ple.Some of these systems are small enough to be implanted B7lS6anRaArsmtMaephimcCeP 40.383199 45531997 Conclusions James.V.Tangpasuthadol.and Kohn The above examples represent only some of the ap and m uang medical problems.Nonetheless. on cance hear II. other treatments.With continuing advances in chemical engi M.EK Park. lexander.cas.. STS Publishing.Cardift.U.K. cation in the future. Acknowledgments dation for supporting their research M.K.Park. iterature Cited .B. er ated Dopamine Se borty, A GH P ARh,没 s (19 er.M.Chow Soc I the 776( nsell, okanoeactci2olearctcdroee c6.23719 190 品 Hrkach Ben-Jebri T.w 7 A.Peppas 、Gels and 229 A ,J.Kohn,and B.D.Ratn 13.135(1 5.T.Lopins,N k Su R.Coh R.S af R nitic and AIChE Journal December 2003 Vol49,No.12 3003ple. Some of these systems are small enough to be implanted by intracutaneous injection by a large gauge hypodermic nee￾dle, thereby eliminating the need for surgical implantation Ž . Troyk, 1999 . Conclusions The above examples represent only some of the ap￾proaches where chemical engineers are employing materials to address medical problems. Nonetheless, materials based systems are now being used in the treatment of cancer, heart disease, the creation of new tissues such as skin, and many other treatments. With continuing advances in chemical engi￾neering, materials science, and biology, we expect continuing and even greater progress in biomaterials research and appli￾cation in the future. Acknowledgments A portion of this article was presented by Robert Langer at the 2002 AIChE meeting as the Institute Lecture. Both authors wish to thank the National Institutes of Health and National Science Foun￾dation for supporting their research. Literature Cited Aebischer, P., P. A. Tresco, S. R. Winn, L. A. Green, and C. B. Jaeger, ‘‘Long-Term Cross-Species Brain Transplantation of a Polymer Encapsulated Dopamine Secreting Cell Line,’’ Exp. Neu￾rol., 111, 269 1991 . Ž . Albin, G, T. A. Horbett, and B. D. Ratner, ‘‘Glucose Sensitive Mem￾branes for Controlled Delivery of Insulin,’’ J. Controlled Release, 2, 153 1985 . Ž . Alcock, S., and A. P. F. Turner, ‘‘Molecular Imprinting: at the Edge of the Third Millennium,’’ Trends in Biotechnol. 19Ž. Ž . 1 , 9 2001 . Alsenz, J., G. J. Russell-Jones, and S. Westwood et al., ‘‘Oral Ab￾sorption of Peptides through the Cobalamin Vitamin B12 Path- Ž . way in the Rat Intestine,’’ Pharmaceut Res., 17Ž. Ž . 7 , 825, July 2000 . am Ende, M. T. and N. A. Peppas, ‘‘Analysis of Drug Distribution in Hydrogels Using FTIR Microscopy,’’ Pharm. Res., 12, 2030 1995 . Ž . Anderson, D. G., D. M. Lynn, and R. Langer, ‘‘Semi-Automated Synthesis and Screening of a Large Library of Degradable Cationic Polymers for Gene Delivery,’’ Angewandte Chemie, 42, 3153 2003 . Ž . Andersson, L. I., R. Muller, G. Vlatakis, and K. Mosbach, ‘‘Mimics of the Binding Sites of Opiod Receptors Obtained by Molecular Imprinting of Enkephalin and Morphine,’’ Proc. Natl. Acad. Sci., 92, 4788 1995 . Ž . Ansell, R. J., and K. Mosbach, ‘‘Molecularly Imprinted Polymers: New Tools for Biomedical Science,’’ Pharmaceutical News, 3Ž . 