Modeling HIV-1 Infection in CNS via Infected Monocytes Using Immunocompetent Brain Organoids.

The development of 3D-organoid models has revolutionized the way diseases are studied. Recently, our brain organoid model has been shown to recapitulate in in vitro the human brain cytoarchitecture originally encountered in HIV-1 neuropathogenesis, allowing downstream applications. Infected monocytes, macrophages, and microglia are critically important immune cells for infection and dissemination of HIV-1 throughout brain during acute and chronic phase of the disease. Once in the brain parenchyma, long-lived infected monocytes/macrophages along with resident microglia contribute to the establishment of CNS latency in people with HIV (PWH). Hence, it is important to better understand how HIV-1 enters and establishes infection and latency in CNS to further develop cure strategies. Here we detailed an accessible protocol to incorporate monocytes (infected and/or labeled) as a model of transmigration of peripheral monocytes into brain organoids that can be applied to characterize HIV-1 neuroinvasion and virus dissemination.

Phosphate-driven H2O2 decomposition on DNA-bound bio-inspired activated carbon-based sensing platform for biological and food samples.

Hydrogen peroxide (H2O2) is one of the most important reactive oxygen species (ROS). Increased endogenous H2O2 levels indicate oxidative stress and could be a potential marker of many diseases, including Alzheimer's, cardiovascular diseases, and diabetes. However, consuming H2O2-incorporated food has adverse effects on humans and is a serious health concern. We used salmon testes DNA with bio-inspired activated carbon (AC) as an electrocatalyst for developing a novel H2O2 sensor. The phosphate backbone of DNA contains negatively charged oxygen groups that specifically attract protons from H2O2 reduction. We observed a linearity range of 0.01-250.0 µM in the H2O2 reduction peak current with a detection limit of 2.5 and 45.7 nM for chronoamperometric and differential pulse voltammetric studies. High biocompatibility of the sensor was achieved by the DNA, facilitating endogenous H2O2 detection. Moreover, this non-enzymatic sensor could also help in the rapid screening of H2O2-contaminated foods.

Trending Technology of Glucose Monitoring during COVID-19 Pandemic: Challenges in Personalized Healthcare.

The COVID-19 pandemic has continued to spread rapidly, and patients with diabetes are at risk of experiencing rapid progression and poor prognosis for appropriate treatment. Continuous glucose monitoring (CGM), which includes accurately tracking fluctuations in glucose levels without raising the risk of coronavirus exposure, becomes an important strategy for the self-management of diabetes during this pandemic, efficiently contributing to the diabetes care and the fight against COVID-19. Despite being less accurate than direct blood glucose monitoring, wearable noninvasive systems can encourage patient adherence by guaranteeing reliable results through high correlation between blood glucose levels and glucose concentrations in various other biofluids. This review highlights the trending technologies of glucose sensors during the ongoing COVID-19 pandemic (2019-2020) that have been developed to make a significant contribution to effective management of diabetes and prevention of coronavirus spread, from off-body systems to wearable on-body CGM devices, including nanostructure and sensor performance in various biofluids. The advantages and disadvantages of various human biofluids for use in glucose sensors are also discussed. Furthermore, the challenges faced by wearable CGM sensors with respect to personalized healthcare during and after the pandemic are deliberated to emphasize the potential future directions of CGM devices for diabetes management.

Novel SeS2-loaded Co MOF with Au@PANI comprised electroanalytical molecularly imprinted polymer-based disposable sensor for patulin mycotoxin.

