Volume 24 (2015) Issue 2 Pages 147-154
The aim of this study was to investigate the effects of local administration of fluvastatin-gelatin complex on the healing of bone defects in low-turnover osteoporosis mice. Gelatin was used as a carrier of the fluvastatin. A fluvastatin-gelatin complex solution was created by dissolving each concentration of fluvastatin in a 75mg/mL gelatin solution. The gelatin solution was mixed with air, then lyophilized for 1 day and cross-linked by dry heating to make a fluvastatin-gelatin complex sponge. After crosslinking, the complex sponge was cut into pieces 1 mm diameter × 1 mm high to fit the bone defect area. The amount of fluvastatin in the sponge was adjusted to control (0 nmol), 0.1 nmol, 0.2 nmol, and 0.4 nmol. Using 20-week-old low-turnover osteoporosis model mice (SAMP6) and normal model mice (SAMR1), cylindrical and bone defects were made in sites 1.0 mm in diameter and depth, 1 mm of 3 mm from both sides of the distal end of the femur. The complex sponge was then inserted into each site, and the wound was closed. Radiographic analysis and histologic examinations were then performed. In SAMP6, the bone volumes of the bone defect areas in the 0.1nmol and 0.2nmol groups were significantly higher compared with those of the control and 0.4nmol groups at 14 and 21 days. Histological observation showed that the volume of newly formed bone increased in the 0.1nmol and 0.2nmol groups compared to those in the control and 0.4nmol groups at 14 and 21 days. The bone volumes of newly formed bone in SAMR1 were higher than were those in SAMP6, and the optimum concentration of fluvastatin was different between SAMP6 and SAMR1. The present study suggests that local administration of a fluvastatin-gelatin complex sponge provides improvement in bone healing in low-turnover osteoporosis.