Abstract:
This study evaluated the sustained release effect of
clarithromycin-loaded in PLGA microspheres in a rabbit calvaria
defect model. Four bone defects (ø5.0) were created in the calvaria
of New Zealand White rabbits (n521, n57/time point). The
defects were randomly designated to four groups. Group 1:
No augmentation (sham), Group 2: beta-tricalcium phosphate
(b-TCP), Group 3: b-TCP with 0.12 mg clarithromycin, and Group 4:
b-TCP with 6.12 mg PLGAmicrospheres loaded with 0.12 mg Clarithromycin.
After 2, 4, and 12 weeks of healing, bone regeneration
was evaluated using micro-computed tomography (mCT) and histology.
Clarithromycin release from PLGA microspheres revealed
sustained release for around 4 weeks with 50% release during
the first week. Histologically, new bone formation was evident at 2
and 4 weeks of healing in all groups and bone formation increased
as a function of healing time. At 12 weeks, Group 4 showed significantly
higher amount of newly formed bone compared to Group 1.
The mCT showed that Group 4 expressed significantly higher bone
formation compared to Group 1 at all time points. The in vivo findings
showed that b-TCP with clarithromycin-loaded microspheres
can enhance bone formation in bone defects.
