1. Approaches to the fabrication of surfaces that combine methods for the topographic patterning of soft materials with opportunities for facile, post-fabrication chemical functionalization will contribute significantly to advances in the design of a broad range of functional materials, including biomaterials. IRG3 has developed new methods that can be used to introduce well-defined topographic features into thin films of thermoplastic polymers containing chemically reactive azlactone functionality using nanoimprint lithography (NIL). The IRG has demonstrated that NIL can be used to imprint topographic patterns into thin films of homopolymers and copolymers containing azlactone functionality with patterns of grooves and ridges ranging in width from 400 nm to 2 µm. The reactive azlactone functionality of these polymers survives temperatures and pressures associated with NIL, and topographically patterned films can be functionalized post-imprinting by treatment with small molecules and polymers containing primary amines. As an example of the potential utility of this approach to biomaterials synthesis, mammalian fibroblast cells were shown to attach and proliferate on topographically patterned azlactone-containing films and align in the direction of the imprinted pattern, and treatment of these films with amine-functionalized poly(ethylene glycol) resulted in topographically patterned films that prevented cell adhesion. These results and others obtained by the IRG suggest approaches to the functionalization of topographically patterned surfaces with a broad range of chemical functionality (e.g., peptides, proteins, carbohydrates, etc.) of biotechnological interest. In particular, the ability to manipulate and define both the physical topography and chemical functionality of these reactive materials provides opportunities to investigate the combined effects of substrate nanotopography and chemical functionality on cell behavior and it may also be useful in a broad range of other materials applications. N.J. Fredin, A.H. Broderick, M.E. Buck, and D.M. Lynn, “Nano-Imprinted Thin Films of Reactive, Azlactone-Containing Polymers: Combining Methods for the Topographic Patterning of Cell Substrates with Opportunities for Facile Post-Fabrication Chemical Functionalization.” Biomacromolecules 2009, 10, in press. Figure Caption: Schematic illustrations of (A) transfer of nano- and micrometer-scale topographic features to a thin film of a reactive, azlactone-containing polymer using nano-imprint lithography (NIL), and (B) post-fabrication chemical modification of azlactone functional groups by reaction with amine-functionalized nucleophiles. (C) Structures of the reactive, azlactone-containing homopolymer and copolymer used in this study. (D,E) Phase contrast (D) and fluorescence microscopy (E) images of NIH-3T3 fibroblasts (stained with calcein AM) seeded on a film of azlactone-containing polymer imprinted with a pattern of lines at a 4-µm pitch. The dotted arrows indicate the direction of the topographic features. Scale bars = 100 µm (25 µm for inset). Nanoimprinted Thin Films of Reactive, Azlactone-Containing Polymers: New Methods for the Topographic Nanopatterning with Facile Post-Fabrication Chemical Functionalization Juan J. De Pablo, University of Wisconsin-Madison, DMR 0520527 This work was supported by the NSF through the University of Wisconsin Materials Research Science and Engineering Center, grant number DMR-0520527.