[bridgettpayseur]

Almost 120,000 Americans are currently waiting for live-saving organ donations. However, there are far too few donors available, and finding appropriate matches between donor and recipient can be difficult. Being able to grow organs in vitro could potentially save tens of thousands of lives. Kidneys are one organ that many Americans need. While dialysis can sustain life for kidney patients, it is only a temporary solution. A kidney transplant is the only available cure for kidney disease. Some groups of scientists have been able to engineer devices to help assist kidney function, but none of these devices can be implanted directly as a donor kidney would be. Recently, however, scientists at Massachusetts General Hospital were able to successfully transplant kidneys grown in lab dishes into rats.

The team removed kidneys from deceased rats, and stripped away the tissues using detergent. This left a bare structure that the scientists termed scaffolding, which could use as a base to make a new kidney. The scaffolding was then seeded with human umbilical cord cells to help regenerate blood vessels, and kidney cells removed from newborn rats to create functional kidney cells.

The kidneys were able to perform the necessary function of filtering the blood and producing urine in the rats. However, they did not function as well as a normal kidney, indicating that further work needs to be performed to help optimize the bioengineered kidneys. The researchers suggest that the implanted kidneys were too immature to function, and might need additional time to properly develop. In addition, because the blood vessels were developed from human umbilical vein cells, they may not have been compatible with the rat cells. Also, as the researchers continue their work, they can determine how to properly build and place kidney cells to develop even more functional bioengineered kidneys. Even if they aren’t able to make kidneys that are one-hundred percent functional, the researchers still believe these bioengineered kidneys will be very helpful. Because dialysis is not begun in patients until the kidneys have dropped to fifteen percent efficiency, the kidneys do not need to have full efficiency in order to be useful. Being able to help a patient avoid dialysis while waiting for a donor kidney would be a big success.

One advantage that the bioengineered kidneys have is that they can be transplanted into the patient, acting as a permanent cure similar to a donor kidney. Another advantage is that the kidneys can be custom made for each patient, thereby seriously reducing the potential of organ rejection due to improper matching. The researchers propose that the scaffolding used to build the bioengineered kidneys could come from deceased donors. The stripping and rebuilding process would allow them to build a new kidney that would be tolerated by the recipient. Another option would be to use the patient’s own damaged kidney as a scaffolding. Again, the kidney would be stripped down and rebuilt to restore proper function.

While the concept of bioengineered organs for transplant is exciting, there are many obstacles involved in moving the technology from rodents to humans. As mentioned above, the kidneys were not fully functional. More research is required to determine how to develop all of the proper cell types, in the proper positions, in the bioengineered kidneys. While finding scaffolding for the kidneys would be fairly straightforward, either from a deceased donor or directly from the patient, obtaining the materials to rebuild the kidneys might be more difficult. Stem cells from human umbilical tissue can be obtained through umbilical blood which is sometimes donated after the birth of a child, but these donations may not be sufficient to meet the needs of all the patients in need of kidney transplants. In addition, the original bioengineered kidneys were rebuilt using kidney cells from newborn rats. It would certainly be unethical to take cells from newborn humans for this purpose. The most likely source of cells to rebuild kidneys would likely be from stem cells grown in culture. This would require additional research to determine how to differentiate the stem cells into the proper kidney cells.

While the use of bioengineered kidneys in humans is likely a long way off, the research performed still provides great insights into how cells in the kidney are developed and organized. This information alone will allow future research that could help provide more options to kidney patients.



References:

http://www.nature.com/news/lab-grown-kid...ts-1.12791

http://donatelife.net/understanding-dona...tatistics/

[sale0303]

As mentioned above, the only cure for kidney failure today is the transplant from matching donor. As it is not always possible, the alternative is dialysis which brings own problems including often hospital visit, need for vascular surgical procedures, etc.

Stem cells seem to bring revolution in all branches of medical science. Embryonic stem cells can be taken from umbilical cord or placenta, and they are the most powerful, but for some purposes, adult stem cells taken from bone marrow can also be useful.

Many studies on laboratory animals have been conducted with the aim to develop functional kidneys using different types of stem cells. It sounds like a dream to develop a fully functional kidney in a Petri dish and implant it in human body. The problem of guided differentiation of stem cells stated in the above article is very real. Namely, during the embryonic period, there are many factors that affect organ development including cytokines, growth factors, and physical contact with surrounding cells and tissues.

Although it may seem unreachable, scientists were working very hard and succeeded to identify most of the mechanisms that guide embryonic stem cells through the differentiation process. A recent study conducted by Narayanan and his collaborators at Institute of Bioengineering and Nanotechnology in Singapore, showed the process of the development of human embryonic stem cell into renal tubular cells in artificial environment. They exposed stem cells to different supplements and growth factors, and succeeded to develop a guideline for stem cell differentiation. The resulting cells showed structural and functional properties of renal tubular cells which was fascinating. However, the results were not perfect as the differentiation was partial in some cases.

In order to improve this technique, further research is needed, but once the scientists develop a fully functional human kidney, it will be the salvation for patients with all types of kidney disease.

[Alyssa03]

the bio engineered renal system have is that they can be replanted into the individual, performing as a lasting treat similar to a contributor renal. Another benefits is that the renal system can be customized for each individual, thereby seriously reducing the potential of body denial due to inappropriate related.