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Bio-Nanoparticles: Nanoscale Probes for Nanoscale Pathogens
Published in Klaus D. Sattler, st Century Nanoscience – A Handbook, 2020
Mohamed S. Draz, Yiwei Tang, Pengfei Zhang
Because polymers can be readily made in large quantities with precise control over their structural and functional properties, they are uniquely versatile precursors for nanoparticle synthesis. Polymer nanoparticles with well-defined colloidal and surface characteristics have attracted considerable recent interest as superior building blocks for nanostructures [168,169]. In the biosensing field, these nanoparticles are frequently used as nanoscale detection platforms. In particular, polymer nanoparticle systems rely on immunological recognition reactions between an antigen and an antibody or on the hybridization of two complementary DNA single strands. The high surface-to-volume ratio and good structural and morphological controllability of polymer nanoparticles make them ideal uniform platforms for virus sensing with enhanced immobilization and bioconjugation capacity [170]. The remarkable encapsulation capability of polymer materials is another prominent feature of polymer nanoparticles that is of great interest in biosensing applications. Polymer nanoparticle encapsulants are currently used to enhance the photonic and chemical stability of different fluorescent dyes and to enhance signal amplification by increasing the number of impregnated dye molecules [144,171]. A variety of polymer nanoparticles for detection purposes have been prepared. Among them, styrene/acrylic acid copolymer nanoparticles that were impregnated with ArcaDia BF 530 dye and that carried influenza B virus antibodies were used to improve influenza B virus detection performance in a fluorescent nanoparticle tracer-based approach [126]. Fluorescent carboxylated polystyrene nanoparticles (mean diameter, ˜92 nm; Dragon Green dye, excitation 480 nm, emission 520 nm) were also conjugated with a gp120 monoclonal antibody specific for HIV [124].
Marine Polysaccharides from Algae
Published in Se-Kwon Kim, Marine Biochemistry, 2023
Wen-Yu Lu, Hui-Jing Li, Yan-Chao Wu
At present, an outbreak of coronavirus called coronavirus disease 19 (COVID-19) has spread to > 210 countries, which is rare in acute infectious diseases in recent years, and posed a great threat to global public health (Liu et al., 2020). In addition, different types of infectious diseases caused by emerging or re-emerging viruses still pose a threat to human health. Therefore, great efforts need to be made in the research and development of antiviral drugs (Clercq, 2004). Despite the increasing number of antiviral drugs approved for clinical use, there are still problems in the treatment of infectious diseases due to the insufficient efficacy, high toxicity and high cost of current antiviral drugs (Scully and Samaranayake, 2016; Wang et al., 2012a). Therefore, there is an urgent need to develop new antiviral drugs as safe and effective alternative drugs or supplementary drugs. Some polysaccharides isolated from natural sources have been found to have antiviral and immunomodulatory activities and are suitable for the development of antiviral reagents (Ivanova et al., 1994). Although the life cycle of virus varies from species to species, there are six basic stages: attachment, penetration (also known as virus entry), uncoating, replication, assembly and release, which may become the target of inhibitory reagents. Marine polysaccharides, especially those from seaweed, have a unique structure, which can interfere with different stages of virus infection process and play a role in killing various viruses (Figure 4.2) (Bouhlal et al., 2011; Wang et al., 2012a), so they have attracted extensive attention (Damonte et al., 2004). A study conducted by Gerber and his colleagues in 1958 showed that polysaccharides from seaweed could inhibit mumps and influenza B virus (Gerber et al., 1958). Subsequently, the antiviral activities of other polysaccharides isolated from red algae against HSV and other viruses have been reported (Burkholder and Sharma, 1970; Deig et al., 1974; Ehresmann et al., 1977; Richards et al., 1978). In addition, the high polysaccharide content of seaweed provides rich resources for drug discovery and development.
Influenza virus RNA recovered from droplets and droplet nuclei emitted by adults in an acute care setting
Published in Journal of Occupational and Environmental Hygiene, 2019
Lily Yip, Mairead Finn, Andrea Granados, Karren Prost, Allison McGeer, Jonathan B. Gubbay, James Scott, Samira Mubareka
Four and nine patient participants were infected with influenza A(H3N2) and influenza A(H1N1) viruses respectively; three participants were infected with influenza B virus. There was insufficient MT sample for quantification from one patient with influenza A(H1N1) virus and one patient with influenza B virus. The mean and median log10 copies/mL for MT swab viral load in patients with available samples was 4.08 (SD 2.39) and 4.13 (IQR 2.93–6.08) respectively. In patients with positive influenza A virus swabs, the mean and median log10 copies/mL for MT swab viral load were 4.71 (SD 2.21) and 4.83 (IQR 2.98–6.12). In patients with swabs positive for influenza A(H1N1) virus, the mean and median MT swab viral loads were 4.79 (SD 2.37) and 4.83 (IQR 3.85–6.12) log10 copies/mL. The mean and median MT swab viral load in patients with influenza A(H3N2) were identical at 4.32 (SD 1.97, IQR 2.93–5.71) log10 copies/mL. Finally, the mean and median MT swab viral load in patients with positive influenza B virus swabs was 1.78 (SD 1.60) and 2.24 (IQR 0–3.11) log10 copies/mL. There was no statistically significant difference between MT viral load and age, sex, number of symptoms, pharyngitis, need for oxygen, vaccination status, smoking status, or chest X-ray changes. However, there was a statistically significant association between higher viral load and fever (p-value 0.032).