Electrochemical Sensor for Tryptophan Determination Based on Trimetallic-CuZnCo-Nanoparticle-Modified Electrodes.

The superior properties of electrodeposited trimetallic CuZnCo nanoparticles, arising from the synergistic effect of combining the unique features of metallic components, were confirmed using voltametric measurements. The surface morphology and structure of the as-prepared electrocatalysts were determined using scanning electron microscopy, energy-dispersive X-ray, and X-ray photoelectron spectroscopy techniques. Here, the trimetallic CuZnCo nanoparticles were synthesized as a powerful redox probe and highly efficient signal amplifier for the electrochemical oxidation of tryptophan. Differential pulse voltammetry studies showed a linear relationship with a tryptophan concentration of 5-230 µM, and the low detection limit was identified at 1.1 µM with a sensitivity of 0.1831 µA µM-1 cm-2.

SI-ATRP Decoration of Magnetic Nanoparticles with PHEMA and Post-Polymerization Modification with Folic Acid for Tumor Cells' Specific Targeting.

Targeted nanocarriers could reach new levels of drug delivery, bringing new tools for personalized medicine. It is known that cancer cells overexpress folate receptors on the cell surface compared to healthy cells, which could be used to create new nanocarriers with specific targeting moiety. In addition, magnetic nanoparticles can be guided under the influence of an external magnetic field in different areas of the body, allowing their precise localization. The main purpose of this paper was to decorate the surface of magnetic nanoparticles with poly(2-hydroxyethyl methacrylate) (PHEMA) by surface-initiated atomic transfer radical polymerization (SI-ATRP) followed by covalent bonding of folic acid to side groups of the polymer to create a high specificity magnetic nanocarrier with increased internalization capacity in tumor cells. The biocompatibility of the nanocarriers was demonstrated by testing them on the NHDF cell line and folate-dependent internalization capacity was tested on three tumor cell lines: MCF-7, HeLa and HepG2. It has also been shown that a higher concentration of folic acid covalently bound to the polymer leads to a higher internalization in tumor cells compared to healthy cells. Last but not least, magnetic resonance imaging was used to highlight the magnetic properties of the functionalized nanoparticles obtained.

Raman Spectroscopy, X-ray Diffraction, and Scanning Electron Microscopy as Noninvasive Methods for Microstructural Alterations in Psoriatic Nails.

Psoriasis is a chronic inflammatory disease associated with immune system dysfunction that can affect nails, with a negative impact on patient life quality. Usually, nail psoriasis is associated with skin psoriasis and is therefore relatively simple to diagnose. However, up to 10% of nail psoriasis occurs isolated and may be difficult to diagnose by means of current methods (nail biopsy, dermoscopy, video dermoscopy, capillaroscopy, ultrasound of the nails, etc.). Since the nail is a complex biological tissue, mainly composes of hard α-keratins, the structural and morphological techniques can be used to analyze the human fingernails. The aim of this study was to corroborate the information obtained using Raman spectroscopy with those obtained by scanning electron microscopy (SEM) and X-ray diffractometry and to assess the potential of these techniques as non-invasive dermatologic diagnostic tools and an alternative to current methods.

Sequencing batch biosorption of micropollutants from aqueous effluents by rapeseed waste: Experimental assessment and statistical modelling.

Rapeseed (RS) waste was used for sequential biosorption from aqueous solutions of two target micropollutants: lead ions and Reactive blue 19 (Rb19) dye, through an integrated approach, combining experimental assessment and statistical modeling. In both cases of sequential biosorption, a pseudo-second order kinetic model fitted the biosorption data well. Intraparticle diffusion proved to be the rate-limiting step in the sequential retention of both micropollutants. A selective desorption of metal ions and anionic dye at pH 2.5 and 10.5, respectively was observed. The quadratic models generated by response surface methodology (RSM) adequately described the sequential biosorption process and the desorption process, respectively. XPS and FTIR analysis indicated the mechanisms involved in the retention of target pollutants.

