The Construction And Biological Verification Of Prostate Specific Membrane Antigen Targeted Radiosensitive Nanoparticles

Background:prostate cancer(PCa)is the second most common cause of cancerrelated death in male.Radiotherapy(RT),as a non-invasive treatment,has always been one of the main treatment methods of PCa.However,radiation resistance and normal tissue damage caused by radiation are the obstacles that we have to face with.The development of nanotechnology provides opportunities to overcome these drawbacks.So far,many synthetic nanoparticles have been used as radiosensitive agents in vitro and in vivo.However,at present,almost all the research on radiotherapy sensitization focuses on the secondary electron derived from enhanced dose deposition effect of high atomic number(z)nanomaterials.Besides dose deposition,cell cycle synchronization is also a potential way of radiosensitization.The goal of this study is to design a prostate cancer targeted radiotherapy sensitizing particle based on the dose deposition of gold nanoparticles and cell cycle synchronization.Methods:4nm gold(Au)nanoparticles were synthesized from chloroauric acid.Au core is connected with SH-PEG2000-NH2 through Au-S bond.DUPA was then modified to the amino terminal of Au-PEG2000-NH2.Docetaxel was loaded into the PEG crown of Au-PEG2000-DUPA through non covalent bond,and finally formed docetaxel loaded PSMA targeted gold nanoparticles(Au@DTX-DUPA NPs).After the construction of nanoparticles,it’s toxicity was verified by EC50.Flow cytometry was used to detect the distribution of cell cycle in each group,and DCF assay was used to detect the production of ROS in each group.The DNA double bond breaks of each group were detected by γ-H2AX assay.The sensitization effect of nanoparticles in vitro radiotherapy was quantified by SER curve.The xenograft tumor model in nude mice was used to evaluate the radiosensitization effect of nanoparticles in vivo.Result:Au@DTX-DUPA NPs were successfully constructed.The nanoparticles can specifically target PSMA(+)prostate cancer cells.By combining with PSMA,the internalization of particles was enhanced,the concentration of intracellular nanoparticles was increased,and therefore the radiation dose deposition was enhanced.In addition,the synthesized nanosystem can effectively block the cell cycle in G2/M phase,which will enhance the sensitivity of DNA to radiation.In addition,G2/M phase arrest will further promote the retention of intracellular NPs.Under radiation,Au@DTX-DUPA NPs greatly promoted ROS production and DNA double strand breaks.All these factors constitute the basis of radiosensitization of the nanoparticles in vitro and vivo levels.Cell and animal experiments confirmed that,Au@DTX-DUPA NPs can significantly enhance the antitumor effect under irradiation.Conclusion:Au@DTX-DUPA NPs increased the cumulative dose of nanoparticles in tumor cells based on targeting prostate cancer cells and blocking G2/M phase,and then increases the severity of ROS and DNA breakage in cells under radiation,realizing the sensitization effect of radiotherapy.All components of nanoparticles have been approved to enter the clinical trials of PCa treatment.Therefore,the nanoparticles have high potential for clinical transformation.