In vivo targeting of breast cancer with peptide functionalized GQDs/hMSN nanoplatform

Graphene quantum dots capped in hollow mesoporous silica nanoparticles (GQDs@hMSN) exhibited great potential in medical applications due to its good optical properties and high drug loading capacity. Compared with antibodies, peptide has a better affinity with target proteins. Herein, we demonstrated efficient targeting of triple-negative breast cancer with GQDs@hMSN, which was conjugated to a peptide ligand, F3 against nucleolin, to form GQDs@hMSN-F3. The core/shell GQDs@hMSN and GQDs@hMSN-F3 had diameters of 100 nm and 130 nm, respectively, based on transmission electron microscope (TEM) and dynamic laser scattering (DLS) measurement. Doxorubicin (DOX) was loaded onto GQDs@hMSN with a relatively high loading capacity. Systematic in vitro and in vivo studies were performed to investigate the targeting specificity and tissue distribution of GQDs@hMSN conjugates. Fluorescence microscopy examination and flow cytometry confirmed the targeting specificity of F3-attached GQDs@hMSN conjugates against cell nucleolin. A more potent uptake of GQDs@hMSN-F3 in MDA-MB-231 nodules was witnessed when compared with that of non-targeted GQDs@hMSN. Based on the findings from cellular targeting and in vivo fluorescence imaging, F3-attached GQDs@hMSN conjugates had the potential to serve as an image-guidable, tumor-selective cargo delivery nanoplatform.