Discussion Forum: Engineered Tissues
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Newly developed artificial tissues have been approved for use in wound healing as well as for skin grafts. These artificial tissues are made by “seeding” cells into a bioengineered scaffold where upon they reorganize it into a material suitable for use as an artificial tissue. In the process of tissue engineering the cell makes use of the scaffold components as nutrients. The starting scaffold is usually three dimensional Jello like material called a collagen gel. Made up mostly of water, sugars, and carbohydrates the gel also contains fibrous proteins like collagen, fibrin, and fibronectin which allow the cells to interact with the scaffold. The fibrous proteins are large and tend to form bundles of fibers, or fibrils. After some time the cells use up the scaffold materials reorganizing some of them into an artificial tissue that can then be used for surgical procedures.
Because the tissue is grown from the patient's own cells, there is almost never any rejection of the transplant. In some cases, such as cancerous tissues, this is not possible. However, using compatible cells from an appropriate donor gives a high success rate with no risk to the cell donor. Further developments of tissue engineers have made it possible to replace not only tissues, but also organs. One such technology is tissue printing which would allow one to produce whole organs from gel scaffolding and cells in an ingenious way.
This advanced technique allows for cells to be arranged within the scaffold in order to shape the tissue into larger structures. Cells are arranged by inserting them into a device analogous to an inkjet printer where cells are ink. The cells are then printed in a two dimensional pattern such as a circle. After a circle of cells is laid down on top of a sheet of scaffold, another layer of scaffold is placed on top, followed by yet another circle of cells and another sheet of scaffold. Several circles placed in this way will reorganize the scaffold to form a tubular tissue, thus creating a tissue with a vascular system. This is one of the biggest breakthroughs in tissue engineering, because it allows blood and nutrients to flow through the artificial tissue. Tissue printing thus allows us to develop microstructures. These developments have lead to externally grown tissues which can replace vital organs, as well as more general tissues like skin, bone, muscles, and arteries. The lack of transplant materials is no longer a problem.
Posted Tuesday, 06/03/2008, 2:33pm AZ Another blogger noted that this could eventually be extended to animals – creating nano-engineered foods without the necessity of breeding and slaughtering other animals. Doubtlessly, there will be many individuals and groups apprehensive about such an application – such as consumer groups against nanotechnology in food. However, there is the potential for nanotechnology to suddenly become attractive to numerous animal rights groups or organizations.
Still, as is the case with virtually every emerging medical treatments – particularly in the United States – there is the lingering concern of who will have this treatment made available to them.
Clearly, this is an aspect of the debate that is not simply limited to nano-engineered treatments but to the whole United States medical community; it raises the question as to whether or not a privatized medical treatment organization is ever morally justified. Ultimately, many believe, the potential advances that nanotechnology may facilitate will bring these expansive ethical issues to a head. Put differently, nanotech treatments could possibly deepen the social chasm between the rich and the poor and, therefore, pursuing them may be immoral.
Full discussion at http://nano-ology.blogspot.com/
Posted Wednesday, 05/14/2008, 5:49am AZ One of the applications of tissue engineering technology is also relevant to the ethical issues of animal welfare. With some adjustments, this technology could be used to produce edible meat grown in culture. While it might use cells from an initial animal donor, self-sustaining lines of high quality muscle tissue could be developed which did not result from any animal death or factory farming process. This might be a welcome alternative for people who support animal welfare but who cannot bring themselves to live a vegetarian lifestyle. If the cultured meat process was economically feasible and widespread, it might also bring up the moral question of whether conventional animal farming should even be allowed if it is not necessary to produce human-appropriate food.
Posted Sunday, 05/11/2008, 9:08am AZ Tissue engineering is the need of the hour for the effective management of number of diseases in the present context.So,if more application using the nanotechnology is possible it is most welcome especially for the IDDM patients who require now transplant or stem cell therapy.The development of B cells in the lab for putting into the body is urgently needed.
Dr.S.Shanmugam,M.D.Consultant Physician,Diabetologist and Nano Reseacher,Tirunelvei,India.
Posted Friday, 05/09/2008, 7:54am AZ I do not see anything really wrong with this either. Sounds great to me actually. Sure a lot of people would not be able to afford it but is that not how most great things in life are?
Posted Friday, 05/09/2008, 1:16am AZ Actually, you don't have to wonder too much how the technology in this scenario will work, or worry about having to prove it possible, as this is actually a technology that is out there (link: http://technology.newscientist.com/article/dn13207 ).
As to ethical questions, I am not sure I see a downside. For one thing, the concern about how psychology of soldiers will be altered seems a bit far fetched. As long as you can get your head blown off in battle, I doubt that superior regenerative tech will change the thinking of soldiers too much. As to the question of resources, it seems to me that this technique is just a far more effective, but no more resource intenseive, way of doing the kind of reconstructive medicine that we are already doing. The biggest difference will be that, to the extent you are able to "put Humpty-Dumpty back together again", you won't need to spend as many resources on tech to help the patient live with disabilities. Sounds like a win all the way 'round to me.
Posted Thursday, 05/08/2008, 3:11pm AZ I am in favor of tissue engineering, but there are other contextual insights that might cause others to consider this scenario differently.
From a healthcare perspective, would these treatments be available only to those that can afford them? For US patients, how would insurance come into play for both prescribing and administering this treatment?
Secondly, considering present day DNA fabrication techniques - synthetic genomics, proteomics, etc. (namely work like that done by Craig Venter, and others) who is to say that we can't eventually improve upon the design given to human tissues beyond those bestowed by evolution? While currently a philosophical argument, there is substantial science and literature that leads me to believe that this isn't out of reach of an innovative mind.
Considering our negligence in addressing environmental challenges and increased resource scarcity we face in the next few decades, pressure to amend our physiology and that of other species may be a course of action we have little choice to pursue without considering longer term socieoeconomic, medical, and environmental consequences. Now is the time to prepare our society accordingly.
Posted Wednesday, 05/07/2008, 11:04am AZ This is more the description of a technology than a scenario that raises questions about the way in which the technology could be used. Place this technology in the context of cosmetic surgery, for example, and it becomes much more interesting. Or imagine the issues of risk homeostasis that might arise if soldiers had less to worry about in terms of disfiguring wounds.
CTR
Posted Monday, 05/05/2008, 12:09pm AZ Just do it... make it happen! Prove the capability, then we can argue the ethics and other issues.