Effect of ion modification of commonly used orthopedic materials on the attachment of human bone-derived cells

Biomaterials which combine optimum properties of strength and biocompatibil ity are desirable in improving the long-term performance of implantable med ical devices. Our study is aimed at developing technology designed to alter the outer atomic layers of a material to give the desired compatibility wi th the tissue while retaining the properties of the bulk substratum. Materi als used in this study were titanium vanadium alloy (Ti-6Al-4V) and cobalt chromium molybdenum alloy (Co-Cr). Soda Lime glass discs and polyethylene t erephthalate (PET) acted as controls. A cathode of either Ti-6Al-4V or Co-C r was used to simultaneously deposit and implant identified substrata. The attachment of human bone-derived cells (HBDC) to various materials was dete rmined using radiolabeling or colorimetric assays. Results show that HBDC a dhere preferentially to the unmodified surfaces of Ti-6Al-4V and Ti-6Al-4V on glass compared to the unmodified Co-Cr surfaces and to that of the Co-Cr on glass. Depositing Ti-6Al-4V on Co-Cr gives significantly better attachm ent of HBDC than when depositing Co-Cr onto Ti-6Al-4V. While cellular attac hment to the created surfaces reflects that of the cathodic materials, it i s not identical to these materials. Ion deposition/implantation is capable of creating permanent surfaces which reflect the adhesion of source materia ls not bulk substrata. (C) 1999 John Wiley & Sons, Inc.