Catalase Immobilization in Wrinkled Mesoporous Silica Nanoparticles
Abstract
Wrinkled mesoporous silica (WMS) has been shown to be a promising material for enzyme immobilization. The WMS possesses a unique wrinkled structure with conical shaped pores which radiate from the center to the surface of each particle leading to increased surface area and pore volume, better particle diffusion related to MCM-41 or related 1D MS materials. This study investigates enzyme loading in modified and nonmodified wrinkled silica nanoparticles (<50 nm) and their required properties for medical applications. Four types of samples were prepared by adsorption (WMS-CAT, A-WMS and DETA-WMS) and covalent binding (X-WMS) strategies. The highest enzyme loading 83% was obtained for X-WMS. DETA-WMS-CAT (80.8%) which showed a higher loading compared to A-WMS-CAT by enzyme adsorption. WMS-CAT showed 69.1% enzyme loading. Moreover, the longest storage time without deactivation and the least leaching was observed for the covalently immobilized X-WMS. Immobilized enzyme activity decreased as of X-WMS > DETA-WMS-CAT > A-WMS-CAT > WMS-CAT.