Fe₃O₄-PEI-RITC Magnetic Nanoparticles with Imaging and Gene Transfer Capability: Development of a Tool for Neural Cell Transplantation Therapies

Magnetic nanoparticles (5–100 nm in diameter) offer the science community a new dimension in many key areas of research, notably nano-medicine. However, use as catalyst support material (including enzyme immobilization) has largely been overlooked despite the benefits of a facile catalyst separation post-reaction with reuse through the application of an external magnetic field. This is largely due to the high cost associated with magnetic nanoparticle synthesis in addition to enzyme operating costs. This can, however, be compensated for by effective catalyst recycling in the production of high value chemicals, particularly chiral drugs and their intermediates, circumventing laborious multi-stage separation and purification procedures in conventional synthesis. Indeed, enzymes (such as lipase) on magnetic carriers have shown prolonged activity in organic solvents, even after recycling, when compared with free enzymes. Further developments can be directed at multi-functional magnetic nanoparticles with the creation of a reactant-specific micro-environment to facilitate multi-stepped reactions. The potential of enzyme-magnetic nanoparticle hybrids is discussed and applications in the synthesis of fine chemicals, including precursors for drugs, are identified.