Application Of Gold Nanoparticles In Tumor Diagnosis And Treatment

Tumors,also known as cancer,today is a long-standing malignant disease human health.The triggering factors include physical,chemical and genetic factors.Early diagnosis and timely treatment of tumors are the methods to improve the cure rate and prolong the survival time of cancer patients.With the development of nanotechnology,metal nanoparticles have been applied to various biological fields,which has special size of metal nanoparticles,unique physical,chemical and biological properties.In particular,gold nanoparticles?AuNPs?has unique optics,thermals,electronics,and strong affinity.At the same time,AuNPs can be made into various forms as required?such as gold nanoparticles,gold nanospheres,gold nanocages?,and new ideas to the diagnosis and treatment of tumors.This article discusses how to use gold nanorods?AuNRs?to detect the tumor marker?2,6-sialylated glycans??2,6-sial-Gs?,and how to use gold nano-bionic drugs to realize the diagnosis and treatment of tumors.The research content is mainly divided into the following two parts:1.Sandwich electrochemical biosensor for the detection of?2,6-sialylated glycans based on AuNRs-SA coupled with c-SWCNHs/S-PtNC nanocomposites signal amplificationThis this study,a new recognition system was constructed using Sambucus nigra agglutinins?SNA?which has specific recognition function for?2,6-sial-Gs,and 3-aminophenylboronic acid?M-APBA?which has non-specific recognition function for?2,6-sial-Gs.At the same time,we have used AuNRs-SA as the sensing matrix and c-SWCNHs/SPtNC as the signal label to design a novel sandwich-type biosensor,and achieve specific detection of?2,6-sial-Gs.The AuNRs-SA and bio-SNA were modified on the surface of a glassy carbon electrode?GCE?,forming a sensing interface with the?2,6-sial-Gs.In the presence of the target,cSWCNHs/S-PtNC/M-APBA could be immobilized on the fabricated biosensor.As a result,an increased current response was recorded in a phosphate buffered saline?PBS?solution through the addition of 20?L of H₂O₂.The sandwich-type biosensor provides an ultrasensitive detection of?2,6-sial-Gs and has great potential for detecting the low level of biomarker.Moreover,the dual-type responsive biosensor has the characteristics of good specificity and high sensitivity,and has the feasibility of the proposed biosensor for clinical application.2.Multifunctional nano-bionic system based on?gold-carbon quantum?Au-CDs nanocomplex for diagnosis and treatment of tumor cellsThis project is based on the fact that when Au-CDs nanoclusters meet a certain concentration of GSH,a more stable Au-S bond is formed,so that the CDs recover fluorescence.At the same time,it will catalyze H₂O₂,generate OH^-,increase the ROS level around tumor cells;combine the drug treatment of DOX;GSH that consumes tumor cells to achieve the killing of tumor cells and achieve therapeutic effects.AuNPs and CDs combine to form Au-CDs nanoclusters.The bond of Au-NH prevents the transfer of electrons and quenches the fluorescence of CDs.In terms of detection,when Au-CDs nanoclusters meet a certain concentration of GSH,GSH has a stronger ability to bind gold nanoparticles,which can cause the Au-CDs nanoclusters to disintegrate by forming stronger Au-S bonds.Therefore,the CDs can recover fluorescence and realize the detection purpose from"off"to"on".In terms of treatment,when Au-CDs loaded with DOX reach the tumor site through the targeting of macrophage-derived microvesicle?MMV?,they disintegrate by consuming GSH in the tumor cells,and release DOX.Undisintegrated Au-CDs can kill tumour cells by catalyzing H₂O₂ to produce OH^-,which can increase the level of ROS around tumor cells.At the same time,the low concentration of GSH in the cell can enhance the ROS effect.This study has proved that Au-CDs nanoclusters can not only realize the detection of tumor cells,but also can be loaded with DOX to achieve killing of tumor cells.It is a feasible drug-targeted delivery system and has the potential to be used in clinical tumor diagnosis and treatment.To sum up,we have used AuNRs-SA as the sensing matrix and c-SWCNHs/SPtNC as the signal label to design a novel sandwich-type biosensor,and achieve specific detection of?2,6-sial-Gs.On the other hand,Au-CDs nanoclusters were used as detection probes to detect tumor cells.At the same time,tumor cell killing was achieved by combining the cellular ROS level,drug therapy,and the consumption of intracellular GSH.Two methods of diagnosing and treating tumors based on AuNPs have brought new technical strategies to the diagnosis and treatment of tumors,and also provided new ideas for the diagnosis and treatment of tumors by other metal nanomaterials.