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Precise timing and dosing of potent small-molecule drugs carries significant potential for effective pharmaceutical management of disorders that exhibit time-varying therapeutic windows such as epilepsy. This study demonstrates the use of alumina-coated nanoporous gold (np-Au) thin film electrodes for iontophoretic release of fluorescein as a small-molecule drug surrogate with picogram dosing and a few seconds temporal resolution. A custom microfluidic platform is engineered to trigger molecular release from an integrated np-Au chip and monitor the resulting time-varying fluorescein concentration. Following a systematic study of the influence of applied voltage on loading capacity and release kinetics, a LabVIEW-based closed-loop control interface is employed to demonstrate voltage-gated fluorescein release with preprogrammed arbitrary concentrations waveforms.

Surface-molecule interactions play an essential role in loading capacity and release kinetics in nanostructured materials with high surface area-to-volume ratio. Engineering the surfaces via immobilizing functional moieties is, therefore, a versatile means to enhance the performance of drug delivery platforms with nanostructured components. Nanoporous gold (np-Au), with its high effective surface area, well-established gold-thiol chemistry, and tunable pore morphology, is an emerging material not only for drug delivery applications but also as a model system to study the influence of physicochemical surface properties on molecular loading capacity and release kinetics. Here, we functionalize np-Au with self-assembled monolayers (SAMs) of alkanethiols with varying functional groups and chain lengths and use fluorescein (a small-molecule drug surrogate) to provide insight into the relationship between surface properties and molecular release. The results revealed that electrostatic interactions dominate the loading capacity for short SAMs (two carbons). As the SAM length increases, the loading capacity displays a nonmonotonic dependence on chain length, where medium-length SAMs (six carbons) allow for higher loading, plausibly due to denser SAM surface packing. For longer SAMs (11 carbons), the steric hindrance due to long chains crowds the pores, thereby hampering fluorescein access to the deeper pore layers, consequently reducing loading capacity.

In this investigation, thin films of YbFeO3, both in its pure form and doped with 10% Co, were fabricated on a p-Si substrate at 500 °C through the radio-frequency magnetron sputtering method. Examination via Scanning Electron Microscopy demonstrated a porous texture for the pure sample, contrasting with a smooth and crack-free surface post-Co doping. Analysis via X-ray photoelectron spectroscopy unveiled Yb’s 3 + oxidation state, alongside the presence of lattice oxygen, oxygen vacancies, and adsorbed oxygen evident in Gaussian fitting curves. Photoluminescence spectroscopy revealed an augmented emission intensity, likely attributed to increased defect initiation in the Co-doped specimen. Moreover, Raman spectroscopy was employed to identify vibration modes in the examined samples, demonstrating shifts in Raman peaks indicative of Co substitution and subsequent distortion in the crystal structure of YbFeO3. Electrical assessments were conducted at room temperature (300 K) under ambient conditions, employing voltage and frequency as variables. Capacitance–voltage measurements illustrated the emergence of an accumulation, with depletion and inversion regions manifesting at different frequencies based on the applied voltage, attributed to the YbFeO3 interfacial layer at the Al and p-Si interface. The conductance-voltage characteristics indicated that the structure exhibited maximum conductance in the accumulation region. Series resistance for these configurations was deduced from capacitance-conductance-voltage measurements, indicating a dependence on both bias voltage and frequency. The doping process led to a reduction in capacitance and series resistance, accompanied by an increase in conductance values. After obtaining corrected capacitance and conductance parameters, it became evident that series resistance significantly influences both parameters. Interface state density (Nss), determined through the Hill-Coleman relation demonstrated a decreasing trend with increasing frequency. The pure sample exhibited higher interface state density compared to the Co-doped sample at each frequency, highlighting that the 10% Co-doped YbFeO3 thin film enhances the quality of the metal–semiconductor interface properties compared to the pure contact. [ABSTRACT FROM AUTHOR]

