纯钛表面GRGDSP多肽对骨结合能力的影响

目的： 将钛合金种植体微弧氧化(MAO)后，以多巴胺（PDA）为偶联，加载GRGDSP多肽，形成复合活性涂层，评价其骨结合能力。方法： 选取18只成年新西兰大白兔，建立单侧下颌骨模型，并将A组（Ti-MAO）、B组（Ti-MAO-PDA）、C组（Ti-MAO-PDA-GRGDSP）分别植入到新西兰大白兔一侧下颌骨，选取2周、4周、8周下颌骨植入样本，应用锥形束CT（CBCT）观察种植体周围骨结合情况。对4周样本以扫描电镜（SEM）观察界面形貌，激光共聚焦显微镜观察样本成骨活跃程度，扭力实验观察骨结合力。采用SPSS19.0软件包对数据进行单因素方差分析。结果： CBCT观察，C组接触区骨结合情况好于B组和A组，且B组优于A组。扫描电镜观察， C组在种植体与骨接触区聚集了更多新骨。激光共聚焦显微镜观察交界处，C组与B组较A组荧光强度明显，其中C组最为明显。扭力观察，8周时B、C组扭力值为A组的2倍，C组较B组多8 N·cm；C组、B组与A组相比，差异有统计学意义（P<0.05）。结论： Ti-MAO-PDA与Ti-MAO-PDA-GRGDSP涂层对骨结合均有促进作用，其中Ti-MAO-PDA-GRGDSP涂层对骨结合的作用最明显。

Effect of GRGDSP peptide coating on pure titanium surface on osteointegration

PURPOSE: Micro-arc oxidation (MAO) of titanium alloy was implemented, then GRGDSP polypeptide was loaded by coupling of dopamine (PDA) to form a composite active coating，in order to enhance esteointegration. METHODS: Eighteen adult New Zealand white rabbits were selected to establish a unilateral mandibular model. Ti-MAO (group A), Ti-MAO-PDA (group B) and Ti-MAO-PDA-GRGDSP (group C) were implanted into the mandible of rabbits. The mandibular bone on one side was selected at 2, 4, 8 weeks to harvest sample. Bone allografts were observed on cone-beam CT (CBCT). The interface of sample at 4w was observed under scanning electron microscopy (SEM), laser scanning confocal microscope was used to observe the degree of osteoblast activity, torsion test was applied to observe osseointegration. The date were compared between groups with one-way ANOVA using SPSS19.0 software package. RESULTS: For osseointegration at contact region, group C was better than group A and group B, and group B was better than group A on CBCT. SEM showed that group C had more new bone aggregated in the contact area between implant and bone. Laser confocal microscopy showed that the fluorescence intensity of group C was significantly higher than that of group B at the junction. The torsional force of group B and C at 8w was 2 times of that of group A, and group C was 8 N·cm greater than group B. The difference was statistically significant between group C and group B, comparing to group A(P<0.05). CONCLUSIONS: Ti-MAO-PDA and Ti-MAO-PDA-GRGDSP coatings can promote osseointegration, of which Ti-MAO-PDA-GRGDSP coating has the strongest osseointegration effect.