A feasibility study for in vitro evaluation of fixation between prosthesis and bone with bone marrow-derived mesenchymal stem cells.
BACKGROUND
It is difficult to quantitatively evaluate adhesive strength between an implant and the neighboring bone using animal experiments, because the degree of fixation of an implant depends on differences between individuals and the clearance between the material and the bone resulting from surgical technique.


METHODS
A system was designed in which rat bone marrow cells were used to quantitatively evaluate the adhesion between titanium alloy plates and bone plates in vitro. Three kinds of surface treatment were used: a sand-blasted surface, a titanium-sprayed surface and a titanium-sprayed surface coated with hydroxyapatite. Bone marrow cells obtained from rat femora were seeded on the titanium alloy plates, and the cells were cultured between the titanium alloy plates and the bone plates sliced from porcine ilium for 2 weeks. After cultivation, adhesive strength was measured using a tensile test, after which DNA amount and Alkaline phosphatase activity were measured.


RESULTS
The seeded cells accelerated adhesion of the titanium alloy plate to the bone plate. Adhesive strength of the titanium-sprayed surface was lower than that of the sand-blasted surface because of lower initial contact area, although there was no difference in Alkaline phosphatase activity between two surface treatments. A hydroxyapatite coating enhanced adhesive strength between the titanium alloy palate and the bone plate, as well as enhancing osteogenic differentiation of bone marrow cells.


CONCLUSIONS
It is believed that this novel experimental method can be used to simultaneously evaluate the osteogenic differentiation and the adhesive strength of an implant during in vitro cultivation.
Morita
Yusuke
Y
Department of Biomedical Engineering, Doshisha University, 1-3 Tatara Miyakodani, Kyotanabe city, Kyoto 610-0394, Japan. ymorita@mail.doshisha.ac.jp
Yamasaki
Kenichi
K
Hattori
Koji
K
D000497:Alloys; D000818:Animals; D001696:Biomechanical Phenomena; D001854:Bone Marrow Cells / Q000166:cytology*; D001842:Bone and Bones / Q000502:physiology*; D002448:Cell Adhesion; D002454:Cell Differentiation; D002478:Cells, Cultured; D005240:Feasibility Studies; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D010012:Osteogenesis; D019736:Prostheses and Implants; D051381:Rats; D013499:Surface Properties; D034421:Sus scrofa; D013718:Tensile Strength; D023822:Tissue Engineering; D014025:Titanium
D000497:Alloys; C031462:titanium alloy (TiAl6V4); D014025:Titanium