Browse by Tags
All Tags » Tissue engineering (RSS)
-
RSC Publishing provides a compact overview of the application of bioprinting technologies: "In order to build an organ, you need four components: cells (the bio-ink), a biomaterial (the biopaper), a device to make three-dimensional structures (the bioprinter), and a method to aid tissue assembly and maturation (the bioreactor). In addition to this shopping list, you need the expertise to put the components together, and you need funding. Enter the hydrogel chemists, the cell and developmental biologists, the physicists, the computational modellers, and a company that builds rapid prototyping devices. ... in many ways, the biomaterial is the easy part. Shaping an artificial 'neo-organ', developing the printing tools and a computer model for layer-by-layer construction, and devising a strategy to mature the neo-organ before transplantation are among the main challenges." If you can build organs from a patient's cells - or even meaningful amounts of undamaged tissue for transplant - that will make an enormous difference to the future of health and longevity.
View the Article Under Discussion: http://www.rsc.org/Publishing/Journals/cb/Volume/2007/5/organ_printing.asp
Read More Longevity Meme Commentary: http://www.longevitymeme.org/news/
-
Scientists are creating artificial bones using a modified version of an inkjet printer. The technology creates perfect replicas of bones that have been damaged and these can then be inserted in the body to help it to heal. The process will re... Read more 
-
The Daily Mail illustrates the use of inkjet printing technology to fabricate scaffolds for bone regrowth: "The 'paper' in our printer is a thin bed of cement-like powder. The inkjets spray the cement with an acid which reacts with it and goes hard. That deals with one layer. Then new layers of fresh powder are sprayed on top, and the layers build up to the shape we need ... It takes only ten minutes for the printer, which is the size of about three filing cabinets, to print a typical bone graft. The printed graft acts as a bridge to allow the body to replace the damaged section with new bone. Crucially, the substance created by the printing process contains the same building blocks as real human bone, allowing the graft to eventually dissolve harmlessly into the body. The sections made by the printer are so precise that spaces can be left to encourage the regrowth of tissue and blood vessels through the graft, mirroring the make-up of normal bone. ... You can design it so you encourage it in a particular direction, to get different tissue repair. It is mainly useful in areas where you need a very good sort of fit, like cosmetic surgery or reconstructive surgery, or in the spine where you don't want to be playing around to get something to fit."
View the Article Under Discussion: http://www.dailymail.co.uk/pages/live/articles/news/news.html?in_article_id=448654
Read More Longevity Meme Commentary: http://www.longevitymeme.org/news/
-
From the Guardian, another modest step towards bioengineered replacement hearts: "A British research team led by the world's leading heart surgeon has grown part of a human heart from stem cells for the first time. If animal trials scheduled for later this year prove successful, replacement tissue could be used in transplants for the hundreds of thousands of people suffering from heart disease within three years. ... By using chemical and physical nudges, the scientists first coaxed stem cells extracted from bone marrow to grow into heart valve cells. By placing these cells into scaffolds made of collagen, [scientists] then grew small 3cm-wide discs of heart valve tissue. Later this year, that tissue will be implanted into animals - probably sheep or pigs - and monitored to see how well it works as part of a circulatory system. ... Growing a suitably-sized piece of tissue from a patient's own stem cells would take around a month but he said that most people would not need such individualised treatment. A store of ready-grown tissue made from a wide variety of stem cells could provide good matches for the majority of the population."
View the Article Under Discussion: http://www.guardian.co.uk/medicine/story/0,,2048062,00.html
Read More Longevity Meme Commentary: http://www.longevitymeme.org/news/
-
Part of a human heart has been grown from stem cells for the first time. The small discs of tissue could represent the first step towards building a whole heart from stem cells.... Read more
-
EurekAlert! look at tissue engineering and the heart: "Some day, heart attack survivors might have a patch of laboratory-grown muscle placed in their heart, to replace areas that died during their attack. Children born with defective heart valves might get new ones that can grow in place, rather than being replaced every few years. And people with clogged or weak blood vessels might get a new 'natural' replacement, instead of a factory-made one. These possibilities are all within reach, and could transform the way heart care is delivered ... Technology has advanced so much in recent years [that] scientists are closer than ever to 'bioengineering' entire areas of the heart, as well as heart valves and major blood vessels. ... Although there remain tremendous technological challenges, we are now at a point where we can engineer first-generation prototypes of all cardiovascular structures: heart muscle, tri-leaflet valves, blood vessels, cell-based cardiac pumps and tissue engineered ventricles." It won't be too many years now until the simpler organs can be rebuilt from your own stem cells.
