Physicochemical, antibacterial properties, and compatibility of ZnO-NPs/chitosan/β-glycerophosphate composite hydrogels.

Chitosan/β-glycerophosphate (CS/β-GP) thermosensitive hydrogel has in-situ injectability and temperature sensitivity. In this experiment, ZnO-NPs and chitosan were combined to prepare ZnO-NPs/chitosan/β-glycerophosphate (ZnO-NPs/CS/β-GP) sodium to improve its antibacterial activity. According to the mass fraction ratio of ZnO-NPs to chitosan, 1%, 3%, and 5% of ZnO-NPs/CS/β-GP were prepared. Using the test tube inversion method, SEM, FTIR, the influence of ZnO-NPs on gelation time, chemical composition, and cross-sectional microstructures were evaluated. Adding ZnO-NPs significantly improved the hydrogel's antibacterial activity as determined by bacteriostatic zone and colony counting. The hydrogel's bacteriostatic mechanism was investigated using live/dead fluorescent staining and scanning electron microscopy. In addition, crystal violet staining and MTT assay demonstrated that ZnO-NPs/CS/β-GP exhibited good antibacterial activity in inhibiting the formation of biofilms and eradicating existing biofilms. CCK-8 and live/dead cell staining methods revealed that the cell viability of gingival fibroblasts (L929) co-cultured with hydrogel in each group was above 90% after 24, 48, and 72 h. ZnO-NPs/CS/β-GP thermosensitive hydrogel exhibits good physical, chemical, and biological characteristics and possesses a certain bacteriostatic effect on Porphyromonas gingivalis and its biofilm. These results suggest that ZnO-NPs/CS/β-GP could be employed as a topical treatment option for oral diseases.