2 , 16 Ž . 1996 . Barrera, D., E. Zylstra, P. Lansbury, and R. Langer, ‘‘Synthesis and RGD Peptide Modification of a New Biodegradable Copolymer System: Poly Lactic Acid-co-Lysine , Ž . ’’ J. of Amer. Chem. Soc., 115, 23, 11010, 1993 . Ž . Bell, C. L., and N. A. Peppas, ‘‘Water, Solute and Protein Diffusion in Physiologically Responsive Hydrogels of Poly methacrylic Acid- Ž g-Ethylene Glycol ,. Ž. ’’ Biomaterials, 17, 1203 1996 . Bell, C. L., and N. A. Peppas ‘‘Modulation of Drug Permeation through Interpolymer Complexed Hydrogels for Drug Delivery Applications,’’ J. Controlled Release, 39, 201 1996 . Ž . Bell C. L., and N. A. Peppas, ‘‘SwellingrSyneresis Phenomena in Gel-Forming Interpolymer Complexes,’’ J. Biomater. Sci., Polym. Ed., 7, 671 1996 . Ž . Belu, A. M., S. Brocchini, J. Kohn, and B. D. Ratner, ‘‘Characteriza￾tion of Combinatorially Designed Polyarylates by Time-of-Flight Secondary Ion Mass Spectrometry,’’ Rapid Commun. Mass Spec￾trom., 14, 564 2000 . Ž . Brazel, C. S., and N. A. Peppas, ‘‘Pulsatile Local Delivery of Throm￾bolytic and Antithrombotic Agents using Poly N-isopropyl Acryl- Ž amide-co-Methacrylic Acid Hydrogels, . ’’ J. Controlled Release, 39, 57 1996 . Ž . Brazel, C. S., and N. A. Peppas, ‘‘Mechanisms of Solute and Drug Transport in Relaxing, Swellable, Hydrophilic Glassy Polymers,’’ Polymer, 40, 3383 1999 . Ž . Brocchini, S., K. James, V. Tangpasuthadol, and J. A. Kohn, ‘‘ Com￾binatorial Approach for Polymer Design,’’ J. Amer. Chem. Soc., 119, 4553 1997 . Ž . Brocchini, S, K. James, V. Tangpasuthadol, and J. Kohn, ‘‘Structure-Property Correlations in a Combinatorial Library of Degradable Biomaterials,’’ J. Biomed Mater Res, 42, 66 1998 . Ž . Bures, P., Y. Huang, E. Oral, and N. A. Peppas, ‘‘Surface Modifica￾tions and Molecular Imprinting of Polymers in Medical and Phar￾maceutical Applications,’’ J. Contr. Rel., 72, 25 2001 . Ž . Burnham, A. S., ‘‘Polymers for Delivering Peptides and Proteins,’’ Am. J. Hosp. Pharm., 51, 210 1994 . Ž . Byrne, M. E., K. Park, and N. A. Peppas, ‘‘Non-Covalent Molecular Imprinting of Glucose: Recognition in Aqueous Media,’’ Molecu￾larly Imprinted Polymer Science and Technology, K. R. Brain and C. J. Alexander, eds., STS Publishing, Cardiff, U.K., p. 111 2000 . Ž . Byrne, M. E., K. Park, and N. A. Peppas, ‘‘Biomimetic Materials for Selective Recognition of Biomolecules,’’ Biological and Biomimetic Materials - Properties to Function, J. McKittrick, J. Aizenberg, C. Orme, P. Vekilov, eds., MRS, Pittsburgh, PA, pp. 193-199 2002 . Ž . Byrne, M. E., E. Oral, J. Z. Hilt and N. A. Peppas, ‘‘Networks for Recognition of Biomolecules: Molecular Imprinting and Micropat￾terning Poly ethylene glycol -Containing Films, Ž . ’’ Polym. Ad®. Tech￾nol., 13, 798 2002 . Ž . Byrne, M., K. Park, and