Saccharides are a class of compounds which are able to target proteins known as lectins on the surfaces of cells and are therefore useful molecules to target cells both in vitro and in vivo. In this work, a library of compounds has been synthesised which allows for the coating of iron oxide nanoparticles with these saccharides. The targeting ability of these saccharide-coated nanoparticles in vitro has been investigated and they have been found to specifically target cells such as 3T3 fibroblasts and HepG2 hepatocytes when coated with the appropriate saccharide. The cells which have been targeted with these nanoparticles have then become magnetically labelled and motion in response to an external magnetic field has been induced and measured. Iron oxide nanoparticles have been synthesised and extensively characterised, confirming that they are superparamagnetic. Superparamagnetic iron oxide nanoparticles have a wide range of uses in biomedicine; including drug delivery, magnetic fluid hyperthermia cancer treatment and magnetic resonance imaging of soft tissues inside the body. Finally, the magnetic relaxivities of coated magnetic nanoparticles have been measured using nuclear magnetic resonance spectroscopy and an increase in nanoparticle concentration has been found to increase the relaxation speed of surrounding water protons. Steps have been taken towards demonstrating that different coatings may cause different relaxation times. This has applications in determining the success of an enzymatic transformation carried out on one of the coatings, due to the relaxation time matching that of the intended product.