I recently watched two videos featuring Anthony Atala, a surgeon and researcher at Wake Forest University who works in the Institute for Regenerative Medicine. The first video is from his talk at TEDMed Oct 2009. In it, he talks about creating artificial tissue and organs. His talk also includes video clips showing working urethras and blood vessels made with biopolymers. He also shows a standard ink jet printer modified to print live endothelial cells to form 3D objects such as heart valves. Finally, he shows a functional liver created using a scaffold made from a decellularized cadaver liver.
Artificial organs. Video from TED Med
The second video is from Dr. Atala’s talk at TED Mar 2011. In this newer video he describes the process of creating a scaffold for a kidney. Much of the content in the first eight minutes is a repeat of the previous talk. The exciting part starts at 10:04 into the video where he describes the process of using a 3D ink jet printer to create the kidney scaffold.
Printing kidneys. Video from TED Med
The work of researchers at Wake Forest developing artificial organs was mentioned in an Aug 2010 blog post.
Also in March, I attended the Annual Faculty Lecture at Univ Washington. The speaker was Buddy Ratner, a professor in the Department of Bioengineering . Mr. Ratner is the Michael L. & Myrna Darland Endowed Chair in Technology Commercialization, the founder of Ratner BioMedical, and a member of the scientific advisory board for Tengion, a firm that has licensed the Wake Forest technology.
His talk, entitled “Regenerate, Rebuild, Restore — Bioengineering Contributions to the Changing Paradigm in Medicine”, described the work he and his graduate students have done in creating biodegradable scaffolds made from biopolymers such as polyHEMA, a common material used commercially for soft contact lenses, using a novel process called 6S.
The 6S process gets its name from the six steps used to make the material. First, polystyrene pellets are sieved to isolate pellets of 35 to 40 microns in diameter. These pellets are shaken to create a close-packed arrangement. The packed material is sintered to create a porous solid. This solid acts as a mold. The desired biomaterial, such as polyHEMA, is poured into the mold and surrounds the sintered pellets. The biomaterial is allowed to solidify. Finally, a solvent is added to dissolve the polystyrene mold, leaving only the biomaterial which contains many pores of 35 to 40 micron diameter. (Pores of this size have been shown to reduce the immune reaction that leads to scarring and infection. The explanation of why is beyond the scope of this blog.)
A company named Healionics was formed to commercialize the 6S process. Mr. Ratner is the chairman of the firm’s scientific advisory board.
Schematic of 6S process. Image from U.S. FDA
After the talk I spoke to Mr. Ratner about artificial kidneys. Unfortunately, he indicated that there are no researchers at Univ Washington working on producing artificial kidneys. I also asked him about the pros and cons of natural and synthetic substrates. He believes that using decellularized organs as the substrate for new artificial organs will prove too difficult except for certain uses and that he expects synthetic substrates, like those created using the ink jet process or the 6S process, to be more likely to lead to successful functional organs.
[Update: Corrected the affiliation of Mr. Ratner with Tengion. He is a member of its scientific advisory board.]