Targeted Tumor Therapy And Biosensing Assisted By DNA Molecules

Malignant tumor?cancer?is one of the malignant diseases with high morbidity and mortality rate that seriously threaten human life and health.It has a significant social and economic impact on individuals,families and the community in terms of premature mortality and the provision of health care infrastructure.Life is the foundation of human existence.A healthy body is the basic condition of all activities.There are thousands of people losing their lives every year in our society.Except for the natural aging people,most of them die of cancer.How to treat cancers is a worldwide challenge.Treating cancer is an important topic.There are many methods to prevent and treat cancer in clinic,such as operation,chemotherapy,gene therapy,radiotherapy and so on.Surgical treatment is effective for some early cancer patients and solid tumor patients with a single tumor.while for other cancer patients,the treatment effect is not good enough and has certain limitations.Chemotherapy has been effective in treating tumors.To a certain extent,it can alleviate the pain and suffering of cancer patients.However this method has a very large toxic side effect which can cause great damage to normal cells.Therefore,the development of a drug delivery method targeting tumor cells has become the focus of research.Food and drug safety is antherimportant topic.Unsafefood and medicine can cause cancer,serious illness or death.Many food additives and drugs are chiral compounds.Now,the study of chiral molecules has become a hot spot in the fields of pharmacy and medicine.The corresponding isomers of chiral molecules have different biological activities,one enantiomer shows can be beneficial functions to human body,while the other enantiomer may be harmful or ineffective for human.For example,D-penicillamine is a drug for metabolic diseases,while L-penicillamine causes visual impairment and damage of bone marrow.Our projects aimed to develop a way to identify chiral molecules that can protect people from these enantiomerrelated disasters.The research content is as follows:In this paper,a multi-functional nano-drug carrier was used for targeted diagnosis and treatment of tumors,and electrochemical biosensor technology was used to detect chiral molecules on the basis of DNA-assisted hybridization chain reaction.1.Nanogold Flower-inspired Nanoarchitectonics Enables Enhanced Light-to-Heat Conversion Ability for Rapid and Target Chemo-Photothermal Therapy of a TumorHere,a multifunctional nano-flower drug carrier was introduced,which combined photothermal therapy and chemotherapy to treat tumor.At present,the temperature of the photothermal method reaches about 50?in 10 minutes,while under the irradiation of near-infrared,the multi-functional nano-drug carrier designed by us can reach about 85?in 2minutes,showing high photothermal performance.Adriamycin,as a drug to treat tumors,can bound to graphene oxide?GO?by a?-?conjugate.Compared with previous drug carriers,the carrier has better drug loading ability.Besides,AS1141 adaptor was modified on graphene-gold nanoflower drug carrier by gold-sulfur bond,so nano-drug carrier has good targeting properties.The nanocarrier modified with polyethylene glycol?PEG?has higher stability and dispersibility.In a word,the designed DNA-assisted graphene-gold nanoflower drug carrier opens up a bright path for the diagnosis and treatment of tumors due to its photothermal properties,targeting and drug loading properties.2.Electrochemical Selective Detection of Carnitine Enantiomers Coupling Copper ion dependent DNAzyme with DNA assistant Hybridization Chain ReactionWe designed an electrochemical biosensor method for the detection of carnitine enantiomers.First of all,We synthesized Cu?II?-L-cysteine complexes.Then,carnitine enantiomers can replaced copper ions from Cu?II?-L-cysteine complexes.In the presence of Cu²⁺,the DNA enzyme structure is activated to shear the DNA strand.The short DNA strand after cutting was reacted with ferrocene labeled DNA strand by Hybrid chain reaction?HCR?to generate ferrocene electrochemical signal.Due to the capacity of d-carnitine and l-carnitine replace Cu²⁺is different,the amount of Cu²⁺displaced and the electrochemical signal strength generated are different.Therefore,the carnitine enantiomer can be determined and detected based on the peak of the electrochemical signal.The method can be used to determine and detect d-carnitine and l-carnitine.This method not only is simple and convenient,but also does not require large instruments.Besides,it has the advantages of high sensitivity and low detection line.Thus this method is expected to show a good application prospect.