Multifunctional biocompatible nanostructured coatings for load-bearing implants

To take advantage of the self-propagating high-temperature synthesis (SHS) technique, magnetron sputtering (MS), and ion implantation assisted magnetron sputtering (HAMS), a new type of biocompatible nanostructured film was developed and studied. Films of Ti-Ca-C-O-(N), Ti-Ca-P-CO-(N), Ti-Si-Zr-O-(N), and Ti-Zi-C-O-(N) were deposited by DC MS or IIAMS of SHS composite targets TiC0.5 + CaO, TiC0.5 + CaO + TiO2, TiC0.5 + Ca-10(PO4)(6)(OH)(2), Ti5Si3 + ZrO2, and TiC0.5 + ZrO2 in an Ar atmosphere or reactively in a gaseous mixture of Ar+ 14% N-2. The films were characterized in terms of their structure, chemical, mechanical, and tribological properties. The biocompatibility of the films was evaluated by both in vitro and in vivo experiments. In vitro studies involved the investigation of adhesion, spreading and proliferation of Rat-1 fibroblasts, MC3T3-E1 osteoblasts, and IAR-2 epithelial cells, morphometric analysis, actin cytoskeleton and focal contacts staining of the cells cultivated on the films. Alkaline phosphatase activity and von Kossa staining of osteoblastic culture were investigated. Three groups of the in vivo investigations were fulfilled. Teflon plates coated with the tested films were inserted subcutaneous in mice and analysis of the population of cells on the surfaces was performed. Implantation studies of Ti rings and Ti rods coated with tested films using rat calvarian and hip defect models were also fulfilled. The results obtained show that Ti-based multicomponent films possess a combination of high hardness and adhesion strength, reduced Young's modulus, low wear and friction, high corrosion resistance with bioactivity, biocompatibility and non-toxicity that makes the films promising candidates as tribological coatings to be used for various medical applications like orthopedic prostheses, materials for connective surgery and dental implants. (c) 2006 Elsevier B.V All rights reserved.