But researchers are finding evidence that regeneration may be possible someday in the future with improvements in technology. They imagine using 3D-printing to make a kidney for someone in need of a replacement. They also talk about possibly using bioelectricity to cause cells to build new tissue and organs.
但是研究人员正在寻找未来某天随着科技进步再生可能成为现实的证据。他们设想利用3D打印为需要换肾者制造一个肾脏。他们还谈到了利用生物电让细胞重新生成新组织和器官的可能性。
These ideas and others were discussed earlier this month at the World Science Festival in New York City. The presentation was called "Forever Young: The Promise of Human Regeneration."
这些以及其它的想法本月初在纽约市世界科学节上进行了讨论。这次发布会名为“永葆青春：人类再生的承诺。”
Scientists talked about the future of regenerative medicine, which combines the body's ability to heal itself with progress in biomedical engineering.
科学家们谈到了结合人体自愈能力和生物医学工程进步的再生医学的未来。
Dany Spencer Adams is a research professor at Tufts University in Massachusetts. He told VOA that researchers have found that bioelectrical signals can lead to cellular processes in frog tadpoles. He said such signals may someday start the formation of nerves, muscles and other body parts.
丹尼·斯潘塞·亚当斯（Dany Spencer Adams）是马萨诸塞州塔夫茨大学的一名研究教授。他对美国之音表示，研究人员已经发现，生物电信号可以引发蝌蚪的细胞进程。他说，这类信号未来某天可能会启动神经、肌肉和其它身体部位的形成。
"This is the cells themselves using electricity to communicate," he said.
他说：“这是细胞自身利用电流进行沟通。”
In an experiment, a frog re-grew one of its legs in six months. But scientists first had to make changes in the characteristics of the animal's cells.
实验中的一只青蛙在六个月内重新长出了一条腿。但是科学家首先必须改造这种动物的细胞的特性。
Researchers say they have a lot more work to do before the process can be used on human beings. They have to learn which bioelectric signals can influence the formation of which organs.
研究人员表示，在该过程可以应用于人类之前，他们还有更多的工作要做。他们必须了解哪些生物信号可以影响哪些器官的形成。
Adams says "it's better to regenerate that organ so that you don't have issues of the immune system attacking, the way we do now with transplants. The hope is that we'll be able to help the body create a better replacement -- really, a perfect replacement, for the person of exactly what they've lost."
亚当斯表示：“最好是重生那个器官，这样就不存在我们现在移植器官时遇到的免疫系统攻击问题。希望我们能够帮助身体创造出更好的替代品，这对已经失去该器官的人来说确实是一个完美的替代品。”
Jonathan Butcher is a professor and biomedical engineer at Cornell University in New York. He and other researchers have combined mechanical engineering with developmental biology to create working heart valves from 3D-printed tissue.
乔纳森·布切尔（Jonathan Butcher）是纽约康奈尔大学的教授和生物医学工程师。他和其他研究人员已经将机械工程和发育生物学结合起来，通过3D打印器官制造出可工作的心脏瓣膜。
Children may get the most help from engineered organs or partial organs that can grow as the child does.
儿童可能从制造器官或部分器官中受益最大，这些器官可以跟随儿童一起发育。