Performance Of Targeted Polyethylenimine Fluorescence Carbon Dots As Gene Carriers

Objectives:Use the traditional carrier Polyethylenimine(PEI) as the basic raw material, Folic acid(FA) as targeting group, prepare two different types of carbon nanomaterials, and compare their physicochemical properties, fluorescent properties, tumor targeting abilities as well as the gene carrying capacity. Methods:1. Use PEI and FA as raw materials, hydrothermal method to prepare folic acidpolyethylenimine carbon dots(FA/PEI CDs). By means of Transmission electron microscopy(TEM), UV-vis-near infrared absorption spectroscopy, Fourier transform infrared spectroscopy, fluorescence spectrometer to characterize the physicochemical properties; Through the quinine sulfate method for the determination of quantum yield; Tumor targeting abilities are observed under Inversed Fluorescent Microscope; Through the Real-Time PCR technique to detect the expression level of mi RNA; MTT method to measure its biocompatibility. Explore the influence factors of cellular uptake by increasing the particle size.2. Use PEI as raw material, hydrothermal method to prepare polyethylenimine dots(PDs), combine with folic acid by electrostatic force to gain PEI PDs-FA. Through the same method to characterize. Results:1. Characterization of FA/PEI CDs: TEM shows the average size of it is less than 5 nm, UV-vis-near infrared absorption spectroscopy and Fourier transform infrared spectrum analysis results show that the two substances form amide bond, fluorescence tests show that the nanomaterial can emit blue fluorescence under ultraviolet light. However the FA/PEI CDs do not have tumor-targeting ability. It may bears on particle size and the combination of folic acid and receptor on cell surface. FA/PEI CDs is a great gene carrier and have good biocompatibility.2. After improving the method, w9 e acquire PEI PDs-FA and characterize as follow: tem result shows the size of this nano-material is between 10 and 40 nm, UVvis-near infrared absorption spectroscopy results show that PEI PDs-FA is similar to PEI and connected to FA molecule. Fluorescence test results show that PEI PDs-FA can emit green fluorescence under blue light. PEI PDs-FA has targeting abilities to tumor cells, and as a gene carrier is superior to the traditional carrier PEI. It also shows good biocompatibility Conclusion:FA/PEI CDs’ fluorescence properties and carry gene ability are better than that of PEI PDs-FA; However, FA/PEI CDs do not have the ability to target tumor cells, and PEI PDs-FA have targeted; Those two kinds of carbon nano-materials have good biocompatibilities.