Fabrication of Ordered Sub-Micron Topographies on Large-Area Poly(Urethane Urea) by Two-Stage Replication Molding
- PDF / 900,361 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 8 Downloads / 142 Views
R2.8.1
Fabrication of Ordered Sub-Micron Topographies on Large-Area Poly(Urethane Urea) by Two-Stage Replication Molding Keith R. Milner1,2, Mallory Balmer1, Henry J. Donahue3, Alan J. Snyder1,2 and Christopher A. Siedlecki1,2 1 Dept of Bioengineering, College of Medicine, Pennsylvania State University, Hershey, PA17033 2 Department of Surgery, College of Medicine, Pennsylvania State University, Hershey, PA17033 3 Musculoskeletal Research Laboratory, Center for Biomedical Devices and Functional Tissue Engineering and Department of Orthopaedics and Rehabilitation, College of Medicine, Pennsylvania State University, Hershey, PA17033 ABSTRACT It has been established that material surface topography can have a significant effect on biological cell adhesion, in the absence of changes in surface chemistry. Such investigations were typically performed using surface features with size on the order of microns, comparable to the dimensions of the cells. It has been demonstrated that sub-micron sized topographies that cannot be created via contact lithography also influence cell behavior. The ability to affect cell adhesion is a prime consideration in the development of novel biomaterials. This study reports a two-stage replication molding process for fabricating ordered sub-micron sized features over a large area of biomedical polyether(urethane urea). Such a technique has great applicability in the area of long-term implantable materials as a method for influencing cell-material interactions. INTRODUCTION Micro- and nano-texturing of material surfaces have been demonstrated to have profound effects on biological cell behavior [1]. The most commonly studied texture is parallel grooves, constructed by standard microfabrication techniques, generally in silicon, polystyrene or quartz [2-4]. The typical minimum width of such features is ~ 1 µm, the limit of the contact photolithographic systems used to pattern the materials. Some studies have examined cell reaction to sub-micron and nano-textured surfaces, occasionally with ordered patterns [5,6] but more usually with random features, such as silicon grass [7], chemically etched materials [8] or demixed polymers [9]. It is suspected that ordered, symmetrical features may have more applicability in controlling the cell-material interaction [10]. The methods for creating ordered structures described above used contact lithography to pattern a substrate that was then etched. This substrate was then used directly for cell studies, or a polymer was cast against this template in a process known as replication molding [11]. This polymer is removed from the substrate, with a negative image of the textures formed on its surface, and this is then used for cell studies. To date, the majority of the research investigating cell-textured material interactions has focused on substrates that have limited applicability in biomedical devices, such as silicon, polystyrene and quartz. These materials are generally chosen for their ease of processing in a microfabrication facility (silicon and quart
Data Loading...
