Drug Delivery Based On PANI Coated Mesoporous Silica Nanoparticles For Cancer Therapy

Although chemotherapy has a better therapeutic effect and efficiently prolongs the patient's life span,it still has a series of weakness such as drug resistance,low drug enrichment capacity at tumor site and various side-effects.Take advantage of the special physical-chemical property of nanoparticles to build special nanodrug delivery systems(DDS),it can realize oncotherapy by enhanced permeability and retention(EPR)effects.Up to now,only liposome based nanodrug has been used in clinic.However,limited therapeutic effect was brought about during clinical treatment.With the emerging of new therapeutic strategies,such as photothermal therapy(PTT),photodynamic therapy(PDT)and gene therapy,establishment a highly efficient combined treatment method has become the new direction of oncotherapy.In this thesis,we design and establishment a new DDS using polyaniline(PANI)coated mesoporous silica nanoparticles(MSNs)to realize chemotherapy,PTT,and gene therapy by using the high drug and siRNA loading capacity of MSNs and photothermal conversion capacity.The nanoplatform was constructed by horseradish peroxidase(HRP)minic DNAzyme to catalyze coating of PAIN which could not only block the pores but also afford ideal surface for siRNA loading.In order to increase its biocompatibility,hyaluronic acid(HA)was further assembled on the outer layer.PANI shows pH dependent photothermal conversion property,which could be activated at acidic condition.When the nanoparticles were located at tumor tissue or the lysosome,the acidic condition activated the photothermal conversion property of PAIN,releasing loaded drug and siRNA under NIR light irradiation.In vitro and in vivo results demonstrated that the released drug and si RNA could effectively induce apoptosis and efficiently suppressed tumor growth.