Application of hypoxia-induced capillary angiogenesis on regenerative tissue engineering

众所周知，缺氧有利于毛细血管生成，尽管氧气是维持再生组织的生命力所必需的。为了澄清这种不合理，我们试图通过使用我们的原始摄像机配备活体显微镜，通过观察体内小鼠模型的微循环来评估伤口愈合过程中的微循环反应。为了建立不同的氧气环境，在背侧皮褶室的窗户上覆盖透氧或不透氧的薄板。比较两组患儿完全恢复的进展时间和创面新生毛细血管总数。高氧条件下组织再生的进展时间比低氧条件下快。高氧组和低氧组伤口床完全恢复时间平均分别为6天和8天，而低氧组伤口床新生毛细血管总数大于高氧组。结果表明，高氧环境有利于创面早期的愈合，因为空气中的氧气能够供应给再生组织。另一方面，当再生组织生长到不能通过大气扩散提供氧气时，就需要新生的毛细血管。

It is well known that the hypoxia facilitates capillary angiogenesis, even though the oxygen is necessary to maintain the vital force in regenerative tissues. To clarify such inconsequence we have tried to evaluate the microcirculatory responses during the wound healing process by visualizing the microcirculation in vivo mice models using our original video-camera equipped intravital microscope. In order to establish different oxygen environments, the window of dorsal skinforld chamber was covered with oxygen permeable or oxygen impermeable sheet. The progress time for the complete recovery and the total numbers of new born capillaries in the wound bed were evaluated in comparison with two different oxygen groups. The progress time for the tissue regeneration was faster under high oxygen conditions rather than low oxygen conditions. The complete recovery time in the wound bed under high oxygen and low oxygen groups averaged 6 days and 8 days, respectively, whereas the total numbers of new born capillaries in the wound bed under low oxygen condition were greater than those of high oxygen condition. From these results, it is suggested that high oxygen condition would be advantaged for the wound healing in the early stage since oxygen is able to supply to regenerative tissue from atmosphere. On the other hand, new born capillaries would be required after when the regenerative tissues have grown up to the size larger than oxygen cannot be supplied by diffusion from atmosphere.