Facile engineering of resveratrol nanoparticles loaded with 20(S)-protopanaxadiol for the treatment of periodontitis by regulating the macrophage phenotype.

Periodontitis is an inflammatory disease, mainly caused by the formation of a subgingival plaque biofilm. In recent years, growing attention has been paid to immunotherapy in the treatment of periodontitis, and the importance of communal intervention associated with macrophage polarization was emphasized. Herein, resveratrol (RES) and 20(S)-protopanaxadiol (PPD) were successfully self-assembled into RES@PPD nanoparticles (NPs) by the phenolic resin reaction. RES@PPD NPs have good stability and biocompatibility. The combined application of PPD and RES enhances the anti-inflammatory and antioxidant properties of nanocomposites, remarkably reduces the level of reactive oxygen species, and finally realizes the coordinated regulation of host immunity in periodontitis. The detailed mechanism is as follows: RES@PPD NPs inhibit M1 polarization of macrophages, promote M2 polarization by scavenging ROS, and then inhibit the NF-κB signalling pathway to regulate host immunity. In the animal model of periodontitis, RES@PPD NPs can remarkably decrease the level of pro-inflammatory cytokines, up-regulate the anti-inflammatory cytokines, and exhibit a profound therapeutic effect on local inflammation. Therefore, RES@PPD NPs are effective in antioxidation and anti-inflammation, thus providing a promising candidate drug for the treatment of periodontitis.

Implant site development using titanium plate and platelet-rich fibrin for congenitally missed maxillary lateral incisors: A case report.

BACKGROUND: Bone deficiency and soft tissue atrophy in the absence of maxillary lateral incisors are among the most challenging problems for implant clinicians. Autologous bone grafting is the gold standard for bone augmentation, but not without limitations. Platelet-rich fibrin (PRF), a biodegradable autologous biomaterial, has been widely used for bone and soft tissue management. Moreover, titanium plate is an advantageous barrier due to its good space-maintaining ability. However, there is a lack of literature on implant site development using titanium plate and PRF for congenitally missing maxillary lateral incisors. CASE SUMMARY: The patient was a 19-year-old girl with a congenitally missing tooth (#12). She underwent implant placement and simultaneous autologous bone grafting with titanium plate and PRF. At the follow-up visit 15 d post-procedure, the vascularization of soft tissue was visible. There was no swelling or pain after the surgery. Six months postoperatively, bone regeneration was evident. Subsequently, the definitive restoration was placed, and the patient was satisfied with the esthetic outcomes. CONCLUSION: Implant site development using titanium plate and PRF for congenitally missing maxillary lateral incisors is a feasible procedure. In this case, the labial bone plate was displaced but remained connected to the base bone, ensuring blood supply. The titanium plate fixed the labial bone plate and maintained the osteogenic space, while the PRF provided growth factors and leukocytes for bone and soft tissue regeneration. Furthermore, the procedure reduced the surgical complexity and adverse reactions, displaying outstanding esthetic outcomes.

[Application status of hypoxia mimetic agents in bone tissue engineering].

OBJECTIVE: To summarize the application status of hypoxia mimetic agents in bone tissue engineering. METHODS: The related literature about the hypoxia mimetic agents in bone tissue engineering was reviewed and analyzed. And the application status and progress of hypoxia mimetic agents in bone tissue engineering were retrospectively analyzed. RESULTS: Hypoxia mimetic agents have the same effect as hypoxia in up-regulating the level of hypoxia inducible factor 1α (HIF-1α). The combination of hypoxia mimetic agents and scaffolds can up-regulate the level of HIF-1α in bone tissue engineering, thus promoting early vascularization and bone regeneration of the bone defect area, which provides a new idea for using bone tissue engineering to repair bone defect. At present, the commonly used hypoxia mimetic agents include iron chelating agents, oxoglutarate competitive analogues, proline hydroxylase inhibitors, etc. CONCLUSION: Hypoxia mimetic agents have a wide application prospect in bone tissue engineering, but they have been used in bone tissue engineering for a short time, more attention should be paid to their possible side effects. In the future research, the hypoxia mimetic agents should be developed in the direction of higher targeting specificity and safety, and the exact mechanism of hypoxia mimetic agents in promoting bone regeneration should be further explored.