Development And Application Of Microwave Ablation Susceptible Agent And Tumor Imaging Agent

Nowadays,cancer has became a big problem to human health which was also a great challenge to researchers and doctors.The ultimate goal is to successfully conquer different types of malignant tumors.Our work focuses on the tumor theranostics including two directions: tumor therapy and tumor diagnosis.For tumor therapy direction,traditional treatments including surgery,chemotherapy and radiotherapy.However,these traditional treatments usually cause systemic cytotoxicity owing to their non-specific drug delivery to all tissues,including healthy ones and they are difficult to completely overcome the tumor.Therefore,we need to develop new type of cancer treatment as therapy or as adjutant therapy.Recently,minimally invasive approaches that use thermal energy for the selective treatment of tumor cells have attracted much attention.In first part,microwave ablation as a clinical cancer treatment approach was employed which is the use of ultra-high temperature to achieve direct coagulation necrosis in tumor tissues.However,the ablation temperature induced by microwave mainly relies on the water content of tissues,which still has the risk of overheating in surrounding healthy tissues.Therefore,a susceptible agent with high permittivity is indispensable in order to enhance the treatment efficiency and protect the healthy tissues.Injectable chitosan hydrogel owing to its good self-healing property and biocompatibility would be a great candidate.Thus,we modified the composition of the injectable hydrogel to ionic injectable hydrogel which has high permittivity.The results showed that our modified ionic hydrogel can not only induce a rapid and remarkable temperature increase but also prossesses good self-healing performance,biocompatibility and in vivo stability.In vivo anti-tumor investigation has demonstrated that excellent therapeutic efficiency can be achieved after repeated microwave thermal therapy with a rather low power density(2.0 W,2.45 GHz).In summary,this simple but novel chitosan-based injectable ionic hydrogel has exhibited huge potential for application in microwave tumor ablation,meanwhile this work will also provide a new thought for the development of microwave ablation susceptible agent.For tumor diagnosis part,the purpose is to develop an imaging agent with high luminescence efficiency and deeper penetration depth.Graphene quantum dots(GQDs)due to the quantum confinement effect shows highly tunable photoluminescence(PL)property and excellent photostability which has became the research hotspot in recent years.Thus,this second part is to employ GQDs for further exploitation.First,we synthesize GQDs by one step bottom-up method.Based on water-phase molecular fusion,single-crystalline and different group functionalized GQDs can be easily obtained which demonstrated excellent optical properties and would be a fantastic candidate for further imaging study.We boldly propose an idea that making GQDs emission red-shift only through structure change.Therefore,Langmuir-Blodgett self-assembly approach was introduced into this issue.We are so excited to discover that only through LB selfassembly stack,solid GQDs ultra-thin monolayers compared to the solution GQDs nanoparticles have a clear red-shift in photoluminescence spectroscopy(PL)while theoretical calculation also shows that there is a bandgap decrease in ultra-thin GQDs monolayers.This monolayers will have good application prospect in tumor imaging sensors and will also provide a new direction for the development of tumor imaging agent.