SYNERGISTIC AND HIERARCHICAL ADHESIVE AND TOPOGRAPHIC GUIDANCE OF BHKCELLS

Guided cell movement is a fundamental process in development and regen eration. We have used microengineered culture substrates to study the interaction between model topographic and adhesive guidance cues in st eering BHK cell orientation. Grooves 0.1, 0.5, 1.0, 3.0, and 6.0 mu m deep together with pitch-matched aminosilane tracks 5, 12, 25, 50, and 100 mu m wide were fabricated on fused silica substrates using photol ithographic and dry-etching techniques. The cues were presented to the cells individually, simultaneously in parallel and orthogonally oppos ed. Cells aligned most strongly to 25-mu m-wide adhesive tracks and to 5-mu m-wide, 6-mu m-deep grooves. Stress fibers and vinculin were fou nd to align with the adhesive tracks and to the grooves and ridges. Ce ll alignment was profoundly enhanced on all surfaces that presented bo th cues in parallel. Cells were able to switch alignment from ridges t o grooves, and vice versa, depending on the location of superimposed a dhesive tracks. Cells aligned preferentially to adhesive tracks superi mposed orthogonally over grooves of matched pitch, traversing numerous grooves and ridges. The strength of the cues was more closely matched on narrower 3- and 6-mu m-deep gratings with cells showing evidence o f alignment to both cues, Confocal fluorescence microscopy revealed tw o groups of mutually opposed f-actin stress fibers within the same cel l, one oriented with the topographic cues and the other with the adhes ive cues. However, the adhesive response was consistently dominant. We conclude that cells are able to detect and respond to multiple guidan ce cues simultaneously. The adhesive and topographic guidance cues mod eled here were capable of interacting both synergistically and hierarc hically to guide cell orientation. (C) 1996 Academic Press, Inc.