Composite Nanomaterial With Multimodal Imaging And Radio-Chemotherapy Based On ZIF-8 Matrix

Nowadays,the imaging diagnostic methods which are commonly used in the clinic include computed tomography(CT)and magnetic resonance imaging(MRI).Among them,CT imaging is good at imaging for high-density skeletal tissues,but has a poor ability to detect the lesions in low-density tissues;while MRI is suitable for observation of tissues or organs with high water content,however,the imaging results are vulnerable by congestion,artificial organs and metal products.Because various imaging methods have their own limitations,the single imaging method for diagnosis often cannot provide comprehensive information in complex situations,which easily leads to misdiagnosis.Constructing a multimodal imaging system and using multifunctional composite nanomaterials as multimodal contrast agents is a feasible solution to solve this dilemma.In addition,by formulating the reasonable strategy of preparation,the functional units of the composite nanomaterial can be designed and replaced and the treatment units are capable of being loaded,then the cancer integrated diagnosis and treatment platform will be constructed.Nowadays,the types of functional units in composite nanomaterials which have been reported are relatively single,and that leads to fewer imaging and treatment forms can be achieved simultaneously.In this work,we designed a multifunctional composite nanomaterial by encapsulating the functional units semiconducting copper bismuth sulfide(CBS)and rare-earth downconversion(DC)material in a zeolitic imidazolate framework-8(ZIF8)with following anticancer drug doxorubicin(DOX)loadings by the inherent porosity of ZIF-8.The prepared CBS&DC-ZIF8@DOX nanoparticles showed a p H-responsive decomposition behavior.The ZIF-8 matrix could decompose in physiological solutions with low p H values similar to tumor microenvironment and the CBS,DC and DOX units would be released.By taking X-ray attenuation capability of CBS and magnetic property of DC,such composites could be used for traditional computed tomography and magnetic resonance imaging.According to the experimental results,the S and r₁value of such nanoparticle were 2.6 and 3.3 times that of the CT and MRI contrast agent in clinic,respectively,which showed excellent imaging performance.In addition,due to the unique optical absorption and fluorescence properties of CBS and DC materials,such nanoparticle could also be used as contrast agents in the emerging photoacoustic imaging(PAI)and fluorescence imaging(FI).In terms of cancer treatment,since the CBS and DOX had radiosensitization and chemotherapy capabilities,respectively,such nanoparticle was able to be adopted with X-ray collectively for synergistic radio-chemotherapy,and 88%tumor inhibition was achieved with no obvious long-term toxicity,which indicated the significant effect of treatment.These results prove that the CBS&DC-ZIF8@DOX composite nanomaterial has a very broad application prospect in integration of cancer diagnosis and treatment where multimodal imaging and synergistic radio-chemotherapy are combined.