Construction And Application Of A New Nano Drug Delivery System To Overcome The Multi-drug Resistance Of Tumor Cells

Cancer has become the second largest cause of death all over the world,in addition to difficult to prevent,early diagnosis and treatment,chemotherapy-induced multi-drug resistance of the tumor presents a huge challenge for cancer clinical treatment.As the effect of traditional treatment of multi-drug resistance is minimal,combined treatment with traditional treatment and emerging gene therapy is becoming a new research direction.This article will discuss the construction of a simple drug delivery system to overcome the multi-drug resistance tumor and the characterization of its therapeutic effect on multi-drug resistant tumor cells.The paper includes:The second chapter mainly discusses the construction,characterization and cell experiment of multiple composite nanocarriers with gene silencing and Dox chemotherapy.Nanocarriers are obtained by double-stranded DNA complexes coated with protamine and HSA layers,and uniform in size and stable in shape to facilitate entry into tumor cells.To characterize the effect of nanocarriers on multi-drug resistant tumor cells,we investigated the enter ability,drug resistance gene inhibition effect,anti-drug efflux effect,and cytotoxicity of multi-drug resistant cells,.The third chapter mainly discusses the construction and in vitro characterization of invisible nano-drug particles for breakthrough of tumor biological barrier..The biological barrier of the tumor hinders the further penetration of the drug into the tumor cells,therefore reduce the efficacy.We constructed the invisible nanoparticles formed by self-assembly of fPAMAM-peptAds,linear poly-?-CD and Ad-CD47 peptides,which could escape the recognition of immune system.Under the stimulation of MMP-2 in the microenvironment of the tumor,the invisible nanoparticles are decomposed into smaller particles,which can penetrate the biological barrier,improve the drug concentration and promote the therapeutic effect.