Nanoscale structure of type I collagen fibrils: Quantitative measurement of D-spacing
Abstract
This article details a quantitative method to measure the D-periodic spacing of type I collagen fibrils using atomic force microscopy coupled with analysis using a two-dimensional fast fourier transform approach. Instrument calibration, data sampling and data analysis are discussed and comparisons of the data to the complementary methods of electron microscopy and X-ray scattering are made. Examples of the application of this new approach to the analysis of type I collagen morphology in disease models of estrogen depletion and osteogenesis imperfecta (OI) are provided. We demonstrate that it is the D-spacing distribution, not the D-spacing mean, that showed statistically significant differences in estrogen depletion associated with early stage osteoporosis and OI. The ability to quantitatively characterize nanoscale morphological features of type I collagen fibrils will provide important structural information regarding type I collagen in many research areas, including tissue aging and disease, tissue engineering, and gene knockout studies. Furthermore, we also envision potential clinical applications including evaluation of tissue collagen integrity under the impact of diseases or drug treatments.
Abstract
The distribution of Type I collagen fibril D-spacing provides important morphological information regarding Type I collagen in diseases such as early stages of osteoporosis and osteogenesis Imperfecta. In this article, the authors use Atomic Force Microscopy (AFM) imaging combined with two Dimensional Fast Fourier Transform (2D FFT) analysis to quantitatively assess Type I collagen fibril D-spacing. This methodology allows imaging and characterization of Type I collagen constituted biological tissues, hydrogels, and other collagen based biomaterials.





