Jennifer F. Mize, Co-Editor
March 1999
NEWSLETTER OF THE NORTHEAST TENNESSEE SECTION OF AIChE
March Meeting: Tour of Siemens
Our March AIChE meeting will be a great opportunity to learn more about an industry whose products are critical to chemical processing. Though chemical engineers heavily depend on automation tools for reliable control of our processes, most of us are unfamiliar with their manufacture. We will visit Siemens' Johnson City plant on March 11 to observe a type of manufacturing that is foreign to the typical chemical engineer.
Founded in 1847, Siemens has grown to be one of the world's largest electrical and electronics companies with annual sales exceeding $73 billion. From memory chips to power plants, from fuel injectors to MRI scanners, Siemens designs, develops and manufactures electrical and electronic systems for the most technologically advanced industries.
Three separate Siemens business units, employing more than 900 people, are in the 320,000 square foot, south Johnson City facility. The largest of the three units, Siemens' Automation Products Business Unit, is Siemens' North American headquarters for factory automation devices and programmable logic controllers. The second major business unit, Siemens' Electronics Manufacturing Center, provides manufacturing services to Original Equipment Manufacturers of industrial, telecommunications, medical equipment and automotive products. The newest business unit to the site, Siemens Automotive Technology, produces electronic assemblies for the worldwide automotive market.
Don't miss this opportunity to tour a site that provides critical equipment to the chemical industry. We'll meet in the Eastman Employee Center parking lot at 5:15 p.m. on March 11 and plan to arrive at Siemens in time to check in and begin touring at 6:00. Following the tour, we'll enjoy a meal at Grady's. Sign up now by contacting Sandra Dudley (224-7376).
Sandra Dudley
Date: Thursday, March 11
Time: 6:00 p.m.
Place: Siemens Johnson City
Meet: Eastman Employee Center parking lot at 5:15 p.m.
We Need Your Local Dues!
Our local dues appear on your National AIChE bill each year, but some of you don’t pay them. Here’s what you need to know about local dues.
Currently, every AIChE member in our area is receiving our newsletter whether they helped pay for it or not. Please help us meet our expenses by paying your local section dues along with your national dues or, if you prefer, mail a check for the $6 local dues directly to:
Karen Maness
Eastman Chemical Company B-348
P.O. Box 511
Kingsport, TN 37662
Joe Bays
MIT's Griffith-Cima Engineers "Spare Parts"
Linda Griffith-Cima, the Karl Van Tassel Assistant Professor of Chemical Engineering at the Massachusetts Institute of Technology (MIT), is growing miniature "livers," which are smaller than a dime. Actually, the livers are growing themselves. Griffith-Cima and her colleagues at MIT and Harvard Medical School place a few droplets containing a mixture of liver cells (hepatocytes) and blood vessel cells (endothelial cells) inside a biodegradable polymer device, which acts as a scaffold to form the tissue, and has an "artery" at one end and a "vein" at the other. In the middle is a network of smaller, branching channels.
Within a few days, the cells sort themselves and begin assembling into natural patterns. Liver cells form a lining inside the channels; blood vessel cells form a layer on top of the liver cells. Then, the cells together form pillars that bridge one side of the channel wall with the opposite wall.
"The cells are trying to do what they normally do: form what are called sinusoidal structures," said Griffith-Cima. "There is a scale at which we see these structures. If the diameter of the channel is too small or too large, it doesn't happen. One of the things we are studying is the scale at which these cells self-assemble." The project's immediate goal is to understand how liver cells grow and organize into a functional liver. Its long-term goal is to cultivate replacement organs for the 30,000 Americans who die annually from liver failure. Fewer than 3,000 livers become available each year for transplant, and there is no widely used assist device like the dialysis machine for kidney patients. Transplantation is the only hope for patients with liver failure.
The liver, the largest of the internal organs, has powerful regenerative properties, like the spire of a starfish or the tail of a chameleon. Cut a liver in half and, within six weeks or so, it will restore itself. Griffith-Cima's group envisions growing enough liver cells to form a small organ, then implanting the small liver in the portal vein that leads from the digestive system to the liver.
The scaffold supporting the cells would dissolve in the same way that internal resorbable sutures do, leaving behind a miniature liver.
"There's an advantage to doing it this way that's clinically important," Griffith-Cima said. "Right now, about 15 percent of all liver transplants do not take hold. That means that in a day or two, another donor has to be found. Our approach would enable a surgeon to implant a functioning liver without taking out the old organ. That might be enough to restore normal function. We don't want to take the old liver out until we are sure the new one is functioning properly." Griffith-Cima's key clinical collaborator is Joseph Vacanti, a Harvard Medical School surgery professor and head of transplant surgery at Children's Hospital in Boston, who originated the idea of growing the tiny livers.
"There is a big difference in the training of an engineer and a physician," Griffith-Cima said. "I'm trained as a chemical engineer. For years, the main thing chemical engineers did was design chemical plants and oil refineries. And, you had to build in a "fudge factor," so that if something failed, it would still work perfectly because of the backup. But, when you're working in medicine, you don't wait until something is perfect. You'll never get anything done. If something has a chance of saving a life, you build it the best way you can now and improve it later."
Griffith-Cima came to national attention in 1995 for her tissue engineering work in developing replacement human ears, grown on the back of a mouse. Her research involved creating a mold in the shape of a human ear, distributing human cartilage cells throughout the form, and implanting the prototype ear on the back of a hairless mouse. The specially bred mouse, which lacks an immune system, nourishes the cells as they grow, and when the ear-shaped cartilage is harvested, the mouse remains alive and healthy. Griffith-Cima said she began growing "mouse ears" to assist a friend, who's a plastic surgeon.
AIChE News Release
E-mail Addresses Requested
This is the first issue of the Pipeline to be sent electronically. If you have received this newsletter in hardcopy and you have an e-mail address, please send a message to Richard Colberg (rcolberg@eastman.com) so that you can be included on our distribution list. Distributing the newsletter electronically saves the local section $65 per month in newsletter expenses. Please help us save money, time, and a few trees.
1999 AIChE Local Officers
Listing of the 1999 Northeast Tennessee local section officers is provided below.
Chair John Aycock 229-8860
Vice Chair David Denton 229-6559
Secretary Richard Colberg 229-3184
Treasurer Karen Maness 229-8896
Directors Tim Nolen 229-8287
Joe Parker 229-3850
Joe Bays 229-5854
PIPELINE Justin Abnee 229-5513
Jennifer Mize 224-7018