title: The inhibitory effect of a polymerisable cationic monomer on functional matrix metalloproteinases.
abstract: OBJECTIVE
  This study examined the use of methacryloxylethyl cetyl dimethyl ammonium chloride (DMAE-CB) as a potential matrix metalloproteinases (MMPs) inhibitor on both soluble recombinant and dentine matrix-bound endogenous MMPs, meanwhile attempted to determine the effective anti-MMP group of quaternary ammonium methacrylates (QAMs).
  
  
  METHODS
  The possible inhibitory effects of five DMAE-CB mass concentrations (0.1%, 0.5%, 1%, 3%, 5%) on soluble rhMMP-9 were measured using a colorimetic assay kit. Methyl methacrylate (MMA) and [2-(methacryloyloxy)ethyl] trimethylammonium chloride (METMAC) were also screened against rhMMP-9 to compare the inhibitory effect with DMAE-CB. Matrix-bound endogenous MMP-activity was evaluated in completely demineralized dentine beams. Thirty beams were randomly divided into three groups (N=10) and respectively placed into 500μL of calcium- and zinc-containing media (CM; control), 0.2% chlorhexidine or 3% DMAE-CB in CM aged for 30 days. The changes in modulus of elasticity, loss of dry mass and solubilization of collagen peptides were measured via three-point bending, precision weighing and hydroxyproline assay, respectively.
  
  
  RESULTS
  0.5-5% mass concentrations of DMAE-CB were highly effective (P<0.05) in inhibiting rhMMP-9 varied between 76.56±6.44% and 97.06±3.24%, the inhibitory effect of MMA was much lower than that of METMAC and DMAE-CB at the same concentration (P<0.05). Dentine beams incubated in 3% DMAE-CB showed only a 26.34% decrease in the modulus of elasticity (75.74% decrease in control), a 1.72±1.56% loss of dry mass (29.70±9.12% loss in control), and significantly less solubilized hydroxyproline when compared with the control (P<0.05).
  
  
  CONCLUSIONS
  DMAE-CB is effective in inhibiting both soluble recombinant MMPs and matrix-bound dentine MMPs. Quaternary ammonium group is the effective anti-MMP group of QAMs.
  
  
  CONCLUSIONS
  The incorporation of DMAE-CB into dental adhesives has the potential to enhance the durability of dentine bonding and thus increases the longevity of restorations.
authors: Department of Prosthodontics, School of Stomatology, Fourth Military Medical University, Changle Xi Road 145, Xi'an 710032, China.
authors: Ning
authors: N
authors: Liu
authors: Fang
authors: F
authors: Li
authors: Yu-Jiang
authors: YJ
authors: Chen
authors: Ling
authors: L
authors: Zhang
authors: Shuai
authors: S
authors: Lu
authors: Jun-Jun
authors: JJ
authors: Kang
authors: Ji-Hua
authors: JH
authors: Chen
mesh_terms: D002710:Chlorhexidine / Q000494:pharmacology; D003094:Collagen / Q000187:drug effects; D003124:Colorimetry; D003804:Dentin / Q000737:chemistry / Q000201:enzymology*; D004151:Dipeptides / Q000494:pharmacology; D055119:Elastic Modulus; D006801:Humans; D006909:Hydroxyproline / Q000032:analysis; D008422:Materials Testing; D020780:Matrix Metalloproteinase 9 / Q000187:drug effects; D061965:Matrix Metalloproteinase Inhibitors / Q000494:pharmacology*; D008689:Methacrylates / Q000494:pharmacology*; D020366:Methylmethacrylate / Q000494:pharmacology; D018583:Pliability; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology*; D012995:Solubility; D013997:Time Factors; D017001:Tooth Demineralization / Q000201:enzymology / Q000378:metabolism
chemical_list: C120889:2-(trimethylammonio)ethyl methacrylate; D004151:Dipeptides; D061965:Matrix Metalloproteinase Inhibitors; D008689:Methacrylates; C078131:N-(2(R)-2-(hydroxamidocarbonylmethyl)-4-methylpentanoyl)-L-tryptophan methylamide; D000644:Quaternary Ammonium Compounds; C540902:methacryloxylethyl cetyl dimethyl ammonium; D020366:Methylmethacrylate; D003094:Collagen; C579270:MMP9 protein, human; D020780:Matrix Metalloproteinase 9; D002710:Chlorhexidine; D006909:Hydroxyproline
keywords: Collagen; Dentine; Hydroxyproline; Inhibitor; Matrix metalloproteinase; Quaternary ammonium compounds