Biopolymeric nano/microspheres for selective and reversible adsorption of coronaviruses

- The cationically modified chitosan-based nano/microspheres were obtained.
- Nano/microspheres were able to adsorb HCoV-NL63 and MHV from aqueous suspensions.
- Nano/microspheres did not adsorb HCoV-OC43 coronavirus.
- HCoV-NL63 particles are desorbed in a solution of increased ionic strength.
- The desorbed HCoV-NL63 particles are still infectious.

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.

Cationically-modified genipin cross-linked chitosan nano/microspheres were obtained which allow for reversible adsorption of coronaviral particles i.e. human coronavirus NL63 (HCoV-NL63) without losing their infectivity.280