Objective To investigate the ability of the 3D printed porous titanium material for bone defect repairing and bone formation.Methods The critical bone defect models (6 mm in depth and 10 mm in diameter) were made of 20 six-month-old New Zealand white rabbits' femoral condyle.One of the porous titanium material was swiftly implanted into the bone defect area (experimental group,n=20),with the opposite side as control group (also the blank group,n=20),washed with saline and sutured without any implants.The samples were harvested and observed by X-ray and CT examinations at 3 days and 4,8,12 weeks after the operation to assess bone growth in the bone defect area.At 12 weeks after the operation,all rabbits were euthanized and evaluate the bone defect repair through X-ray,CT,histology and Micro-CT.Results Both the experimental group and control group recovered with good condition.At 12 weeks after the operation,we can see that the bone defect area was filled with new bone in the experimental group after removing the soft tissue surrounding the bone defect area;In contrast,the bone defect in control group was seen hollow and covered with fibrous capsule.According to the radiological observation,the demarcation line between the defect area and the surrounding area was obscure in the experimental group;the bone defect area in control group saw an entire translucency with no obvious shadow reflecting the new-borne bone.The Micro-CT observations proved fresh bone tissue formed in the plantation area at 12 weeks after the operation,and the surrounding area could see bone trabecula grown,In comparison,there was no obvious bone formed in the defect area of control group,which was filled by fiber tissue and relatively less bone trabecula and new-borne bone tissue.The results of un-decalcificated bones slicing showed the implanted material appeared combined with osteoblast,and the matureharversian system was seen distributed within the new-borne bone;for control group,a small amount of unordered bone formed in the defect area,filled with a lot of fiber texture.The area ratio of new-borne bone and the defect area was calculated via the IPP5.1 software,producing differences that have statistical significance.Conclusion A series of experiments prove that the porous titanium material has high biosecurity and ability to promote bone growth and healing.The new-borne bone tissue can grow and fill the lacuna,thereby effectively repairing bone defect.In short,the 3D printed porous titanium is a kind of promising repairing material in the tissue engineering field.%目的 研究3D打印的多孔钛材料对骨缺损的修复能力和成骨性能.方法 选取20只6月龄新西兰白兔,在其股骨髁上制备直径6 mm,深10 mm的临界性骨缺损.实验组将多孔钛材料迅速注入骨缺损区.对侧生理盐水冲洗,不植任何材料,作为对照组.术后3d、4周、8周、12周通过X线及CT观察骨缺损处生长变化,术后12周处死所有新西兰白兔,通过大体观察、X线、CT、Micro-CT及组织学观察骨缺损处的修复情况.结果 实验组与对照组一般情况良好,术后12周取出标本清理周围软组织,实验组缺损部位被新生骨填充;对照组见缺损处骨质凹陷;影像学观察,实验组植入物区域与周围界限模糊不清;对照组未见明显新生骨阴影;Micro-CT观察,术后12周实验组植入物区域空隙内长入新生骨组织,植入物附近可见骨小梁长入;对照组缺损区未见明显的骨长入;硬组织切片观察,实验组植入材料与成骨细胞结合,可见成熟的哈佛氏系统散在分布于新生骨内;对照组骨缺损区被大量纤维组织填充.IPP5.1计算新生骨与缺损区面积比,差异有统计学意义.结论 多孔钛材料可以促进骨组织的生长愈合,新生骨组织可以长入并充满孔隙,是一种很有应用前景的组织工程修复材料.
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