TY - JOUR
T1 - Evaluation by bone scintigraphy of osteogenic activity of commercial bioceramics (porous β-TCP and HAp particles) subcutaneously implanted in rats
AU - Nakayama, Hitoshi
AU - Kawase, Tomoyuki
AU - Kogami, Hiroyuki
AU - Okuda, Kazuhiro
AU - Inoue, Hikaru
AU - Oda, Takaaki
AU - Hayama, Kazuhide
AU - Tsuchimochi, Makoto
AU - Wolff, Larry F.
PY - 2010/5/1
Y1 - 2010/5/1
N2 - Osteogenic potential of biomaterials used in bone regenerative therapy has been mainly examined in an animal-implantation study. We have here evaluated the applicability of bone scintigraphy in imaging ectopic bone formation, especially its initial phase, by β-tricalcium phosphate (β-TCP) particles that were implanted in rat dorsal subcutaneous tissues. In implanted osteogenic osteosarcoma cells used as a positive control, osteoid formation was found by histological examination and bone scintigraphy using 99mTc- hydroxymethyl diphosphonate (HMDP) at 2 and 3 weeks post-implantation, respectively, while the microfocuscomputed tomography (μCT) system required further mineralization, which occurred at 4 weeks. Implantation of β-TCP particles alone induced only faint biomineralization inside the particles, which could be microscopically detected by calcein chelation at 2 weeks post-implantation, but not by other histological examinations (e.g., HE staining) or μCT. However, the bone scintigraphy successfully detected this microscopic change at 1 week. Implanted hydroxyapatite (HAp) particles alone used as a negative control did not induce mineralization at microscopic levels, and therefore nothing was detected by either calcein chelation or bone scintigraphy. In conclusion, the bone scintigraphic methodology, although exhibiting less quantitation and resolution, would be applicable as a non-invasive, highly sensitive methodology in detecting the initial, microscopic changes associated with mineralization.
AB - Osteogenic potential of biomaterials used in bone regenerative therapy has been mainly examined in an animal-implantation study. We have here evaluated the applicability of bone scintigraphy in imaging ectopic bone formation, especially its initial phase, by β-tricalcium phosphate (β-TCP) particles that were implanted in rat dorsal subcutaneous tissues. In implanted osteogenic osteosarcoma cells used as a positive control, osteoid formation was found by histological examination and bone scintigraphy using 99mTc- hydroxymethyl diphosphonate (HMDP) at 2 and 3 weeks post-implantation, respectively, while the microfocuscomputed tomography (μCT) system required further mineralization, which occurred at 4 weeks. Implantation of β-TCP particles alone induced only faint biomineralization inside the particles, which could be microscopically detected by calcein chelation at 2 weeks post-implantation, but not by other histological examinations (e.g., HE staining) or μCT. However, the bone scintigraphy successfully detected this microscopic change at 1 week. Implanted hydroxyapatite (HAp) particles alone used as a negative control did not induce mineralization at microscopic levels, and therefore nothing was detected by either calcein chelation or bone scintigraphy. In conclusion, the bone scintigraphic methodology, although exhibiting less quantitation and resolution, would be applicable as a non-invasive, highly sensitive methodology in detecting the initial, microscopic changes associated with mineralization.
KW - Bone scintigraphy
KW - Osteogenic activity
KW - β-TCP.
KW - μCT
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U2 - 10.1177/0885328209341845
DO - 10.1177/0885328209341845
M3 - Article
C2 - 19726531
AN - SCOPUS:77952644396
SN - 0885-3282
VL - 24
SP - 751
EP - 768
JO - Journal of Biomaterials Applications
JF - Journal of Biomaterials Applications
IS - 8
ER -