Research Themes:
Biomaterials and Regenerative Medicine
Molecular and Cellular Engineering

Education

ScD (chemical engineering), MIT, 1957
MS (chemical engineering), MIT, 1955
BS (chemical engineering), MIT, 1953

Research Interests

• Intracellular drug delivery
• Smart polymers & hydrogels
• Smart polymer-biomolecule conjugates in drug delivery
• Separations & diagnostics

Contact Information

Department of Bioengineering
University of Washington
Box 355061
William H. Foege Building, Room N530R
Phone: 206-543-9423
E-mail

Research Description

The major activities in my laboratories include the following:

• SMART POLYMER BIOCONJUGATES: Synthesis and application of conjugates of stimuli-responsive polymers and proteins. Applications include affinity separations, diagnostics, biosensors, bioprocesses, and drug delivery.
• SMART HYDROGELS: Synthesis and characterization of smart polymer hydrogels for use as injected drug delivery depots, or as tissue engineering matrices or as coatings for implants (to enhance implant healing and integration). We incorporate various drugs into the matrices. The matrices are designed to be biocompatible and biodegradable.
• DRUG DELIVERY: Design and synthesis of acid sensitive polymers for incorporation into drug delivery formulations where acidic environments in the endosome are encountered during intracellular delivery. Currently, the polymers are specifically designed to facilitate the endosomal escape of "fragile" biomolecular drugs (eg, DNA, ODNs, siRNA, peptides, and proteins) to the cytosol to avoid being trafficked to lysosomes, where enzymes would degrade the drugs.
• POLYMER SURFACES: Surface modification and characterization of polymeric biomaterials. Surfaces are modified to make them more (or less) chemically reactive or bioreactive. Biomolecules may be immobilized on the treated surfaces. This is relevant to biomedical implants, as well as for applications in affinity separations, microfluidic diagnostics, biosensors, bioprocesses, and drug delivery.

Teaching Activities

• BIOEN 491: Controlled Drug Delivery Systems
• BIOEN 490: Biomaterials
• BIOEN 590: Advanced Biomaterials
• BIOEN 511: Biomaterials Seminar

Honors and Awards

• 2007 Founder's Award, Controlled Release Society (Lifetime Achievement Award)
• 2006 International Award from Society for Polymer Science, Japan
• 2005 Elected to National Academy of Engineering for "Pioneering Work on the Medical Uses of Polymeric Materials"
• 2003 Chandra Sharma Award of the Society for Biomaterials and Artificial Organs of India, Mumbai, India
• 2002 Symposium in honor of 70th Birthday, Maui, Hawaii. Festschrift of papers published in J. Biomaterials Science, Polymer Edition (book published in 2005)
• 2000 Founder's Award, Society for Biomaterials (Lifetime Achievement Award) 6th World Congress on Biomaterials, Maui, Hawaii
• 1999 Special Recognition Award for "Excellence in Guiding Graduate Student Research", Controlled Release Society, Boston, MA
• 1997 Alan S. Michaels Lectureship, MIT
• 1996  Elected Founding Fellow, International College of Fellows, Biomaterials Science and Engineering, Society for Biomaterials
• 1993-94 Festschrift in honor of 60th birthday, J. Biomaterials Science, Polymer Edition (book published from Festschrift in 1955)
• 1992 Elected Founding Fellow of American Institute of Medical and Biological Engineering (AIMBE)
• 1992 Symposium in honor of 60th birthday, Maui, Hawaii. Festschrift of papers published in J. Biomaterials Science, Polymer Edition (book published in 1994)
• 1990 Biomaterials Science Prize, Japanese Society for Biomaterials, Tsukuba, Japan
• 1990 Special Recognition Award for "Excellence in Guiding Graduate Student Research", Controlled Release Society, Chicago, IL
• 1986-89 Trustee and Member, Board of Directors of the International Society of Artificial Organs
• 1984 Clemson Award for "Contributions to the Scientific Literature on Biomaterials"
• 1983 President, Society for Biomaterials
• 1977 Chairman, Gordon Conference on Biomaterials
• 1957 Fulbright Fellowship, Paris, France

