Gadolinium-hybridized mesoporous organosilica nanoparticles with high magnetic resonance imaging performance for targeted drug delivery

Magnetic resonance (MR) imaging techniques, which can provide images with excellent anatomical detail, are widely used in clinical diagnosis. However, the current clinical small molecule gadolinium (Gd) contrast agents have the defects of relatively low sensitivity and poor tumor-target specificity, preventing their adoption in biology and medicine. Herein, a facile synthetic strategy to fabricate gadolinium-hybridized mesoporous organosilica nanoparticles (MOSG) through a nanoprecipitation reaction, with the surface of nanoparticles grafted with the fluorescent dye isothiocyanate (FITC) and arginine-glycine-aspartic acid (RGD) for delivery of the antitumour drug doxorubicin hydrochloride (DOX), resulting in a high-performance nanotheranostic (RGD-MOSG-FITC/DOX) for targeted magnetic resonance imaging and chemotherapy of tumors. The prepared MOSG had a particle size of 60-80 nm and gadolinium elements were distributed in clusters that exhibited boosted longitudinal relaxivity. Routine blood tests and histopathology indicated good biocompatibility of MOSG. Furthermore, after being decorated with Arg-Gly-Asp peptide (RGD), RGD-MOSG-FITC demonstrated more preferable cellular uptake by HeLa cells (high expression of αⅤβ3) than MOSG without RGD grafting. Additionally, the tumor growth inhibition effect of RGD-MOSG-FITC/DOX was substantially more effective than that of the other groups. Therefore, this new delivery platform has good application potential in the field of tumor diagnosis and treatment.