes and diminishing endolysosome Dox trapping. Furthermore, as the nanohybrid carriers are capable of sustained drug delivery, those that remain in the cytoplasm and still contain Dox are expected to exert a prolonged anticancer activity. Briefly, Dox is loaded onto biocompatible anionic Laponite(®) (LP) nanodisks with a high aspect ratio (25 nm in diameter and 0.92 nm in thickness) through strong electrostatic interactions to get Dox-loaded LP disks. Alginate (AG), a biocompatible natural polymer, is then coated onto the Dox-loaded LP disks (LP/Dox/AG nanohybrids) to prevent the burst release of the drug. The results demonstrate that the nanohybrids have a high encapsulation efficiency (80.8 ± 10.6%), are sensitive to pH and display a sustained drug release behavior. Cell culture experiments indicate that the LP/Dox/AG nanohybrids can be effectively internalized by CAL-72 cells (an osteosarcoma cell line), and exhibit a remarkable higher cytotoxicity to cancer cells than the free Dox. The merits of Laponite(®)/alginate nanohybrids, such as biocompatibility, high loading capacity and stimulus responsive release of cationic chemotherapeutic drugs, render them as excellent platforms for drug delivery., (Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Herein, we have studied the structural, optical and magnetic properties of Y 3-x Ce x Fe 5-y Er y O 12 (0.00 ≤ x ≤ 0.02), (0.00 ≤ y ≤ 0.06) compound synthesized via sol gel process. Structural characterization by X-ray diffraction (XRD) confirmed the YIG single phase formation, belong to the I a 3 ‾ d cubic centrosymmetric crystal structure. The lattice constant, lattice strain, dislocation density and average crystallite size variations were calculated and discussed in terms of the rare earth's dopant concentrations. Fourier Transform Infrared Spectroscopy (FTIR) analysis showed redshift for the Fe–O stretching modes as the dopant content increase, testifying the crystal lattice expansion. Raman spectra inspection corroborated the YIG single phase formation and shifts in the vibrational modes confirmed the Ce3+ and Er3+ rare earths inclusion in the sites occupied by Y3+ and Fe3+ cations, respectively. The coral-like of YIG nanoparticles were confirmed by scanning (SEM) and transmission (TEM) microscopies, whereas the existence of the elements Y, Fe, O, Ce and Er, were verified by Energy Dispersive Spectroscopy analysis (EDS). The optical band gap (E g) decreases, while Urbach energy (E u) increases varying the Er content. The result confirms the effect of Ce3+ and Er3+ addition on the optical properties of YIG, contributing to localized oxygen vacancy defects formation. Using a phenomenological model, it was shown that, the highest probability of Er3+ cations occupation corresponds to octahedral sites. For the Y 2.98 Ce 0.02 Fe 5-y Er y O 12 (0.00 ≤ y ≤ 0.06) compound, the theoretical saturation magnetization (M s) was calculated from the cation distribution obtained by the phenomenological model, resulting a slight increase with the Er content. The result agrees with the experimental M s measurements, although for y = 0.06 a discrepancy was detected, which can be attributed to the breaking of collinear array of magnetic moments due to high lattice distortions. [ABSTRACT FROM AUTHOR]

Abstract: Preferential oxidation of CO in excess hydrogen (PROX) was studied over Pt catalysts supported on multi-wall carbon nanotubes in the temperature range between room temperature and the temperature of the water–gas shift unit (∼473K). Experimental results show that the Pt/CNT catalyst exhibit a superior performance in terms of catalytic activity and selectivity towards CO2 formation compared to a Pt/AC catalyst prepared under similar conditions. Apparently, preferential CO oxidation in excess hydrogen over Pt nanoparticles supported on carbon materials is a particle size dependent reaction, i.e. larger particles exhibit higher activity and selectivity. In any case, the incorporation of oxygen functionalities to the carbon support becomes detrimental for the CO oxidation reaction independently of the carbon support used. Finally, CeO2 addition to the Pt/CNT catalyst further improves both catalytic activity and selectivity at low temperatures (CO conversion rate of 46% at 313K), the catalytic performance being superior to that exhibited by a traditional PROX catalyst such as Pt/CeO2. [Copyright &y& Elsevier]

The article presents a method for developing and characterizing nanocoated particles based on halloysite nanoclay particles. It explains that the halloysite nanoclay is nanocoated with titanium dioxide (TiO2) and nickel (Ni) using the polymeric precursor method to obtain the size of the particles. It also mentions the use of the synthesis in the preparation of nanocoatings proved to be an effective approach for fabricating novel composites based on TiO2 and Ni.

