Biomedical Engineering Reference
In-Depth Information
4.1 ± 0.6 mg/L, respectively. Chromium is one of the essential
elements for human, so slight amount of this element may contribute
to cell proliferation, and resulting in higher cell growth. Additionally,
in all studied extracts calcium was present at the concentration of
64 ± 8 and 82 ± 11 mg/L, respectively. The existence of Ca could
promote the formation of apatite. Titanium element cannot be
detected.
This study provided evidence of signiicant differences in the
amount of calcium and phosphorus deposition by osteoblasts as
well as their precipitation from culture media between common
orthopedic (Ti6Al4V, CoCrMo) alloys due to nanometer particle sizes
[142].
12.3.6
Biocompatibility of Ni-Free Stainless Steel
Ni-free austenitic stainless steels with nanostructure were
synthesized by mechanical alloying (MA), heat treatment, and
nitrogenation of elemental Fe, Cr, Mn, and Mo microcrystalline
powders [120−125]. The phase transformation from ferritic to
austenitic was conirmed by XRD analysis. The mechanical and
corrosion properties of the produced biomaterials were investigated.
Additionally, the biocompatibility of nickel-free austenitic stainless
steels with nanostructure and microcrystalline 316L steel, were
analyzed studying the behavior of Normal Human Osteoblast
(NHOst) cells from Cambrex (CC-2538). An enhancement of the
properties due to the nanoscale structures in the bulk consolidated
materials was observed.
Biocompatibility tests were performed for synthesized bulk
nanomaterials and 316L stainless steel. The AFM images of the cells
cultured on Fe
54
Cr
24
Mn
21
Mo
1
N disks sterilized by autoclaving for 1,
7, and 14 days are shown in Fig. 12.10. After incubation for 1 day,
the cells were observed as scattered dots but after 7 days incubation
the cells had grown to cover almost entire surface of the disks. There
was a large difference in number of cells in the studied samples. Two
factors may inluence cell growth on the disks: adsorbing protein
onto the disks and released metal ions from the disks.
Cytotoxicity tests of the extracts of the studied materials under
wear conditions are shown in Fig. 12.11.
