Tumor Diagnosis And Therapy Based On Functional Peptides And Nucleic Acids

Cancer is one of the diseases that threaten human life and health.Chemotherapy is an significant therapy of tumour,but traditional chemotherapy has the disadvantages of poor targeting and side effects.Accurate diagnosis is the key of therapy of tumors.At present,Tumor-targeted therapy has been gradually popular in biological therapy,it can effectively overcome the potential adverse effects of the traditional chemotherapy,avoid the damage of normal tissues and improve the accumulation of drugs in tumor tissues.In recent years,functional peptides and nucleic acids have been widely used in the diagnosis and therapy of tumors owing to their good biocompatibility,easy synthesis and chemical modification diversity.Based on the advantages of peptides and nucleic,we proposed several simple,selective and cost effective strategies for tumor diagnosis and therapy.The main contents are as follows:1、Artificial receptor mediated tumor fluorescence imaging in an acidic tumor microenvironment.Based on the property of pH-Low-Insertion-Peptide(p HLIP)rapidly insert into the lipid bilayer by forming a helical structure in an acidic microenvironment,biotin-p HLIP is comprised of a low-pH plasma membrane insertion peptide(pHLIP)covalently linked to a molecule-recognizing motif which,in our model,involves biotin.It can effectively insert into cancer cell plasma membrane as an AR in an acidic microenvironment,then the biotin can recruit Cy5-streptavidin(Cy5-SA),an extracellular imaging agent,to cancer cells and tumors in vivo,resulting in the fluorescent imaging of tumors.2、Artificial receptor(Biotin-pHLIP)mediated deep targeting of tumors and cell-cell interactions.Co-cultivate between cells was used to study the transfer of artificial receptors between cells in vitro.The depth penetrating of artificial receptors in multicellular tumor spheres and the distribution of imaging agents in solid tumors were used to study the deep tumor penetrating ability of artificial receptors.Streptavidin-bridged different cancer cells were labeled by artificial receptors has shortened the distance of different cell,which provided new research means for studying cell-cell interactions.3、The study of the assembly and delivery of Drug-siRNA.The metal-ligand bonds between Lewis basic organic donors and Lewis acid metal acceptors guided several anticancer drugs,which were comprised of Cis-platinum(Pt)and camptothecin(CPT).The assembled drug is positively charged,it can form nucleic acid nano-assembly with siRNAs by electrostatic interaction.The nanostructures can effectively deliver siRNA into cells and achieve gene silencing.