Paper BI-ThM3
Importance of a In Depth Characterisation for the Design of Functional Gold Nanoparticles for Bioapplications

Thursday, October 25, 2018, 8:40 am, Room 101B

The design and fabrication of functionalized nanoparticles (NPs) are of great interest in biotechnology and biomedicine, especially for diagnostic and therapeutic applications.¹ However, at the moment the challenges related to the characterization of complex, multi-functional nanoparticles are still hampering the development of advanced bio-nano-materials.^2,3 In particular the interaction of NPs with protein has been the subject of many investigations in the last years and although important advances were made, several important issues (e.g. thermodynamic constants, protein structure changes) are still not completely understood.^4-6

In this work, the interaction of gold nanoparticles (AuNPs) with human serum albumin (HSA) has been investigated as model system. First a simple method to determine the structure and morphology of the AuNPs-HSA complexes will be described.⁷ Then the interaction of HSA with a model system consisting of AuNPs functionalized with two differentially-terminated poly(ethylene oxide) ligands, providing both “stealth” properties and protein-binding capabilities to the nanoparticles have been investigated. In particular, the purpose of this study was to: i) monitor and quantify the ratios of ligand molecules per nanoparticle; ii) determine the effect of coating density on non-specific protein adsorption; iii) to assess the number and structure of the covalently-bound proteins. For this a combination of techniques, including Centrifugal Liquid Sedimentation, Dynamic Light Scattering, Flow Field Flow Fractionation, Transmission Electron Microscopy, Circular Dichroism, XPS and ToF-SIMS have been employed to compare complementary outcomes from typical and orthogonal techniques used on nanoparticle characterisation.⁸