Hyperpolarised NMR to follow water proton transport through membrane channels via exchange with biomolecules.

Water uptake in vesicles and the subsequent exchange between water protons and amide -NH protons in amino acids can be followed by a new, highly sensitive, type of magnetic resonance spectroscopy: dynamic nuclear polarisation (DNP)-enhanced NMR in the liquid state. Water hydrogen atoms are detected prior to and after their transfer to molecular sites in peptides and proteins featuring highly-accessible proton-exchangeable groups, as is the case for the -NH groups of intrinsically disordered proteins. The detected rates for amide proton-water proton exchange can be modulated by membrane-crossing rates, when a membrane channel is interposed. We hyperpolarised water proton spins via dynamic nuclear polarisation followed by sample dissolution (d-DNP) and transferred the created polarisation to -NH groups with high solvent accessibility in an intrinsically disordered protein domain. This domain is the membrane anchor of c-Src kinase, whose activity controls cell proliferation. The hindrance of effective water proton transfer rate constants observed in free solvent when a membrane-crossing step is involved is discussed. This study aims to assess the feasibility of recently-introduced hyperpolarised (DNP-enhanced) NMR to assess water membrane crossing dynamics.

Superparamagnetic Composites Based on Ionic Resin Beads/CaCO3 /Magnetite.

The preparation of superparamagnetic composites obtained by CaCO3 mineralization from supersaturate aqueous solutions is presented. The preparation was conducted in the presence of oleic acid stabilized magnetite nanoparticles as a water-based magnetic fluid and insoluble templates as gel-like cross-linked polymeric beads. The presence of the magnetic particles in the composites provides a facile way for external manipulation using a permanent magnet, thus allowing the separation and extraction of magnetically modified materials. Two ion exchangers based on divinylbenzene/ethyl acrylate/acrylonitrile cross-linked copolymer-a cation ion exchanger (CIE) and an amphoteric ion exchanger (AIE)-were used, as well as different addition orders of magnetite and CaCO3 crystals growth precursors. The morphology of the composites was investigated by SEM, the polymorphs content by X-ray diffraction, and the thermal stability by thermogravimetric analysis. Polymer, CaCO3 , and magnetite in the composite particles were shown to be present by energy dispersive X-ray (EDX), XPS, and TEM. The sorption capacity for CuII ions was tested, as compared to samples prepared without magnetite.

Dynamic constitutional frameworks (DCFs) as nanovectors for cellular delivery of DNA.

We introduce Dynamic Constitutional Frameworks (DCFs), macromolecular structures that efficiently bind and transfect double stranded DNA. DCFs are easily synthesizable adaptive 3D networks consisting of core connection centres reversibly linked via labile imine bonds both to linear polyethyleneglycol (PEG, ∼1500 Da) and to branched polyethyleneimine (bPEI, ∼800 Da). DCFs bind linear and plasmid DNA, forming particulate polyplexes of 40-200 nm in diameter. The polyplexes are stable during gel electrophoresis, well tolerated by cells in culture, and exhibit significant transfection activity. We show that an optimal balance of PEG and bPEI components is important for building DCFs that are non-toxic and exhibit good cellular transfection activity. Our study demonstrates the versatility and effectiveness of DCFs as promising new vectors for DNA delivery.

Radiolabeled multi-layered coated gold nanoparticles as potential biocompatible PET/SPECT tracers.

