Fabrication and selective surface modification of 3-dimensionally textured biomedical polymers from etched silicon substrates.
A new method is described for producing biomedically relevant polymers with precisely defined micron scale surface texture in the x, y, and z planes. Patterned Si templates were fabricated using photolithography to create a relief pattern in photoresist with lateral dimensions as small as 1 micron. Electroless Ni was selectively deposited in the trenches of the patterned substrate. The Ni served as a resilient mask for transferring the patterns onto the Si substrate to depths of up to 8.5 microns by anisotropic reactive ion etching with a fluorine-based plasma. The 3-dimensional (3-D) textured silicon substrates were used as robust, reusable molds for pattern transfer onto poly (dimethyl siloxane), low density poly (ethylene), poly (L-lactide), and poly (glycolide) by either casting or injection molding. The fidelity of the pattern transfer from the silicon substrates to the polymers was 90 to 95% in all three planes for all polymers for more than 60 transfers from a single wafer, as determined by scanning electron microscopy and atomic force microscopy. Further, the 3-D textured polymers were selectively modified to coat proteins either in the trenches or on the mesas by capillary modification or selective coating techniques. These selectively patterned 3-D polymer substrates may be useful for a variety of biomaterial applications.
Kapur
R
R
Department of Biochemistry, Georgetown University, Washington, District of Columbia, USA. rkapur@cbmse.nrl.navy.mil
Spargo
B J
BJ
Chen
M S
MS
Calvert
J M
JM
Rudolph
A S
AS
D001672:Biocompatible Materials / Q000138:chemical synthesis* / Q000737:chemistry*; D004129:Dimethylpolysiloxanes; D015195:Drug Design; D008855:Microscopy, Electron, Scanning; D011091:Polyesters; D011095:Polyethylenes; D011100:Polyglycolic Acid; D012825:Silicon; D012828:Silicones; D013499:Surface Properties
D001672:Biocompatible Materials; D004129:Dimethylpolysiloxanes; D011091:Polyesters; D011095:Polyethylenes; D012828:Silicones; D011100:Polyglycolic Acid; C033616:poly(lactide); C013830:baysilon; D012825:Silicon