RGD多肽修饰的SLA钛片对糖尿病小型猪骨结合影响研究

Effects of RGD peptide modified SLA titanium discs on osseointegration in diabetic mini-pigs

目的探讨精氨酸-甘氨酸-天冬氨酸(Arg-Gly-Asp,RGD)多肽修饰的喷砂大颗粒酸蚀(sandblasted,large-grit and acid-etched,SLA)钛片对糖尿病小型猪骨结合的影响。方法本研究于2014年6月至2015年10月在南京军区总医院比较实验室进行。选取健康的广西巴马小型猪5只,用链脲佐菌素(STZ)随机诱导3只小型猪建立糖尿病模型,作为糖尿病组(diabetes model group,DM组);另2只正常饲养,作为非糖尿病组(non-diabetes model group,NDM组)。利用化学偶联法将RGD多肽接枝到SLA钛片上。每只小型猪上颌骨按预定方案植入6枚直径为5 mm的钛片,其中包含3枚SLA钛片(分别为DM-SLA组和NDM-SLA组)、3枚RGD多肽修饰的SLA钛片(分别为DM-RGD-SLA组和NDM-RGD-SLA组)。在植入钛片后1个月处死动物,取上颌骨,4%多聚甲醛固定。用Micro CT、硬组织切片以及SPSS21.0软件对实验结果进行分析。结果 Micro CT检测结果显示,在观察期内各组骨密度(BMD)、骨小梁厚度(Th.Th)、骨小梁数量(Th.N)和骨小梁间隙(Th.Sp)的差异均无统计学意义(均P>0.05)。硬组织切片分析显示,NDM-RGD-SLA组的钛片周围骨结合率(64.8%±18.4%)与DM-RGD-SLA组(33.9%±11.7%)、NDM-SLA组(39.5%±20.9%)和DM-SLA组(36.4%±15.9%)比较,差异均有统计学意义(均P<0.05);而其他各组两两比较,差异均无统计学意义(均P>0.05)。结论 (1)RGD多肽对SLA钛片周围骨结合有明显促进作用。(2)在实验的观察期内,动物是否患有糖尿病,对钛片与颌骨的骨结合无明显影响;当SLA钛片复合RGD多肽后,能明显促进非糖尿病动物的骨结合,但对糖尿病动物的骨结合作用不明显,提示糖尿病可能抑制了RGD多肽的促成骨作用。

Objective To observe whether the modified sandblasted, large-grit and acid-etched （SLA） surface titanium discs by the immobilized Arg-Gly-Asp （RGD）peptide via chemical grafting methods would promote the osseointegration in diabetic Guangxi BA-MA mini-pig models. Methods The experiment was carried out in the Comparative Laboratory of General Hospital of Nanjing Military Region from June 2014 to October 2015. Five Guangxi BA-MA mini-pigs were used for this research. Three of them were randomly induced into diabetes models by using streptozotocin （STZ）as diabetes model（DM）group, and the other two pigs were set as non-diabetes model（NDM）group. RGD peptite was Krafted on the SLA surface of titanium implant discs with chemical coupling method. Each mini-pig was implanted separately three SLA titanium discs and three RGD-SLA titanium discs （discs diameter = 5 mm） in maxilla. All animals were sacrificed at one month. Samples were fixed by 4% formaldehyde and analyzed by MicroCT and undecalcified histology methods. Results During the observation period, there were no significant differences in the parameters of bone mineral density （BMD） , bone trabecular thickness （Th.Th） , trabecular number （Th.N） and trabecular spacing （Th.Sp） between the groups. Resin embedded tissue histological analysis showed that the bone contact ratio of NDM-RGD-SLA group （64.8%± 18.4% ） are significant higher than DM-RGD-SLA group （33.9%± 11.7% ） , NDM-SLA group （39.5%± 20.9%） and DM-SLA group（36.4%± 15.9% ）. No significant differences were found when compared within other groups. Conclusion RGD peptide modified SLA titanium discs obviously promoted bone to implant contact. Whether animals have diabetes or not, there is no significant effect on the osseointegration between titanium discs and the jaw bones. However, when modified by RGD peptide, the SLA discs can obviously improve bone formation around implants in NDM animals, not in DM animals. It implies that diabetes may inhibit the osseointegration effects of RGD peptide.