The current study sought to identify a collagen coating methodology for app
lication to polymer surfaces that would provide for the development of adhe
sive structures responsible for the sustained adhesion of corneal epithelia
l tissue. We compared an uncoated microporous polycarbonate surface and equ
ivalent surfaces coated with either covalently immobilized collagen 1 or ch
emically crosslinked collagen 1 gel in a corneal explant outgrowth assay ov
er 21 days. Electron microscopy was used to examine the formation of hemide
smosomes, basal lamina, and anchoring fibrils at the tissue-polymer interfa
ce. The crosslinked collagen gel preparation supported the overlying epithe
lial tissue across the pore openings and allowed for the formation of ident
ifiable basal lamina, hemidesmosomes, and anchoring fibrils between the epi
thelial tissue and the polymer surface. Hemidesmosomal plaque, but no basal
lamina or anchoring fibril formation, occurred on the uncoated surface or
on that coated with covalently immobilized collagen 1. We propose that the
collagen matrix provided by the crosslinked collagen gel was reorganized by
the epithelial tissue and that this, combined with the secretion of ECM mo
lecules, served to limit the diffusion of basement membrane components, whi
ch permitted an increase in the local concentration of these molecules, whi
ch favored the assembly of epithelial adhesive structures. (C) 2001 John Wi
ley & Sons, Inc.