Natural polyphenol self-assembled pH-responsive nanoparticles loaded into reversible hydrogel to inhibit oral bacterial activity.

Periodontitis is one of the most prevalent chronic inflammatory diseases and Polyphenols isolated from Turkish gall play a major role in the treatment of inflammatory diseases for their antibacterial, anti-inflammatory and antioxidant activities. In this work, Turkish Galls effective constituent (TGEC, T) was prepared into nanoparticles (T-NPs) by principle of oxidative self-polymerization. The pH-sensitive T-NPs was encapsulated into thermosensitive type in-situ hydrogel, and 42.29 ± 1.12% of effective constituent from T-NPs were continuously released within 96 h under the periodontitis environment. In addition, the weakly alkaline oral micro-environment of patients with periodontitis is more conducive to the sustained release of effective constituent, which is 10.83% more than that of healthy periodontal environment. The bacteriostatic test showed that T-NPs had stronger antibacterial activity on oral pathogens than that of TGEC. Compared with TGEC, the minimum inhibitory concentration (MIC) of T-NPs against P. gingivalis and A. viscosus was reduced by 50% and 25%, respectively. Interestingly, T-NPs induced bacteria lysis by promoting the excessive production of ROS without periodontal tissue damage caused by excessive oxidation reaction. In conclusion, a simple method of preparing microspheres with natural polyphenols was developed, which provides beneficial reference for one-step prepared drug carriers from effective components of natural product, likewise the method offers a green and effective solution to synthesis a new adjuvant therapy drugs for treatment of gingivitis associated with periodontal pockets.