The demand for tailored, disease-adapted, and easily accessible radiopharmaceuticals is one of the most persistent challenges in nuclear imaging precision medicine. The aim of this work was to develop two multimodal radiotracers applicable for both SPECT and PET techniques, which consist of a gold nanoparticle core, a shell involved in radioisotope entrapment, peripherally placed targeting molecules, and biocompatibilizing polymeric sequences. Shell decoration with glucosamine units located in sterically hindered molecular environments is expected to result in nanoparticle accumulation in high-glucose-consuming areas. Gold cores were synthesized using the Turkevich method, followed by citrate substitution with linear PEG α,ω-functionalized with thiol and amine groups. The free amine groups facilitated the binding of branched polyethyleneimine through an epoxy ring-opening reaction by using PEG α,ω-diglycidyl ether as a linker. Afterwards, the glucose-PEG-epoxy prepolymer has been grafted onto the surface of AuPEG-PEI conjugates. Finally, the AuPEG-PEI-GA conjugates were radiolabeled with 99mTc or 68Ga. Instant thin-layer chromatography was used to evaluate the radiolabeling yield. The biocompatibility of non-labeled and 99mTc or 68Ga labeled nanoparticles was assessed on normal fibroblasts. The 99mTc complexes remained stable for over 22 hours, while the 68Ga containing ones revealed a slight decrease in stability after 1 hour.

Photoluminescence of Argan-Waste-Derived Carbon Nanodots Embedded in Polymer Matrices.

In this work, photoluminescent (PL) carbon nano dots (CNDs) prepared from argan waste were embedded in highly optical transparent poly(styrene-co-acrylonitrile) (PSA) and cyclo-olefin copolymer (COC) matrices, which were further processed into thin films. In the first step, the luminescent CNDs were prepared through thermal processing of fine-groundargan waste, followed, in the second step, by direct dispersion in the polymer solutions, obtained by solving PSA and COC in selected solvents. These two polymer matrices were selected due to their high optical transparency, resilience to various environmental factors, and ability to be processed as quality thin films. The structural configuration of the CNDs was investigated through EDX, XPS, and FTIR, while DLS, HR-SEM, and STEM were used for their morphology investigation. The luminescence of the prepared CNDs and resulted polymer nanocomposites was thoroughly investigated through steady-state, absolute PLQY, and lifetime fluorescence. The quality of the resulted CND-polymer nanocomposite thin films was evaluated through AFM. The prepared highly luminescent thin films with a PL conversion efficiency of 30% are intended to be applied as outer photonic conversion layers on solar PV cells for increasing their conversion efficiency through valorization of the UV component of the solar radiation.

Theoretical study on ß-cyclodextrin inclusion complexes with propiconazole and protonated propiconazole.

The synthesis of the ß-cyclodextrin/propiconazole nitrate inclusion complex and the advantages of the encapsulation of this drug were recently reported, but the experimental data only partially revealed the structure of the supramolecular complex due to the limitations in understanding the intermolecular association mechanism. The present work describes the equilibrium molecular geometries of ß-cyclodextrin/propiconazole and ß-cyclodextrin/protonated propiconazole, established by the AM1 and PM3 semi-empirical methods. The affinity between different parts of the guest molecule and the cyclodextrin cavity was studied considering that propiconazole possesses three residues able to be included into the host cavity through primary or secondary hydroxyl rims. The results have revealed that the most stable complex is formed when the azole residue of the propiconazole enters the cavity of the cyclodextrin through the narrow hydroxyl's rim.

Targeted Cancer Therapy via pH-Functionalized Nanoparticles: A Scoping Review of Methods and Outcomes.

(1) Background: In recent years, several studies have described various and heterogenous methods to sensitize nanoparticles (NPs) to pH changes; therefore, in this current scoping review, we aimed to map current protocols for pH functionalization of NPs and analyze the outcomes of drug-loaded pH-functionalized NPs (pH-NPs) when delivered in vivo in tumoral tissue. (2) Methods: A systematic search of the PubMed database was performed for all published studies relating to in vivo models of anti-tumor drug delivery via pH-responsive NPs. Data on the type of NPs, the pH sensitization method, the in vivo model, the tumor cell line, the type and name of drug for targeted therapy, the type of in vivo imaging, and the method of delivery and outcomes were extracted in a separate database. (3) Results: One hundred and twenty eligible manuscripts were included. Interestingly, 45.8% of studies (n = 55) used polymers to construct nanoparticles, while others used other types, i.e., mesoporous silica (n = 15), metal (n = 8), lipids (n = 12), etc. The mean acidic pH value used in the current literature is 5.7. When exposed to in vitro acidic environment, without exception, pH-NPs released drugs inversely proportional to the pH value. pH-NPs showed an increase in tumor regression compared to controls, suggesting better targeted drug release. (4) Conclusions: pH-NPs were shown to improve drug delivery and enhance antitumoral effects in various experimental malignant cell lines.

