Electrospun, Biofunctionalized Fibers as Tailored in vitro Substrates for Keratinocyte Cell Culture Dirk Grafahrend, Karl-Heinz Heffels, Martin Mo ¨ller, Doris Klee,* Ju ¨rgen Groll Introduction Enhancing dermal tissue regeneration has significant implications for patients suffering from chronic non- healing wounds, such as diabetic ulcers and venous ulcers, as well as large area burn wounds. [1] Hence, physicians as well as patients ask for implantable compliant biodegrad- able scaffolds that target accelerating chronic wound repair. Numerous requirements seem to be crucial for the success of a scaffold used inside the human body, for tissue engineering and cell culture. [2] Most frequently, biodegrad- able materials (such as poly(glycolic acid) (PGA) and polymers based on poly(lactic acid) (PLA) have been used. Degradation products are cleared from the body and a second surgery to remove the scaffold becomes unnecessary. While Communication D. Grafahrend, K.-H. Heffels, M. Mo ¨ller, D. Klee, J. Groll DWI e.V. and Institute of Technical and Macromolecular Chemistry, RWTH Aachen Pauwelsstr. 8, D-52056 Aachen, Germany E-mail: klee@dwi.rwth-aachen.de Cell adhesion preventing fiber surfaces were tailored differently with bioactive peptides (a fibronectin fragment (GRGDS), a collagen IV fragment (GEFYFDLRLKGDK) and a combination of both) to provide an artificial extracellular matrix as a substrate for HaCaT keratinocyte cell culture. Therefore, a polymer blend containing a six-arm star-shaped statistical copolymer of ethylene oxide and propylene oxide in the ratio 80:20 (NCO-sP[EO-co-PO]) and poly- [D,L-(lactide-co-glycolide)] (PLGA) was electrospun. The resulting fibers were biofunctionalized and investigated as in vitro substrates using the HaCaT kerationcyte cell line. Appropriate surface chemistry on these electrospun fibers proved to prevent adhesion of keratinocytes, while additional immobilization of certain pep- tide sequences induced cell adhesion. These specific fibers enable investigation of immobil- ized active molecules and the subsequent cellular response to the scaffold. HaCaT keratinocytes were found to selectively adhere to those fibers modified with either collagen IV segment GEFYFDLRLKGDK or a mixture of the two peptide sequences GEFYFDLRLKGDK and GRGDS (1:1). However, the synergistic effects of both (the fibro- nectin fragment and the collagen IV fragment) seem to significantly increase the numbers of adherent keratinocytes. 1022 Macromol. Biosci. 2010, 10, 1022–1027 ß 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim wileyonlinelibrary.com DOI: 10.1002/mabi.201000068