Enzyme-Loaded Magnetic Nanoparticles Suitable for Therapeutic and Industrial Applications

Members of a novel class of nano-sized transport vessels are composed of only two biocompatible components: an enzyme and magnetite nanoparticles.

Magnetically controlled enzymatic nanoparticles have received much attention for both therapeutic and industrial applications. Such materials usually comprise at least four components: the enzyme, magnetic nanoparticles, stabilizing components, and an organic or inorganic (or hybrid) matrix as a carrier. However, such combinations can affect the magnetic response and/or the enzymatic activity, and also face regulatory restrictions that prevent them from being used for intravenous administration.

To overcome these difficulties, investigators at ITMO University (St. Petersburg, Russia) and their colleagues at the Hebrew University of Jerusalem (Israel), and Cyril and Methodius University (Skopje, Macedonia) developed a new class of magnetically controlled nanoparticles made from enzymes that have been entrapped directly within magnetite particles.

These particles were made by adding enzymes directly to a magnetite hydrosol mixture. Magnetite particles surrounded the enzymes, and after drying, formed a firm porous structure from which the enzyme could not escape.

The investigators reported in the March 16, 2016, online edition of the journal Chemistry of Materials that they had used the direct entrapment approach to create a series of magnetic biocomposites with enzymes of therapeutic and industrial interest including carbonic anhydrase, ovalbumin, horseradish peroxidase, acid phosphatase, proteinase, and xylanase.

The activity of the entrapped enzymes was studied at different temperatures and concentrations, and it was found that they showed remarkable thermal stabilization induced by the magnetite matrix. For example, entrapped carbonic anhydrase catalyzed the decomposition of p-nitrophenylacetate at a temperature of 90 degrees Celsius, while the free enzyme completely lost activity and denaturized at 70 degrees Celsius.

"The nanocomposite is absolutely biocompatible and harmless for injection into the human body," said Dr. Andrey Drozdov, a research associate in the international laboratory of solution chemistry of advanced materials and technologies at ITMO University. "Separately, both magnetite and therapeutic enzymes have medical approval for intravenous injection. Therefore, to approve their joint use should not be difficult. The body already knows what to do with these substances and how to incorporate them into the process of metabolism. Using a magnetic field, the particles can be condensed on blood clots; moreover, such systems will work for quite a long time until the enzyme is completely oxidized."

Related Links:
ITMO University
Hebrew University of Jerusalem
Cyril and Methodius University