Colloids and Surfaces B: Biointerfaces 111 (2013) 134–141 Contents lists available at SciVerse ScienceDirect Colloids and Surfaces B: Biointerfaces jou rn al hom epage: www.elsevier.com/locate/colsurfb Interaction of preosteoblasts with surface-immobilized collagen-based nanotubes Deepak M. Kalaskar 1 , Sophie Demoustier-Champagne, Christine C. Dupont-Gillain ∗ Institute of Condensed Matter and Nanosciences - Bio & Soft Matter (IMCN/BSMA), Université catholique de Louvain, Croix du Sud, 1 (Box L7.04.01), B-1348 Louvain-la-Neuve, Belgium a r t i c l e i n f o Article history: Received 21 December 2012 Received in revised form 21 May 2013 Accepted 22 May 2013 Available online 29 May 2013 Keywords: Collagen Nanotube Biointerface Nano/micro topography Cell–material interactions a b s t r a c t In a previous work, we demonstrated the successful use of electrophoretic deposition (EPD) to immobi- lize collagen-based nanotubes onto indium-tin-oxide-coated glass (ITO glass), leading to the creation of biointerfaces with protein-based chemistry and topography [1]. In this work, we present a first study of preosteoblasts behavior in contact with surface-immobilized collagen-based nanotubes. Changes in cell morphology after their interaction with ITO glass modified with collagen-based nanotubes were studied using fluorescence microscopy and compared to those observed on virgin ITO glass as well as on ITO glass on which a collagen layer was simply adsorbed. Scanning electron microscopy (SEM) was used to study interactions of cell filopodias with the deposited nanotubes. Cytotoxicity of these biointerfaces was examined as well in short term cultures, using Alamar blue assay. Cells showed particular morphologies on ITO glass coated with nanotubes compared to virgin ITO glass or collagen adsorbed layer on ITO glass. High resolution SEM images suggest that apart from cell mor- phology, length and thickness of filopodias seem to be significantly affected by surface modification with collagen-based nanotubes. Moreover, nanotube-coated ITO glass did not show any obvious cytotoxicity in short term culture, opening new perspectives for the surface modification of biomaterials. We show the versatility of the proposed surface modification procedure by tailoring biointerfaces with a mixture of micro- and nanometer-scale collagen-based tubes. © 2013 Elsevier B.V. All rights reserved. 1. Introduction Surface modification of biomaterials is widely applied to improve their functionality. In order to achieve predictable cell responses from biomaterials, different surface modification strate- gies have been developed and evaluated over the last few decades [2–4]. These strategies may alter a variety of surface properties, including topography, chemical composition, wettability, electri- cal potential, mechanical behavior, etc. [5]. The spatial distribution of topographical or chemical cues, at the micro- and more recently at the nanometer scale, was moreover shown to affect cell adhe- sion, morphology, migration, proliferation, gene expression and differentiation [6–11]. These cues may be brought at the inter- face through the immobilization of nanoparticles. A comprehensive review on the use of nanoparticles for tissue engineering applica- tions has been recently published by Zhang and Webster [4]. ∗ Corresponding author. E-mail address: christine.dupont@uclouvain.be (C.C. Dupont-Gillain). 1 Current address: Department of Surgery & Interventional Science, Centre of Nanotechnology & Regenerative Medicine, University College London, 9th Floor, Royal Free Campus, Pond Street, London NW3 2QG, United Kingdom. Such surface modifications are especially useful for orthopedic materials [5,11] with the aim to improve cell–material interac- tions and thereby promote integration with the surrounding bone tissue [12]. Surface modification of orthopedic implants is gen- erally achieved either by anodisation to introduce micro/nano features [13] or by coating with ceramic particles of interest such as hydroxyapatite or bioglass [2]. More recently, the use of polymer- based particles, the polymer being of natural or synthetic origin, has been explored as well to enhance osseointegration [5]. The com- bination of hydroxyapatite and collagen in biointerfacial coatings, both being natural components of bone, may open the way to novel biomimetic strategies [4,14]. However, little is known regarding the appropriate structure and composition to be tailored for the success of such composite biomimetic interfaces. Recently, we have synthesized collagen-based nanotubes using layer-by-layer assembly within the nanopores of a polycarbonate membrane used as a template [15,16]. The dimensions of these nanotubes can be precisely controlled through the choice of the template: their outer diameter is indeed equal to the pore diam- eter, while their length is equal to the template thickness. We have then shown that electrophoretic deposition (EPD) can be used to immobilize collagen-based nanotubes onto indium-tin- oxide-coated glass (ITO glass), leading to the creation of original 0927-7765/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.colsurfb.2013.05.035