Development of new method of therapeutic angiogeneis using sustained-release of multiple growth factors.

到目前为止，我们已经报道了碱性成纤维细胞生长因子（bFGF）的持续释放增强了心肌梗死和后肢缺血动物模型的组织再灌注和功能改善。然而，仅靠bFGF的持续释放不足以产生稳定的血管。此外，在临床情况下，糖尿病或高胆固醇血症的存在可能阻碍bFGF的血管生成作用。为了克服这些问题，我们研究了辅助治疗联合bFGF缓释的效果。在本研究中，我们发现缓释bFGF和肝素联合治疗可协同促进缺血刺激下血管生成反应受损的高胆固醇血症小鼠后肢缺血新生血管。我们也报道了5HT受体阻滞剂sarpograte对糖尿病大鼠也有类似的作用。我们还证明，与单独使用高剂量bFGF或HGF相比，低剂量bFGF和肝细胞生长因子（HGF）的持续双重释放在缺血肢体中实现了相当的组织再灌注和更成熟的血管。利用大鼠慢性心肌梗死模型，我们证明了促红细胞生成素的缓释改善左心室功能而不诱导红细胞增多症。我们还检查了粒细胞集落刺激因子（G-CSF）缓释的效果，与对照组相比没有显着改善。根据这些结果，我们正在设计治疗性血管生成治疗肢体缺血和慢性心肌缺血的临床方案。

We have reported so far that sustained-release of basic fibroblast growth factor (bFGF) augments tissue reperfusion and functional improvement both in animal models of myocardial infarction and hindlimb ischemia. However, sustained-release of bFGF alone is not sufficient to generate stable blood vessels. Moreover, in the clinical situations, presence of diabetus or hypercholesterolemia may hamper the angiogenic effect of bFGF. To overcome these problems, we investigated the effects of adjuvant thearapies combined with sustained-release of bFGF.In the present study, we have found that combined treatment with sustained-release bFGF and heparin synergistically enhances neovascularization in the hindlimb ischemia of hypercholesterolemic mice with impaired angiogenic responses to the ischemic stimulus. We are also reporting that 5HT receptor blocker, sarpogrerate has similar effect in diabetic rats. We also demonstrated that the sustained dual release of a lower dose of bFGF and hepatocyte growth factor (HGF) achieve equivalent tissue reperfusion and more mature vasculature in the ischemic limb than a higher dose of bFGF or HGF alone.Using a rat model of chronic myocardial infarction, we demonstrated the sustained-release of erythropoietin improved left ventricular function without inducing polycythemia. We also examined the effect of sustained-release of granulocyte colony stimulating factor (G-CSF), which revealed no significant improvement compared with control.From these results, we are designing clinical protocols of therapeutic angiogenesis to treat limb ischemia and choronic myocardial ischemia.