Patterned Enzymatic Degradation of Poly(ε-caprolactone) by High- Affinity Microcontact Printing and Polymer Pen Lithography Manoj Ganesh, † Jonathan Nachman, ‡ Zhantong Mao, § Alan Lyons, § Miriam Rafailovich, ‡ and Richard Gross* ,† † NSF I/UCRC for Biocatalysis & Bioprocessing of Macromolecules, Polytechnic Institute of NYU, Six Metrotech Center, Brooklyn, New York 11201, United States ‡ Department of Materials Science and Engineering, State University of New York at Stony Brook, Stony Brook, New York 11794-2275, United States § Center for Engineered Polymer Materials, Department of Chemistry, College of Staten Island (CUNY), Building 6S - Room 225, 2800 Victory Boulevard, Staten Island, New York 10314, United States * S Supporting Information ABSTRACT: This paper reports deposition of Candida antarctica Lipase B (CALB) on relatively thick poly(ε-caprolactone) (PCL) films (300-500 nm) to create well-defined patterns using two different writing techniques: high-affinity microcontact (HA-μCL) and polymer pen (PPL) lithography. For both, an aqueous CALB ink is absorbed onto a polydimethylsiloxane (PDMS) writing implement (PDMS stamp or a PDMS pen tip), which is transferred to a spun-cast PCL film. HA-μCL experiments demonstrated the importance of applied pressure to obtain high-resolution patterns since uniform contact is needed between raised 20 μm parallel line regions of the PDMS stamp and the surface. AFM imaging shows pattern formation evolves gradually over incubation time only in areas stamped with CALB cutting through spherulites without apparent influence by grain boundaries. Strong binding of CALB to PCL is postulated as the mechanism by which lateral diffusion is limited. PPL enables formation of an arbitrary image by appropriate programming of the robot. The PDMS pen tips were coated with an aqueous CALB solution and then brought into contact with the PCL film to transfer CALB onto the surface. By repeating the ink transfer step multiple times where pen tips are brought into contact with the PCL film at a different locations, a pattern of dots is formed. After printing, patterns were developed at 37 °C and 95% RH. Over a 7-day period, CALB progressively etched the PCL down to the silicon wafer on which it was spun (350 nm) giving round holes with diameters about 10 μm. AFM images show the formation of steep PCL walls indicating CALB degraded the PCL film in areas to which it was applied. This work demonstrates that high-resolution patterns can be achieved without immobilizing the enzyme on the surface of polymeric stamps that limits the depth of features obtained as well as the throughput of the process. ■ INTRODUCTION There is significant interest in using the selective deposition of enzymes to define high resolution features on biocompatible polymer substrates without adversely affecting the polymer substrates biocompatibility. Thus far, research aimed at “writing with enzymes” has focused on highly sophisticated and expensive technologies to deliver the enzyme. 1-3 In one approach, a nanopipet is used to deliver precise quantities of a biocatalyst onto a polymer surface at specific locations. For example, trypsin was transferred through a cantilevered nanopipet onto a bovine serum albumin (BSA) film surface such that holes with widths and depths of about 2 μm were etched into the surface. Varying the time that the nanopipet was in contact with films resulted in controlled hole dimensions. 4 Caffeic acid was polymerized using horseradish peroxidase and used in creating nanoscale surface patterning. 5 A Received: April 18, 2013 Revised: June 20, 2013 Communication pubs.acs.org/Biomac © XXXX American Chemical Society A dx.doi.org/10.1021/bm400552u | Biomacromolecules XXXX, XXX, XXX-XXX