Zolidronic Acid-loaded Gelatin Nanoparticales for Alveolar Bone Restitution

Objectives: The resorption of the rest ridge after tooth extraction, which brings difficulties to the design of denture restoration is very common in dental clinical treatment. Zoledronic acid is the most potent bisphosphonate which is widely used to inhibit bone resorption, whereas it also brings severe side effects while systemically administrated. The objectives of this work is to prepare zoledronic acid-loaded gelatin nanoparticles(ZAGN) and study its efficiency on the restitution of alveolar bone.
Methods: ZAGNs are prepared by improved two-step desolvation. ZAGNs containing different dosage of zoledronic acid are inserted into the tooth extracted sockets (TESs) of Wistar rats. And then, bone mineral density and histological section are analyzed respectively.
Results: 50nm-450nm ZAGNs with an average size of 163 nm were prepared. The nanoparticles were found regular round and relatively dispersed well. The drug loading and encapsulation efficiency of ZAGNs were 6.85% and 60.52% respectively. They dissolved well in the TESs within 15 days. In the experimental group, bone trabaculars in the TESs were found more and bigger than that of the control group through histology section, they extended towards the center of the TESs. In the group which 6μg zoledronic acid was administrated, the TES was full of massive and reticular bone trabaculars after 30 days whereas in the control group, the bone trabaculars were significantly less and thinner. According to statistical analysis, the bone mineral density in the TESs of the experimental group was significantly higher than that of the control group at different period (P<0.01).
Conclusions: It is an ideal method to prepare ZAGNs by improved two-step desolvation. The ZAGNs could promote the restitution and inhibit the resorption of Wistar rats’ alveolar bone by slow release. During the experiment, no obvious side effects of ZAGN were detected.