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【bio-news】生物工程师创造稳定可靠的血管网络
New Haven, Conn. -- Yale biomedical engineers have created an implantable system that can form and stabilize a functional network of fine blood vessels critical for supporting tissues in the body, according to a report in the Proceedings of the National Academy of Sciences.
For body tissue to survive it must receive oxygen delivered through the finest of blood vessels. Led by Erin Lavik, assistant professor of Biomedical Engineering, this study shows that the fine network of blood vessels can be formed. Further, detailed microscopic studies showed that the vascular networks were stable as implants for up to six weeks and were able to connect with larger blood vessel structures.
"This expands our understanding of the neuro-vascular niche and opens up ways to address repair of severed nerves," said Joseph Madri professor of pathology at Yale School of Medicine and a co-author. "We can now study what affects the attraction and repulsion of nerve growth and drug delivery in a model system that can be used in vitro and in vivo."
The researchers used two important engineering enhancements to develop stable functional microcirculation. First, they created a "micro-scaffold" of a macroporous hydrogel polymer. The hydrogel is a three-dimensional, sponge-like material -- highly water-saturable, with a structure of connected pores for cells to grow on and through.
Second, they seeded the hydrogel scaffolds with endothelial cells that make up blood vessel structure along with nerve progenitor cells from the brain. Because there is often an association of nerve connections with vascular networks, they tested to see if a combination of the blood vessel-forming and nerve-forming cells would enhance development of the vascular networks.
"By their nature, hydrogels are well suited for the transport of soluble factors, nutrients or drugs, and waste," said Lavik. "The hydrogel scaffold materials are generally highly biocompatible and safe to implant due to the presence of large volumes of water." 认领了
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生物工程师创造稳定可靠的血管网络
美国康涅狄格州纽黑文－根据国家科学院学报的报道，耶鲁生物医学工程师已制造了一种可植入的系统，这种系统能构建并坚固细微的血管功能性网络，这对机体结缔组织来说是关键性的。
机体组织要存活，就必须吸收从最细微的血管运输而来的氧气。生物医学工程学助教Erin Lavik主持的这项研究表明这种细微的血管网络能够成功建立。而且，详细的显微镜观察显示这种血管网络被植入后至到六周后都是稳定的，仍能同很多的血管结构连接。合著者之一，耶鲁药学院病理学教授Joseph Madr说：“这能扩展我们对神经血管微环境的认识，并为寻找离断神经修复方法开创途径。现在我们正在研究是什么影响了神经生长的吸收和排斥，以及在模式系统中如何给药以便能在活体内或活体外试验中应用”。
研究者们使用了两种重要的增强技术来形成稳定的功能微环境。首先，他们制造了一种大孔水凝胶聚合物的微支架。这种水凝胶是一种三维的、强吸水性海绵状物质，具有一种能让细胞生长和通过的连接孔结构。第二步，他们将带有上皮细胞的水凝胶支架植入并拼接血管结构和来自大脑的神经祖细胞。因为在血管网络和神经连接之间常常存在关联，他们通过试验来明确血管形成复合物和神经形成细胞是否能促进血管网络的形成。
Lavik说：“由于它们自身的特性，水凝胶能很好地适合可溶性物质、营养素或药物、及代谢产物的运送，其做成的支架材料也有高度的、普遍的生物相容性，同时由于含有大量的水故可以安全地植入”。 [标签:content1][标签:content2]
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作者:admin@医学,生命科学 2011-01-08 05:14
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