The solid-state reaction technique was employed to synthesize compounds of YMnO3 (YMO) and YMn1-xCoxO3 (YMCO) with various Co doping levels (x = 0.01, 0.10, 0.20, and 0.40), where Co atoms partially substituted Mn sites. XRD studies confirmed the presence of two phases, YMO and Y0.98CoO3 (YCO), for doping ratios above x = 0.10. Additionally, an increase in crystalline size was observed with cobalt substitution. Surface characteristics of synthesized pellets were examined using scanning electron microscopy (SEM), revealing a less porous structure with cobalt doping. XPS analysis elucidated valence states, showing the presence of both Mn3+ and Mn4+, as well as Co2+ and Co3+. The x = 0.20 and 0.40 Co-doped samples exhibited lower grain and grain boundary energies compared to other samples, such as a decrease from 0.556 eV (undoped) to 0.195 eV (x = 0.20). Moreover, the dielectric constants of x = 0.20 and 0.40 cobalt-doped samples (around 320) significantly surpassed the undoped sample (around 22) at 106 Hz and 100 °C. The x = 0.20 cobalt-doped sample demonstrated the highest conductivity at 100 °C and 106 Hz (31 × 10–4 S/cm). FT-IR analysis provided insights into vibration and bending modes, and frequency- and temperature-dependent electrical features were investigated. It was observed that a single conduction model is insufficient to fully explain the conduction mechanism in these samples. [ABSTRACT FROM AUTHOR]

Michela Morano,1,* Sandra Wrobel,2,3,* Federica Fregnan,1 Ofra Ziv-Polat,4 Abraham Shahar,4 Andreas Ratzka,2 Claudia Grothe,2,3 Stefano Geuna,1 Kirsten Haastert-Talini2,3 1Department of Clinical and Biological Sciences, Università Degli Studi di Torino, Orbassano, Piemonte, Italy; 2Institute of Neuroanatomy, Hannover Medical School, Hannover, Lower-Saxony, Germany; 3Center for Systems Neuroscience (ZSN), Hannover, Lower-Saxony, Germany; 4NVR Research Ltd, Ness-Ziona, Israel *These authors contributed equally to this work and share first authorship Purpose: Innovative nerve conduits for peripheral nerve reconstruction are needed in order to specifically support peripheral nerve regeneration (PNR) whenever nerve autotransplantation is not an option. Specific support of PNR could be achieved by neurotrophic factor delivery within the nerve conduits via nanotechnology or stem cell engineering and transplantation.Methods: Here, we comparatively investigated the bioactivity of selected neurotrophic factors conjugated to iron oxide nanoparticles (np-NTFs) and of bone marrow-derived stem cells genetically engineered to overexpress those neurotrophic factors (NTF-BMSCs). The neurite outgrowth inductive activity was monitored in culture systems of adult and neonatal rat sensory dorsal root ganglion neurons as well as in the cell line from rat pheochromocytoma (PC-12) cell sympathetic culture model system.Results: We demonstrate that np-NTFs reliably support numeric neurite outgrowth in all utilized culture models. In some aspects, especially with regard to their long-term bioactivity, np-NTFs are even superior to free NTFs. Engineered NTF-BMSCs proved to be less effective in induction of sensory neurite outgrowth but demonstrated an increased bioactivity in the PC-12 cell culture system. In contrast, primary nontransfected BMSCs were as effective as np-NTFs in sensory neurite induction and demonstrated an impairment of neuronal differentiation in the PC-12 cell system.Conclusion: Our results evidence that nanotechnology as used in our setup is superior over stem cell engineering when it comes to in vitro models for PNR. Furthermore, np-NTFs can easily be suspended in regenerative hydrogel matrix and could be delivered that way to nerve conduits for future in vivo studies and medical application. Keywords: iron oxide nanoparticles, conjugated neurotrophic factors, bone marrow-derived mesenchymal stem cells, genetic cell engineering, neurite outgrowth

Context. Thyroid hormones have metabolic effects such as relationship between hypothyroidism and atherosclerosis. Objective. Evaluate the effects of hypothyroidism on Non-Alcoholic Fatty Liver Disease and atherosclerosis by using AIP, APRI score, FIB-4 indices. Material and Methods. 1370 patients with hypothyroidism who applied to the Endocrinology and Metabolism outpatient clinic between 01.01.2017-30.12.2021 were included the study. Pregnants, patients with a history of thyroid carcinoma, cardiovascular and liver diseases were excluded. TSH, fT4, Anti TPO, Anti TG, thrombocyte, ALT, AST, HDL, Triglyceride values of the cases were analyzed and atherogenic index of plasma (AIP), AST to Platelet Ratio Index (APRI) and Fibrosis-4 (FIB-4) indices were calculated. Results. 1170 (85.4%) of the cases were female. The age of those who had high risk of AIP was found to be higher than those with low and moderate risk (p=0.001; p=0.003; p<0.01). The ages of those who had low-risk FIB-4 Index were found to be lower than those with moderate risk and high risk (p=0.001; p=0.001; p<0.01). A positive relationship was detected between APRI and FIB-4 (r=0.681; p=0.001; p<0.01). AIP increased as TSH increased in hypothyroid patients. No significant correlations were detected between TSH, APRI, and the FIB-4 Index. No significant differences were detected between AIP, APRI, FIB-4, and thyroid autoantibodies. Conclusion. In hypothyroid patients, the AIP index increased with age and the increase in TSH. A strong relationship was detected between AIP and TSH. For this reason, we think that keeping TSH within the normal range with regular follow-ups and treatment in patients with hypothyroidism will reduce the risk of atherosclerosis. [ABSTRACT FROM AUTHOR]

