Preparation and X-ray visibility evaluation of radiopacity enhanced silicone rubber by ironic nanopartides

Abstract

Objective To explore the feasibility of iron nanoparticles as radiopaque agents for modifying medical silicone rubber and to evaluate image visibility of modified materials.Methods Methyl vinyl silicone elastomer was mixed with iron nanoparticles,carbon-coated ferric nanoparticles,respectively,in accordance with the designed formula ratios.The composites were blended,mixed,molded and vulcanized with.Two groups of new materials,iron nanoparticle enhanced silicone rubber （INESR,Group1） and carbon-coated ferric nanoparticle enhanced silicone rubber（Fe/CESR,Group2）,were harvested.Medical silicone rubber was as a negative control group.CT scanning of each group of material samples in vitro was performed,and both CT images and measured CT values were collected.Differences in CT mean values between the groups were compared.Samples of new material groups were implanted subcutaneously in a dog and standardized radiographic images were obtained.X-Ray Diffraction was used to analyze the component stability of iron nanoparticles dispersing in the silicone rubber.Results Two groups of radiographic image enhanced silicone rubber were prepared.The X-ray images of new composites were clearly visible both in vitro and in vivo.CT values were increased with the increase of added metal nanoparticles and metal atomic weight.CT mean values of each group and the materials in Group 1 and Group2 with the same material formulation were significantly different （P〈0.001）.After placed for 180 days,the diffraction peak positions of elemental iron in both groups of materials remained essentially unchanged,and it showed that dispersed iron nanoparticles and carbon-coated iron nanopaarticles in silicone rubber were stable.Conclusion The metal nanoparticles of iron and carbon-coated ferrum can be used as radiographic markers for improving quality of X-Ray image of the medical silicone rubber. Key words: Biomaterials; Metal nanoparticles; Radiopacity; Silicone rubber