▎ 摘　　要

NOVELTY - Preparing small interfering RNA (siRNA) complex nano-graphene oxide carrier involves adding graphite powder into a round-bottom flask, adding phosphoric acid and sulfuric acid, uniformly mixing, allowing to stand in an ice water bath, gradually adding potassium permanganate, incubating while stirring, heating the solution, cooling, adding hydrogen peroxide solution to the solution until the solution is bright yellow, discarding the supernatant, washing the product with dilute hydrochloric acid and deionized water until neutral, vacuum freeze drying to obtain graphene oxide powder, modifying the graphene oxide powder with six-arm polyethylene glycol (PEG) and polyethylenimine (PEI) to obtain positively charged functionalized graphene oxide and adsorbing negatively charged siRNA sequence by electrostatic action. USE - The method is useful for preparing siRNA complex nano-graphene oxide carrier. ADVANTAGE - The method produces carrier which has improved biocompatible and no obvious biological toxicity, improves functionalized graphite oxide loading capacity and ensures siRNA sequence is not easy to fall off and be degraded. The system has good dispersion, high biocompatibility and strong load capacity. DETAILED DESCRIPTION - Method for preparing small interfering RNA (siRNA) complex nano-graphene oxide carrier involves (a) adding 3 g graphite powder into a round-bottom flask, adding 40 ml concentrated phosphoric acid and 360 ml concentrated sulfuric acid, uniformly mixing and allowing to stand in an ice water bath, (b) gradually adding 18 g potassium permanganate into the solution and incubating at 15 degrees C while stirring for 2 hours, (c) heating the solution at 50 degrees C for 12 hours, cooling to room temperature and stirring the solution in round bottom flask in ice water, (d) adding suitable amount of 30% hydrogen peroxide solution to the solution until the solution is bright yellow, discarding the supernatant, and washing the product with dilute hydrochloric acid and deionized water until neutral, (e) vacuum freeze drying to obtain 2.5 g graphene oxide powder, (f) modifying the graphene oxide powder with six-arm polyethylene glycol (PEG) that ensures the strong hydrophilicity of the system and (g) modifying the six-arm PEG-modified graphene oxide product with polyethylenimine (PEI) to obtain positively charged functionalized graphene oxide and adsorbing negatively charged siRNA sequence by electrostatic action. An INDEPENDENT CLAIM is included for graphene oxide delivery siRNA system, which is prepared using gene siRNA sequence and delivery carrier GO-PEG-PEI.