Microfluidic Synthesis of Multimode Au@CoFeB-Rg3 Nanomedicines and Their Cytotoxicity and Anti-Tumor Effects

Nanomedicines (i.e., Au@CoFeB-Rg3) were developed by conjugating multimode nanohybrids with active ingredients of natural herbs using Au@CoFeB nanoparticles as one model of multimode nanohybrids and the ginsenoside Rg3 as one model of active ingredients of natural herbs. Au@CoFeB nanoparticles were first synthesized using a temperature-programmed microfluidics process. Then, the surface of Au@CoFeB nanoparticles was modified via an amino-silane coupling agent of (3-aminopropyl) trimethoxysilane (APTMS) and then activated by the bifunctional amine-active cross-linker. They were thereafter conjugated to ginsenosides preactivated by APTMS by cross-linking the surface-activated nanohybrids, forming Au@CoFeB-Rg3 nanomedicines. Their multimode imaging functions were evaluated with the characterization of their magnetic and optical properties and the response to X-ray radiation. They can be optically detected via dark-field microscopy and can be imaged through X-ray computed tomography. They can also be used as magnetic resonance imaging contrast agents with excellent T2-weighted spin–echo imaging effects. Au@CoFeB-Rg3 nanomedicines exhibited distinct cytotoxicity and inhibitory effects on the proliferation of human hepatocellular carcinoma cells (HepG2/C3) and human chronic myeloid leukemia cells (K562) but were less toxic to 3T3 cells than other cells at concentrations more than 200 μg/mL. However, Au@CoFeB nanoparticles showed markedly lower cytotoxicity and inhibitory effects on the proliferation of these cell lines, particularly at concentrations <100 μg/mL, than Au@CoFeB-Rg3 nanomedicines. Clearly, there is a distinct synergistic effect between nanohybrids and Rg3. Additionally, Au@CoFeB nanohybrids showed almost no toxicity to Jurkat-CT cells at low concentrations (47 μg/mL), indicating that they may be used as multimode nanoprobes at a suitable concentration. These findings provide an efficient alternative for the synthesis of multifunctional antitumor nanomedicines based on multimode nanohybrids and active ingredients of natural resources.