Plasma treated polyethylene grafted with adhesive molecules for enhanced adhesion and growth of fibroblasts Silvie Rimpelová a , Nikola Slepičková Kasálková b , Petr Slepička b , Helena Lemerová a , Václav Švorčík b , Tomáš Ruml a, ⁎ a Department of Biochemistry and Microbiology, Institute of Chemical Technology, Prague, Technická 5, Prague 6, 166 28, Czech Republic b Department of Solid State Engineering, Institute of Chemical Technology, Prague, Technická 5, Prague 6, 166 28, Czech Republic abstract article info Article history: Received 29 March 2012 Received in revised form 30 October 2012 Accepted 1 December 2012 Available online 11 December 2012 Keywords: Polyethylene Plasma treatment Surface characterization Biomolecules grafting Mouse embryonic fibroblasts The cell–material interface plays a crucial role in the interaction of cells with synthetic materials for biomedical use. The application of plasma for tailoring polymer surfaces is of abiding interest and holds a great promise in biomedicine. In this paper, we describe polyethylene (PE) surface tuning by Ar plasma irradiating and subsequent grafting of the chemically active PE surface with adhesive proteins or motives to support cell attachment. These simple modifications resulted in changed polymer surface hydrophilicity, roughness and morphology, which we thoroughly characterized. The effect of our modifications on adhesion and growth was tested in vitro using mouse embryonic fibroblasts (NIH 3T3 cell line). We demonstrate that the plasma treatment of PE had a positive effect on the adhesion, spreading, homogeneity of distribution and moderately on prolifer- ation activity of NIH 3T3 cells. This effect was even more pronounced on PE coated with biomolecules. © 2012 Elsevier B.V. All rights reserved. 1. Introduction Research of biomaterials involves studies of processes aimed on tailoring their capability to interact with cells, control tissue formation and regain of body parts functions. Materials that elicit and stimulate tissue formation, involve various classes, including metals, ceramics, polymers, and composites [1,2]. Biological functionality of polymeric material can be improved by grafting of various structures onto material surfaces [3]. Such materials can participate, both as optimal scaffolds for cellular functional expression and as carriers for release of any biologi- cal molecule relevant in this process. Polymers are widely used in various applications e.g. as vascular grafts [4], orthopedic bearings [5], screws [6], suture anchors [7], bone cement [8], soft-tissue reconstruction [9] or drug delivery systems [10]. For some applications, it is also necessary to prevent the cell growth on the polymer surface (balloon catheters, stent coatings). Plasma-assisted treatment was successfully used for surface modifica- tions of organic biopolymers to prevent bacterial attachment [11]. The most common polymeric materials used for biomedical applica- tions involve polyethylene (low or high density polyethylene [LDPE or HDPE]), polytetrafluoroethylene (PTFE), polypropylene (PP), polyesters (PES), polyamides (PA), polyurethane (PU), or polyetheretherketones (PEEK). They are preferably used for their long-term structural stability and biocompatibility, which is often enhanced using plasma discharge treatment [12,13]. The choice of appropriate polymer substrate for tissue engineering application is based on evaluation of their surface chemistry, surface morphology and many other physico-chemical properties. This may be followed by appropriate alteration, if necessary [14]. However, the most important is the understanding of the effect of polymer materials on viability, growth, and physiology of attached or adjacent cells. Designing biomaterials that specifically regulate cell behavior is often significant for optimal performance of biomedical device. Numerous cell functions are regulated by extracellular matrix (ECM), which is primarily composed of a complex meshwork of fibrous proteins surrounded by space-filling molecules [15] such as glycosami- noglycans as well as mineral deposits in hard tissues. Cell–ECM interac- tions can directly modulate cell morphology, survival, proliferation, and differentiation in cell systems. Various fibrous proteins forming the ECM, including collagen (CG) [16], fibronectin (FN) [17], elastin, tenascin, and laminin, have both structural and adhesive functions and are secreted in specific tissues by specialized cells, including fibroblasts (present in most of the connective tissues) or osteoblasts (in bones). The design criteria for artificial ECMs vary considerably depending on the type of engineered tissue [18]. The objective of the present work was to create and study artificial bio-inspired nanostructured matrices composed of polyethylene (PE) that was chosen as a model material for potential biomedical use. We combined advantageous features of PE, plasma treatment and grafting to improve the polymer surface for cell adhesion. Thus, we studied changes in surface of the PE samples after the treatment in argon (Ar) plasma discharge and after grafting of chemically active surface with selected biomolecules and adhesive proteins: glycine Materials Science and Engineering C 33 (2013) 1116–1124 ⁎ Corresponding author. Tel.: +420 220 44 5173; fax: +420 220 44 3022. E-mail address: tomas.ruml@vscht.cz (T. Ruml). 0928-4931/$ – see front matter © 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.msec.2012.12.003 Contents lists available at SciVerse ScienceDirect Materials Science and Engineering C journal homepage: www.elsevier.com/locate/msec