title: [Inhibitory effect of a novel crosslinking quaternary ammonium methacrylates on matrix metalloproteinases].
abstract: OBJECTIVE
  To evaluate the anti-matrix metalloproteinase (MMP) activity of a novel crosslinking quaternary ammonium methacrylates, 2-methacryloxylethyl dodecylmethyl ammonium bromide (MAE-DB).
  
  
  METHODS
  The effects of MAE-DB at different concentrations (1%, 3%, 5%, 7%) on soluble matrix metalloproteinase-8 (MMP-8) were investigated using fluorescent assay kit. Readings were taken every 20 min for 3 h. The 1, 10-phenanthroline provided by the assay kit served as control group. Demineralized dentin beams were randomly divided into three groups (n = 50) and immersed in different solutions: artificial saliva, MAE-DB incorporated artificial saliva and chlorhexidine incorporated artificial saliva. After temperature cycling, the changes of ultimate tensile strength were measured to determine the effect of MAE-DB on the activity of matrix-bound endogenous matrix metalloproteinases. The morphology of dentin collagen fibrils in the three groups was observed via transmission electron microscopy (TEM).
  
  
  RESULTS
  MAE-DB could effectively inhibit the activity of soluble MMP-8. The inhibition percentage of 3% MAE-DB was 99.53% after 1 h, and it was significantly higher than that of 1, 10-phenanthroline (95.71%, P < 0.05). After temperature cycling, the ultimate tensile strengths of MAE-DB groups were significantly higher than those of the artificial saliva groups and the chlorhexidine groups (P < 0.05). TEM micrographs of MAE-DB group revealed that the microstructure of the collagen fibrillar was intact, while the fibrillar in the artificial saliva group was disrupted, indicating a protective function of MAE-DB on dentin collagen.
  
  
  CONCLUSIONS
  MAE-DB can inhibit the activity of MMP and protect dentin collagen from enzyme degradation.
authors.affiliation: Department of Prosthodontics, College of Stomatology, The Fourth Military Medical University, Xi'an 710032, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Liu
authors.forename: Fang
authors.initials: F
authors.lastname: Li
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.forename: Yu-Jiang
authors.initials: YJ
authors.lastname: Chen
authors.forename: Ji-Hua
authors.initials: JH
authors.lastname: Chen
mesh_terms: D064751:Ammonium Compounds / Q000494:pharmacology; D002710:Chlorhexidine / Q000494:pharmacology; D003804:Dentin / Q000187:drug effects; D020784:Matrix Metalloproteinase 8; D008689:Methacrylates / Q000737:chemistry
chemical_list: D064751:Ammonium Compounds; D008689:Methacrylates; D020784:Matrix Metalloproteinase 8; D002710:Chlorhexidine