Nanocarbon-Polymer\nComposites for Next-Generation\nBreast Implant Materials

Most\nbreast implants currently used in both reconstructive and\ncosmetic surgery have a silicone outer shell, which, despite much\nprogress, remains susceptible to mechanical failure, infection, and\nforeign body response. This study shows that the durability and biocompatibility\nof breast implant-grade silicone can be enhanced by incorporating\ncarbon nanomaterials of sp<sup>2</sup> and sp<sup>3</sup> hybridization\ninto the polymer matrix and onto its surface. Plasma treatment of\nthe implant surface can be used to modify platelet adhesion and activation\nto prevent thrombosis, postoperative infection, and inflammation disorders.\nThe addition of 0.8% graphene flakes resulted in an increase in mechanical\nstrength by 64% and rupture strength by around 77% when compared to\npure silicone, whereas when nanodiamond (ND) was used as the additive,\nthe mechanical strength was increased by 19.4% and rupture strength\nby 37.5%. Composites with a partially embedded surface layer of either\ngraphene or ND showed superior antimicrobial activity and biocompatibility\ncompared to pure silicone. All composite materials were able to sustain\nthe attachment and growth of human dermal fibroblast, with the preferred\ngrowth noted on ND-coated surfaces when compared to graphene-coated\nsurfaces. Exposure of these materials to hydrogen plasma for 5, 10,\nand 20 s led to substantially reduced platelet attachment on the surfaces.\nHydrogen-treated pure silicone showed a decrease in platelet attachment\nfor samples treated for 5–20 s, whereas silicone composite\nshowed an almost threefold decrease in platelet attachment for the\nsame plasma treatment times. The absence of platelet activation on\nthe surface of composite materials suggests a significant improvement\nin hemocompatibility of the material.