Study on the angiogenesis-mediated promotion of bone fracture healing using repeated stimuli induced by microbubble destruction

骨折可能引发老年人患上骨质疏松症、卧床不起或需要护理，此外，还会干扰正在生长的儿童的骨骼生长，并增加未来的骨质疏松症储备。为了避免这些问题，需要加速骨折愈合，防止因长期休息而导致的骨萎缩，允许术后早期截肢和康复。因此，本研究旨在阐明微泡破坏促进新生血管生成对骨折愈合的影响，并在第一年进行了基于μCT的大鼠皮质骨骨缺损区骨再生和新生血管形成的初步研究。术后1周缺损区及邻近髓区出现编织骨及新生血管形成.再一周后，髓区编织骨消失，血管消失，皮质骨区编织骨仍有稀疏分布的血管 ...更多信息 S.也就是说，血管生成仅参与骨愈合过程的早期阶段。第二年，我们建立了小鼠胫骨骨愈合过程的在体μCT测量技术，并开发了骨形态计量学时间变化分析软件。在体μCT测量的基础上，我们可以确认编织骨的生成和由圆周向中心的新骨的替代。去年，为了研究微泡循环对骨折愈合的影响，我们在微泡灌注下对大鼠胫骨骨缺损进行了μCT测量。微泡对骨折愈合无影响。随后，我们开发了一个超声波发生系统。然后，考虑到气泡自发衰减的半时间段和给药后气泡到达骨缺损区域的循环时间，我们检查了加载声压的时间和持续时间。目前，我们正在评估微泡破坏对血管生成和骨再生的促进作用。少

Bone fracture may trigger elderly people to have osteoporosis, become bedridden, or require nursing care, and furthermore, disturb the bone growth of growing children and increase osteoporosis reserves in the future. To evade these issues, it is required to hasten bone fracture healing and prevent bone atrophy due to the long-term rest, allowing early postoperative ambulation and rehabilitation. Thus, this study was undertaken to clarify the effect of angiogenesis, which promoted by microbubble destruction, on bone fracture healing.In the 1st year, we performed the pilot study based on μCT to observe the process of bone regeneration and angiogenesis within the bone deficit in rat cortical bone. Woven bone and angiogenesis appeared one week later the deficit operation and its adjacent medullary region. Another week later, the woven bone in the medullary region disappeared with blood vessels, while the woven bone in the cortical bone region remained with sparsely-distributed blood vessel … More s. That is, angiogenesis participated only in the early period of bone healing process. In the 2nd year, we established an in vivo μCT technique to measure bone healing process in the mouse tibia and developed the software to analyze the temporal changes of bone morphometry. On the basis of the in vivo μCT measurement, we could confirm the generation of woven bone and the replacement of it with new bone from the circumference toward the center. As for the last year, to examine the effect of microbubble circulation on bone fracture healing, we performed a μCT measurement of rat tibial bone deficit under microbubble perfusion. No effect of microbubble was found on bone fracture healing. Subsequently we developed an ultrasonic wave generation system. Then, considering a half-time period of spontaneous decay of bubbles and a circulatory time for bubbles to reach the bone deficit region after administration, we examined the timing and the duration to load sound pressure. Presently, we are evaluating the promotive effect of microbubble destruction on angiogenesis and bone regeneration. Less