Covalent Immobilization of Carbonic Anhydrase into Mesoporous Silica Nanoparticles for Drug Delivery Applications

Abstract

The overall goal of this research project is to develop a novel nanoparticle drug delivery system through the covalent immobilization of a bio‐therapeutic agent into mesoporous silica nanoparticles (MSN). We activated the MSN through its functionalization with thiol groups. Carbonic anhydrase (CA) was modified with a cross‐linker, which will allow its immobilization into the carrier. Characterization of the activated surface was performed utilizing XPS, DLS, and SEM. We determined the level of modification for the enzyme and studied the impact of the modification on its residual activity and tertiary structure. The results demonstrated that the MSN were functionalized successfully and that the activation process decreased the size of the particles, but did not impact their morphology. Residual enzyme activity after modification was determined to be 76% and 50% for a 6% and 19% degree of modification, respectively. The CD spectra revealed that not significant changes in the tertiary structure occurred due to enzyme activation. Subsequently, the enzyme was covalently immobilized into the MSN and experiments related to establish the maximum amount of enzyme that can be immobilized into the thiol‐functionalized MSN were conducted. The release profile of the immobilized enzyme at physiological conditions was determined. Future experiments will include characterization of the released enzyme from the MSN.