Leveraging immunoliposomes as nanocarriers against SARS-CoV-2 and its emerging variants

Abstract

The global COVID-19 pandemic arising from SARS-CoV-2 has impacted many lives, gaining interest worldwide ever since it was first identified in December 2019. Till 2023, 752 million cumulative cases and 6.8 million deaths were documented globally. COVID-19 has been rapidly evolving, affecting virus transmissibility and properties and contributing to increased disease severity. The Omicron is the most circulating variant of concern. Although success in its treatment has indicated progress in tackling the virus, limitations in delivering the current antiviral agents in battling emerging variants remain remarkable. With the latest advancements in nanotechnology for controlling infectious diseases, liposomes have the potential to counteract SARS-CoV-2 because of their ability to employ different targeting strategies, incorporating monoclonal antibodies for the active and passive targeting of infected patients. This review will present a concise summary of the possible strategies for utilizing immunoliposomes to improve current treatment against the occurrence of SARS-CoV-2 and its variants.

Keywords: COVID-19; Coronavirus; Immunoliposomes; Liposomes; SARS-CoV-2.

Graphical abstract

Fig. 1

(A) Conjugation of monoclonal antibodies or their fragments to liposomes. (B) Nanocarriers with a focus on liposomes as a smart delivery system. a) Liposomes with various targeting strategies b) Standard liposomes where the phospholipids can be changed to obtain different charges. c) Multifunctional liposomes. d) PEGylated liposomes are formed by incorporating PEG to provide stealth properties, subsequently improving the circulation time. (Created with BioRender.com).

Fig. 2

Activation of a carboxylic acid in a liposome followed by coupling reaction with lysine residue in a protein. (Created with BioRender.com).

Fig. 3

Schematic representation of EDC/NHS activated liposomes. Adapted from .

Fig. 4

Synthesis of GA-N and DSPE-PEG-GA.

Fig. 5

Schematic diagram of steps for testing of CNT-FET biosensor and SARS-CoV-2 S1. Adapted from . PBASE: 1-pyrene butanoic acid succinimidyl-ester.

Fig. 6

Schematic diagram of surface engineered liposomes with site-specific antibodies. The lipid bilayer, consisting of cholesterol and two different phospholipids-2-dioleoyl-sn‑glycero-3-phosphoethanolamine (DOPE) and l-α-phosphatidylcholine (egg PC) was formed with a molar ratio of 1:1:1. Effective coupling of CD11c to the DBCO-functionalized liposomes was efficiently performed through the SPAAC approach, and the conjugation was further confirmed by a binding assay based on flow cytometry using fluorescent labeled secondary antibodies. Adapted from .

Fig. 7

Schematic illustration of the production of immunoliposome by using carbodiimide coupling reaction. (Created with BioRender.com).