Intense Blue Photo Emissive Carbon Dots Prepared through Pyrolytic Processing of Ligno-Cellulosic Wastes.

In this work, Carbon Dots with intense blue photo-luminescent emission were prepared through a pyrolytic processing of forestry ligno-cellulosic waste. The preparation path is simple and straightforward, mainly consisting of drying and fine grinding of the ligno-cellulosic waste followed by thermal exposure and dispersion in water. The prepared Carbon Dots presented characteristic excitation wavelength dependent emission peaks ranging within 438-473 nm and a remarkable 28% quantum yield achieved at 350 nm excitation wavelength. Morpho-structural investigations of the prepared Carbon Dots were performed through EDX, FT-IR, Raman, DLS, XRD, and HR-SEM while absolute PLQY, steady state, and lifetime fluorescence were used to highlight their luminescence properties. Due to the wide availability of this type of ligno-cellulosic waste, an easy processing procedure achieved photo-luminescent properties, and the prepared Carbon Dots could be an interesting approach for various applications ranging from sensors, contrast agents for biology investigations, to photonic conversion mediums in various optoelectronic devices. Additionally, their biocompatibility and waste valorization in new materials might be equally good arguments in their favor, bringing a truly "green" approach.

Microporous Polymelamine Framework Functionalized with Re(I) Tricarbonyl Complexes for CO2 Absorption and Reduction.

A mixture of polymeric complexes based on the reaction between Re(CO)5Cl and the porous polymeric network coming from the coupling of melamine and benzene-1,3,5-tricarboxaldehyde was obtained and characterized by FTIR, NMR, SEM, XPS, ICP, XRD, and cyclic voltammetry (CV). The formed rhenium-based porous hybrid material reveals a noticeable capability of CO2 absorption. The gas absorption amount measured at 295 K was close to 44 cm3/g at 1 atm. An interesting catalytic activity for CO2 reduction reaction (CO2RR) is observed, resulting in a turn over-number (TON) close to 6.3 under 80 min of test at -1.8 V vs. Ag/AgCl in a TBAPF6 0.1 M ACN solution. A possible use as filler in membranes or columns can be envisaged.

All-polysaccharide hydrogels for drug delivery applications: Tunable chitosan beads surfaces via physical or chemical interactions, using oxidized pullulan.

The present work reports a versatile approach to the manufacture of chitosan beads with tunable pore size and targeted properties. To achieve this, the as prepared chitosan beads were allowed to interact with aqueous solutions of two types of oxidized pullulan derivatives. Depending on the functional groups present on the pullulan structure after oxidation, i.e., carboxyl or aldehyde, covalent or physical hybrid hydrogels could be prepared. The attachment of oxidized pullulan onto chitosan structure was checked by FTIR, RMN, XPS and thermal analysis. The morphology of the hybrid structures was evaluated by using Scanning Electron Microscopy (SEM). After structural evaluations, all the prepared hydrogels were characterized by means of dynamic vapor sorption and swelling degree studies, exhibiting a Case-II swelling mechanism. Drug model compounds, such as ibuprofen, bacitracin and neomycin were used for drug loading and release assays, proving high drug loading capacity and tunable release behavior. Drug loaded beads exhibited antibacterial activity and hemocompatibility experiments indicated no coagulation phenomena.

