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Novel explant model to study mechanotransduction and cell–cell communication
Author(s) -
Hoffler C. Edward,
Hankenson Kurt D.,
Miller Joshua D.,
Bilkhu Sukhinderdeep K.,
Goldstein Steven A.
Publication year - 2006
Publication title -
journal of orthopaedic research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.041
H-Index - 155
eISSN - 1554-527X
pISSN - 0736-0266
DOI - 10.1002/jor.20207
Subject(s) - osteocyte , explant culture , chemistry , matrix (chemical analysis) , mechanotransduction , bone cell , context (archaeology) , anatomy , microbiology and biotechnology , osteoblast , biology , in vitro , biochemistry , paleontology , chromatography
To understand in situ behavior of osteocytes, we characterized a model of osteocytes in their native bone matrix and demonstrated real‐time biologic activity of osteocytes while bending the bone matrix. Using 43 male Sprague‐Dawley rats, dumbbell‐shaped explants were harvested from stainless steel femoral implants after 6–12 weeks and incubated in culture medium or fixed. Sixteen specimens were used to determine bone volume density (BV/TV), volumetric bone mineral density (BMD) and histology for different implantation periods. Osteocyte viability was evaluated by L‐lactate dehydrogenase (LDH) activity in 12 cultured explants. Confocal microscopy was used to assess tracer diffusion in three explants and changes in osteocyte pH of a mechanically loaded explant. From 6 to 12 weeks, explant BV/TV and volumetric BMD trended up 92.5% and 101%, respectively. They were significantly and highly correlated. Tissues were uniformly intramembranous and all bone cell types were present. Explants maintained LDH activity through culture day 8. Diffusion at 200 µM was limited to 1,209 Da. Explants appeared capable of reproducing complex bone biology. This model may be useful in understanding osteocyte mechanotransduction in the context of a physiologically relevant bone matrix. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:1687–1698, 2006