The Construction Of A Nano Gene Carrier And Study On Combined Gene And Photodynamic Therapy On The Treatment Of Oral Cancer

Photodynamic therapy,by importing the photosensitizer into the targeted tissue and activated by the laser to produce the active oxygen,can destroy the targeted tissue specifically.It has been widely used in the clinical treatment of superficial head and neck pre-cancer and cancer.However,during the PDT process,the poor specific accumulation in tumor region of traditional photosensitizer and existence of anti-apoptosis cytokines limited the efficacy of PDT.Therefore it is crucial to improve the absorption of photosensitizer and block the recurrence factor of anti-apoptosis.In this study we proposed to construct a new nano gene carrier to accumulate the drug concentration in tumor region by enhanced permeation and retention(EPR)effect and inhibit Wnt-1 gene expression for the sake of inhibiting the anti-apoptosis and EMT progression,therefore improving the therapeutic efficacy for oral cancers by a combination of PDT and gene therapy.Firstly,we prepared the positively charged nanoparticles composed of polyethylene glycol(PEG),polyethylenimine(PEI)and chlorine e6(Ce6)to form the nano gene carrier(PEG-PEI-Ce6).Then,we loaded Wnt-1 siRNA with the nanoparticles by electrostatic adsorption to form the PEG-PEI-Ce6/siWnt-1 nano-complexes.The nanoparticles were characterized and their stability and functional properties were verified.In vitro,we tested the cellular uptake,cytotoxicity and RNA delivery ability of PEG-PEI-Ce6/siWnt-1 nano-complexes.We tested the effect of cancer cell killing and apoptosis with combined gene and photodynamic therapy and examined the expression of Survivin and EMT procession related proteins.In vivo,we studied the tumor targeting ability of PEG-PEI-Ce6/siWnt-1 nano-complexes and tested the efficacy and safety of PEG-PEI-Ce6/siWnt-1 nano-complexes mediated combined gene and photodynamic therapy in tumor bearing mice.The nano gene carrier PEG-PEI-Ce6 and PEG-PEI-Ce6/siWnt-1 nano-complexes were successfully constructed.These nanoparticles are stable under physiological conditions and have the efficient siRNA delivering ability.In vitro,PEG-PEI-Ce6/siWnt-1 nano-complexes can be effectively uptaken by tumor cells with little cytotoxity.PEG-PEI-Ce6/siWnt-1 nano-complexes can deliver the siRNA into tumor cell efficiently and block the Survivin expression and inhibit the EMT process.PEG-PEI-Ce6/siWnt-1 nano-complexes mediated combined gene and photodynamic therapy inhibited the cancer cellular activity and enhanced the level of cancer cell apoptosis.In vivo,PEG-PEI-Ce6/siWnt-1 nano-complexes can be effectively and specifically uptaken by tumor tissue under the EPR effect and its mediated combined gene and photodynamic therapy can inhibit the Wnt-1 expression and tumor survival related cytokines to enhance the effect of photodynamic therapy for tumor killing.Therefore,with little side reaction,its mediated combined gene and photodynamic therapy has broad clinical application prospect.