Chitosan Based Nano Drug Delivery Systems:Fabrication, Characterization And Application In Cancer Therapy

Due to the special physical and chemical properties of nanomaterials,nanotechnology has been successfully applied in environment,energy and medicine,especially in the field of nanomedicine.Environmental stimulus responsive drug delivery system makes it possible to deliver drugs on demand.In this paper,chitosan nano drug delivery systems with endogenous responsiveness and exogenous responsiveness were prepared,respectively,into which Chlorin e6(Ce6)and Doxorubicin hydrochloride(Dox)was encapsulated to realize photodynamic therapy and chemotherapy in cacner.(1)The pH-responsive chitosan nanoparticles were prepared by a non-solvent assisted counterion complex cross-linking method,and a highly drug-loaded nanoparticles were prepared by entrapping Ce6 into it.Orthogonal experiments were used to optimize the morphology and size of chitosan nanoparticles,and their properties of photochemistry,stability and pH responsiveness have been fully evaluated.(2)Photodynamic therapy effect of Ce6 loaded chitosan nanoparticles has been explored on cancer cells.The results showed that the Ce6 loaded chitosan nanoparticles had a higher singlet oxygen yield and cell lethality,while the blank chitosan nanoparticles had non-toxicity to cancer cells and normal cells and had an excellent biocompatibility.So the pH-responsive chitosan nanoparticles can be used as a reliable drug delivery system.(3)Guest-responsiveness chitosan nanoparticles have been studied by self-assembly of two building blocks: supramolecular CB[8] and phenylalanine grafted chitosan,into which chemotherapeutic agent Dox was entrapped in nanoparticles.The properties of this nanoparticles have been fully characterized.Drug release properties of drug loaded nanoparticles have been detected with a competitive guest based adamantine.Additionally,the Dox loaded chitosan nanoparticles have good therapeutic effects and guest responsiveness in the treatment of cancer cells in vitro.This paper provided two highly biocompatible and two environmental stimulus-responsiveness chitosan nano delivery systems.