Novel Coating Technology for Immuno-Directing NP Coatings

The project will attempt to lay the groundwork for a new functional coating technology applicable to diagnostic and medical devices. Surface modifications will be carried out using self-assembled monolayer procedures on a new generation of functional, hydrophilic, non-fouling polymers.

The self-assembly approach is ideal for surface modifications of different (nano)materials. In particular, the nanoparticle’s surface modification allows the introduction of relevant functionalities for nano-vaccines, which can be safer to use and cut expenditures. This project will be structured into three
main phases.

1. Formulation of synthetic approaches with theoretical suitability assessment
2. Synthesis of multifunctional polymers and chemical characterization
3. Surface- and active group-functionalisation followed by generation and characterisation of functional coatings on flat and nanoparticle substrates.

The coating is planned to be synthesised in a two-step process

Firstly, alkyl oxazolines will be utilised to synthesise a polymer with non-fouling characteristics and the ability to further engage in bioconjugation reactions. For this purpose, azide functionalised oxazoline monomers will be synthesised and copolymerised with methyl oxazoline via a cationic ring opening polymerisation (CROP). This could lead to a new type of multi-azide oxazoline polymer.

The azide groups should enable highly specific strain promoted click chemistry to link other biomolecules to the oxazoline polymer chain, which could be used to specifically target cancer cells. Furthermore, the use of a functionalised initiator and terminator agent will allow the control of the polymer chain end-groups enabling a later combination with the PAcrAmTM technology of the SuSoS
AG. The polymer’s composition and size will be characterised with Nuclear Magnetic Resonance spectroscopy (NMR) and Gel Permeation Chromatography (GPC) whereas the presence of the azide groups will be investigated by Fourier Transformed Infrared spectroscopy (FTIR).

In the next step

The PAcrAmTM technology will be utilised to achieve a strong binding to several surfaces. This technology allows the grafting of the new oxazoline polymers and various functional groups on a multipurpose backbone. Depending on the aimed substrate’s surface functional groups can be chosen to enable the formation of a self-assembled monolayer while also providing a stable covalent binding to the surface.

The coating’s performance will be initially investigated on flat silicon surfaces. The binding strength, non-fouling ability and capability for specific bioconjugation reaction will be tested in different environments. The resulting change in adlayer thickness of the surfaces will be analysed with Variable Angle Spectroscopic Ellipsometry (VASE) and the surface composition will be characterised with X-Ray Photoelectron Spectroscopy (XPS).

Tobias Komsthoeft - Early Stage Researcher

Department of Mechanical and Process Engineering - SuSoS AG (Switzerland)