View the Article Under Discussion: http://www.eurekalert.org/pub_releases/2007-03/uomh-eth032707.php
Read More Longevity Meme Commentary: http://www.longevitymeme.org/news/
-
(From the Technology Review). Scientists continue to explore the use of scaffolds to convince the body to heal and regrow where it normally will not: "Surgical reconstruction is typically required to repair the [anterior cruciate ligament (ACL)], but current methods continue to take significant recovery time, during which a patient may sustain a loss of strength and function. Now, [researchers]have bioengineered a new ACL replacement using a 3-D polymeric fiber braiding process. It's the first synthetic scaffold design to demonstrate exceptional tissue regeneration and healing, and it could lead to a promising ligament-replacement technology. ... Our goal was to regenerate the ACL using classic design principles from engineering and material that has mechanical properties that mimic the natural ACL ... There just hasn't been very much successful work done on tissue-engineering ligaments. This [is] a very significant discovery. I haven't seen anybody do what they are doing with ligaments before." This work is still in the animal study stage; a few years yet before human trials start by the look of it.
View the Article Under Discussion: http://www.technologyreview.com/printer_friendly_article.aspx?id=18421
Read More Longevity Meme Commentary: http://www.longevitymeme.org/news/
-
The New Scientist reports on another step forward for medical engineering: "a 'bioscaffold' made of collagen impregnated with stromal and dendritic cells extracted from the thymus of newborn mice [was] then implanted into mice with healthy immune systems that had been vaccinated against a harmless antigen (something that triggers an immune response). ... After the artificial node had filled with antigen-specific T and B cells, Watanabe transplanted it into a mouse with no functioning immune system. The lymphocytes quickly spread out from the artificial node into the animals' own lymph nodes ... After a month, these cells' 'memory' was still maintained, and they were able to fight off challenges from the antigen. ... The next step is to use human cells in humanised mice. Then, maybe in four or five years, we might be able to make the first prototypes of a human model ... By implanting artificial nodes plump with healthy T and B cells in AIDS patients, he believes he might be able to revitalise their damaged immune systems. For cancer, he hopes to adopt a similar approach in which the transplanted nodes will contain T cells trained to hunt down the antigens produced by tumour cells and kill them off."
View the Article Under Discussion: http://www.newscientist.com/article/dn11389-artificial-lymph-node-transplanted-into-mice.html
Read More Longevity Meme Commentary: http://www.longevitymeme.org/news/
-
Scientists are making progress in growing more lifelike and larger masses of tissue: researchers "have created new heart muscle with its own blood supply through the use of human embryonic stem cells. ... Despite progress over the past two decades in treating cardiac disease, there are few good ways to fix damaged heart muscle. One possibility would be to rebuild a broken heart with a transplant of healthy heart tissue. However, scientists have been stymied in these efforts by a lack of human heart tissue to work with and the failure of transplanted tissue to thrive in its new home. ... heart tissue grown by the [researchers] is threaded throughout with a network of tiny blood vessels that would improve the tissue's survival after being transplanted in a human heart ... researchers engineered the heart muscle by seeding a sponge-like, three-dimensional plastic scaffold with heart muscle cells and blood vessel cells produced by human embryonic stem cells, along with cells called embryonic fibroblasts. ... Four to six days after being seeded on the scaffold, patches of the new muscle cells began to contract together, a movement that spread until the entire tissue scaffold was beating like normal heart muscle."
View the Article Under Discussion: http://www.juf.org/news_public_affairs/article.asp?key=7884
Read More Longevity Meme Commentary: http://www.longevitymeme.org/news/
-
A good demonstration of the state of practical tissue engineering for muscles and connective tissue can be found at ABC Online: "The researchers used a synthetic scaffold seeded with ligament cells to regenerate the new tissue in the damaged anterior cruciate ligament (ACL) of rabbits. The bunnies were able to begin bearing weight on their knees 24 hours after surgery, and by the end of the 12-week experiment, the animals had fresh collagen and blood vessels growing in the damaged area. ... The ACL is the stabilising ligament that connects the thighbone to the leg bone. It unravels like a plait when ruptured, making healing difficult. In humans, the standard treatment for this is reconstructive surgery. Surgeons remove healthy tissue from tendons around the knee and graft it onto the damaged ligament to regenerate it. But it can take five to six months for a full recovery, and surgeons would prefer not to harvest healthy tissue if possible. Researchers have tried to craft ligament-like scaffolds to help the healing process before, but success has been limited. This is the first time that researchers have combined synthetic materials with ACL cells and been able to substantially engineer new ligament tissue."
View the Article Under Discussion: http://www.abc.net.au/science/news/stories/2007/1852113.htm?health
Read More Longevity Meme Commentary: http://www.longevitymeme.org/news/
|