Nuclear factor‐kappa B decoy oligodeoxynucleotide‐loaded poly lactic‐co‐glycolic acid nanospheres promote periodontal tissue healing after tooth replantation in rats

Background Excessive inflammation in the periodontal tissue after tooth replantation can lead to inflammatory root resorption and interrupt periodontal tissue regeneration. We tested the hypothesis that nuclear factor‐κB decoy oligodeoxynucleotide‐loaded poly lactic‐co‐glycolic acid nanospheres (NF‐PLGA) inhibit excessive inflammation and promote healing of periodontal tissue after replantation in rats. Methods The upper right incisors of rats were extracted, immersed in different specific solutions, and replanted. The rats were euthanized at 7, 14, and 28 days after replantation. Morphological evaluation with micro‐CT and histological assessment with hematoxylin and eosin and tartrate‐resistant acid phosphatase (TRAP) staining was performed. Additionally, we examined the expression of interleukin (IL)‐1β, IL‐6, transforming growth factor‐β1 (TGF‐β1), and fibroblast growth factor‐2 (FGF‐2) in the periodontal ligament (PDL) by performing immunohistological assessment. Results The NF‐PLGA group showed significantly greater dental root thickness than the other experimental groups. Root resorption was not observed after the application of NF‐PLGA on day 7. The application of NF‐PLGA also resulted in a significantly lower number of TRAP‐positive osteoclasts on days 7 and 14 after replantation. Significantly lower expression of IL‐1β and IL‐6 and higher expression of TGF‐β1 and FGF‐2 were observed under the application of NF‐PLGA in the PDL. Conclusions NF‐PLGA promoted the healing process by inhibiting the initial excessive inflammatory response in the PDL, preventing root resorption, and promoting periodontal tissue regeneration. The findings also suggested that the PLGA nanospheres‐mediated transfection of the decoy oligodeoxynucleotides can be useful for the clinical application of replanted tooth root surfaces.