Functionalized Graphene Oxide With Si-PD-L1 And Sorafenib Inhibits HCC Progression

Liver cancer is predicted to be the sixth most commonly diagnosed cancer and the fourth leading cause of cancer death worldwide.The current curative treatment for liver cancer is traditional surgical treatment,but the tumor-free survival rate within 5 years after surgery is less than 30.5%,which results from the metastasis and recurrence of liver cancer.Recently,immunotherapy has become an emerging treatment strategy in tumor therapy,which mainly enhances the whole anti-tumor immune functions.However,these therapies are relatively expensive,and only have good curative effects on certain tumors,which has not reached clinical requirements for liver cancer treatment.Therefore,based on the principles of immunotherapy and gene therapy,this study uses nano-scale functionalized graphene oxide as a carrier to co-deliver PD-L1 siRNA and sorafenib to treat liver cancer.In this paper,graphene oxide was prepared.Then it was modified by polyethylene glycol and polyethylene imine to produce functionalized graphene oxide.We detected the peak spectra of GO-PEG-PEI complexes using a Fourier infrared spectrometer,an ultraviolet-visible near-infrared spectrometer,and a laser Raman spectrometer.To observe its morphology,we employed atomic force microscope,transmission electron microscope and scanning electron microscope.Besides,we also used a dynamic light scattering instrument to measure the particle size and zeta potential of the GO-PEG-PEI complex.In order to determine the N / P ratio of the best binding of GO-PEG-PEI to siRNA,we determined the element N content in GO-PEG-PEI by elemental analysis and performed agarose gel electrophoresis retention experiments.Interfering with PD-L1 in combination with sorafenib were performed in SMMC7721 and MHCC97 H cells,we examined the effects on liver cancer cells with MTT assay,Transwell assay,clone formation,Western blot,cell cycle and apoptosis.Developing a co-culture system of Jurkat T cells and liver cancer cells,we detected the mutual influence of two types of cells in the coculture system by flow cytometry and T cell-mediated tumor killing ability analysis.We established a nude mouse models bearing subcutaneous tumors to study the therapeutic effect of the complex of GO-PEG-PEI codelivered PD-L1 siRNA and sorafenib in vivo,and we used small animal imagers to observe the targeting of the complex in vivo.The experimental results show that GO-PEG-PEI have a diameter of191.14 nm and a thickness of 13.3 nm.The zeta-potential of GO-PEG-PEI was determined to be +44.93 m V.It is 0.5 that the N/P ratio of the best binding of GO-PEG-PEI to siRNA.GO-PEG-PEI has no obvious toxic effect on cells.Interfering with PD-L1 in liver cancer cells is able to inhibit cell proliferation and migration,also induce G1 phase cell cycle to arrest and apoptosis.GO-PEG-PEI co-delivering PD-L1 siRNA and sorafenib significantly inhibits cell proliferation and promotes apoptosis.The results show that GO-PEG-PEI specifically targets liver cancer and tumor sites in vivo and tumor growth rate was markedly inhibited in mice by tail vein injection GO-PEG-PEI/PD-L1 siRNA.Simultaneously,GO-PEG-PEI codelivering PD-L1 siRNA and sorafenib is better than GO-PEG-PEI delivering PD-L1 siRNA to treat liver cancer.