ISSN:
0021-9304
Keywords:
in situ hybridization
;
collagen I
;
osteoblast
;
β-tricalcium phosphate
;
osteoconduction
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
,
Technology
Notes:
Temporal and spatial patterns of osteoblast activation around β-TCP particles implanted into bone were analyzed by in situ hybridization with digoxygenin-labeled procollagen α1(I) RNA probes. β-TCP particles (150-300 μm in diameter) were implanted into rat tibiae, and specimens were collected 3, 5, 7, 14, and 28 days after operation. Activated osteoblasts displayed intense procollagen α1(I) RNA specific labeling. At day 3, osteoblasts lining pre-existing trabeculae in places showed a specific signal. Additionally, scattered activated cells compatible with preosteoblasts also were observed in the vicinity of the trabeculae among red blood cells that filled the space between β-TCP particles. Osteoblast activation on the surface of β-TCP rarely was observed. At days 5 and 7, osteoblast activation and bone formation advanced centripetally. At the forefront of bone formation positive cells were scattered in the blood cell clots, and some of the positive cells colonized forming new bone matrix. Formation of new bone did not always begin at the surface of β-TCP. At day 14, most of the β-TCP particles were tightly associated with newly formed bone, and the number of positive osteoblasts was reduced. At day 28, absorption of the newly formed bone and the β-TCP by multinuclear cells was sporadically demonstrated. Such cells often were accompanied by active osteoblasts, suggesting early bone remodeling. In conclusion, in situ hybridization with procollagen α1(I) was employed to demonstrate precisely the mode of recruitment of bone cell precursors. β-TCP does not positively guide collagen I expressing bone cells along its surface. It has no apparent effects on bone regeneration. © 1998 John Wiley & Sons, Inc. J Biomed Mater Res, 39, 71-76, 1998.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
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