Vault nanocapsule-mediated biomimetic silicification for efficient and robust immobilization of proteins in silica composites

Abstract

Silica materials are attractive protein supports for applications in catalysis, sensing, water purification, and protein therapy. However, current approaches for loading proteins in silica are limited by inefficient protein immobilization, unintended leaching, the requirement for large quantities of silica precipitants, and associated protein inactivation. Here, we report a highly efficient and robust strategy that directly synthesizes protein-embedded silica via a vault protein nanocapsule-templated biomimetic silicification route. The vaults serve as nucleation sites for the deposition and condensation of silica precursors to form vault/silica composites. Using vaults encapsulated with proteins as the templating agent enables direct embedding of proteins in silica composites with nearly 100% immobilization efficiency. The vaults also act as protective shelters to preserve high protein activity during silica condensation. With the dual advantages of vault templating and protection, the proteins immobilized via this strategy retained over 90% activity after 30 reuse cycles and exhibited high activity, minimal leaching, and improved stability, which would be valuable in a broad variety of medical, industrial, and environmental applications.