Entrapment of Enzymes within Sol–Gel-Derived Magnetite

Magnetically controlled enzymatic composites have received much attention for both therapeutic and industrial applications. Until now, such materials have been composed of at least four components: the enzyme, magnetic nanoparticles, their stabilizing components, and an organic or inorganic (or hybrid) matrix as a carrier. However, such compositions affect the magnetic response and the enzymatic activity, and also pose obstacles for intravenous administration, because of regulatory restrictions. Here, we present a methodology for the creation of magnetic bioactive nanocomposites composed of only two biocompatible components: an enzyme and magnetite nanoparticles. A series of magnetic biocomposites with a full set of therapeutical and industrial proteins (carbonic anhydrase, ovalbumin, horseradish peroxidase, acid phosphatase, proteinase, and xylanase) were successfully created by the direct entrapment of the proteins within a sol–gel magnetite matrix specially developed for these aims. The activity of the...