A new way to repair damaged heart tissue
Mar 28th 2018
ALTHOUGH the possibility is several years away, people may one day be helped to recover from heart attacks by having specially engineered patches that have been seeded with cardiac cells placed over the damaged tissue in their hearts. The idea is that these cell-impregnated patches will encourage the regeneration of heart muscle. Laboratory studies using animals suggest the advantages could be so great that it is worth the risk of the surgery needed to put such patches in place; they might even provide an alternative to heart transplants. The problem is finding a suitable way to make the patches stay put.
尽管这种可能性还需要几年的时间，但人们可能有一天会通过专门设计的补丁来帮助他们从心脏病中恢复过来，这些补丁被植入心脏细胞，置于心脏受损组织的位置。他们的想法是，这些细胞浸渍的贴片会促进心脏肌肉的再生。利用动物进行的实验室研究表明，这种优势可能非常大，因此值得冒手术风险将这样的补丁放到合适的位置。他们甚至可能提供心脏移植的替代方案。现在的问题是找到一种合适的方法使补丁保持不变。
Stitching is one possibility, but sutures bring risks. They might block the blood supply to the vulnerable area, or injure nearby healthy tissue, or cause haemorrhages. They might also introduce harmful bacteria. Nor is gluing—an obvious alternative to stitching—much better in practice. Some glues stiffen with age. Some are mildly toxic. Some are not porous enough to permit cells to grow and move around. To ameliorate these problems one of the researchers working on such patches, Tal Dvir of Tel Aviv University, in Israel, is developing a new type of cardiac scaffold that can secure a patch in place using light instead of stitches or glues.
缝合是一种可能，但缝合会带来风险。它们可能会阻塞血液供应到脆弱地区，或损伤附近的健康组织，或造成出血。它们也可能引入有害细菌。但是胶合不会——这是一种很显而易见可以代替缝合的方式——在实践中效果更好。有些胶水随着年龄的增长而变硬，有些轻微的毒性。有些还没有足够的多孔来允许细胞生长和移动。为了改善这些问题，以色列特拉维夫大学的Tal Dvir正在开发一种新型的心脏支架，它可以用光代替针线或胶水来固定补丁。
Dr Dvir’s inspiration came from recent work his research group has carried out using tiny particles of gold. These can be warmed and manipulated by light from the red end of the spectrum, which travels well through tissue. He found himself wondering whether he could create a supportive scaffold by mixing albumin, a common protein, with tiny particles of gold and then sculpting the resultant material with a laser into a shape that would fit the damaged tissue so snugly that neither stitches nor glue would be needed.
德维尔博士的灵感来自于他的研究小组最近利用黄金微粒进行的研究。这些可以通过光谱的红端来加热和操纵，这些光线通过组织传播得很好。他在想他是否能通过混合白蛋白——一种普通的蛋白质——和微小的黄金颗粒混合而成一个支撑支架，然后用激光雕刻相应的材料成一种形状，使其能够适应受损的组织，这样就不需要缝合或粘合。
To this end, as he and his colleagues explained recently in Nano Letters, they mixed albumin with a solution of beta-mercaptoethanol and trifluoroethanol, which softened the protein so that they could spin it into ribbonlike fibres. They used these fibres to build cardiac scaffolds, then soaked the scaffolds in suspensions of the golden particles for an hour, during which period most of the particles attached themselves to the scaffolds. After that, they added the cardiac cells.
为了达到这个目的，正如他和他的同事最近在纳米快报中解释的那样，他们将白蛋白和一种beta巯基乙醇和三氟乙醇混合在一起，从而软化了蛋白质，使其能够将其转化为带状纤维。他们用这些纤维来制造心脏支架，然后将支架浸泡在黄金颗粒的悬浮体中一个小时，在此期间，大部分的粒子都附着在支架上。然后，他们增加了心脏细胞。
This done, they tried attaching the scaffolds to hearts taken from pigs. They laid them on the organs and played the laser over them. As they had hoped, this softened the scaffolds, which then moulded themselves to the surrounding tissue and subsequently remained in place.
完成后，他们试着将支架固定在猪的心脏上。他们把支架放在器官上，然后用激光照射它们。正如他们所希望的那样，这软化了支架，使得他们将自己和周围的组织塑造在一起，然后留在原来的位置。
Dr Dvir worried, however, that heat generated when the laser struck the gold would end up cooking nearby tissue. To assess that risk he ran a second experiment. In this the team applied the scaffolds to the hearts of living rats, fused them into place with the laser and then studied those hearts for cell damage. They found none. More importantly, when they analysed the patched hearts in situ for health and function, they noted that the scaffolds were not impeding them at all.
然而，Dvir博士担心，当激光照射到黄金时产生的热量最终会在加热附近的组织中。为了评估这一风险，他进行了第二次实验。在这个实验中，研究小组将这些支架应用到活鼠的心脏，用激光将它们融合到特定位置，然后研究这些心脏细胞损伤情况，他们发现没有损伤，更重要的是，当他们分析了修复点心脏的健康和功能时，他们注意到支架并没有妨碍他们。
There is a long way to go, but Dr Dvir does seem to have found a promising way that one day could help people recover from heart failure.
还有很长的路要走，但是Dvir博士似乎找到了一种很有前景的方法，可以帮助人们从心脏衰竭中恢复过来。
This article appeared in the Science and technology section of the print edition under the headline "Patching broken hearts"
英文原文选自《经济学人》