Multifunctional Nanoprobes For Cancer Theranostics

Organic fusion of molecular imaging and cancer treatment through nanotechnology can achieve cancer theranostics.Currently,molecular imaging techniques mainly include fluorescence imaging?FLI?,photoacoustic imaging?PAI?,magnetic resonance imaging?MRI?,positron emission computed tomography?PET?,and so on.Cancer treatment mainly include surgery,chemotherapy,radiotherapy,photodynamic therapy,photothermal therapy,immunotherapy,and so on.In this thesis,three kinds of nanoprobes were designed and synthesized for molecular imaging diagnosis and efficient treatment of malignant tumors,and eventually achieve cancer theranostics.The detail research contents are as follows:?1?BODIPY-basednanoprobe?PFH@PEG-F54-BODIPY?for fluorescence/photoacoustic/magnetic resonance multi-modality imaging guided photodynamic therapy of tumorA poly?ethylene glycol?-boron dipyrromethene amphiphile(PEG-F₅₄-BODIPY)with 54fluorine-19(¹⁹F)was synthesized and employed to emulsify perfluorohexane?PFH?into a theranosticnanoemulsion(PFH@PEG-F₅₄-BODIPY).Theas-prepared PFH@PEG-F₅₄-BODIPY can perform architecture-dependent fluorescence/photoacoustic/¹⁹F magnetic resonance multimodal imaging.Importantly,this nanoemulsion significantly enhanced the therapeutic effect of BODIPY through both the high oxygen dissolving capability and less self-quenching of BODIPY molecules.?2?Magnetic melanin nanoprobe for magnetic resonance/photoacoustic dual-modality imaging guided chemotherapy of tumorMagnetic melanin nanoparticles?MMNs?were designed and prepared.The chemotherapy drug Obatoclax?OBX?was successfully loaded by MMNs for cancer theranostics.The integration of MRI and PAI could provide the complementary information for accurate cancer diagnosis and imaging guided therapy.Upon laser irradiation,the mild hyperthermia generated by MMNs can significantly increase tumor tissue accumulation and internalization of OBX-MMNs.Both pH changes and near-infrared?NIR?laser irradiation can specifically stimulate OBX release from OBX-MMNs.?3?Salinomycin nanocrystals for fluorescence imaging guided chemotherapy of tumorThe chemotherapeutic drug salinomycin?SAL?was successfully prepared into salinomycin nanocrystals?SAL NCs?by the nanocrystal synthesis technology.The drug formed nanocrystals without any other carriers,so the drug loading efficiency was as high as100%.After the conjugation of fluorescent dyes?FITC or IR800?,the as-prepared SAL NCs can be used for fluorescence imaging guided chemotherapy of tumor.In summary,this whole study successfully constructed three kinds of nanoprobes for molecular imaging guided cancer treatment.The“all-in-one”theranostic nanoprobes have simple composition,remarkable theranostic efficacy,and novel treatment pattern,and thus presented an intriguing solution for cancer diagnosis and treatment.