Osteoporosis is a major age-related
bone disease characterized by
low bone mineral density and a high risk of fractures.
Bisphosphonates are considered as effective agents treating
osteoporosis. However, long-term use of
bisphosphonates is associated with some serious side effects, which limits the widespread clinical use of
bisphosphonates. Here, we demonstrate a novel type of bone-targeting anti-resorptive agent,
bisphosphonate-
enoxacin (BE). In this study, ovariectomized rat model was established and treated with PBS,
zoledronate (50 μg/kg) and different dose of BE (5 mg/kg and 10 mg/kg), respectively. The rats subjected to
sham-operation and PBS treatment were considered as control group. Then, micro-computed tomography scanning, biomechanical tests, nano-indentation test and Raman analysis were used to compare the effects of
zoledronate and BE on cortical bone mass, strength, and composition in ovariectomized rats. We found that both
zoledronate and BE were beneficial to cortical bone strength. Three-point bending and nano-indentation tests showed that
zoledronate- and BE-treated groups had superior general and local biomechanical properties compared to the ovariectomized groups. Interestingly, it seemed that BE-treated group got a better biomechanical property than the
zoledronate-treated group. Also, BE-treated group showed significantly increased
proteoglycan content compared with the
zoledronate-treated group. We hypothesized that the increased bone strength and biomechanical properties was due to altered bone composition
after treatment with BE. BE, a new bone-targeting agent, may be considered a more suitable anti-resorptive agent to treat
osteoporosis and other
bone diseases associated with decreased bone mass.