Ofra Ziv-Polat1, Hadas Skaat1, Abraham Shahar2, Shlomo Margel11Department of Chemistry, Bar-Ilan Institute of Nanotechnology and Advanced Materials, Ramat-Gan 52900, Israel; 2NVR Research Ltd, Nes-Ziona 74031, IsraelAbstract: Novel tissue-engineered magnetic fibrin hydrogel scaffolds were prepared by the interaction of thrombin-conjugated iron oxide magnetic nanoparticles with fibrinogen. In addition, stabilization of basal fibroblast growth factor (bFGF) was achieved by the covalent and physical conjugation of the growth factor to the magnetic nanoparticles. Adult nasal olfactory mucosa (NOM) cells were seeded in the transparent fibrin scaffolds in the absence or presence of the free or conjugated bFGF-iron oxide nanoparticles. The conjugated bFGF enhanced significantly the growth and differentiation of the NOM cells in the fibrin scaffolds, compared to the same or even five times higher concentration of the free bFGF. In the presence of the bFGF-conjugated magnetic nanoparticles, the cultured NOM cells proliferated and formed a three-dimensional interconnected network composed mainly of tapered bipolar cells. The magnetic properties of these matrices are due to the integration of the thrombin- and bFGF-conjugated magnetic nanoparticles within the scaffolds. The magnetic properties of these scaffolds may be used in future work for various applications, such as magnetic resonance visualization of the scaffolds after implantation and reloading the scaffolds via magnetic forces with bioactive agents, eg, growth factors bound to the iron oxide magnetic nanoparticles.Keywords: thrombin, fibroblast growth factor, fibrin scaffold, iron oxide nanoparticles, tissue engineering, magnetism, bioactive nanoparticle

Among the multiferroics, yttrium manganite YMnO3 (YMO) is one of the most frequently studied magnetic ferroelectric oxides and has attracted a great deal of concern, thanks to its potential magnetoelectric features. Furthermore, it has been reported in the literature that yttrium manganite is a useful interface material in thin film devices. It has been documented that the dopant into Y and/or Mn site(s) plays significant roles on the electrical and magnetic properties of YMO. The YMn0.95Os0.05O3 (YMOO) oxide powders were prepared by the well-known solid-state reaction technique. The YMOO thin films were deposited on the p-Si (100) substrate via a radio frequency sputtering method with a thickness of approximately 62 nm. The oxidation states of the constituted elements have been investigated by using the X-ray photoelectron spectroscopy method. Furthermore, the surface features of the obtained thin film have been investigated using a scanning electron microscope measurement. The I–V measurements were performed in the 50–310 K range, and consequently, the Schottky diodelike reverse and forward bias I–V characteristics were observed in the Al/YMOO/p-Si heterojunction. Moreover, the ideality factor and the barrier height values were calculated as 0.77 and 2.23 at room temperature, respectively. [ABSTRACT FROM AUTHOR]

In this work, we carefully examined how Ir substitution into Fe sites can change the band of the LuFeO3 (LFO) material. LFO and Ir-doped LFO (LuFe1−xIrxO3 or LFIO for short, where x = 0.05 and 0.10) thin films were synthesized by utilizing magnetron sputtering techniques. The films were grown on silicon and indium tin oxide (ITO) substrates at 500 °C. The crystallographic orientation of the films was examined using X-ray diffraction (XRD) analysis. The crystallographic orientation of the thin films was examined using an X-ray diffractometer (XRD). For surface topography research, atomic force microscopy (AFM) was employed. To look for the recombination of photogenerated electron–hole pairs in the materials under investigation, photoluminescence (PL) spectroscopy was used. Raman spectroscopy is then utilized to gather data on crystal symmetry as well as disorders and defects in the oxide materials. It was demonstrated that the LFO band gap was altered from 2.35 to 2.72 eV by Ir substitution into Fe sites. Moreover, diffuse reflectance spectroscopy (DRS) was used to analyze conductivity, real and imaginary components of the dielectric constant, refractive index (n), extinction coefficient (k), and reflectance percentage. [ABSTRACT FROM AUTHOR]