Synthesis And Evaluation Of Nanoparticles Modified With Folate As Ultrasound Contrast Agent For Targeting Breast Cancer

Background: Breast cancer,one of the most common malignancies,threatens women’s physical and mental health.Early detection,diagnosis and treatment of it are the key to increase survival rate.At present,however,there is still lack of the non-invasive and effective method for diagnosis of early breast cancer in clinical.Previous studies have shown that nano-scale ultrasound contrast agents have strong penetrating ability to pass through the vascular endothelial gap and arrive at the target tissues.And this makes it possible to overcome the shortcoming that micron-scale ultrasound contrast agents only can develop blood pool imaging.Consequently,it has potential to improve early diagnosis of cancer and other major diseases.Objective: To construct folate-modified nanoparticles targeting breast cancer as ultrasound contrast agents,and to characterize their morphological features,as well as to detect their biocompatibility and to observe the capability of nanoparticles to specifically bind to different cell lines and imaging effect in vitro.Methods: FA-PEG-PLGA polymer was synthesized by condensation reaction method.And its structure characteristics were confirmed by means of UV spectroscopy,FITR,1H-NMR as well as GPC.Ultrasound contrast agents m PP/PFOB,m PPF/PFOB,Cy5/m PP/PFOB and Cy5/m PPF/PFOB were constructed by phacoemulsification-evaporation method.The morphology,particle diameter and Zeta potential were characterized.Toxicity of them to cells was evaluated by CCK8 assay.And their impacts on liver function of nude mice were examined by Elisa.Their targeting effects on cells were detected and Ultrasound imaging of m PPF/PFOB nanoparticles was evaluated in vitro.Results and Conclusion: Synthesis of FA-PEG-PLGA was successful,which was confirmed by UV、FITR、1H NMR、GPC.All nanoparticles were spherical in shape.The mean diameter and Zeta potential of freshly prepared nanoparticles m PPF/PFOB,m PP/PFOB,Cy5/m PPF/PFOB and Cy5/m PP/PFOB was(347.3±22.2)nm,(306.2±12.9)nm,(348.4±25.9)nm,(308.5±22.4)nm and-(21.4±1.4)mv,-(26.1±1.2)mv,-(21.3±1.6)mv,-(26.3±0.95)mv,respectively.Both nanoparticles had low cytotoxicity,and they did not have obvious damage to the liver in nude mice.The results of flow cytometry showed the mean fluorescence intensity of m PPF/PFOB group was significantly higher than m PP/PFOB group and m PPF/PFOB + FA group in MCF-7 cells(P<0.05);but there were no significant differences among the average fluorescence intensity of all the three groups in HFF-1 cells(P>0.05).It was observed that m PPF/PFOB nanoparticles gathered around MCF-7 cell membrane while m PP/PFOB randomly distributed in the cytoplasm.And more m PPF/PFOB adhered to the surface of MCF-7 cells.After m PPF/PFOB nanoparticles binding to MCF-7 cells in vitro,they could enhance ultrasound echo.Those findings indicate the targeted nanoparticles m PPF/PFOB have good biocompatibility and can specially bind to breast cancer MCF-7 cells in vitro,enhancing imaging capability.