We describe our investigations of the surface physicochemical and biological properties of polylactic acid modified by silver, argon and carbon ion implantation to doses of 1 × 1014, 1 × 1015 and 1 × 1016 ion/cm2 at energies of 20 keV (for C and Ar) and 40 keV (for Ag). X-ray analysis shows enhancement of coherent scattering regions and lattice constant increase after ion implantation. Secondary electron mass-spectrometry indicates that Ag concentration in the subsurface layer is less than 80%, but at a depth of 500 nm does not exceed 1–2%. The silver forms metal particles in the subsurface layer rather than making additional chemical bonds with polymer atoms. Atomic force microscopy reveals that the higher the irradiation dose the larger the surface roughness of the samples. Ag-irradiated samples implanted to a dose of 1 × 1016 ions/cm2 have the highest roughness, 190 nm. Our investigation of the cytotoxicity of two individual donor macrophages shows that Ag-implanted polylactic acid has no negative impact on immune system cells and could be a promising material for biomedical application.
Surface Property Modification of Polylactic Acid by Ion Implantation