Manganese-Doped N-Hydroxyphthalimide-Derived Carbon Dots-Theranostics Applications in Experimental Breast Cancer Models.

BACKGROUND: Theranostics, a novel concept in medicine, is based on the use of an agent for simultaneous diagnosis and treatment. Nanomaterials provide promising novel approaches to theranostics. Carbon Dots have been shown to exhibit anti-tumoral properties in various cancer models. The aim of the present study is to develop gadolinium, Fe3+, and Mn2+-doped N-hydroxyphthalimide-derived Carbon Dots. The resulted doped Carbon Dots should preserve the anti-tumoral properties while gaining magnetic resonance imaging properties. METHODS: Normal and cancer cell lines have been treated with doped Carbon Dots, and the cell viability has been measured. The doped Carbon Dots that exhibited the most prominent anti-tumoral effect accompanied by the lowest toxicity have been further in vivo tested. Magnetic resonance imaging evaluates both in vitro and in vivo the possibility of using doped Carbon Dots as a contrast agent. RESULTS: According to the results obtained from both the in vitro and in vivo experimental models used in our study, Mn2+-doped Carbon Dots (Mn-CDs-NHF) exhibit anti-tumoral properties, do not significantly impair the cell viability of normal cells, and reduce lung metastasis and the volume of mammary primary tumors while allowing magnetic resonance imaging. CONCLUSIONS: Our findings prove that Mn-CDs-NHF can be used as theranostics agents in pre-clinical models.

Synthesis and Characterization of New Ferrite-Lignin Hybrids.

The paper presents the synthesis and characterization of new cobalt ferrite-lignin hybrids. The hybrids were obtained through the combustion of cobalt nitrate and ferric nitrate, two kinds of lignin being used as combustion agents. The temperatures of calcination were 500 °C and 900 °C, respectively. The hybrids were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and X-ray photoelectron spectroscopy (XPS). The magnetic properties were also assessed by vibrating sample magnetometer system (VSM). This facile synthesis method made it possible to obtain cobalt ferrite-lignin hybrids with a spinel structure. Their particle sizes and crystallite sizes have increased with an increment in the calcination temperature. A different occupancy of cations at octahedral and tetrahedral sites also occurred upon the increase in temperature. The hybrids comprising organic lignin presented the best magnetic properties.

Hair EDX Analysis-A Promising Tool for Micronutrient Status Evaluation of Patients with IBD?

Micronutrient deficiencies can arise in various conditions, including inflammatory bowel diseases (IBD), and diagnosing these deficiencies can be challenging in the absence of specific clinical signs. The aim of this study was to evaluate the status of various trace elements hair concentration in IBD patients compared to a healthy control group and to identify potential correlations between the micronutrient status and relevant parameters related to disease activity. The concentrations of iron, magnesium, calcium, zinc, copper, manganese, selenium and sulfur in the hair of 37 IBD patients with prior diagnosed IBD (12 Crohn's disease and 25 ulcerative colitis) and 31 healthy controls were evaluated by Energy Dispersive X-Ray spectroscopy (EDX). Significant differences in hair concentration profile of studied trace elements were identified for IBD patients compared to healthy controls. A significantly decreased hair concentration of iron, magnesium, calcium and selenium and a significantly increased sulfur hair concentration were observed in IBD patients at the time of evaluation. A decreased hair calcium concentration (r = -0.772, p = 0.003) and an increased sulfur concentration (r = 0.585, p = 0.046) were significantly correlated with disease activity. Conclusion: Hair mineral and trace elements evaluation may contribute to a proper evaluation of their status in IBD patients and improving the management of nutritional status of IBD patients.

NHF-derived carbon dots: prevalidation approach in breast cancer treatment.

