2022, Vol. 26 ›› Issue (22): 3467-3473

Preparation and properties of graphene oxide/silk fibroin/rifampicin drug-loading microspheres

Jiang Chaorui, Xu Yan, Xiong Ying, Zhang Xujing   

Abstract: BACKGROUND: The cure rate of severe bone tuberculosis is low and long-term medication is needed, but the adverse reaction of oral drugs is large. Quantitative placement of drug-loaded sustained-release microspheres in lesions can not only ensure drug concentration and precise treatment, but also effectively regulate the rate of drug release and reduce adverse reactions.
OBJECTIVE: To optimize the preparation process of graphene oxide/silk fibroin/rifampicin microspheres.
METHODS: Graphene oxide/silk fibroin/rifampicin microspheres were prepared by emulsion method. In determining the concentration of silk fibroin 3.5%, water oil ratio 1:6, Span80 and paraffin ratio 1:10, temperature of 50℃, rifampicin and drug carrier solution than 50 mg:1 mL as quantitative premise, the micromorphology, loading rate and encapsulation rate of the drug-loading microspheres were prepared at different stirring speeds (200, 500, 800 r/min), different organic solvents and water phase volume ratio (1:1, 4:1, 6:1) and different solute ratios of graphene oxide solution to silk fibroin solution (0.1%, 0.25%, 0.5%); and the better preparation technology was determined.
RESULTS AND CONCLUSION: (1) Scanning electron microscopy showed that the microspheres prepared at 500 r/min were uniform in size and had good pellet-forming property. When the volume ratio of organic solvent to water phase was 4:1, the pellet forming efficiency of microspheres was better. When the solute ratio of graphene oxide solution to silk fibroin solution was 0.1%, the pellet formation rate of microspheres was higher. (2) Comprehensive test results of drug-loading rate and coating rate, coupled with the graphene oxide/silk fibroin microspheres cytotoxicity experiment result, the microspheres were prepared under the condition of the stirring speed 500 r/min, organic solvent and water phase volume ratio of 4:1, graphene oxide solution and fibroin solution solute ratio of 0.1%. Microsphere formation rate was high; the loading rate was 13.5%; the encapsulation rate was 61%. The microspheres could stably release drugs in vitro, and the cumulative release dosage within 96 hours was about 67.3%. Drug release was processed by diffusion and dissolution.
Key words: graphene oxide, silk fibroin, drug-loaded microsphere, emulsifying solvent evaporation method, drug loading rate, encapsulation rate, cumulative release rate, drug release mechanism