Why People Will Live Longer & Better
Ken Ball
Dr. Langer presented an outstanding Institute Lecture at the 2002 AIChE Annual. He is among many persons expecting a quantum jump in lifespans and human usefulness at older ages. His career accomplishments certainly justify his beliefs.
Dr. Robert Langer, MIT's Kenneth J. Germeshausen Professor of Chemical & Biomedical Engineering, delivered the 54th Institute Lecture during the AIChE's Annual Conference. Professor Langer is listed among the world's top 25 persons in biotechnology by Time and Forbes magazines. With a staff of 50, his development efforts center around polymer controlled drug release and tissue engineering.
Dr. Langer is a MIT Chemical Engineer who was encouraged to accept a post-doctoral fellowship at Harvard Medical School. He recalled that--at the time--most biomedical devices were developed by medical doctors who had little training in engineering or materials science. He provided some examples of MD developed devices wherein the developer simply used a material which appeared to be applicable for an intended biomedical use.
Regarding controlled drug release, Langer stated that some 100,000 deaths occur each year from improper use of or unexpected reactions to prescribed drugs. His group has developed spongy polymers that are slowly dissolved by body fluids allowing entrapped medications to be released at a slow and constant rate. They have demonstrated constant releases over time periods of several days to more than 5 years. Fewer prescriptions, drug administrations, and refills obviously reduce the number of drug related errors.
The constant release rates also obviate the peaks and valleys associated with oral or hyperdermic administered medications. They have successfully delivered nitroglycerin to heart patients, insulin to diabetics and human growth hormones to underdeveloped children. Anti-coagulant polymer enclosed medications have been coated on implanted stents used to keep blood vessels open.
The drug structures can be implanted in or near the organ or tissue requiring medication thereby not exposing the entire body to high dosages which are only helpful to certain organs. For example, polymers containing slow release chemotherapy compounds have been implanted just prior to closure in brain tumor and prostate cancer surgeries. These deliver higher dosages for a month or so at the precise location needed.
Materials scientists on the Langer team have extended the application of biodegradable polymers to various body parts. The polymers act as patterns or structural scaffolds and can be shaped to provide a base structure for skin; nose or ear cartileges; bones; or various organs. A key aspect is that the patients own cell samples can be introduced to the polymer structure and grown for an eventual implant as indicated in this approach about eliminates body rejection problems.
Skin is grown over screen-like polymers and the skin tissue grows quickly so that burn victims can quickly have their own new skin to repair burn damage. These polymers are now in use. A series of Langer slides showed a badly burned baby--chin to navel--and then with replacement skin; and then about a year later, a toddler with little evidence of the earlier burn trauma.
They have had success in porous cartilage forms for nose and ear structures; again wherein the patients own tissue grows in and around the basic polymer form. Similar approaches for bone tissue are showing promise. They have had some early success in rebuilding damaged vocal chords which afflict about a million persons in the US. In fact, Julie Andrews was a vocal chord patient.
The Langer group is now experimenting with implantable chips having a well or series of wells etched into the silicon chip structure medications are stored in the wells and sealed by a thin layer of gold. An electronic signal can be applied to deplate the gold seal and initiate a release of the medication. This capability could lead towards implanted closed loop control wherein an implanted sensor can determine the medication need.
