The Synthesis And Drug Carrying Performance Of Phosphorylcholine Oligomer Grafted Graphene Oxide

Since graphene was first reported in 2004, the two dimensional nano material with excellent physical and chemical properties has led to great research enthusiasm of scientists. Graphene has shown great potential in many fields, such as physics, chemistry, material science and biomedical science. In the biomedical field, graphene and its derivatives as drug carriers has attracted wide attention in the field of tumor therapy. Graphene has a large specific surface area and the characteristics of both sides can be loaded molecules, which make graphene broad application prospects as drug carriers. At the same time, the water dispersion of graphene is poor and graphene show a certain biological toxicity, which restricts the application of graphene in biomedical applications. Therefore, the modification of graphene has become an important part in the study of graphene. In this paper, we use the method of covalent modification to synthetise the phosphorylcholine oligomer grafted graphene oxide(GO-PCn) with good water dispersion and biocompatibility. We select irinotecan as a model drug to study the drug loading properties of GO-PCn. The specific research contents and results are as follows.(1) Firstly, we synthetised graphene oxide by Humers method. Then the graphene oxide was hydroxylated. We selected 2-methacryloyloxyethyl phosphorylcholine as modifying agent, using a atom transfer radical polymerization method to synthetise GO-PCn. After that, the GO-PCn was characterized by Fourier transform infrared spectroscopy, X-ray photeelectron spectroscopy, X-ray diffraction, thermogravimetric analysis, Raman spectroscopy, Nuclear magnetic resonance, Particle size analysis and Zeta potential test. And then, two cell lines(L929 murine fibroblasts and Human Hepatoma Cell Line HepG2) were cultured in different concentrations of GO and GO-PCn in order to study the in vitro cytotoxicity of GO-PCn. Results show that the GO-PCn presents a better biocompatibility.(2) We select irinotecan as a model drug. In water solution, irinotecan was attached onto GO-PCn nanosheets via π-π stacking interactions. The hybrid was characterized by Fourier transform infrared spectroscopy and thermogravimetric analysis. After that, a high efficiency liquid chromatography was used for studying the drug loading ratio and efficiency of irinotecan loaded on GO-PCn. The drug loading ratio has reached to 16%. The release was studued by dynamic dialysis method. Results show that the drug loading hybrid showed pH sensitive drug release properties. At last, two cell lines(L929 murine fibroblasts and Human Hepatoma Cell Line HepG2) were cultured in different concentrations of drug loading hybrid, GO-PCn and Irinotecan to study the in vitro cytotoxicity. From the results, we found that the hybrid could still present in vitro cytotoxicity consistent with the free irinotecan, which gave GO-PCn a bright future in biomedical field.