Ian Wark Research Institute
ARC Special Research Centre
ARC Special Research Centre
Research Area: Bio-interfacial science, colloid science
Degree: Honours
Supervisor: A/Prof Benjamin Thierry
Description: Magnetic nanoparticles have attracted much interest in many biotechnology areas such as Magnetic Resonance Imaging (MRI), magnetic targeted drug delivery and cell sorting. These applications rely on one hand on the possibility to target/capture the magnetic nanoparticles using a magnetic field and on the other hand on specific immunological interaction between the nanoparticles and cells/tissues/serum proteins. Such specific interaction can be achieved through the covalent immobilization of antibodies on the surface of the particles. The immunological antibody/antigen interaction can then be used to control the bio-interfacial events at the nanoparticles surface in biological environment. The key points towards more efficient therapeutic/diagnostic strategies are to avoid loss of activity of the antibody during the covalent immobilization and to prevent non-specific events through the use of a non-fouling interlayer. This interlayer, covalently immobilized on the surface of the particles, should prevent non-specific protein adsorption and allow the covalent coupling of fully functional antibody. The focus of this project is to optimize the immobilization of a model antibody onto magnetic nanoparticles using polyethylene glycol (PEG) and dextran.
Experimental Approach: Magnetic nanoparticles prepared following the innovative procedure of M. Niederberger et al., and stabilized with dopamine will be used in this project. These monocrystalline nanoparticles have a size distribution between 15 and 40 nm (Figure 1). Carboxymethyl dextran and PEG will be covalently attached onto the particles using carbodiimide chemistry. Characterization/optimization will be conducted using FTIR, XPS spectroscopy, dynamic light scattering, transmission electron microscopy (TEM). The immobilized dextran and PEG interlayers will then be further reacted with a model antibody which a special emphasis on the preservation of its biological activity.
Figure
1:
Magnetic nanoparticles stabilized with dopamine hydrochloride
