Polyethylene (PE) and polyethylene terephthalate (PET) substrates were irradiated by the simultaneous use of oxygen (O2) cluster and monomer ion beams to improve their hydrophilic property. The hydrophilic groups such as COOH and C-OH groups were formed at the PE and PET surfaces by the irradiation. The contact angles of PE and PET substrates were decreased remarkably by the irradiation. Bioactive calcium silicate (CS) gel layer was successfully formed on the irradiated PE and PET substrates, and the irradiated and CS-coated PE and PET substrates formed uniform bonelike apatite layer on their surfaces in SBF within 4 d.
