Protein Immobilization on Heterogeneous (SiO₂/ZnO) Hollow-Mesoporous Nanocapsules Prepared by Imprinting CPMV: Drug Delivery and Possibility of Immunological Applications

Herein, we report the protein immobilization and stability studies of heterogeneous hollow mesoporous nanocapsules (Hhmn) for drug and protein delivery. The final results of the diverse precursors such as TEOS, TMOS, APTES, and zinc acetate on the formation of the hollow-mesoporous architecture of nanocapsules have been assimilated in this work. Three types of Hhmn of various sizes were synthesized. Among the three Hhmn, sample I and II nanocapsules were synthesized in the presence of zinc acetate and were identified to be amorphous in nature. Sample III nanocapsules synthesized in the absence of zinc acetate were analogous to the other two synthesized samples. Physiochemical analysis showed the formation of zinc phosphate in the silica matrix for the samples when synthesized with zinc acetate. Specific surface area analysis revealed that sample III has a relatively higher specific surface area. Further, the drug/dye loading and release capacity for the nanocapsules were studied using doxorubicin (DOX) and imatinib mesylate (IM) as model anticancerous drugs and rhodamine 6G as a model dye. Among the synthesized nanocapsules, sample III was shown to have a higher loading capacity for DOX (∼128 μg). From the release kinetic studies of drug/dye, sample III nanocapsules demonstrate a controlled release pattern of DOX and IM. Additionally, protein adsorption and stability studies of samples I and II revealed that the BSA adsorption capacity increases with the increase in the initial concentration of BSA. Furthermore, analysis of the release profiles of BSA and OVA leads to the conclusion that the heterogeneous nanocapsules show a higher loading capacity and sustained release pattern toward OVA. These properties of the nanocapsules highlight their path to immunological applications.