Nanoassembly and Multiscale Computation of Multifunctional Optical-Magnetic Nanoprobes for Tumor-Targeted Theranostics.

Gold nanorods, mesoporous silica, gadolinia, folic acid, and polyethylene glycol (PEG) derivatives have been investigated due to their own advantages in cancer theranostics. However, it remains a great challenge to assemble these components into a stable unity with the diverse and enhanced functionality for more potential applications. Herein, as inspired by the first-principles calculation, a highly stable and safe all-in-one nanoprobe is fabricated via a novel nanoassembly strategy. Multiscale calculations were performed to address the atomistic bonding of a nanoprobe, heat necrosis of a tumor adjacent to the vasculature, and thermal diffusion in a photothermal circumstance, respectively. The nanoprobe gains an 8-fold increase in magnetic resonance imaging (MRI) relaxivity compared to the clinical gadolinium diethylenetriaminepentaacetate, achieving a significant MRI signal in vivo. Conjugated with folate-PEG, the nanoprobe can be effectively absorbed by tumoral cells, obtaining a vivid two-photon cell imaging. A specific multisite scheme for photothermal therapy of a solid tumor is proposed to improve low photothermal efficacy caused by thermal diffusion in a large tumor, leading to the successful cure of the mice with xenograft tumor sized 10-12 mm. In vitro and in vivo toxicity, long-term excretion data, and the recovery of the treated mice demonstrate that the theranostic nanoprobe possesses good biocompatibility and metabolism efficacy.