An SeS2-loaded Co MOF and Au@PANI nanocomposite comprising the base matrix of the electrode was developed with electropolymerized molecularly imprinted polymer (MIP) consisting of p-aminobenzoic acid (PABA) and patulin (PT) to detect PT molecules based on the PT imprinted cavities. SeS2@Co MOF and Au@PANI were synthesized using hydrothermal synthesis and interfacial polymerization strategies, respectively. A suitable functional monomer to fabricate the MIP platform was selected using the density functional theory (DFT/M06-2X method). Higher electrochemical active surface area (0.985 cm2 which is 6.99 times higher than the bare SPE) and a lower charge transfer resistance (Rct = 27.8 Ω) at the MIP/Au@PANI/SeS2@Co MOF electrode was achieved based on the higher number of adsorptive sites and enhanced conductivity (electron transfer rate constant (ks = 3.24 × 10-3 s-1) of the sensing platform. The fabricated MIP sensor performance was studied in 10 mM PBS (pH = 6.4), where an improved detection limit (0.66 pM) for PT and a broad logarithmic linear dynamic range (0.001-100 nM) were both observed. The sensor possessed higher selectivity (Imprinting factor = 15.4 for PT), excellent reusability (%RSD of 10 cycles = 2.49%), high storage stability (6.7% lost after 35 days), and robust reproducibility (%RSD = 3.22%) The as-prepared MIP-based PT sensor was applied to detect PT in a real-time apple juice sample (10% diluted with PBS) with a recovery % ranging from 94.5 to 106.4%. The proposed sensor possesses great advantages in terms of cost-effectiveness, providing a simple detection strategy for long-term storage stability, and reversible cycle measurements.

Differential Pulse Voltammetric Electrochemical Sensor for the Detection of Etidronic Acid in Pharmaceutical Samples by Using rGO-Ag@SiO2/Au PCB.

An rGO-Ag@SiO2 nanocomposite-based electrochemical sensor was developed to detect etidronic acid (EA) using the differential pulse voltammetric (DPV) technique. Rapid self-assembly of the rGO-Ag@SiO2 nanocomposite was accomplished through probe sonication. The developed rGO-Ag@SiO2 nanocomposite was used as an electrochemical sensing platform by drop-casting on a gold (Au) printed circuit board (PCB). Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) confirmed the enhanced electrochemical active surface area (ECASA) and low charge transfer resistance (Rct) of the rGO-Ag@SiO2/Au PCB. The accelerated electron transfer and the high number of active sites on the rGO-Ag@SiO2/Au PCB resulted in the electrochemical detection of EA through the DPV technique with a limit of detection (LOD) of 0.68 µM and a linear range of 2.0-200.0 µM. The constructed DPV sensor exhibited high selectivity toward EA, high reproducibility in terms of different Au PCBs, excellent repeatability, and long-term stability in storage at room temperature (25 °C). The real-time application of the rGO-Ag@SiO2/Au PCB for EA detection was investigated using EA-based pharmaceutical samples. Recovery percentages between 96.2% and 102.9% were obtained. The developed DPV sensor based on an rGO-Ag@SiO2/Au PCB could be used to detect other electrochemically active species following optimization under certain conditions.

Ultrasound assisted photocatalytic degradation of diclofenac in an aqueous environment.

Diclofenac (DF) is an anti-inflammatory drug found in aqueous environments as a pollutant due to its widespread use. The sonolytic, photocatalytic and sonophotocatalytic degradation of DF using three photocatalysts (TiO(2), ZnO and Fe-ZnO) were studied. The degradation of DF followed first-order like kinetics. The sonophotocatalytic degradation using TiO(2) under UV-vis radiation showed a slight synergistic enhancement in the degradation of the parent compound, whereas a detrimental effect was observed for the mineralization process. In the case of Fe-ZnO, both degradation and mineralization showed near additive effects. A number of degradation products were identified.

Visible light assisted photocatalytic degradation of acid red 88 using Au-ZnO nanophotocatalysts.

Photocatalytic degradation of acid red 88 (AR88) in aqueous suspensions of Au-ZnO nanoparticles under visible light illumination was studied in order to evaluate various effects of the Au deposition on the ZnO photocatalytic activity. Au-ZnO nanoparticles were prepared by deposition precipitation method and characterized by different analytical techniques. In Au-ZnO system, all gold nanoparticles were tethered on the surface of zinc oxide particles. This enhanced the AR88 adsorption on the Au-ZnO surface and acted as electron traps which is the main reason for significant enhancement in the AR88 photodegradation under visible light illumination compared to ZnO alone. Further in the presence of electron acceptors complete decolorization of the dye was observed, which might be due to immediate trapping of the photogenerated electrons by electron acceptors.