Nurrohman H, Saeki K, Carneiro K, Chien Y C, Djomehri S, Ho S P, Qin C, Marshall S J, Gower L B, Marshall G W, Habelitz S
Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, San Francisco, California 94143, USA.
Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University Baylor College of Dentistry, Dallas, Texas 75246, USA.
J Mater Res. 2016 Feb 15;31(3):321-327. doi: 10.1557/jmr.2015.406. Epub 2016 Jan 26.
Dentinogenesis imperfecta type II (DGI-II) lacks intrafibrillar mineral with severe compromise of dentin mechanical properties. A knockout () mouse, with a phenotype similar to that of human DGI-II, was used to determine if poly-L-aspartic acid [poly(ASP)] in the "polymer-induced liquid-precursor" (PILP) system can restore its mechanical properties. Dentin from six-week old and wild-type mice was treated with CaP solution containing poly(ASP) for up to 14 days. Elastic modulus and hardness before and after treatment were correlated with mineralization from Micro x-ray computed tomography (Micro-XCT). Transmission electron microscopy (TEM)/Selected area electron diffraction (SAED) were used to compare matrix mineralization and crystallography. Mechanical properties of the dentin were significantly less than wild-type dentin and recovered significantly ( < 0.05) after PILP-treatment, reaching values comparable to wild-type dentin. Micro-XCT showed mineral recovery similar to wild-type dentin after PILP-treatment. TEM/SAED showed repair of patchy mineralization and complete mineralization of defective dentin. This approach may lead to new strategies for hard tissue repair.
II型牙本质发育不全（DGI-II）缺乏纤维内矿物质，严重损害牙本质的机械性能。利用一种基因敲除（）小鼠（其表型与人类DGI-II相似）来确定“聚合物诱导液态前驱体”（PILP）系统中的聚-L-天冬氨酸[聚（ASP）]是否能恢复其机械性能。将六周龄基因敲除小鼠和野生型小鼠的牙本质用含有聚（ASP）的磷酸钙溶液处理长达14天。处理前后的弹性模量和硬度与显微X射线计算机断层扫描（Micro-XCT）的矿化情况相关。采用透射电子显微镜（TEM）/选区电子衍射（SAED）来比较基质矿化和晶体学情况。基因敲除小鼠牙本质的机械性能显著低于野生型牙本质，经PILP处理后显著恢复（<0.05），达到与野生型牙本质相当的值。Micro-XCT显示经PILP处理后矿化恢复情况与野生型牙本质相似。TEM/SAED显示片状矿化得到修复，缺陷牙本质完全矿化。这种方法可能会带来硬组织修复的新策略。
