AUSTIN, Texas—Dr. Nicholas Peppas, one of the world’s leading authorities on biomaterials and drug delivery, has joined the faculty of The University of Texas at Austin College of Engineering and College of Pharmacy.
Dr. Peppas’ research projects focus on drug delivery systems that eliminate insulin injections by diabetics, “nano-robots” that circulate through the human body removing harmful substances, improved materials for contact lenses and laser surgery implants.
Dr. Peppas received his doctor’s degree in chemical engineering from the Massachusetts Institute of Technology. He came to Austin following a 27-year career at Purdue University, where, among other distinctions, he became the most-cited U.S. authority in biomedical engineering worldwide. At The University of Texas at Austin he holds appointments in the College of Engineering’s departments of Chemical and Biomedical Engineering and the Department of Pharmaceutics within the College of Pharmacy.
“I want to be in the best place to do our work, and to attract others to biomedical engineering,” he says, citing the university’s strength in chemical engineering (#5 nationally) and pharmaceutics (#2)—and the great promise of the fledgling Biomedical Engineering Department. Established just a year ago, it already ranks in the top 20.
Peppas, who arrived with a team of 12, is establishing strong ties with Texas Medical Center and M.D. Anderson Cancer Center in Houston, and is pursuing interdisciplinary biomedical collaborations with investigators across campus. To the university’s already-rich research environment, he brings his own portfolio of projects in protein-based drug delivery, bio-nanotechnology and biomaterials.
Peppas’ work is geared toward investigating and understanding the molecular and cellular fundamentals of the biomedical field, and also toward engineering products to improve the quality of life of persons suffering from severe, long-term medical conditions. His work—which has been recognized with more than 60 national and international awards—falls into three principal categories:
1. Protein Delivery. His search for improved protein dispersion methods targets in particular the protein-based (peptidic) drugs used to treat diabetes, osteoporosis, cancer and multiple sclerosis. At present, those drugs—insulin, calcitonin and the interferons—must be administered through injection because they are broken down by stomach acids before they can reach the bloodstream. Not only are the drugs unstable and expensive, they can pose serious side effects.
“With multiple sclerosis, for example, the patient’s condition weakens for the next 24-36 hours after taking the drug,” Peppas says. “A system that would release the drug over a longer period of time would make an enormous improvement.”
His team has developed such time-release systems, which bypass exposure to digestive juices. They consist of tiny capsules filled with acrylic-based gel microparticles of the peptide medication. The gel, impervious to attacks by acids or digestive enzymes, protects its cargo while passing through the mouth and stomach. In the upper small intestine’s less acidic environment, the capsules bind firmly to the intestinal wall and the mucus cells lining it—via a unique molecular mechanism based on chemical tethers—at the same time swelling to release their beneficial contents. The pharmaceutical is then slowly absorbed into the bloodstream. The empty capsules and gel particles are flushed from the body every few hours with no ill effects.
2. Biorecognition. This process imprints the chemical identity of a biomolecular substance on the surface of a gel. The treated gel then attracts and captures that same substance.
Peppas’ group is exploring applications of the process, called biorecognition, to “treating disease by subtraction.”
“Heart attack patients have unhealthy cholesterol levels; they have triglycerides,” Peppas says. “Our goal is to devise a system that would recognize these undesirable compounds and remove them.”
He has already successfully imprinted glucose and several triglycerides. His use of polyethylene glycol in the process creates ‘stealth conditions,’ allowing these particles circulating in the blood to go unrecognized by the body’s defenses.
“If they were, they would be destroyed immediately,” he explains. His present research program is directed at creating highly selective imprinted nanoparticles to recognize a larger variety of harmful chemical compounds. He foresees a day—perhaps seven to 10 years from now—when a mixture of nanoparticle types will be administered to a patient.
“Some will recognize glucose; some will recognize angiotensin, a substance linked to high blood pressure; some will recognize one triglyceride or another,” he says. “They will circulate in the body like little nano-robots. And they will grab the substance they’re looking for.”
After a few days, the nano-particles will biodegrade into harmless products that can be absorbed by the body.
3. Biomaterials. Peppas calls the research on the synthesis of bio-compatible materials for medical applications his first love. During the 1970s, he developed artificial vocal cord and cartilage materials, which remain in wide use. He is working on advanced contact lenses designed to resist the usual debris buildup on the underside; as well as on improved intra-ocular lenses for cataract surgery implants.
He looks forward to building his team and pursuing more basic biomedical research, which could one day advance patient care through licensed technology. To date, his research programs have yielded 22 patents.
“We are excited about solving a major health problem, improving the quality of life for patients, and getting an answer about a fundamental problem—such as how we can pass the protein to the blood,” he says. “Ultimately, if successful, such solutions will become products that we can bring to market.”
Dr Peppas’ work—totaling nearly $40 million in funding over 20 years—has been supported by the National Institutes of Health, the National Science Foundation, the U.S. Department of Energy and several private companies. He holds the Paul D. and Betty Robertson Meek Centennial Professorship in chemical engineering, biomedical engineering and pharmaceutics, and the Cockrell Family Regents Chair.
For more information contact: Becky Rische, College of Engineering, 512-471-7272.
