Biopolymeric nano/microspheres for selective and reversible adsorption of coronaviruses

Abstract

A novel biopolymeric material in the form of nano/microspheres was developed which was capable of adsorbing coronaviruses. The biopolymer was obtained by crosslinking of chitosan (CHIT) with genipin, a nontoxic compound of plant origin, in inverted emulsion and reacting the chitosan nano/microspheres obtained (CHIT-NS/MS) with glycidyltrimethyl-ammonium chloride (GTMAC). As a result the nano/microspheres of N-(2-hydroxypropyl)-3-trimethyl chitosan (HTCC-NS/MS) were obtained. HTCC-NS/MS were studied as the adsorbents of human coronavirus NL63 (HCoV-NL63), mouse hepatitis virus (MHV), and human coronavirus HCoV-OC43 particles in aqueous virus suspensions. By studying cytopathic effect (CPE) caused by these viruses and performing PCR analyses it was found HTCC-NS/MS strongly adsorb the particles of HCoV-NL63 virus, moderately adsorb mouse hepatitis virus (MHV) particles, but do not adsorb HCoV-OC43 coronavirus. The adsorption capacity of HTCC-NS/MS well correlated with the antiviral activity of soluble HTCC against a given virus. Importantly, it was shown that HCoV-NL63 particles could be desorbed from the HTCC-NS/MS surface with a salt solution of high ionic strength with retention of virus virulence. The obtained material may be applied for the removal of coronaviruses, purification and concentration of virus samples obtained from biological matrices and for purification of water from pathogenic coronaviruses.

Elucidating the microscopic and computational techniques to study the structure and pathology of SARS‐CoVs

“…A thin layer of flash-frozen sample is scanned using low energy electrons to get a 2D image of the sampleResolution: 3.4 Å 3D reconstruction of the HCoV-NL63 spike glycoprotein trimmer Walls et al, 2016;Baker, 2018 Atomic force microscope (AFM) AFM works by scanning the sample surface with a cantilever probe to which a LASER is pointed to measure surface variationsWorking modes-tapping mode, contact mode, and noncontact modeResolution: up to 30 nm Study the surface ultrastructure of SARS-CoVObserve the changes in the cell membrane during the release of a virion particleStudy the absorption of SARS-CoV viral particles in biopolymeric vesiclesTo study the structure and size of spike proteins which is present in the viral coat Yang, 2004;Lin et al, 2005;Eaton & West, 2010;Ng et al, 2004;Ciejka, Wolski, Nowakowska, Pyrc, & Szczubiałka, 2017;Lee et al, 2004 Fluorescence Lichtman & Conchello, 2005;Wang et al, 2008;Lu, Liu, & Tam, 2008;Manopo et al, 2005;Yuan et al, 2006;Yuan et al, 2005;Knoops et al, 2008 novel coronavirus that was successfully isolated from patients with SARS and identified them using TEM. The oropharyngeal sample from the patient was inoculated into Vero E6 mammalian cell lines (Ksiazek et al, 2003).…”

“…After the initial adsorption quantified using reverse transcriptase‐quantitative polymerase chain reaction (RT‐qPCR), AFM was used to confirm that the virus particles were successfully attached to the biopolymer. AFM images revealed densely distributed particles approximately 140 nm (diameter) on the surface which were absent in the case of untreated vesicles (Ciejka et al, 2017).…”

“…After the initial adsorption quantified using reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR), AFM was used to confirm that the virus particles were successfully attached to the biopolymer. AFM images revealed densely distributed particles approximately 140 nm (diameter) on the surface which were absent in the case of untreated vesicles(Ciejka et al, 2017).Hence, AFM studies on coronavirus have provided substantial evidence on the efficiency of the technique for imaging and identifying coronavirus specifically. The present pandemic 2019-nCoV exhibits characteristic features very similar to that of SARS-CoV, thus the findings of these studies can be extended for revealing more information and further improve our understanding of 2019-nCoV.4 | FLUORESCENCE MICROSCOPY OF SARS-COVS INFECTED CELLFluorescence microscopy is one of the mainstays for imaging various biological components and systems with high selectivity and specificity.…”

“…Scan size and the vertical scale on 3D figures: 2.5 × 2.5 μm and 100 nm (c); 2.0 × 2.0 μm and 50 nm (e), respectively. Source: This figure is adapted with permission fromCiejka et al (2017) [Color figure can be viewed at wileyonlinelibrary.com] Apart from studying how the virus enters the cell, immunofluorescence was also used to investigate antibody response to the SARS-CoV and use it as an efficient detection method. A 441-700 amino acid domain (called the protein C) representing the S1 of the spike protein was identified to be responsible for the immune response.Protein C domain expressing baculovirus was allowed to infect Spodoptera frugiperda (Sf-9) cells and the cells were fixed on coverslips (forming the antigen part of immunoassay).…”

Promising Nanostructured Materials against Enveloped Virus

“…Several new approaches based on nanostructured materials have recently been established. Studies have reported the use of gold and silver nanoparticles, magnetic nanoparticles, carbon and polymeric nanostructured materials (Cao et al 2002, Theek et al 2014, Ye et al 2015, de Souza et al 2016, Ciejka et al 2017. Gold nanoparticles are particularly exciting and commonly described to be appropriated for many applications.…”