Synthesis and characterization of enzymatically active micrometer protein-capsules

Abstract

This work describes a general method for the encapsulation of enzymes with albumin as wall material and the enzyme catalase as prime example. Care was taken for the preparation of biochemically active sub-micrometer particles in order to prevent oxygen toxicity induced by artificial oxygen carriers of any type. In cell culture experiments, capsules containing catalase did not exhibit any harmful activities in the absence of peroxides. In the presence of hydrogen peroxide application of low and medium dosed capsules below 0.05 vol% (final concentration 0.001 vol%) even increased the cell damaging process. However, a higher dosage of capsules (>0.05 vol%) prevented completely cellular disruption induced by 5 mM hydrogen peroxide and decreased up to 90% of cellular damage at higher peroxide concentrations. These results demonstrated that encapsulated catalase was enzymatically active and the over-all activity of prepared catalase capsules was determined to be >1900 U mL⁻¹ vol%⁻¹.

Keywords:

• Catalase
• albumin: oxygen
• microencapsulation
• microcapsules
• enzymes
• peroxide

Acknowledgements

The authors thankfully express their gratitude to Mr. Bernd Walkenfort from the Electron Microscopy Unit of the Imaging Centre Essen (IMCES) for the performance of TEM imaging and Mrs. Susanne Eitner from the Institute of Physiological Chemistry of the University Hospital Essen for counting cells. Furthermore, authors express gratitude to Mr. Robin Meya from the Labor für Mikroanalytik of the University Duisburg-Essen for performing AAS. No external funding was provided for this work.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

All data used in this work is publicly available at https://www.doi.org/10.7303/syn23519345