Tuesday, 18 December 2012

Bio-Printing from Steaks to Organs and DNA


Additive manufacturing or 3D printing is a process of making three dimensional solid objects from a digital model. The technology is used in jewelry, footwear, industrial design, architecture, engineering and construction (AEC), automotive, aerospace, dental and medical industries, education, geographic information systems, civil engineering, and many other fields.
Billionaire investor Peter Thiel's (pay-pal co-founder) philanthropic foundation plans to announce today a six-figure grant for bioprinted meat, part of an ambitious plan to bring to the world's dinner tables a set of technologies originally developed for creating medical-grade tissues.
The recipient of the Thiel Foundation's grant, a Columbia, Mo.-based startup named Modern Meadow, is pitching bioprinted meat as a more environmentally-friendly way to satisfy a natural human craving for animal protein. Co-founder Andras Forgacs has sharply criticized the overall cost of traditional livestock practices, saying "if you look at the resource intensity of everything that goes into a hamburger, it is an environmental train wreak".
"Modern Meadow is combining regenerative medicine with 3D printing to imagine an economic and compassionate solution to a global problem," said Lindy Fishburne, executive director of Breakout Labs, a project of the Thiel Foundation. "We hope our support will help propel them through the early stage of their development, so they can turn their inspired vision into reality."
Breakout Labs is also giving grants to Bell Biosystems and Entopsis, both medical startups. A Breakout Labs representative declined to give exact figures, saying that each grant was for a sum between $250,000 and $350,000.
Tissue engineering in the traditional method was the use of a combination of cells, engineering and materials methods, and suitable biochemical and physio-chemical factors to improve or replace biological functions. While it was once categorized as a sub-field of bio materials, having grown in scope and importance it can be considered as a field in its own right.
In practice the term is closely associated with applications that repair or replace portions of or whole tissues (i.e., bone, cartilage, blood vessels, bladder, skin, muscle etc.). Often, the tissues involved require certain mechanical and structural properties for proper functioning. The term regenerative medicine is often used synonymously with tissue engineering, although those involved in regenerative medicine place more emphasis on the use of stem cells to produce tissues.
Mean while in 2002 Professor Makoto Nakamura realized that the droplets of ink in a standard inkjet printer are about the same size as human cells. The theory is that as ink jet technology continues to grow it would be conceivable to print cells in order to create human organs. The tissue is created by printing layer upon layer of living cells.
Typically a dissolvable gel which has been coined bio-paper is also printed to protect the cells. The cells printed have been termed bioink, made of anywhere between 10,000 to 80,000 aggregated cells. The bioink is circular and is printed from a bioprint head which moves left to right, back and forth and up and down in order for the cell to be placed exactly where needed.The process takes several hours of printing layer upon layer of cells to create the organic object. The bio-paper is printed first from part of the print head and then cells are printed after from another part of the print head. The bio-paper is made from collagen, gelatin, or other hydrogels. Once the bioink is in place the individual droplets or circles merge on their own with the others to form the organic structure. At this point the biopaper evaporates.

Recently Julie Phillippi at Carnegie Mellon University in Pennsylvania, US, and colleagues have demonstrated a novel bio-ink printer that directs a population of muscle-derived stem cells from adult mice to differentiate into both muscle and bone tissue. It is the first such system to grow multiple tissues from a single population of adult stem cells, the researchers say. The technique works by firing various patterns of different growth factor proteins onto the stem cells. By tweaking the spatial patterning of the doses, using different print-heads to deliver various concentrations of the protein "bio-ink", the cells can be directed to differentiate into different tissue types, says Phillippi. The team has already grown muscle and bone tissue in the same dish. Their next step is to investigate "patterns" for other tissue types that occur naturally in the body.
By 2010, other research by Organovo had created blood vessels bioprinted from cells cultured from a single person. In a few years it is hoped that medical researchers would be able to test drugs on bioprinted models of liver and other organs and reduce the need for animals in testing. Organovo has become quite good at producing bio-printed blood vessels and hopes that one day these blood vessel grafts could be used in heart bypass surgery. The kidneys being one of the most straight forward body parts could very well be the first artificial human organ created.
And Scientists at the Wake Forest Institute for Regenerative Medicine are in the process of creating a bioprinter that would be used to print new skin cells for burn victims. They are being funded by the U.S. Department of Defense as 5 to 20% of combat related injuries are burns. A piece of skin half the size of a postage stamp is taken from a patient using a chemical solution. Those cells are then separated and replicated on their own in a specialized environment.
Once the new cells have been expanded into large quantities they are put into a bio-printer cartridge and printed onto the patient. The printer is placed over the wound of the patient at a fair distance and once the cells have been printed onto the wound they mature and form new skin. Depending on the size of the burn, the process could take anywhere from minutes to many hours. The size of the wound is scanned and recorded on a computer so the cells would only be printed where necessary. It is unclear at this time when the printer could pass federal regulations and make its way to the battlefields, although the Institute estimates an approximate five year period before the printer would be ready for human patients. The trial tests done on mice have yielded positive results. New skin printed onto the wounded areas of mice healed in 3 weeks, half the time of the mice in the non treated group.
Ultimately Craig Venter, the geneticist who made headlines in 2010 when he and colleagues created the first self-replicating cell with a synthetic genome, is on to his next big idea of a 3D printer for DNA, which could one day allow people to download, print, and inject vaccines at home.
Speaking at the inaugural Wired Health Conference in New York City, Venter said that his team of scientists at the J. Craig Venter Institute in Rockville, Maryland, are already testing a version of his digital biological converter designed for what Venter calls “biological teleportation”.
Biological printers could be used to plausibly shuttle vaccines around the globe, but their use could be problematic as vaccines could easily be used as bio-weapons.
If it’s possible to email troops the 3D instructions for printing a replacement gun part, then it should be possible to email macromolecules, as long as the printer can deposit an array of nucleotides, sugars, and amino acids where they belong, then link the whole molecule up chemically. Modern vaccines are made up partially of key molecules. DNA vaccines, which work well in experiments but haven’t been commercialized due to safety concerns, could be synthesized. Venter’s bio-printer could theoretically distribute macromolecular vaccines quickly. However, these instructions could be used in bio-terrorism, especially if these emails are as vulnerable to hackers as current electronic mail protocols. The additive synthesis of organic life told by optimists explains the radical change that possibly allow interchangeable parts for the human body.
The current technology is as good as its print resolution, I am left wondering is nano sized cells built from the ground up layer by layer could produced a organ in a short space of time. The fact is that 3d printers would take a long time to construct a simple organ in 3D, considering that a few billion cells is needed and each one is placed carefully. While the use of DNA printers can be a possibility, as a few strands of DNA can be grown organically for the beneficial reasons of vaccine transportation. The real commercial potential is the simple idea of synthetic meat which needs to scale up its raw material or laboratory grown meat and placed in a clean 3D printer for construction. While the mechanics of food related printing maybe simple, the future of organ printing still remains a vague optimistic picture. The human body normally contains 10 trillion different cells, reconstruction of each cell layer by layer will need a lighting fast printer. With the current speeds of todays 3d printer, it might take more then 20 years to perfect this type of technology...


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1 comment:

  1. Great post. I need a Plastic card printing machine for home use. Where i can get the best one?

    ReplyDelete