Regional quantification of glycosaminoglycans and their association with collagen fibril ultrastructure in the sclera following enzymatic degradation

Kazaili, Ahmed ORCID: 0000-0002-0400-7432, Zhuola, Sadek, Noor Ali, Al-Hindy, Hayder Abdul-Amir Maki, Geraghty, Brendan ORCID: 0000-0003-0561-6667, Kharaz, Yalda Ashraf, Comerford, Eithne ORCID: 0000-0002-5244-6042, Yates, Edwin ORCID: 0000-0001-9365-5433, Liu, Lu-Ning ORCID: 0000-0002-8884-4819 and Akhtar, Riaz ORCID: 0000-0002-7963-6874 (2025) Regional quantification of glycosaminoglycans and their association with collagen fibril ultrastructure in the sclera following enzymatic degradation JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS, 172. 107169-. ISSN 1751-6161, 1878-0180

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Abstract

Sclera biomechanics play an important role in clear vision. Understanding the biomechanical, composition and ultrastructural topography of the sclera may help provide better insight into eye health. Some prior research has investigated the ultrastructural and biomechanical properties of the sclera in relation to regional variations. However, the complex association between regional variations in collagen fibril morphology and elasticity with proteoglycan types and quantities has not been investigated. This study aimed to explore regional variations in scleral collagen fibril topography and proteoglycan quantities and to investigate their role in the mechanical properties of the sclera. Atomic force microscopy (AFM), collagen autofluorescence, glycosaminoglycans (GAGs) quantification, and Coomassie blue staining techniques were used to assess alterations of the porcine sclera following treatment with amylase (Amy) and chondroitinase ABC (ChABC). Collagen fibril diameters were found to vary among the regions of the scleral stroma, with the largest diameters (268 ± 23 nm) in the anterior region and smallest diameters (148 ± 14 nm) in the posterior region. Collagen fibril stiffness and diameters were reduced following incubation with these enzymes. GAGs were depleted from the enzymatically treated tissues with the greater depletion in the posterior region. GAG depletion was inversely correlated (Pearson's r = −0.75 and −0.85 for the amylase and ChABC treated groups) with collagen fibril diameter and elastic modulus. In summary, we show the direct link between GAGs and collagen fibril properties at the nano-scale from the anterior to the posterior region of the porcine sclera.

Item Type:	Article
Additional Information:	Source info: JMBBM-D-25-00838
Uncontrolled Keywords:	Sclera biomechanics, Sclera elasticity, Collagen fibrils, Sclera proteoglycans, Glycosaminoglycans, Sclera ultrastructure
Divisions:	Faculty of Health & Life Sciences Faculty of Science & Engineering Faculty of Science & Engineering > School of Engineering Faculty of Health & Life Sciences > Inst. Life Courses & Medical Sciences Faculty of Health & Life Sciences > Inst. Systems, Molec & Integrative Biology > Inst. Systems, Molec & Integrative Biology
Depositing User:	Symplectic Admin
Date Deposited:	16 Sep 2025 07:16
Last Modified:	16 Jun 2026 16:53
DOI:	10.1016/j.jmbbm.2025.107169
Related Websites:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3194419
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