Uniform dendrimer-like mesoporous silica nanoparticles as a nano-adjuvant for foot-and-mouth disease virus-like particle vaccine†
Dendrimer-like mesoporous silica nanoparticles (MSNs) with large center-radial mesopores have been prepared for macromolecular protein loading and delivery. Due to their unique structure, the dendrimer-like MSNs with small and uniform particle size (156 ± 11 nm) exhibited large surface area (637 m2 g−1), high pore volume (3.08 cm3 g−1) and center-radial pores with an average size of ca. 22 nm, and were utilized as nano-carriers for bovine serum albumin (BSA) and foot-and-mouth disease virus-like particle (FMD VLP) protein loading and release in vitro. The degradation behavior of the MSNs has been investigated in simulated body fluid (SBF) solution. The cellular uptake of MSN-FITC was visualized by using laser scanning confocal microscopy. Furthermore, the biocompatibility of the MSNs was systematically evaluated by cell viability assay, hemolysis assay and histological examination. Finally, the adjuvant effect of MSNs was evaluated by immunization and challenge experiments of guinea pigs. Our results suggested that the dendrimer-like MSNs are excellent nano-carriers for large proteins with high molecular weight (large antigens) and have potential to be used as a safe and stable adjuvant for VLP-based vaccines and other subunit vaccines.