Modulation of periodontitis progression using pH ‐responsive nanosphere encapsulating metronidazole or N ‐phenacylthialzolium bromide

Background and Objective This study aimed to develop pH ‐responsive polylactide‐glycolic acid co‐polymer and chitosan ( PLGA /chitosan) nanosphere as an inflammation‐responsive vehicle and evaluate the potential of the nanosphere encapsulating metronidazole, an antibiotic, and N ‐phenacylthiazolium bromide ( PTB ), a host modulator, for treating periodontitis. Material and Methods PLGA /chitosan nanospheres were fabricated using oil‐in‐water emulsion method. Experimental periodontitis was induced on the rat maxillae, and the sites were randomly allocated to four treatment categories, including periodontitis alone ( PR ), periodontitis with nanospheres alone, nanospheres encapsulating metronidazole ( MT ) and nanospheres encapsulating PTB ( PB ). The ligature was retained until the animals were killed, and the treatment outcome was evaluated by the progression of periodontal bone loss ( PPBL ), inflammatory cell infiltration and collagen deposition. Results The encapsulated drug was released rapidly from the nanospheres without significant initial burst release at pH 5.5. Compared with group PR , PPBL was significantly reduced in groups MT and PB on day 4 ( P <.05). On day 21, PPBL was significantly lower in group PB ( P <.05). In groups MT and PB , inflammation was significantly reduced in groups MT and PB relative to groups PR and periodontitis with nanospheres alone ( P <.05), and collagen deposition was significantly greater relative to group PR ( P <.05). Conclusion PLGA /chitosan nanospheres encapsulating metronidazole or PTB showed potential for modulating periodontitis progression.