Construction Of DNA Self-assembled Nanosystems And Tumor Targeted Therapy

DNA self-assembled nanomaterials are a kind of nanomaterials that have a special two-dimensional or three-dimensional spatial structure based on DNA.DNA self-assembly nanomaterials have the advantages of programmability,spatial addressability,easy functionalization and good biocompatibility.These advantages make DNA nanomaterials have the possibility to be used in the field of biomedicine,such as targeted drug delivery,DNA logic gates or biological imaging.Cancer is one of the world’s enemy number one for human life.According to the global data statistics of 2012,there are about 14 million people being diagnosed as a cancer patient and eight million died of cancer.The study shows that the immaturity of early detection and cure of cancer must be responsible for the high incidence and mortality of cancer.Therefore,in the field of current cancer research,the researchers mainly focus on the effective early diagnosis of cancer and the establishment of mature targeted therapy.In this paper,we design functionalized DNA nanomaterials,and investigated their application in targeted delivery of small interfering RNA and antisense oligonucleotides.The main contents of the paper are as follows:In the second chapter,through a cascade of reaction between DNA molecules,we will construct a customized nanodrug delivery system that specifically targets cancer cells and be specifically activated by tumor markers over-expressed in cancer cells.The system consists of three functional components:a aptamer end-capped sequence,an intermediate portion of the nanodrugs,and a blocked sequence that will be specifically activated in the cancer cell.Subsequently,we carry out a series of experiments,such as flow cytomerty and confocal experiments,to characterize the linear nanodrug delivery system.It proves that the nanodrug delivery system can target to a variety of cancer cells and been specific activatived in cancer cells,whcih provide the possibility for personal treatment of tumors.In the third chapter,we will construct a cancer cells targeted DNA self-assembled nanostructure that can carry a large amount of small interfering RNAs.The structure is composed of a series of DNA cubes,and has good stability and relatively low cytotoxicity.Through the terminal modification of the aptamer,the structure can be targeted delivery to cancer cells.It is foreseeable that the DNA self-assembled nanostructure can targeted delivery other different functional DNA or RNA fragments and regulate cancer-related genes in cancer cells.Through that method,we can interfere with the physiological processes of cancer cells and finally achieve the purpose of cancer therapy.