Selected Publications

• Eun Ju Oh, Kitae Park, Ki Su Kim, Jiseok Kim, Jeong-A Yang, Ji-Hyun Kong, Min Young Lee, Allan S. Hoffman, Sei Kwang Hahn, “Target specific and long-acting delivery of protein, peptide, and nucleotide therapeutics using hyaluronic acid derivatives” J Contr Rel, 141, 2–12 (2010)
• Convertine, AJ, Benoit, DSW, Duvall, CL, Hoffman, AS, and Stayton, PS, “Development of a novel endosomolytic diblock copolymer for siRNA delivery, J Contr Rel. 133 (2009) 221-229
• Henry SM, Convertine AJ, Benoit DS, Hoffman AS, Stayton PS “End-functionalized polymers and junction-functionalized diblock copolymers via RAFT chain extension with maleimido monomers” Bioconj Chem 20(6):1122-8 (2009)
• Flanary S, Hoffman AS, Stayton PS “Antigen delivery with PPAA [poly(propylacrylic acid)] conjugation enhances MHC-1 presentation and T-cell Activation” Bioconj Chem 20(2):241-8 (2009)
• Lai JJ, Nelson KE, Nash MA, Hoffman AS, Yager P, Stayton PS. “Dynamic bioprocessing and microfluidic transport control with smart magnetic nanoparticles in laminar-flow devices” Lab Chip 9(14):1997-2002 (2009)
• Nash MA, Lai JJ, Hoffman AS, Yager P, Stayton PS. "Smart Diblock Copolymers as Templates for Magnetic-Core Gold-Shell Nanoparticle Synthesis” Nano Letters (2009)
• Rodriguez VB, Henry SM, Hoffman AS, Stayton PS, Li X, Pun SH. 2008. Encapsulation and stabilization of indocyanine green within poly(styrene-alt-maleic anhydride) block-poly(styrene) micelles for near-infrared imaging. J Biomed Opt 13(1):014025.
• McGonigle JS, Tae G, Stayton PS, Hoffman AS, Scatena M. 2008. Heparin-regulated delivery of osteoprotegerin promotes vascularization of implanted hydrogels. J Biomater Sci Polym Ed 19(8):1021-34.
• Tae G., Kim, Y.J., Choi, W.I., Kim, M., Stayton, P.S., and Hoffman, A.S., "Formation of a novel heparin-based hydrogel in the presence of heparin-binding biomolecules", Biomacromol., 8 1979-1986 (2007).
• Lai, J., Hoffman, A.S., and Stayton, P.S., "Dual Magnetic-Termperature Responsive Nanoparticles for Microfluidic Separations and Assays", Langmuir, 23, 7385-7391 (2007).
• Narain , R., Gonzales , M., Hoffman, A.S., Stayton, P.S., and Krisnan , K.M., "Synthesis of Monodisperse Biotinylated p(NIPAAm)-Coated Iron Oxide Magnetic Nanoparticles and their Bioconjugation to Streptavidin", Langmuir 23(11); 6299-6304 (2007)
• S. Kulkarni, C. Schilli, B. Grin, A.H.E. Müller, A.S. Hoffman, and P.S. Stayton, “Controlling the Aggregation of Conjugates of Streptavidin with Smart Block Copolymers Prepared via the RAFT Copolymerization Technique”, Biomacromol., 7, 2736-41 (2006)
• S.M. Henry, M.E.H. El-Sayed, C.M. Pirie, P.S. Stayton, and A.S. Hoffman, “pH-Responsive Poly(styrene-alt-maleic anhydride) Copolymers for Intracellular Drug Delivery”, Biomacromol., 7, 2407-14 (2006).
• X. Yin, P.S. Stayton and A.S. Hoffman, “Temperature- and pH-Responsiveness of Poly(N-Isopropylacrylamide-co-Propylacrylic acid) Copolymers Prepared by RAFT Polymerization” Biomacromol., 7, 1381-5 (2006).
• M. Ebara, J.M. Hoffman, A.S. Hoffman, and P.S. Stayton,“Switchable surface traps for injectable bead-based chromatography in PDMS microfluidic channels”, Lab Chip, 6(7), (2006).
• A.S. Hoffman, “Selecting the Right Polymer for Biomaterial Applications”, Chapter 1 in “Drug Delivery”, ed. I. F. Uchegbu, Taylor & Francis, London (2006) p 7-23.
• D. Pack, A.S. Hoffman, S. Pun and P.S. Stayton, “Design and Development of Polymers for Gene Delivery”, Nature Reviews, Drug Discovery, 4, 581-593 (2005)
• T. Kiang, C. Bright, C.Y. Cheung, P.S. Stayton, A.S. Hoffman and K.W. Leong, “Formulation of Chitosan/DNA Nanoparticles with Poly(propylacrylic acid) Enhances Gene Expression”, J. Biomater. Sci, Pol. Ed, 15, 1405-1422 (2005)
• Stayton, P.S., Ding, Z. and Hoffman, A.S., “Smart polymer-streptavidin conjugates”, Methods Mol Biol. 283: 37-44 (2004).
• Ratner, B.D., A.S. Hoffman, F.J. Schoen, and J.E. Lemons, Eds., "Biomaterials Science: An Introduction to Materials in Medicine", 2nd Edition, Elsevier/Academic Press, NY, NY (2004).  The 3rd Edition is expected to be published in 2011.