Lactoferrin-Conjugated Nanoparticles as New Antivirals

Abstract

Lactoferrin is an iron-binding glycoprotein with multiple functions in the body. Its activity against a broad spectrum of both DNA and RNA viruses as well as the ability to modulate immune responses have made it of interest in the pharmaceutical and food industries. The mechanisms of its antiviral activity include direct binding to the viruses or its receptors or the upregulation of antiviral responses by the immune system. Recently, much effort has been devoted to the use of nanotechnology in the development of new antivirals. In this review, we focus on describing the antiviral mechanisms of lactoferrin and the possible use of nanotechnology to construct safe and effective new antiviral drugs.

Keywords: lactoferrin; nanoparticles; viruses.

Figure 1

Schematic figure describing the possible mechanisms of antiviral actions by lactoferrin and lactoferrin-modified nanoparticles. (A) Lactoferrin can be internalized via endocytosis; the binding of lactoferrin-modified nanoparticles requires confirmation. (B) Endocytosis of lactoferrin-modified nanoparticles requires confirmation. (C) Lactoferrin or lactoferrin-modified nanoparticles can block HSV-1/2 infection through binding to heparan sulphate moieties present in the glycoproteins of the cell surface/extracellular matrix. (D) Lactoferrin or lactoferrin-modified nanoparticles can block the binding of a virus by binding to the virus attachment ligands (VALs), thus blocking the attachment of the virus to its specific receptor(s).

Figure 2

Human epithelial MRC-5 cells (A) uninfected and (B) infected with HCoV-229e at 48 h post infection. (C) HCoV-229e titers in MRC-5 cells at 48 h, treated with 7.5 μg/mL of lactoferrin modified 5 nm AuNPs, 5 nm AgNPs or 30 nm AgNPs. Data represent means ± SEM (Own unpublished data).