Graphene oxide-loaded rapamycin coating on airway stents inhibits stent-related granulation tissue hyperplasia

Abstract OBJECTIVES To explore the safety and efficacy of a graphene oxide-loaded rapamycin-coated airway stent (GO@RAPA-SEMS) in a rabbit model. METHODS The dip coating method was used to develop GO@RAPA-SEMS and PLGA-loaded rapamycin coating airway stents (PLGA@RAPA-SEMS). The surface structure was evaluated by SEM. The in vitro drug release profiles of the two stents were explored and compared. In the animal study, a total of 45 rabbits were randomly divided into three groups and underwent 3 kinds of stent placement. Computed tomography was performed to evaluate the degree of stenosis at 1, 2, and 3 months poststent surgery. Five rabbits in each group were sacrificed after CT. The stented trachea and blood were collected for further pathological analysis and laboratory testing. RESULTS The in vitro drug release study revealed that GO@RAPA-SEMS exhibited sudden release on the first day and maintained a certain release rate on the 14th day. The PLGA@RAPA-SEMS exhibited a longer sustained release time. All 45 rabbits underwent successful stent placement. Pathological results indicated that the granulation tissue thickness in the GO@RAPA-SEMS group was less than that in the PLGA@RAPA-SEMS group. The TUNEL and HIF-1α staining results support that the granulation inhibition effect in the GO@RAPA-SEMS group was greater than that in the PLGA@RAPA-SEMS group. CONCLUSIONS GO@RAPA-SEMS effectively inhibited stent-related granulation tissue hyperplasia.