Abstract
Reindeer antler was studied for its possible use as a bone implant material. A
molecular biological study showed that antler contains a growth factor promoting
bone formation. Ectopic bone formation assay showed that antler is not an equally
effective inducer as allogenic material.
Ectopic bone formation assay was optimised for biocompatibility studies of
orthopaedic NiTi implants. Ti-6Al-4V and stainless steel were used as reference
materials. The assay showed differences in bone mineral densities, with superior
qualities in NiTi. The rate of endochondral ossification varied between the
implants, NiTi ossicles had larger cartilage and bone areas than ossicles of the
two other materials.
The cytocompatibility of NiTi was studied with three different methods. Cell
viability, cell adhesion and TGF-β1 concentration were assessed in
ROS-17/2.8 cell cultures. Cells grown on NiTi had better viability than cells
grown on pure nickel or stainless steel. Cell attachment on the materials was
studied with paxillin staining of focal contacts. The number of focal contacts
was clearly higher in cells grown on NiTi than in cells grown on pure titanium,
pure nickel or stainless steel. TGF-β1 concentration was measured with
ELISA. The results showed that there was only some minor variation between NiTi,
pure titanium and stainless steel. Nickel showed a lower TGF-β1
concentration. Taken together, these results suggest that NiTi is well tolerated
by ROS-17/2.8 cells. The cytocompatibility of stainless steel is not so good as
that of NiTi.
The same tests were used to study the effects of the surface roughness of the
implant on cytocompatibility. Three different surface roughness grades were
compared in cell cultures on NiTi and titanium alloy discs. Titanium alloy was
subjected to two different heat treatments, to compare the effects of the
treatments on cytocompatibility. The studies showed that NiTi had a lesser impact
on cell viability and attachment than titanium alloy. Further, rough NiTi was
found to be a better tolerated surface than the others. In this study, heat
treatment of titanium alloy at +850° C did not interfere with cell viability
or attachment, as did the +1050° C treatment of the alloy. On the contrary,
TGF-β1 concentrations decreased on the +850° C treated alloy and were
approximately same on the +1050° C treated alloy and on NiTi.
| Identifer | oai:union.ndltd.org:oulo.fi/oai:oulu.fi:isbn951-42-6606-4 |
| Date | 22 February 2002 |
| Creators | Kapanen, A. (Anita) |
| Publisher | University of Oulu |
| Source Sets | University of Oulu |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/doctoralThesis, info:eu-repo/semantics/publishedVersion |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess, © University of Oulu, 2002 |
| Relation | info:eu-repo/semantics/altIdentifier/pissn/0355-3221, info:eu-repo/semantics/altIdentifier/eissn/1796-2234 |
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