Accurate models for the light-scattering form factors of nanoparticles are of crucial importance to characterize the optical properties of the particles and to develop new photonic devices. Analytical or semi-empirical models exist for particles of spherical and cylindrical shape. The angular spectrum of scattering for particles of more complex shape is very complex and can only be obtained by numerical simulations. Moreover, the light scattering of metallic particles depends on many parameters as size, shape, optical constants, substrate and polarization of light. Experimental verification of the differential scattering cross-sections obtained from different calculation methods is always necessary. Measurements done on single nanoparticles are very sensitive to their local properties and the sinal-to-noise ratio may be very poor. Arrays of identical particles illuminated by a planes waves produce Bragg diffraction and the resultant patterns depend on the averaged values of the form factors of the particles. In order to test the validity of models for the scattering form factor, we present an experimental setup capable of measuring Bragg diffraction patterns of arrays of nanoparticles in the visible and near-infrared regions of the spectrum. The approach is similar to that of X-ray diffraction of crystals. [ABSTRACT FROM AUTHOR]

Daylight bactericidal cotton (100% cotton) textiles are presented and proposed for future hospital use. Amorphous titania (a-TiO2) and amorphous titania/chitosan complexes (a-TiO2//CS) were the selected bactericidal agents. Nanoparticles (NPs) and films were the two paths designed. Cotton textiles were impregnated with a-TiO2-based NPs or coated with a-TiO2 films. Industrial impregnation/coating will be implemented during the textile finishing treatments. A novel (room temperature and base-catalyzed), green (hydrothermal water as a catalyst), time-saving, and easy scale-up sol–gel process was established to produce the a-TiO2-based NPs. Amorphous-TiO2 films were produced by a dip-in (acid catalyzed) sol–gel solution. The daylight bactericidal performance (without the need of an external ultraviolet light source) of a-TiO2 NPs, films, and impregnated/coated textiles was proven according to AATCC 100 and ASTM E2149, using Staphylococcus aureus (ATCC®6538TM) as the bacterial indicator strain. A bacterial reduction of 99.97% was achieved for the a-TiO2 films and of 99.97% for the a-TiO2//CS NPs. Regarding the impregnated textiles, a bacterial reduction of 91.66% was achieved with a-TiO2//CS NPs, and 99.97% for cotton textiles coated with an a-TiO2 film. [ABSTRACT FROM AUTHOR]

Core–shell nanoparticles (NPs) formed by superparamagnetic iron oxide NPs (SPIONs) coated with inorganic or organically modified (ORMOSIL) sol gel silica exhibited promising properties as negative contrast agents (CA) for MRI applications. The potentiality of these new core–shell NPs as negative CA for MRI is demonstrated and quantified. The longitudinal and transverse relaxivities of NPs with three different coating compositions were studied at a 7 T magnetic field: silica (TEOS), (3-aminopropyl) triethoxysilane (APTES) and (3-glycidoxypropyl) methyldiethoxysilane (GPTMS). Clearly, it was found that the core–shell NPs efficiency as CA was strongly depend on the SPIONs coating. All the three core–shell NPs studied presented a very small effect on the longitudinal relaxation time but a pronounced one on the transverse relaxation time, leading to a very high transverse longitudinal relaxivities ratio, decisive for their efficiency as negative CA for MRI. The effect of the core–shell NPs on the MRI contrast enhancement is obtained and quantified in a set of MRI of agar phantoms obtained at 7 T magnetic field and with a imaging gradient field of 1.6 T/m. The core–shell NPs were tested in Zebra-fish (Danio rerio) animal model. Zebra-fish MRI were obtained with animals injected with the three core–shell NPs and the contrast enhancement validated. [ABSTRACT FROM AUTHOR]

Four silica-based porous nanosystems were synthesized with different organic substitutes and the molecular dynamics of water in these constrained environment was investigated. The nanosystems were silica and three organic modified silica nanoparticles (NP) with diameters in the range 80–300 nm with different porous dimensions, surface areas, and surface properties (e.g. hydrophilicity/hydrophobicity). Molecular dynamics was studied by pulsed field gradient NMR and by proton spin-lattice relaxation in a broad range of Larmor frequencies. A coherent analysis of the diffusion coefficients and spin-lattice relaxation data is presented taking into account a relaxation model associated to water molecular dynamics in close contact with NP surfaces. From our results it was possible to access the details of the water molecular movements in the nanosystems and to single out two water populations presenting distinct molecular dynamics. Characteristic distances for water rotations mediated by translational diffusion were estimated in consistency with the NP's dimensions and pores sizes obtained by TEM and BET experimental techniques. This knowledge has both fundamental and practical relevance since these NP have applications in nanomedicine, not only in therapy but also in diagnostic procedures and more recently in theranostic. [ABSTRACT FROM AUTHOR]

Abstract: Sol–gel processing was used to obtain monosized silica spheres of 270nm in diameter. Starting from these spheres, two different systems have been fabricated: (i) 3D Photonic Crystals by means of vertical deposition and evaporation-assisted sedimentation deposition methods; (ii) core-shell-like Er3+-activated silica spheres, where the core is the silica sphere and the shell is an Er2O3–SiO2 coating. Optical and spectroscopic assessment, as well as morphological and structural characterization of the systems, have been performed. [Copyright &y& Elsevier]