Pepetide Dendron-Functionalized Mesoporous Silica Nanoparticle-Based Nanohybrid: Biocompatibility and Its Potential as Imaging Probe

In this study, we designed and fabricated a nanohybrid of mesoporous silica nanoparticles (MSNs) functionalized with peptide dendrons and evaluated its potential biocompatibility. The nanohybrid was prepared by combining azido-MSNs with alkynyl peptide dendrons via click chemistry to improve graft ratio. By modifying the azido-MSNs through the addition of the alkynyl peptide dendrons, we amplified and broadened the scope of their applications. After labeling with Cy5.5 dye, the nanohybrid was characterized by transmission electron microscopy (TEM), thermogravimetric analysis (TGA), nitrogen adsorption-desorption isotherms, dynamic light scattering (DLS) and zeta potential. The resulting nanohybrid showed high mono-dispersivity with a spherical diameter of 60 nm, negative surface charge and aqueous environment stability. Finally, a systematic assessment was conducted to evaluate the biocompatibility of the MSN-dendron-Cy5.5-based nanohybrid, both in vitro and in vivo. Cytotoxicity measurements, body weight shifts, histological analysis, and routine blood tests with mice demonstrated that the nanohybrid had good biocompatibility. Hemocompatibility evaluations demonstrated that the nanohybrid had improved blood safety compared to bare MSNs. Healthy nude mice were used to analyze the in vivo optical fluorescence images. Ex vivo fluorescence images of the major organs were studied to further evaluate the in vivo biodistribution of the nanohybrid, with results suggesting that the MSN-dendron-Cy5.5-based nanohybrid provided promise in biomedical applications. Overall, we provided a preliminary but important research piece on the safety and efficiency of MSN-dendron-Cy5.5-based nanohybrid as an in vivo functional vehicle used in diagnosis and therapy.