Stabilization of Enzymes and Antibodies by Entrapment in Silica Biominerals

Entrapment of proteins leads to a number of advantages over free enzymes, such as stabilization, reusability and rapid reaction quenching by the removal of the enzyme-containing silica particles. They are highly relevant for applications in pharmaceuticals, industrial catalysis and from a biomedical point of view as biodegradable materials, biosensoring and screening devices.

The presented methodology utilizes the silica sol-gel technique, where entrapping of an enzyme is achieved randomly throughout the chemical formation of highly porous silica under physiological temperature and pH conditions, avoiding degradation during entrapment.
Using a polycationic polyamine to biomimetically form silica particles, controlling their morphologies with the reaction conditions, this study established a generalized entrapment protocol which suppresses protein specific effects.

For eGFP, the enzymes lipase, DHFR, β-galactosidase and a monoclonal antibody from mouse, entrapment led to temperature and chaotrope resistance. Furthermore, leaching of the proteins from the silica network could be induced and influenced by the morphology of the silica particles.