Wen Du

In this study, hydroxypropyl methylcellulose (HPMC) was mixed with particle-type xenografts, derived from two different species (bovine and porcine), to increase the manipulability of bone grafts and compare the bone regeneration ability. Four circular defects with a diameter of 6 mm were formed on each rabbit calvaria, and the defects were randomly divided into three groups: no treatment (control group), HPMC-mixed bovine xenograft (Bo-Hy group), and HPMC-mixed porcine xenograft (Po-Hy group). At eight weeks, micro-computed tomography (µCT) scanning and histomorphometric analyses were performed to evaluate new bone formation within the defects. The results revealed that the defects treated with the Bo-Hy and the Po-Hy showed higher bone regeneration than the control group (p < 0.05), while there was no significant difference between the two xenograft groups (p > 0.05). Within the limitations of the present study, there was no difference in new bone formation between porcine and bovine xenografts with HPMC, and bone graft material was easily moldable with the desired shape during surgery. Therefore, the moldable porcine-derived xenograft with HPMC used in this study could be a promising substitute for the currently used bone grafts as it exhibits good bone regeneration ability for bony defects.

通过检测机械应力相关调控蛋白〔肌动蛋白纤维（F-actin）、非肌肉肌球蛋白ⅡB（non-muscle myosin ⅡB，NMⅡB）和细胞黏着斑蛋白Vinculin〕在牙发育过程的时空性表达，探究机械应力与牙早期发育之间可能的联系。 以小鼠磨牙为研究模型，通过免疫荧光染色，检测构成化学机械系统的重要分子F-actin、NMⅡB和Vinculin在牙发育蕾状期、帽状期、钟状早期和钟状末期的表达。 染色结果显示F-actin、NMⅡB和Vinculin均在牙发育各阶段广泛或局限性表达于牙上皮，其中F-actin亦稳定表达于间充质细胞中。荧光表达强度定量分析显示，F-actin和NMⅡB的表达均在牙发育早期阶段有明显上升，但分别于钟状早期和钟状末期回落，相邻发育阶段间的表达变化差异均有统计学意义（PP<0.05）。 机械应力参与牙早期发育过程。其中，F-actin可能在分散和传导机械应力的方面发挥重要作用，NMⅡB作用于牙发育中的牙上皮内陷及牙尖形成，Vinculin可响应力学刺激并与细胞黏附分子相互作用影响牙发育过程，而由肌动蛋白与肌球蛋白结合形成的肌动球蛋白复合体和细胞黏附分子在牙发育中的联系及具体作用机制依然有待进一步探究。