Enzyme–Iron Oxide Nanoassemblies: A Review of Immobilization and Biocatalytic Applications

Abstract

In the search for new biotechnological advances, increasing attention is currently being paid to the development of magnetic nanoplatforms loaded with enzymes, since, on the one hand, they can be recovered and reused, and on the other hand, they improve their catalytic activity and increase their stability, avoiding processes such as aggregation or autolysis. In this review, we evaluate a series of key parameters governing the enzyme–nanoparticle immobilization phenomena from a thermodynamic and kinetic point of view. We also focus on the use of magnetite nanoparticles (MNPs) as multifunctional vectors able to anchor enzymes, summarize the most relevant aspects of functionalization and immobilization and, finally, describe some recent and relevant applications of the enzyme–MNP hybrids as biocatalysts with especial emphasis on cancer therapy.

Recent Advances in Surface Functionalization of Magnetic Nanoparticles

“…Magnetic nanoplatforms are currently enhanced by loading with enzymes, affording easier recovery and reutilization as well as improved stability and catalytic activity [45]. Belleti et al synthesized hybrid Au/Fe 3 O 4 NPs of ~15 nm mean diameter using L-cysteine (Cys) as the polymer capping agent or dithiol-terminated polyethylene glycol (PEG(SH) 2 ), yielding NPs of type PEG(SH) 2 Au/F 3 O 4 NPs or CysAu/F 3 O 4 NPs [46].…”

Enhancing enzymatic activity with nanoparticle display – an updated compendium and engineering outlook

“…17–19 This is believed to arise as a result of the linkage chemistry decreasing the enzyme's overall freedom of movement, or by blocking or limiting access to its active site, along with the possibility of chemically modifying key residues needed for catalysis during attachment or association with the scaffold. 20–22 Another aspect to appreciate is that, in many cases, enzyme structures are somewhat metastable, which allows them to better sample their substrates, and any structural impediment to this can be functionally deleterious. 23–26…”