[ti:American Scientists Work on Printing of Living Tissue Replacements] [ar:Jonathan Evans] [al:Technology Report] [by:www.51voa.com] [00:00.00]From VOA Learning English, [00:02.37]this is the Technology Report. [00:04.75]Three-dimensional printers [00:13.57]are fast becoming everyday devices [00:16.92]in the United States. [00:18.46]Three-D printers are used to make everything [00:22.64]from automobile parts to bone replacements [00:26.05]for human patients. [00:27.76]American research scientists [00:30.65]are now working on creating replacements [00:33.14]for living tissue. [00:35.19]Researchers at the Medical University [00:38.67]of South Carolina [00:40.22]have been working on creating [00:42.71]and manufacturing living tissue since 2003. [00:46.90]This process is called biofabrication. [00:51.05]It requires special printing equipment [00:54.35]and a special kind of ink. [00:56.90]Traditional printers require ink [00:59.85]to produce an image or design [01:02.20]on a piece of paper. [01:03.70]For their three-D printer, [01:06.30]the South Carolina researchers [01:08.40]prepare complex nutritious solutions [01:11.82]they call bio-inks. [01:13.96]Bio-inks are made of proteins and glucose, [01:18.29]which normally provides energy [01:21.09]for most cells of the body. [01:22.89]The researchers also add living cells [01:26.72]taken from the animal [01:28.61]that will receive the new, printed tissue. [01:31.65]The bio-inks are then added to a device [01:35.34]that researchers call the Palmetto bio-printer. [01:39.32]Sarah Grace Dennis is one of the researchers [01:43.40]at the Medical University of South Carolina. [01:46.73]She says new technology, [01:48.97]like the Palmetto bio-printer, [01:51.67]is a great help to the biofabrication process. [01:55.45]"When I got here a year ago, [01:57.89]we were printing a-cellular bio-inks [02:00.08]to see if patterns could be printed. [02:02.67]And now we are printing skeletal muscle replica implants [02:08.04]that we have been implanting into rats." [02:10.48]The bio-inks are placed in three dispensers, [02:14.86]containers, inside the printer. [02:17.55]Lasers control both the position of the printing surface [02:22.29]and the places where the bio-ink is released. [02:25.97]Michael Yost is a leader of the research team. [02:30.30]He says the printing process is fully [02:33.88]automated - - machine-operated. [02:36.27]He says that the Palmetto bio-printer [02:39.86]makes it possible to create complex tissue types. [02:43.95]"And with our 3-D bio-printer, [02:46.49]we have been able to create [02:48.93]new microvascular networks [02:51.18]that we can then grow new tissues in very key areas [02:55.41]such as pancreas, liver and kidney." [02:57.99]The researchers say bio-printing is still experimental. [03:02.47]But they hope in a few years [03:05.72]they may be able to print tissue [03:07.96]to replace damaged human organs. [03:10.84]But there are still concerns with biofabrication. [03:15.42]Some scientists worry about [03:18.36]how to get blood to the replacement tissue. [03:21.24]The flow of blood is important [03:23.98]to keeping the printed tissue alive. [03:26.72]Michael Yost hopes that more people [03:29.55]will believe in the benefits of biofabrication. [03:33.48]"Tissue biofabrication is a reality, [03:36.67]and it is a reality now, [03:38.82]and if you come here and you get to see it. [03:41.87]You will get to see it. [03:43.30]You can not touch it, [03:44.75]but you will see it and think this is real. [03:47.74]And this is really human." [03:48.99]And that's the Technology Report [03:51.85]from VOA Learning English. [03:54.60]I'm Jonathan Evans.