Aqueous-Based Silica Nanoparticles as Carriers for Catalytically Active Biomacromolecules

Silica nanoparticles have emerged as excellent hosting matrices for the immobilization of biomacromolecules due to good biocompatibility, chemical stability, low toxicity, and facile controllability. However, most of the traditional synthesis protocols for silica nanoparticles are based on hydrolysis and condensation of alkoxysilane in aqueous alcohol solutions in the presence of ammonia as a catalyst. Such conditions are too harsh for encapsulation of certain biomacromolecules. Herein, a one-step method for the synthesis of silica nanoparticles with encapsulated biomacromolecules in an aqueous solution without alcohol and catalyst is proposed. To demonstrate the feasibility of this strategy, six different kinds of biomacromolecules were encapsulated in the silica nanoparticles as model systems. The biomacromolecules encapsulated in the silica nanoparticles still preserved high bioactivity. The composites showed an excellent reusability and a good protective effect against various extreme environments. This study demonstrates how silica nanoparticles can be prepared for biomacromolecule immobilization without any alcohol and catalyst and thus offers improved encapsulation.