Conjugable, Antifouling, and Non-immunogenic Coatings for Gold Nanoparticles by Multivalent Grafting of Azide-Bearing Polyoxazoline Brushes

TL;DR

This paper introduces a new coating for gold nanoparticles that prevents protein adhesion and immune activation while allowing easy modification.

Contribution

A novel polyoxazoline-based coating for gold nanoparticles is developed, offering antifouling, non-immunogenic, and conjugable properties.

Findings

The coating provides excellent colloidal stability to gold nanoparticles.

The coating significantly reduces protein adsorption and immune cell activation.

The polymer coating allows for easy functionalization of gold nanoparticles.

Abstract

Inorganic nanoparticles (NP), particularly gold nanoparticles,
hold great promise for biomedical applications. However, one of the
major challenges in the implementation of therapeutic applications
based on inorganic nanoparticles is the individuation of appropriate
coatings, which are indeed responsible for stability, escape from
the immune system, and further functionalization. In this paper, we
explore the properties of the multi-azide-containing and highly nonfouling
polymer PAcrAm-g-(PMCA, NH2, ND), based on poly­(oxazoline)
derivatives grafted to a poly­(acrylamide), as a coating for gold nanoparticles
that can grant stability and easiness of derivatization and can prevent
nonspecific protein adhesion on gold nanoparticles (Au-NP). We found
that the addition of the polymer to citrate-stabilized gold nanoparticles
led to the formation of NP suspensions with excellent colloidal stability,
as confirmed by dynamic light scattering (DLS), ζ potential,
thermogravimetric analysis (TGA), and transmission electron microscopy
(TEM) investigations. In addition, the AuNP coating strongly decreases
the protein adsorption corona and does not activate dendritic cells
(DCs), showing low immunogenicity and potentially decreasing the NP
clearance by the mononuclear phagocyte system.

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