TITLE:
The Role of Microstructure of Highly Purified Beta-Tricalcium Phosphate for Osteoinduction in Canine Dorsal Muscles
AUTHORS:
Takashi Ariizumi, Akira Ogose, Naoki Kondo, Hiroyuki Kawashima, Tetsuo Hotta, Naoko Kudo, Makiko Hoshino, Hikaru Inoue, Hiroyuki Irie, Naoto Endo
KEYWORDS:
Osteoinduction; Beta-Tricalcium Phosphate; Micropore; Bioresorption; Osteoclast
JOURNAL NAME:
Journal of Biomaterials and Nanobiotechnology,
Vol.4 No.2,
April
18,
2013
ABSTRACT: Porous β-tricalcium phosphate (TCP) displays osteoinductivity in certain
animals in the absence of osteoinductive agents. We evaluated whether the
microstructure may be an important determinant of osteoinduction, and also investigated how bone formation was promoted
using β-TCP combined with bone marrow
aspirates. We prepared two types of β-TCP,
namely, β-TCP A, which possessed
interconnected macropores and micropores, and β-TCP B, which possessed macropores but had less detectable
micropores. These were implanted with or without marrow in canine muscles. Bone
formation and the resorption of each β-TCP
implant were evaluated histologically. Newly formed bone began to appear at day 42 in the implants of β-TCP A alone, but the implants of β-TCP B alone did not show any bone
formation by day 42. Meanwhile, bone formation was already evident on day 14 by
loading with bone marrow aspirates with or without micropores. By
immunohistochemistry, the number of cathepsin K-positive cells (osteoclasts)
increased as time passed in the implants of β-TCP
A alone, while the number of the osteoclasts did not change obviously in the
implants of β-TCP B alone from day 14
to 56. Reticular fibrils were evident within the β-TCP A, and were barely observed in the β-TCP B in the silver impregnation. The present result would bring
about the possible role to enhance the importance of the surface microstructure
for the better osteoinductivity. Our findings suggest that the combination of
porous β-TCP and bone marrow
facilitates bone formation.