N. A. Peppas, ‘‘Molecular Imprinting within Hydrogels,’’ Ad®. Drug Deli®. Re®s., 54, 149 2002 . Ž . Byrne, M. E., D. B. Henthorn, Y. Huang, and N. A. Peppas ‘‘Micro￾patterning Biomimetic Materials for Bioadhesion and Drug Deliv￾ery,’’ Biomimetic Materials and Design: Biointerfacial Strategies, Tis￾sue Engineering and Targeted Drug Deli®ery, A. K. Dillow and A. Lowman, eds., Dekker, New York, p. 443 2002 . Ž . Chakraborty, A. K. ‘‘Disordered Heteropolymers: Models for Biomimetic Polymers and Polymers with Frustrating Quenched Disorder,’’ Phys. Rep., 342, 1 2001 . Ž . Chappel, S., ‘‘Can GHRH or GH Secretagogues Re-Initiate Pituitary GH Pulsatility,’’ Clinical Endocrinology, 50, 547 1999 . Ž . Cheong, S. H., S. McNiven, A. Rachkov, R. Levi, K. Yano, and I. Karube, ‘‘Testosterone Receptor Binding Mimic Constructed Us￾ing Molecular Imprinting,’’ Macromolecules, 30, 1317 1997 . Ž . Cohen, S., M. Bano, K. Visscher, M. Chow, H. Allcock, and R. Langer, ‘‘Ionically Crosslinkable Polyphosphazene: A Novel Poly￾mer for Microencapsulation,’’ J. Am. Chem. Soc., 112, 7832 1990 . Ž . Davis, H., ‘‘Cationic Polymers for Gene Delivery: Designs for Over￾coming Barriers to Systemic Administration,’’ Curr. Opin. Mol. Therapeut., 3, 183 2001 . Ž . Doyle, F. J., III, C. Dorski, J. E. Harting, and N. A. Peppas, ‘‘Con￾trol and Modeling of Drug Delivery Devices for the Treatment of Diabetes,’’ Proceed. Amer. Control Confer., 776 1996 . Ž . Duncan, R., S. Dimitrijevic, and E. G. Evagorou, ‘‘The Role of Poly￾mer Conjugates in the Diagnosis and Treatment of Cancer,’’ STP Pharma Sci., 6, 237 1996 . Ž . Duncan, R., ‘‘The Dawning Era of Polymer Therapeutics,’’ Nature Re®iews Drug Disco®ery, 3, 347 2003 . Ž . Edwards, D., J. Hanes, G. Caponetti, J. Hrkach, A. Ben-Jebria, M. Eskew, J. Mintzes, D. Deaver, N. Lotan, and R. Langer, ‘‘Large Porous Aerosols for Pulmonary Drug Delivery,’’ Science, 276, 1868 Ž . 1997 . Enoki, T., K. Tanaka, T. Watanabe, T. Oya, T. Sakiyama, Y. Takeoka, K. Ito, G. Wang, M. Annaka, K. Hara, R. Du, J. Chuang, K. Wasserman, A. Y. Grosberg, S. Masamune, and T. Tanaka, ‘‘Frus￾trations in Polymer Conformation in Gels and their Minimization through Molecular Imprinting,’’ Phys. Re®. Lett., 85, 5000 2000 . Ž . Foss, A. C., and N. A. Peppas, ‘‘Acrylic-Based Copolymers for Oral Insulin Delivery Systems,’’ Polym. Prepr., 42Ž. Ž . 2 , 94 2001 . Goldreich, M., and J. Kost, ‘‘Glucose-Sensitive Polymeric Matrices for Controlled Drug Delivery,’’ Clin. Mater., 13, 135 1993 . Ž . Griffith, L, and S. T. Lopina, ‘‘Network Structures of Radiation￾Crosslinked Star Polymer Gels,’’ Macromolecules, 28, 6787 1995 . Ž . Hansbrough, J. F., M. L. Cooper, R. Cohen, R. Spielvogel, G. Green￾leaf, R. L. Bartel, and G. Naughton, ‘‘Evaluation of a Biodegrad￾able Matrix Containing Cultured Human Fibroblasts as a Dermal Replacement Beneath Meshed Skin-Grafts on Athymic Mice,’’ Surgery, 111, 438 1992 . Ž . AIChE Journal December 2003 Vol. 49, No. 12 3003