Basic studies on remodeling of fibrous tissues and their application to reconstruction of ligaments

1.考虑组织重塑的韧带重建装置的设计以稀疏排列纤维组成的涤纶织物作为人工韧带的模型移植物。生物固定有望通过自发的骨长入纤维之间的间隙来实现。采用兔模型进行实验性前交叉韧带重建。力学测试和组织计量学测量表明，甲壳素涂层移植物的附着强度和骨面积明显较大。从而成功地实现了前交叉韧带的生物固定，论证了重建前交叉韧带的可能性。利用引导胶原纤维重塑的经皮装置和牙科植入物的生物固定。研制了模型装置，实现了对周围软纤维组织的自发锚定。利用大鼠后肢皮肤进行的植入试验表明，…组织学观察显示，无锚定结构的标本有较多的皮肤脱落，而有锚定结构的标本没有进一步脱落，组织学观察显示胶原纤维自发锚定。这种自发锚定有望有益于经皮装置和牙科植入物。机械刺激下大鼠股筋膜软纤维组织的体外重建光镜下可观察到胶原纤维取向的肌肉周围纤维软组织--股筋膜在静态拉伸的机械刺激下培养。在无负荷培养的情况下，纤维的取向变得无序，负荷-位移曲线上的脚趾区消失。相反，进行递增小幅拉伸的标本显示出高度排列的胶原纤维和延伸的脚趾区域。另一方面，承受较大拉伸的组织显示出排列整齐的胶原纤维和小脚趾区域。因此，适当大小的机械刺激可导致胶原纤维的重新排列和机械性能的过继改变，而大的机械刺激不会引发重塑。较少

1. Design of devices for ligament reconstruction considering the tissue remodeling Polyester fabrics composed of sparsely aligned fibers were utilized as the model grafts for the artificial ligaments. the biological fixation was expected to be realized through the spontaneous bone ingrowth into the space between fibers. experimental anterior cruciate ligament reconstruction was performed with using the rabbit model. the mechanical test and histometric measurement demonstrated that the attachment strength and amount of bone area were significantly large in the group of chitin-coated grafts. thus biological fixation was successfully realized and the possibility of ACL reconstruction was demonstrated.2. Biological fixation of percutaneous devices and dental implants with use of the guided remodeling of collagen fibers. Model devices were developed to which spontaneous anchoring of surrounding soft fibrous tissue was realized. implantation test with using rat's hind skin demonstrated the a … More ll specimens without anchoring structure dropped out of skin, whereas the specimens equipped with the anchoring structure did not Further, histological observation revealed the spontaneous anchoring of collagen fibers. such spontaneous anchoring is expected to be beneficial for percutaneous devices and dental implants.3. In vitro remodeling of soft fibrous tissues under mechanical stimuli Femoral fascia of rat, a thin fibrous soft tissue surrounding muscle, in which orientation of collagen fibers can be monitored with a light microscope was cultured under the mechanical stimuli of static stretching. In case of the culture free from load, the orientation of fibers became random, and the toe region in the load-displacement curve disappeared. Contrarily, the specimens subjected to incremental small stretching demonstrated highly aligned collagen fibers and extended toe region. On the other hand, the tissue subjected to a large stretch demonstrated aligned collagen fibers and small toe region. Thus suitable magnitude of mechanical stimuli induced the realignment of collagen fibers and adoptive change of mechanical properties, whereas large stimuli do not trigger remodeling. Less