Organization of corneal collagen fibrils during the healing of trephined wounds in rabbits

Abstract

The purpose of this study was to investigate the structure and organization of collagen during the healing of penetrating rabbit corneal wounds. Full-thickness wounds were produced in both corneas of six New Zealand White rabbits with a 2-mm trephine. After 5, 10, and 16 months, wounds were examined using transmission electron microscopy and wide-angle synchrotron X-ray diffraction, which allowed the quantification of the relative amount of collagen and fibril orientation in different parts of the cornea. The intensity of the diffraction patterns taken from the wound edge was much higher than patterns collected at the wound center, indicating a greater amount of collagen near the wound edge. This collagen was shown to have a preferred orientation, forming a circular pattern around the wound. As the wounds healed, the amount of preferentially aligned collagen decreased and lamella formation and ordered fibrillar arrangement increased as shown by electron microscopy. The orientation of collagen fibrils in healing penetrating corneal wounds is not random. Instead, fibrils tend to be circularly arranged within and without the wound, gradually becoming more normal over time. We speculate that collagen is artefactually displaced during trephination, resulting in an abnormal alignment of the fibrils surrounding the wound edge, and that this influences the wound healing process.

Changes in Collagen Orientation and Distribution in Keratoconus Corneas

“…2c), taking into account the fact that the x-ray intensity appears at right angles to the fibril axis. 10,11 The radial length of the polar plot at a given angle is directly proportional to the mass of collagen fibrils aligned at that angle. The overall size of the plot is therefore related to the total mass of aligned collagen, and the asymmetry gives an indication of the preferential direction(s) of this collagen.…”

Fully automated, quantitative, noninvasive assessment of collagen fiber content and organization in thick collagen gels

“…Monitoring and detection of the collagen characteristics within tissue has important implications in disease detection, wound healing, angiogenesis, and regenerative medicine applications. [1][2][3][4][5][6][7][8] For example, changes in the organization and crosslinking or content of collagen are characteristic of cancerous transformations. [9][10][11][12] Therefore, it is important to develop quantitative methods that can provide detail with regards to the content, organization, and dynamic remodeling of collagen fibers.…”

Microfluidic alignment of collagen fibers for in vitro cell culture

“…The precise spatial organization of collagen fibers in vivo determines properties such as the tensile strength in tendons (Pins, 1997;Tower, 2002) and the transparent tissue of the cornea (Connon, 2003;Newton, 1998). The molecular alignment of collagen is also believed to play a role in cell signaling and development, and has been reported to orient fibroblast cells in culture (Glass-Brudzinski, 2002;Guido, 1993).…”