Supermolecular Nanodrugs With Redox Double Response For Cancer Diagnosis And Treatment

Cancer,commonly known as cancer,is the second leading cause of death in the world.Emerging cancer treatment technologies include immunotherapy,monoclonal antibody therapy and stem cell transplantation.Chemotherapy is still the main choice for cancer treatment.Most of the chemicals used in clinic are hydrophobic,including adriamycin,docetaxel and camptothecin.However,chemotherapy shows serious side effects.And low molecular weight compounds,plasma half-life is very short,quickly disappear from the blood,and did not accumulate in tumor tissue.Therefore,it is urgent to develop a new drug delivery system(DDS)to selectively release chemotherapeutic drugs to tumor sites,and use lower drug doses to treat cancer more effectively.Because of the over expression of oxidized reactive oxygen species(ROS)and reduced glutathione(GSH)in tumor microenvironment,many drug delivery systems have been developed to address the redox heterogeneity of tumor microenvironment.However,the low drug loading rate of conventional drug delivery system(such as vesicles)has been the main reason for its poor application effect.Therefore,we synthesized two kinds of supramolecular prodrug nanoparticles for redox heterogeneity,which can double respond to reactive oxygen species and glutathione to release anti-tumor drug camptothecin.Compared with the single responsive prodrug,the prodrug synthesized in this paper has a great improvement in response sensitivity.Through the hydrophilic fluorescent group rhodamine and hydrophobic camptothecin,it can form self-assembled supramolecular prodrug particles,which can be enriched in the tumor site through EPR effect.Fluorescent groups facilitate the visualization of drugs in vivo and can be used for tumor diagnosis.Camptothecin is not only a drug but also a component of nanoparticles,which greatly increases the drug loading rate of nanoparticles.