Gold nanoparticles (AuNPs) provide excellent platforms for the development of colorimetric biosensors as they can be easily functionalised, displaying different colours depending on their size, shape and state of aggregation.

Neurodegenerative diseases (NDDs) are incurable and debilitating conditions that result in progressive degeneration and/or death of nerve cells in the central nervous system (CNS). Identification of viable therapeutic targets and new treatments for CNS disorders and in particular, for NDDs is a major challenge in the field of drug discovery. These difficulties can be attributed to the diversity of cells involved, extreme complexity of the neural circuits, the limited capacity for tissue regeneration, and our incomplete understanding of the underlying pathological processes. Drug discovery is a complex and multidisciplinary process. The screening attrition rate in current drug discovery protocols mean that only one viable drug may arise from millions of screened compounds resulting in the need to improve discovery technologies and protocols to address the multiple causes of attrition. This has identified the need to screen larger libraries where the use of efficient high-throughput screening (HTS) becomes key in the discovery process. HTS can investigate hundreds of thousands of compounds per day. However, if fewer compounds could be screened without compromising the probability of success, the cost and time would be largely reduced. To that end, recent advances in computer-aided design, in silico libraries, and molecular docking software combined with the upscaling of cell-based platforms have evolved to improve screening efficiency with higher predictability and clinical applicability. We review, here, the increasing role of HTS in contemporary drug discovery processes, in particular for NDDs, and evaluate the criteria underlying its successful application. We also discuss the requirement of HTS for novel NDD therapies and examine the major current challenges in validating new drug targets and developing new treatments for NDDs.

Asphalt deposits are distributed in many areas on earth and released natural asphalt of various chemical composition. Rheological properties of natural asphalt are usually improved by the addition of synthetic additives to convert it into a useful material for various industrial applications. In this work, the chemical composition of natural asphalt obtained from Al-Qayyarah/Iraq was analysed to detect its alluvial system using column chromatography and infrared spectrophotometer. Moreover, Natural asphalt was then treated by the addition of food waste product particularly eggshell powder (ESP) and commercially available low density polyethylene (LDP) in different ratios. The asphalt was separated into four main parts using column chromatography in a manner called SARA. The relative amounts of the paraffin compounds (28.58%), aromatic (29.34%), resins (19.88%) and asphalt (20.04%) determined the quality of asphalt system. The study showed that the aromatic and resin parts ratio were higher than the asphaltene part added to the negative value of penetration index. The results indicated that natural asphalt has a colloidal system of SOL type and its rheological properties were improved by the addition of both additives (ESP and LDP). This was confirmed by the application of various thermal and physical tests (softening, penetration, ductility, viscosity and water absorption tests).

In this report, we investigated three stabilization strategies of gold nanoparticles and their practical application for the visual detection of dipeptidyl peptidase IV (DPP-IV). Citrate-capped gold nanoparticles (Au NPs) are generally unstable in high-ionic-strength samples. Au NPs are easily tagged with various proteins and biomolecules rich in amino acids, leading to important biomedical applications including targeted drug delivery, cellular imaging, and biosensing. The investigated assays were based on different modes of stabilization, such as the incorporation of polyethylene glycol (PEG) groups, stabilizer peptide, and bifunctionalization. Although all approaches provided highly stable Au NP platforms demonstrated by zeta potential measurements and resistance to aggregation in a high-ionic-strength saline solution, we found that the Au NPs modified with a separate stabilizer ligand provided the highest stability and was the only platform that demonstrated sensitivity to the addition of DPP-IV, whilst PEGylated and peptide-stabilized Au NPs showed no significant response.

A review of plasmonic effects in NANOPHOTONIC WAVE-GUIDE; FLUORESCENCE LIFETIME; METAL NANOPARTICLES; LIGHT; NANOSTRUCTURES; NANOPLASMONICS; SCATTERING; EMISSION; ANTENNAS; MIRRORS