Si+ and N+ ion implantation for improving blood compatibility of medical poly(methyl methacrylate)

Si+ and N+ ion implantation into medical poly(methyl methacrylate) (PMMA) were performed at an energy of 80 keV with fluences ranging from 5×1012 to 5×1015 ions/cm2 at room temperature to improve blood compatibility. The results of the blood contacting measurementsin vitro showed that the anticoagulability and anticalcific behaviour on the surface morphology were enhanced after ion implantation. No appreciable change in the surface morphology was detected by scanning electron microscopy (SEM). X-ray photoelectron spectroscopy (XPS) analysis indicated that ion implantation broke some original chemical bonds on the surface to form some new Si- and N-containing groups. These results were considered responsible for the enhancement in the blood compatibility of PMMA.