Metastatic breast cancer dominates the female cancer-related mortality. Tumour-associated molecules represents a crucial for early disease detection and identification of novel therapeutic targets. Nanomaterial technologies provide promising novel approaches to disease diagnostics and therapeutics. In the present study we extend the investigations of antitumoral properties of Carbon Dots prepared from N-hydroxyphthalimide (CD-NHF) precursor. We evaluate the effect of CD-NHF on tumour cell migration and invasion in vitro and their impact on tumour progression using an in vivo model. Furthermore, we investigate the molecular mechanisms involved in CD-NHF antitumour effects. In vivo mammary tumours were induced in Balb/c female mice by injecting 4T1 cells into the mammary fat pad. Conditional treatment with CD-NHF significantly impair both migration and invasion of metastatic breast cancer cells. The presence of CD-NHF within the 3D cell cultures strongly inhibited the malignant phenotype of MDA-MB-231, 4T1 and MCF-7 cells in 3D culture, resulting in culture colonies lacking invasive projections and reduction of mammospheres formation. Importantly, breast tumour growth and metastasis dissemination was significantly reduced upon CD-NHF treatments in a syngeneic mouse model and is associated with down-regulation of Ki67 and HSP90 expression. CD-NHF nanostructures provide exciting perspective for improving treatment outcome in breast cancer.

Effect of TAT-DOX-PEG irradiated gold nanoparticles conjugates on human osteosarcoma cells.

The paper aims to investigate the cytotoxic effect on tumor cells of irradiated AuNPs in green light and subsequently functionalized with HS-PEG-NH2. The toxicity level of gold conjugates after their functionalization with DOX and TAT peptide was also evaluated. The AuNPs were prepared using the modified Turkevich method and exposed to visible light at a wavelength of 520 nm prior their PEGylation. The optical properties were analyzed by UV-vis spectroscopy, the surface modification was investigated using FTIR and XPS spectroscopies and their sizes and morphologies were evaluated by TEM and DLS techniques. DOX and TAT peptide were linked to the surface of PEGylated AuNPs by reacting their amino groups with glycidyloxypropyl of PEGylated DOX or TAT conjugates under mild conditions at room temperature and in the presence of ethanol as catalyst. The conjugates containing DOX or DOX and TAT have been characterized by fluorescence and FTIR techniques. The changes of electrochemical features were observed using cyclic voltammetry, suggesting a better stability of irradiated nanoparticles. By mass spectrometry it was confirmed that the compounds of interest were obtained. The cell viability test showed that irradiated and non-irradiated nanoparticles coated with PEG are not toxic in normal cells. Tumor cell viability analysis showed that the PEGylated nanoparticles modified with DOX and TAT peptide were more effective than pristine DOX, indicating cytotoxicity up to 10% higher than non-irradiated ones.

New insights into human hair: SAXS, SEM, TEM and EDX for Alopecia Areata investigations.

BACKGROUND: Alopecia areata (AA) is a T-cell-mediated autoimmune disease and affects up to 2% of the population. There is a need for a more profound and rigorous understanding of the structure and composition of human hair affected by AA in order to manage this disease. The aim of this article is to understand the effects of AA on the structure and composition of human hair. METHODS: Several physico-chemical investigation methods, such as Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy-Dispersive X-ray Spectroscopy (EDX), and microbeam Small Angle X-ray Scattering (SAXS), were used to analyze human hair samples obtained from healthy donors and patients with AA. RESULTS: SEM revealed more severe hair surface defects for the white regrown hair (W-AA) samples. TEM showed the presence of air-like vesicles located in the endocuticle of regrown hair. Analysis of ultrathin sections of W-AA showed the existence of empty vesicles and smaller melanin granules compared to control samples. SAXS demonstrated that unaffected hair of patients with AA (B-AA) and W-AA melanin aggregates are different in their sizes and shapes compared to the control samples. EDX data showed that W-AA elemental composition was significantly different from the other sample groups. Our study showcases promising non-invasive techniques for a better and more accurate understanding of changes in the internal structure and composition of hair affected by AA.