| Nanocarriers for tumor diagnosis and therapy have been attracting attention from researchers over the world in recent years. Multifunctional nanoplatforms can not only achieve the combination of diagnosis and therapy, but can also enhance diagnostic accuracy with different imaging methods, and multimodal therapeutic efficiency by combinating different strategies. Drug-loaded nanoparticle is currently a promising strategy to overcome the clinic difficulties in tumor therapy. However, much more effort is still needed on the design and fabrication of applicable theranostic nanomaterials for clinic translation.In this dissertation, we prepare two kinds of multifunctional nanoparticles for applications in tumor imaging and therapy. The characterization, in vitro and in vivo behaviors of the nanoparticles are performed. These investigations are as follows:Chapter 1. Recent research progresses in tumor diagnosis and therapy, and the applications of multifunctional nanoparticles are reviewed in this chapter. The basis and main contents of this dissertation are listed.Chapter 2. We prepare the Cy/Ce6-loaded micelles as potential theranostic nanoparticles for precise anatomical tumor localization via dual photoacoustic(PA)/near-infrared fluorescent(NIRF) imaging modalities, and simultaneously superior cancer therapy via sequential synergistic phototheramal therapy(PTT)/ photodynamic therapy(PDT). The micelles exhibit enhanced photostability, cell internalization and tumor accumulation. The dual imaging modalities of the micelles cause the high imaging contrast and spatial resolution of tumors. Moreover, the micelles can generate severe photothermal damage on cancer cells and destabilization of the lysosomes upon PTT photoirradiation, which subsequently facilitate synergistic photodynamic injury via Ce6 under PDT treatment. The sequential treatments of PTT/PDT trigger the enhanced cytoplasmic delivery of Ce6, which contributes to the synergistic anticancer efficacy of Ce6.Chapter 3. We synthesize p H-responsive photothermal nanoparticles for NIRF imaging and enhanced PTT efficacy, in which graphene oxide(GO) is a receptor of FRET, and Cypateacts as the donor. GO-Cypate nanoparticles exhibit different conformations in aqueous solutions at various p H, which can trigger p H-dependent FRET effect between GO and Cypate and thus induce p H-responsive photothermal effect of GO-Cypate. GO-Cypate exhibits severe cell damage owing to the enhanced photothermal effect inlysosomes, and thus generate synergistic PTT efficacy with tumor ablation upon photoirradiation after a single-dose intravenous injection. |
