Abstract
Purpose: The aim of this study was to evaluate the combination of TAK-778-SR which was sustainedrelease microcapsules of a bone formation stimulant, TAK-778, and its carrier β-tricalcium phosphate (β-TCP) blocks (pore rates 60%, 75% respectively).The difference of their abilities in boneformation was evaluated histomorphologically by varying the following conditions: with or without TAK-778, pore ratio of carrier and embedding period.
Methods: Nine-week-old female SD rats were used. After removing the parietal bone from the head with a trephine bar, the defects were refilled by β-TCP blocks immersed with or without TAK-778 under the following conditions: saline solution, release microcapsules only, and release microcapsules with TAK-778 (TAK-778-SR).These rats were sacrificed after 5 and 10 weeks and their histological specimens were prepared.Morphological change was observed and the formation rates of each new bone were compared using an NIH imaging program.
Results: A significant amount of new bone was morphologically observed in all β-TCP samples that were treated with TAK-778-SR.A high rate of new bone formation was confirmed in the 10-week samples (pore rate 75%, with TAK-778-SR) with the NIH imaging.
Conclusions: 1.β-TCP and release microcapsules did not disturb the recovery process.2.Five-and 10-week samples (pore rate 60%) were absorbed marginally.3.Absorption was observed in the 5-week samples (pore rate 75%), and it was accelerated further at 10 weeks.4.An accelerating boneformation effect of TAK-778-SR was confirmed and β-TCP block was proved to be highly useful as a carriage material.
