RESUMEN
Multifunctional nanocomposites have the potential to integrate sensing, diagnostic, and therapeutic functions into a single nanostructure. Herein, we synthesize Fe3O4@polydopamine core-shell nanocomposites (Fe3O4@PDA NCs) through an in situ self-polymerization method. Dopamine, a melanin-like mimic of mussel adhesive proteins, can self-polymerize to form surface-adherent polydopamine (PDA) films onto a wide range of materials including Fe3O4 nanoparticles used here. In such nanocomposites, PDA provides a number of advantages, such as near-infrared absorption, high fluorescence quenching efficiency, and a surface for further functionalization with biomolecules. We demonstrate the ability of the Fe3O4@PDA NCs to act as theranostic agents for intracellular mRNA detection and multimodal imaging-guided photothermal therapy. This work would stimulate interest in the use of PDA as a useful material to construct multifunctional nanocomposites for biomedical applications.
Asunto(s)
Indoles/química , Espacio Intracelular/metabolismo , Nanocompuestos/uso terapéutico , Nanopartículas/química , Polímeros/química , Radioterapia Guiada por Imagen/métodos , Humanos , Células MCF-7 , Imagen por Resonancia Magnética , Nanocompuestos/química , Técnicas Fotoacústicas , Polimerizacion , ARN Mensajero/genética , ARN Mensajero/metabolismo , Propiedades de Superficie , TemperaturaRESUMEN
Graphitic-phase carbon nitride (g-C3N4) nanosheets, the newly emerging two-dimensional (2D) layered nanomaterials, have been demonstrated to be promising bioimaging agents due to their high photoluminescence (PL) quantum yields, good biocompatibility and low toxicity. However, the therapeutic applications of g-C3N4 nanosheets have not been explored until now. In this study, we have proven for the first time that g-C3N4 nanosheets can be used as efficient photosensitizers for photodynamic tumor therapy and as pH-responsive nanocarriers for drug delivery. On one hand, as photosensitizers, g-C3N4 nanosheets are able to generate reactive oxygen species (ROS) and kill cancer cells efficiently under low-intensity light irradiation (20 mW cm-2). On the other hand, as nanocarriers, g-C3N4 nanosheets possess an ultrahigh drug-loading capacity owing to their high surface-to-volume ratio. More importantly, g-C3N4 nanosheets loaded with the anticancer drug doxorubicin (DOX) exhibit a pH-responsive release property which is beneficial for the delivery of DOX into cancer cells for chemotherapy. Furthermore, due to their high PL quantum yields, the fluorescent g-C3N4 nanosheets can enable visualization of the delivery. These findings demonstrated the potential of g-C3N4 nanosheets as low-toxic and biocompatible photosensitizers and pH-responsive drug nanocarriers for biomedical applications.