Leveraging Optical Anisotropy of the Morpho Butterfly Wing for Quantitative, Stain-Free, and Contact-Free Assessment of Biological Tissue Microstructures

TL;DR

This paper introduces MorE-PoL, a stain-free, contact-free optical imaging method leveraging butterfly wing anisotropy to quantitatively assess tissue microstructures, especially collagen organization, with potential for broad biomedical applications.

Contribution

The authors develop a novel polarization microscopy technique based on butterfly wing anisotropy and a mathematical model to quantify tissue microstructure without staining or contact.

Findings

Successfully analyzed collagen density in breast cancer tissues.

Compared favorably with traditional H&E and SHG microscopy.

Demonstrated robustness and accessibility of the new method.

Abstract

Changes in the density and organization of fibrous biological tissues often accompany the progression of serious diseases ranging from fibrosis to neurodegenerative diseases, heart disease and cancer. However, challenges in cost, complexity, or precision faced by existing imaging methodologies pose barriers to elucidating the role of tissue microstructure in disease. Here, we leverage the intrinsic optical anisotropy of the Morpho butterfly wing and introduce Morpho-Enhanced Polarized Light Microscopy (MorE-PoL), a stain- and contact-free imaging platform which enhances and quantifies the birefringent material properties of fibrous biological tissues. We develop a mathematical model, based on Jones calculus, which quantifies fibrous tissue density and organization. As a representative example, we analyze collagen-dense and collagen-sparse human breast cancer tissue sections and leverage our technique to assess the microstructural properties of distinct regions of interest. We compare our results with conventional Hematoxylin and Eosin (H&E) staining procedures and second harmonic generation (SHG) microscopy for fibrillar collagen detection. Our findings demonstrate that our MorE-PoL technique provides a robust, quantitative, and accessible route toward analyzing biological tissue microstructures, with great potential for application to a broad range of biological materials.