Preparation And Process Optimization Of Drug Carrier Material-Functionalized Nano-Graphene Oxide

Functionalized nano-graphene oxide(FNGO)has a very high specific surface area and is rich in oxygen-containing functional groups such as hydroxyl,carboxyl,epoxy,etc.,enabling molecular loading and bioconjugation,thus possessing favourable drug/gene delivery capabilities.At present,research on the drug-loading application of FNGO needs to be explored in the preparation of functional nano-graphene oxide drug carriers.Therefore,in this paper,a staged high-temperature reaction Hummers method was used to prepare FNGO water dispersions,and hyaluronic acid and polyethylene glycol were used to modify GO to verify its good modifiability.Finally,centrifugation was used to separate FNGO.The specific research content of this paper includes the following three parts:(1)Based on the Hummers method,a six-stage heating reaction method was obtained by combining the oxidation mechanism of concentrated sulfuric acid,potassium permanganate and sodium nitrate on graphite powder under heating and regulating the reaction temperature and time.Since the preheating reaction time is sufficient,the reaction system,what is added with water to produce an instantaneous high temperature(slow operation,relatively dangerous),is improved to cool the ice bath to 20 °C and then add deionized water ice cubes.FNGO with few layers and good dispersion was obtained by 600 w probe ultrasound.The results showed that the thickness of go obtained by the improved experimental scheme was less than 1 nanometer,and the particle size was concentrated between dozens of nanometers and hundreds of nanometers,with hydroxyl groups,carboxyl groups,epoxy groups and other functional groups,which could be modified directly without the usual carboxylation.The improved experimental scheme greatly reduced the insecurity and uncertainty caused by rapid heating and rapid heating,providing a basis for the industrialization of FNGO drug carriers.(2)Based on(1)for the preparation of FNGO carrier to make the necessary modification,with the commonly used molecular biocompatibility of Hyaluronic acid(HA)and Polyethylene glycol(PEG)functional FNGO carrier.The results showed that the FNGO and HA wera chemically linked to the prepared FNGO-HA through the carbodiimide method,and the resulting FNGO-HA was more stable in saline than FNGO.FNGO successfully formed an amide bond with PEG,and the resulting FNGO-PEG compound was more stable than FNGO-HA in 0.2 MPBS buffer.(3)Differential centrifugation,sucrose density gradient centrifugation and glycerine density gradient centrifugation were used to separate FNGO water dispersions.After centrifugation,samples were observed by atomic force microscope and size distribution statistics.FNGO with mean particle diameter of 52.06 nm was obtained under differential centrifugation;FNGO with mean particle diameter of 59.68,69.75,76.96,102.69,155.64 and 199.30 nm were obtained under sucrose density gradient centrifugation;FNGO with mean particle diameter of 52.14,61.30,82.46 and 103.31 nm were obtained under glycerol density gradient centrifugation.