China 
Africa 
Explore chapters and articles related to this topic
Viruses as Nanomaterials
Published in Devarajan Thangadurai, Saher Islam, Charles Oluwaseun Adetunji, Viral and Antiviral Nanomaterials, 2022
Dushyant R. Dudhagara, Megha S. Gadhvi, Anjana K. Vala
Additionally, for the surface modification of CPMV, there has also been an interest in stuffing the internal structure with metals and other functional chemicals. Previously, icosahedral plant viruses like Cowpea chlorotic mottle virus (CCMV) were observed to be capable of encapsulating nanoparticles like those made up of vanadate, tungstate, titanium, and Prussian blue; this process occurs when the nucleic acid-free empty particles use in vitro assembly (Liepold et al. 2007; Klem et al. 2008). It is tough to get RNA-free capsids of CPMV that can be filled because they present in small numbers in infected plants. Utilizing cutting edge plant-expression technology, empty CPMV particles can be achieved in high quantity by expressing the coat protein precursor with the 24 K proteinase in plants; in this study, the proteinase split the coat protein precursors and permitted their self-assembly in empty capsids (Saunders et al. 2009; Montague et al. 2011). The pure empty CPMV particles (eCPMV) can be filled with any cargo, such as drugs, fluorescent dyes, or metals. Aljabali et al. (2010b) auspiciously filled the internal cavity of eCPMV with cobalt or iron ions earlier to reduction with sodium borohydride, and that action led to the development of a cobalt metal or iron oxide core. This perspective has not changed the structure of the particles or affected their ability to be functionalized on their exterior side. The capacity to encapsulate materials within eCPMV and modify the exterior surface increases the range of how that CPMV can be customized for a certain nanotechnological intention.
2+) and Their Signaling in Alzheimer's and Other Neurological-Related Disorders
Published in Suvardhan Kanchi, Rajasekhar Chokkareddy, Mashallah Rezakazemi, Smart Nanodevices for Point-of-Care Applications, 2022
Neha Chauhan, Smita Jain, Kanika Verma, Swapnil Sharma, Raghuraj Chouhan, Veera Sadhu
In AD, there are sequential cleavages of amyloid protein precursor by β, and γ-secretase produces amyloid β-peptide. It gives rise to oligomers inside the PM and generates pores that provide passage of Ca2+ to the cytoplasm. Phosphatidylserine (PtdS) binding facilitates the amyloid-β interaction with the PM. Mitochondrial impairment, i.e., reduction in ATP, might stimulate PtdS flipping from the inner portion of the PM to the surface of the cell. This results due to Ca2+ influx or release from the ER or mitochondria which results in activation of PLSCR1 (phospholipids scramblase). Interaction between amyloid-β with Fe2+ and Cu+ produces OH and H2O2 causes the peroxidation of membrane lipid which produces toxic aldehydes impairing the functioning of Na+ and Ca2+pumps, resulting in membrane depolarization. After that both NMDAR and VDCC open and flux high toxic amounts Ca2+ into the cytoplasm. Amyloid-β will also affect mitochondria either directly or indirectly by increasing [Ca2+] and oxidative stress which results in increased production of free radical generates ATP and Ca2+ overloads. Amyloidogenic processing produces AICD (APP intracellular cytoplasmic/c-terminal domain), the smaller cleavage product by γ-secretase which finally translocate to the nucleus. Thus, it alters the transcription of genes in a variety of ways, due to which it will lead to Ca2+ dysregulation (Figure 25.2C).
Optical Nanosensors
Published in Vinod Kumar Khanna, Nanosensors, 2021
Rev is a vital HIV-1 regulatory protein within the env gene (a gene that encodes a protein precursor for the envelope proteins, found in the retroviral genome) of HIV-1 RNA genome (the entirety of the organism’s hereditary information). The HIV-1 regulatory protein Rev is expressed early in the virus life cycle and thus may be an important target for the immune control of HIV-1 infection and for effective vaccines. Zhang and Johnson (2006) used QDs instead of organic dyes to develop a sensor to determine the dissociation constant (Kd) between Rev and RRE (the Rev response element is a region in the RNA molecule of the HIV env gene), based on FRET. The QDs (emission ~605 nm) were functionalized with streptavidin, a tetrameric protein that binds very tightly to the small molecule, biotin (C10H16N2O3S). The streptavidin-coated QDs functioned as both a nano-scaffold and a FRET donor in this QD-based NS. Streptavidin was bound to biotin-labeled RRE. Nano-scaffolding is a medical process used to regrow tissue and bone, including limbs and organs.
One-pot, aqueous synthesis of multifunctional biogenic Ag NPs for efficient 4-NP reduction, Hg2+ detection, bactericidal, and antioxidant activities
Published in Inorganic and Nano-Metal Chemistry, 2021
Dasari Ayodhya, Guttena Veerabhadram
The green synthesized PDS extract stabilized Ag NPs exhibited effective antibacterial activity against all the Gram-positive and Gram-negative bacteria such as E. coli, S. aureus, P. aeruginosa, and B. subtilis. The antibacterial activities of PDS extract stabilized Ag NPs (20 µL/mL) were evaluated by measuring the diameter of the inhibition zone and the results are shown in Figure 4. The results indicate that there was a zone of growth of inhibition for all the disks tested against Ag NPs. The strains that were susceptible to the Ag NPs showed the diameter of the inhibition zone greater than 10 mm, which is comparable to the standard ampicillin control. The negative control, 20 µL of 1 mM of AgNO3 showed negligible zone of inhibition with all the tested organisms. Generally, the bactericidal activity of Ag NPs is due to the attachment between the Ag NPs and the cell wall of the bacteria.[51] Consequently, this attachment leads to the build-up of envelope protein precursor that causes protein denaturation, proton motivation force loss, and eventual cell death.[52] The size of the NPs plays an important role in its antibacterial activity; hence the smaller NPs are more easily taken up by the cell membranes of the bacteria. This is because particles with small size give a greater surface area for interaction with microorganisms and thus release Ag+ by oxidation. This accelerates the generation of reactive oxidative species that causes more damage to the cellular constitution and in the end, results in cell death.[53,54] Thus, the small size of the PDS extract stabilized Ag NPs must have allowed them to have free entry into the cell and damage them and exhibited remarkable antibacterial activity.
Nonspecific interaction between plasminogen and modified magnetic iron oxide nanoparticles
Published in Preparative Biochemistry & Biotechnology, 2021
Anna V. Bychkova, Elizaveta A. Kostanova, Eleonora Z. Sadykova, Marina I. Biryukova, Aytan G. Muradova, Alexander I. Sharapaev, Evgeniy N. Degtyarev, Alexander L. Kovarski
In the last decade, the instrumental quantitative methods for analyzing the blood of patients in acute pathological conditions or chronic diseases has been intensively developed in connection with quick procedures to extract protein markers (analytes) from the blood for their further quantitative instrumental analysis. Plasminogen, a protein precursor of plasmin, which plays a major role in the fibrinolytic system, is one of such markers.