Research Focus

Drug Delivery, Biotechnology, Immobilized Enzymes, Biomedical Engineering

Our work is at the interface of bio-technology and materials science. A major focus is the study and development of polymers to deliver drugs, particularly genetically engineered proteins, continuously at controlled rates and for prolonged periods of time. Work in progress in several areas including:

• Investigating the mechanism of release from polymeric delivery systems with concomitant microstructural analysis and mathematical modeling.
• Studying applications of these systems including the development of effective long-term delivery systems for insulin, interferon, growth hormones and vaccines.
• Developing controlled release systems that can be magnetically, ultrasonically, or enzymatically triggered to increase release rates.
• Synthesizing new biodegradable polymeric delivery systems which will ultimately be absorbed by the body.
• Creating new approaches for delivering drugs across complex barriers in the body such as the blood-brain barrier and the skin.
• Synthesizing new biodegradable polymer systems to be used in mammalian cell transplants for engineering new organs (e.g. the liver, cartilage).

Our interest in drug delivery systems has extended to situations where drugs may serve a potentially useful purpose and then cause toxicity. In such cases, it would be useful to have a selective drug or substance removal system. Examples include removal of heparin, bilirubin, and cholesterol. All of these studies involve reactor design, understanding biomaterials with respect to blood interactions, and modeling of in vivo situations.

Finally we are developing drugs that specifically inhibit the process of neovascularization but do not interfere with existing blood vessels. Neovascularization is critical to the progression of several diseases, including cancer, retinopathy, rheumatoid arthritis and psoriasis. These projects involve biochemical purification and tissue culture studies.

Selected Publications

Click here for a complete list of publications.

1. Lahann, J., Mitragotri, S., Tran, T., Kaido, H., Sundaran, J., Hoffer, S., Somorjai, G. A., Langer, R. Reversible switching of surfaces, Science, 299: 371-374, 2003.

2. Lee, P., Langer, R., Shastri, V., Novel microemulsion enhancer formulation for simultaneous transdermal delivery of hydrophilic and hydrophobic drugs, Pharmaceutical Research, 20: 261-266, 2003.

3. Sasiskharan, R., Rational design of low molecular weight heparins with improved in vivo activity, PNAS, 100: 651-656, 2003.

4. Radisic M., Euloth M., Yang L., Langer R., Freed L.E., Vunjak-Novaakovic G, High density seeding of myocyte cells for tissue engineering, Biotech. & Bioeng., 82: 403-414, 2003.

5. Langer, R. Where a pill won’t go, Scientific American, 288: 50-57, 2003.

6. LaVan, D., George, P.M, Langer, R., Simple three-dimensional microfabrication of electrodeposited structures, Angewandte Chemie, 42: 1262-1265, 2003.

7. Yu, B., Kim, K.H., So, P.T.C., Blankschtein, D., Langer, R, Visualization of oleic acid-induced transdermal diffusion pathways using two-photon fluorescence microscopy., Journal of Invest. Derm., 120: 448-455, 2003.

8. Fu, K., Harrell, R., Zinski, K., Um, C., Frazier, J., Lotan, N., Burke, P., Klibanov, A., Langer, R., A Potential Approach for Decreasing the Burst Effect of Protein from PLGA Microspheres, Journal of Pharm. Sci., 92: 1582-1591, 2003.

9. Lendlein, A., and Langer, R., Biodegradable, Elastic Thermoplastic Shape Memory Polymers with Adjustable properties for potential biomedical applications, Science, 296: 1673-1676, 2002.

10. Langer, R., Perspectives: Drug delivery – drugs on target, Science, 293: 58-59, 2001.

11. Niklason, L.E., Gao, J., Abbott, W.M., Hirschi, K.K., Houser, S., Marini, R., Langer, R., Functional arteries grown in vitro, Science, 284, 489-493, 1999.

12. Santini, J.T. Jr., Cima, M.J., and Langer, R.: A controlled release microchip, Nature, 397- 335-338, 1999.

13. Langer, R., Langer, R., Drug delivery and targeting, Nature, 392 (Suppl), 5-10, 1998.

14. Langer, R., New methods of drug delivery, Science, 249, 1527-1533, 1990.

15. Langer, R. and Tirrell, D., Novel biomaterials, Nature, in press.

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