Synergistic Therapy Of Tumor Phototherapy And Radiotherapy Based On Nano-graphene

In recent years,owing to its unique physical and chemical properties,nano-graphene have been widely used in the nanomedicine.Utilizing its strong near-infrared absorption,nano-graphene could be used as a photothermal agent for photothermal therapy?PTT?of cancer,achieving a good therapeutic efficiency.Nano-graphene-based PTT had a well selectivity and specificity,and induced no obvious toxicity to the normal tissue and cells.Therefore,in this dissertation,according to the previous reported that nano-graphene based PTT,we labeled radionuclide iodine-131 to the surface of nano-graphene for nuclear imaging guided combination of PTT and radiotherapy?RT?,achieving excellent tumor therapeutic efficiency.The iodine-131 labeled nano-graphene did not cause significant toxicity to the mice at the tested dose by analyzing the blood biochemistry and blood routine,as well as tissue sections.The main results of this dissertation are summarized as following:Chapter 1:This chapter is an introductive overview that summarizes the application of functional nanomaterials in tumor radiotherapy,and summary of the application of nano-graphene in bio-imaging and cancer therapy.Chapter 2:Nano-graphene oxide?GO?were synthesized by Hummers method,and then reduced by hydrazine hydrate to prepare reduced nodular graphene?RGO?,which were then functionalized with PEG?RGO-PEG?to keep well biocompatibility and water solution.RGO-PEG were labeled with iodine-131 by the chloramine-T oxidation.The radiostability of ¹³¹I-RGO-PEG were tested in physiological solutions,showing great stability.Chapter 3:We investigated the in vitro toxicity of RGO-PEG,free ¹³¹I,PTT,RT and PTT+RT.The results showed that ¹³¹I-RGO-PEG induced significant toxicity to cancer cells.Chapter 4:We investigated the biodistribution and potential toxicity in vivo of¹³¹I-RGO-PEG after intravenous injection.The in vivo combined PTT and RT was also conduced again.¹³¹I-RGO-PEG exhibited long-term blood circulation and tumor uptake ability?⁴.38%?.In vivo combined therapy showed that tumors of mice via intravenous injected with ¹³¹I-RGO-PEG were completely killed compared with other control groups.More important,¹³¹I-RGO-PEG induced no obvious toxicity when the mice were administrated.In summary,this dissertation,we first combined PTT and RT to treat cancer based on nano-graphene,then achieving excellent therapeutic efficiency.¹³¹I-RGO-PEG did not induce significant side effects during the treatment course.It is hoped that our study further promote the application of nano-graphene in biomedicine and provide novel ideas and strategies for cancer treatment.