ABSTRACT
BACKGROUND:Cuttlebone/racemic polylactic acid composite artificial bone has been prepared in the previous studies to improve the incomplete degradation of cuttlebone. OBJECTIVE:To observe the degradation and biocompatibility of cuttlebone/racemic polylactic acid composite artificial bone in animals. METHODS:Thirty healthy New Zealand white rabbits were randomly divided into four groups. Models of right radial defects were prepared in rabbits, and model rabbits were subjected to implantation of cuttlebone/racemic polylactic acid composite artificial bone into the defects and muscular sac between the radial lateralis muscle and rectus (experimental group), implantation of cuttlebone into the defects and muscular sac between the radial lateralis muscle and rectus (control group 1), implantation of racemic polylactic acid into the defects and muscular sac between the radial lateralis muscle and rectus (control group 2), or no treatment (blank control group), respectively. At 2, 4, 8 weeks after operation, X-ray and histological examinations were performed in the four groups. RESULTS AND CONCLUSION:(1) Compared with the other three groups, the bone mineral density of the experimental group was significantly higher at 4 and 8 weeks after material implantation into the defects (P < 0.05), and moreover, the bone mineral apposition rate of the experimental group was significantly higher at different time after operation (P< 0.05). At 8 weeks after operation, the bone tissues in the experimental group grew from the both ends to the center to form multiple bone island-like structures, with less residual materials, and the marrow cavity and implanting material were in a traffic manner; in the control group 1, there were many residual materials, and no intercommunication was found between the marrow cavity and implant material. (2) At 2 weeks after material implantation into the muscle capsule, there were more inflammatory cels, but the inflammation relieved at 4 weeks and disappeared basicaly at 8 weeks, and the material was degraded partialy. These findings indicate that the cuttlebone/racemic polylactic acid composite artificial bone is a kind of good bone substitute material that has good biocompatibility and degradability.