季铵盐包裹溴化银纳米复合物对基质金属蛋白酶活性的影响

The effect of Ag Br/cationic polymer nanocomposite on matrix metalloproteinase activities

目的研究季铵盐包裹溴化银纳米复合物(Ag Br/BHPVP)对牙本质基质金属蛋白酶(MMP)活性的影响。方法采用比色试剂盒检测浓度为0.5%~1.5%Ag Br/BHPVP对游离型重组人基质金属蛋白酶rh MMP-2、rh MMP-8、rh MMP-9活性的影响。将脱矿的牙本质经0.2%氯己定(CHX)或不同浓度Ag Br/BHPVP处理,分别在第3、5、7天测定释放Ⅰ型胶原吡啶交联终肽(ICTP)水平和第30天时测量牙本质条干重损失量,以及使用明胶酶谱法检测对牙源性明胶酶MMP-2、MMP-9活性的影响,用以评估Ag Br/BHPVP对结合型MMP活性的影响。采用单因素方差(One-Way ANOVA)分析各处理组rh MMP活性以及各处理组牙本质条干重损失量总体差异,使用重复测量方差分析各处理组在不同时间点对ICTP释放水平的影响,Tukey检验进行组间两两对比。结果检测浓度Ag Br/BHPVP对游离型MMP均具有明显的抑制作用,浓度达1.5%时对rh MMP-2、rh MMP-8、rh MMP-9活性抑制接近90%。ICTP释放量在7 d时,Ag Br/BHPVP组<CHX组<空白组,差异有统计学意义(F=65.389,P<0.001);相比空白组牙本质条干重损失百分比(16.34±3.60)%,1.5%Ag Br/BHPVP组损失最少(4.30±0.98)%,各组差异有统计学意义(F=48.564,P<0.001);明胶酶谱中除Ag Br组外,其余组对明胶酶均有明显抑制效果。结论适量浓度Ag Br/BHPVP对游离型rh MMP和结合型MMP活性具有明显的抑制作用,具有进一步运用于牙科材料提高牙本质粘接性能的前景。

Objective This study was aimed to evaluate the effects of AgBr/cationic polymer nanocomposite(AgBr/BHPVP)on dentin matrix metalloproteinase(MMPs).Methods Inactivation effects of AgBr/BHPVP at different concentrations on soluble recombinant human MMPs(rhMMPs)were evaluated using a colorimetric assay kit.Matrix-bound endogenous MMPs activity was evaluated via dry mass loss and C-terminal cross-linked telopeptide(ICTP)release of demineralized human dentin.Demineralized dentin beams or powder were respectively pretreated with 0.2%chlorhexidine(CHX)or AgBr/BHPVP at different mass%.Changes in ICTP release were examined after 3,5 and 7 days,and loss of dry mass was measured after 30 days.Besides this,gelatin zymography was also used to evaluate the effects of different pretreated groups on MMP-2 and MMP-9.One-Way ANOVA test was applied to analyze the overall difference of inactivation function on rhMMPs and dry mass loss in each group.Repeated measures ANOVA was used to analyze the effects of time on the ICTP release in different groups,while Tukey′s test was used for the comparison between every two groups.Results AgBr/BHPVP exhibited inactivation function on soluble MMPs,with about 90%of inhibition on rhMMP-2,rhMMP-8 and rhMMP-9 at 1.5%AgBr/BHPVP concentration.Compared with control group and CHX group,AgBr/BHPVP pretreated demineralized dentin exhibited the lowest ICTP release after 7 days(F=65.389,P<0.001).Dentine beams incubated in 1.5%AgBr/BHPVP showed only(4.3±0.98)%loss of dry mass vs.(16.34±3.60)%loss for control.Except for AgBr group,other pretreated groups had obvious inhibition on gelatinase activity in gelatin zymography.Conclusions A moderate amount of AgBr/BHPVP is effective in inhibiting both soluble and matrix-bound MMPs.AgBr/BHPVP may have the potential to be used in dental materials and improve the resin-dentin bonding durability.