Understanding the structural characteristics of macromolecular assemblies in connective tissues

TL;DR

The paper explores how X-ray techniques reveal collagen structure in connective tissues and how this relates to tissue function and disease.

Contribution

The study introduces multimodal X-ray and electron microscopy to analyze collagen fibril structure and its macromolecular interactions in tissues.

Findings

X-ray microdiffraction reveals collagen fibril distribution patterns in tissues like bone and cartilage.

Collagen fiber assembly is influenced by proteoglycans, affecting tissue architecture and performance.

Multimodal imaging helps correlate collagen structure with tissue function and pathology.

Abstract

Synchrotrons provide a variety of X-ray techniques for fast, high-resolution structural, compositional, and functional analysis of biological tissues. Micro- and nano-CT enable ultra-fast high-resolution 3D imaging of relatively large samples, while X-ray fluorescence provides elemental composition of fixed biological samples with highest sensitivity. X-ray fiber diffraction allows to push resolution limit even further and analyze partially-ordered and disordered biological composites, such as bones, muscles, spider silk, and connective tissues. Collagen fibrils are key components of ligaments, tendons, cartilage, intervertebral discs, cardiac valves and chordae tendineae.

Complex architecture, cellular activity, and performance of these tissues strongly depend on proper collagen fiber assembly, governed by proteoglycans. X-ray microdiffraction study of collagenous tissues, such as bone, cardiac tissues, tendons, and cartilage, revealed different fibril distribution patterns and detected presence of different collagen types in these samples. Multimodal x-ray and electron microscopy imaging will shine the light on correlation of collagen fibril structure with its macromolecular ligands and their role in proper tissue functioning, as well as in pathological cases of trauma and disease.