Caerin 1.9–Titanium Plates Aid Implant Healing and Inhibit Bacterial Growth in New Zealand Rabbit Mandibles

Abstract

Objectives: With rising rates of maxillofacial fracture, postoperative infection following rigid internal fixation is an important issue that requires immediate resolution. It is important to explore an alternative antibacterial method apart from conventional antibiotics. A controlled experiment was conducted to evaluate the effectiveness of a caerin 1.9 peptide–coated titanium plate in reducing mandibular infection in New Zealand (NZ) rabbits, aiming to minimise the risk of post–metallic implantation infection. Methods: Twenty-two NZ rabbits were randomly divided into 3 groups. The experiment group received caerin 1.9 peptide–coated titanium plates and mixed oral bacteria exposure. The control group received normal titanium plates with mixed oral bacteria exposure. The untreated group served as a control to prove that bacteria in the mouth can cause infection. Weight, temperature, hepatic function, and C-reactive protein levels were measured. Wound and bone conditions were evaluated. Further analysis included local infection, anatomic conditions, histology, and bacterial load. Results: No significant differences were found in temperature, weight, blood alanine aminotransferase, and C-reactive protein levels amongst the 3 groups. The experiment group showed the lowest amount of bacterial RNA in wounds. Additionally, the experiment group had higher peripheral lymphocyte counts compared to the control group and lower neutrophil counts on the third and seventh day postoperatively. Histologic analysis revealed lower levels of inflammatory cell infiltration, bleeding, and areas of necrosis in the experimental group compared with the controls. Conclusions: A caerin 1.9–coated titanium plate is able to inhibit bacterial growth in a NZ rabbit mandibular mixed bacteria infection model and is worth further investigation.

Keywords

• Caerin 1.9
• Antimicrobial peptide
• Titanium plate
• Animal model