Proton micromachining of substrate scaffolds for cellular and tissue engineering

Three dimensional patterns (grooves and ridges) were micromachined in PMMA using a 600 keV proton beam from the nuclear microscopy facility at the Res earch Centre for Nuclear Microscopy, National University of Singapore. Swis s 3T3 fibroblasts (ATCC CCL92, Rockville, MD) have been seeded onto these p atterns, and the following observations have been made: (a) Cells were not found in the grooves (depth 9 mu m, width 6.6 mu m); (b) Cells were highly aligned and elongated on narrow ridges (4.2 mu m wide), with the degree of alignment and elongation reduced for wider ridges. The underlying mechanism responsible of this cellular behaviour is assumed to be induced by the mec hanical restrictions imposed by the topographic features on cellular migrat ion, cell adhesion and concomitant changes in the cytoskeletal. The use of topographical stimuli to regulate cell function is an area of high potentia l, with implications in the engineering of tissue for spare-part surgery. P roton micromachining, which has the unique advantage of being the only tech nique capable of direct-write 3D micromachining at sub-cellular dimensions has unique advantages in this area of research. (C) 1999 Elsevier Science B .V. All rights reserved.