This work demonstrates the fabrication of a hydroxyapatite (HA) composite material for potential use in biomedical implant applications. A composite powder is prepared by introducing graphene oxide (GO) and F- ions, which are incorporated in the HA crystal structure via in-situ chemical synthesis. The powder is consolidated through spark plasma sintering, resulting in a biocomposite (GO-FHA) material that is mechanically stronger and more chemically stable after implantation than HA. The addition of GO and partial substitution of F- also promote osteoblast proliferation as in-vitro bioactivity tests show.

This paper presents a summary of some of the research conducted on sponge-like titanium coatings developed for orthopedic use. It assesses the pore structure, adhesion properties, and in-vitro and in-vivo biological characteristics of porous titanium coatings deposited by vacuum plasma spraying on metals, PEEK polymer, and two bioceramics, Mg-toughened ZrO 2 and ZrO 2 -toughened Al 2 O 3 . The plasma sprayed coatings show good flexibility in terms of pore size (100-800 µm), overall porosity (40-70%), and coating thickness (600-1500 µm).

In this study, titania and hydroxyapatite nanopowder mixtures are deposited on medical grade titanium substrates by HVOF spraying. To assess bioperformance, human mesenchymal stem cells (hMSCs) were cultured from 1 to 21 days on the surface of HVOF-sprayed TiO 2 and TiO 2 -HA samples. Plasma sprayed HA and uncoated Ti-6Al-4V substrates were used as controls. The active cultures were evaluated for cell proliferation, cytoskeleton organization, and cell-substrate interaction. The results for HVOF-sprayed TiO 2 -HA nanocomposite coatings show strong evidence of bone growth, proliferation, and attachment with cell-substrate interaction levels superior to those of air plasma sprayed HA coatings. Although there are no clear explanations for this favorable behavior, the topography and chemical composition of the surface of the coating appear to be playing important roles.

In this investigation, bioactive ceramic materials, including dicalcium silicate, titania, and zirconia, were deposited on titanium substrates by plasma spraying in order to determine their effect on the bioactivity of metal implants. Cell-seeding tests show that MG63 osteoblast-like cells grow and proliferate well on each of the coating materials. In the case of Ca 2 SiO 4 , the presence of silicon ions is thought to be the key to this behavior. In regard to TiO 2 and ZrO 2 , the bioactivity is thought to result from the nanostructured surfaces and special surface compositions.