A new three-dimensional model of the organization of proteoglycans and collagen fibrils in the human corneal stroma

Corneal collagen—its role in maintaining corneal shape and transparency

“…The enzymatic sulphation of keratan sulphate glycosaminoglycan chains has been identified as the key requirement for collagen matrix organization (Hayashida et al 2006). Using cationic dyes, it has been shown that corneal proteoglycans associate noncovalently with collagen fibrils at specific axial locations (Scott and Haigh 1985;Meek et al 1986;Miyagawa et al 2001), and this staining technique has been the basis of a three-dimensional (3-D) model in which proteoglycans connect next nearest-neighbour fibrils by groups of six proteoglycans, attached orthogonal to the circumference of the fibrils (Müller et al 2004). However, 3-D electron micrograph reconstructions by our group showed that there are no systematic six-fold interactions between collagen and proteoglycans in the hexagonal array.…”

Effect of Substrate Composition and Alignment on Corneal Cell Phenotype

“…8 The type I collagen fibers are regularly spaced, uniformly aligned, and 25-35 nm in diameter. [8][9][10][11][12][13] The collagen fibers are arranged parallel to each other in a 200-2,500-nm-thick lamella. 14,15 The stromal layer contains over 300 interlaced lamellae, stacked on each other at varying angles ranging from 08 to 908.…”

The Development of a Tissue-Engineered Cornea: Biomaterials and Culture Methods

“…The fibers are aligned parallel to each other with regular 30-nm spacing between fibrils. This regular spacing is thought to be regulated by the proteoglycans, which have been observed to form ring-like structures around collagen fibrils in the normal cornea (14). The aligned fibers are grouped into layers called lamellae and stacked in an alternating lattice pattern (15).…”