Mechanical evaluation and cell response of woven polyetheretherketone scaffolds S. L. Edwards, J. A. Werkmeister CSIRO Materials Science and Engineering, Normanby Road, Clayton, Australia 3168 Received 5 March 2012; revised 2 May 2012; accepted 17 May 2012 Published online 00 Month 2012 in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/jbm.a.34286 Abstract: Polyetheretherketone (PEEK) is a high performance polymer, with high melting temperature and high resistance to wear. PEEK biomedical devices are typically manufactured to produce nonflexible structures. In this study, we fabricated flexible PEEK scaffolds from multifilament and monofilament yarns, using weaving technologies. Scaffolds were compared for structural and mechanical properties, and assessed for in vitro biological response to L929 mouse fibroblast cells. PEEK scaffolds were found to support fibroblast cell attach- ment and proliferation, with similar cell numbers to a polyeth- ylene terephthalate scaffold. The large pores (261–280 lm) of the monofilament scaffold prevented pore coverage by cells, confining cells to filaments, whereas the smaller pores (81–100 lm) of the multifilament scaffold permitted partial pore cover- age. Poor cell adhesion, due to large filament curvature angles, created a checkered pattern on the woven surface, a previously undocumented phenomenon. The multifilament scaffold was found to be lighter, thinner, and less porous, with better me- chanical properties (load at break: 657 N, elastic recovery: 66%, burst strength: 492 N) than the monofilament scaffold (load at break: 534 N, elastic recovery: 30%, burst strength: 401 N). Results indicate that flexible PEEK woven structures may find application as tissue engineering scaffolds, particularly for en- gineering soft tissues. V C 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 00A: 000–000, 2012. Key Words: polyetheretherketone, scaffold, tissue engineer- ing, fibroblasts, PEEK-OPTIMA V R How to cite this article: Edwards SL, Werkmeister JA. 2012. Mechanical evaluation and cell response of woven polyetheretherketone scaffolds. J Biomed Mater Res Part A 2012:00A:000–000. INTRODUCTION Polyetheretherketone (PEEK) is a linear, aromatic, semicrys- talline polymer. It is thermoplastic, melting at an approxi- mate temperature of 334  C, and is perhaps best known for its excellent thermal, chemical and mechanical resistance at elevated temperatures. PEEK has an ultimate tensile strength of up to 100 MPa, an elongation to break of 50–150%, and a Young’s Modulus of 3.7 GPa. 1 These prop- erties may be tailored by the incorporation of carbon fibres 2 to produce fiber-reinforced composites. 2–5 PEEK has been shown to possess good biocompatibility, 6 with neither cytotoxicity 7 nor mutagenicity 8 in vitro. These studies have predominantly used either osteoblasts 5–7,9,10 or fibroblasts 7,10 on either PEEK substrates, 5,6,10 PEEK compo- sites, 5,7,9 or extracts derived from them, 7 with cell spread- ing 5,6,9 and proliferation 6,9 determined up to 14 days culture. In vivo studies have determined a minimal inflammatory reaction, 2,11–13 with no adverse reaction to injected PEEK particles on nervous tissue. 14 These described properties, combined with a natural radiolucency and MRI compatibility, renders PEEK an obvious replacement for metals in ortho- paedic applications, for example, spinal fusion devices, 15 bone plates, 3,4 knee joints, 16 and craniofacial repair. 17 PEEK biomedical devices are typically produced by con- ventional manufacturing methods like injection moulding, 5,12 machining, 5 and extrusion. Laser sintering 6,11,18 has also been used to produce complex geometries based on digital computer data. These manufacturing methods usually pro- duce rigid structures, limiting PEEK to orthopaedic applica- tions. So that PEEK polymer properties may be used to advantage in other biomedical applications, such as scaffolds for tissue engineering, more flexible methods of manufacture are required. Techniques such as knitting and braiding 3,4 have been used to produce structures with higher deform- abilities, compared to those manufactured using conventional methods. Use of such textile technologies in the production of PEEK devices are slowly gaining recognition, and are only possible due to the availability of PEEK yarns. A textile tech- nology which produces flexible structures from yarns that has, until now, not been used in the fabrication of PEEK structures, is weaving. This technology presents an opportu- nity to fabricate structures of different architectures, with different porosity and pore size, and a range of mechanical properties. The aim of this work was to fabricate novel PEEK scaf- folds from multifilament and monofilament yarns, using Correspondence to: S. L. Edwards; e-mail: sharon.edwards@csiro.au Contract grant sponsor: Invibio V C 2012 WILEY PERIODICALS, INC. 1