Development of a facile method to compute collagen network pathological anisotropy using AFM imaging

Area of Science:

• Biophysics
• Materials Science
• Biochemistry

Background:

• Type I collagen is a crucial extracellular matrix (ECM) protein providing tissue integrity and mechanical stability.
• Alterations in collagen ultrastructure are linked to various pathological conditions, including connective tissue disorders (CTDs).
• Existing methods for analyzing collagen fibril morphology at the nanoscale have limitations.

Purpose of the Study:

• To introduce a novel computational approach for quantifying collagen fibril morphology at the nanoscale.
• To investigate the structural changes in collagen fibrils associated with Ehlers-Danlos Syndrome (EDS).
• To assess the potential of this method for automated diagnosis of CTDs.

Main Methods:

• Utilized Atomic Force Microscope (AFM) imaging to capture high-resolution images of collagen fibrils.
• Applied a 2D Fast Fourier Transform (2D-FFT) computational approach to analyze AFM images and quantify structural parameters.
• Studied collagen fibrils from skin of genetically mutant mice (Col1a1^Jrt/+) exhibiting an EDS phenotype.

Main Results:

• Qualitative analysis revealed morphological differences in collagen fibril clarity, D-banding, orientation, and linearity between healthy and EDS models.
• The FFT approach successfully quantified fibril disorganization, distinguishing healthy from diseased tissues.
• FFT analysis provided insights into collagen fibril orientation, anisotropy, and clinically relevant phenotypic information.

Conclusions:

• The combined AFM and FFT method offers a powerful tool for nanoscale analysis of collagen fibril structure.
• This computational approach shows significant potential for the automated diagnosis of connective tissue disorders.
• The findings contribute to fundamental research on collagen and clinical diagnostics for CTDs.