Spatial relationship between histological staining intensity and corneal stiffness variations: Insights from AFM indentation in infant African green monkeys

IF 3.3 2区医学 Q2 ENGINEERING, BIOMEDICAL

Journal of the Mechanical Behavior of Biomedical Materials Pub Date : 2025-05-08 DOI:10.1016/j.jmbbm.2025.107047

Yingnan Zhai , Jianing Wang , Valentina O. Mendoza , Ming Ye , Kourosh Shahraki , Donny W. Suh , Donald S. Minckler , Tatiana Karpova , Kenia Nunes , Pengfei Dong , Linxia Gu

{"title":"Spatial relationship between histological staining intensity and corneal stiffness variations: Insights from AFM indentation in infant African green monkeys","authors":"Yingnan Zhai , Jianing Wang , Valentina O. Mendoza , Ming Ye , Kourosh Shahraki , Donny W. Suh , Donald S. Minckler , Tatiana Karpova , Kenia Nunes , Pengfei Dong , Linxia Gu","doi":"10.1016/j.jmbbm.2025.107047","DOIUrl":null,"url":null,"abstract":"<div><div>This study investigated the spatial variations of mechanical properties and microstructure in the cornea using atomic force microscopy (AFM) indentation tests and histological analysis. Corneal samples were collected from three infant African green monkeys, approximately 6 months old. Hematoxylin and eosin (H&E) staining was performed on corneal cross-sections to examine microstructure and quantify staining intensity. AFM indentations were conducted to quantify stiffness variations through pathline scanning and 16 × 16 stiffness mappings. Results showed that the corneal microstructure transitions from thinner, denser lamellae in the anterior layer to thicker, looser lamellae in the posterior layer. Stiffness variations along pathlines in the central, paracentral, peripheral, and limbus regions correlate positively with the corresponding staining intensities. The average stiffness across all samples was highest at the central anterior cornea (392.6 ± 118.4 kPa) and anterior limbus (645.4 ± 158.1 kPa). Additionally, both the anterior and posterior layers showed higher stiffness than the middle layer, except in the central region. AFM stiffness maps further revealed the layered structure of the lamellae. The stiffness variations between layers may result from different orientations of collagen fibrils in each lamellae. These observations were expected to provide valuable insights into corneal microstructure and mechanical properties variations during the progression of corneal diseases, aiding in the design of optimal artificial corneas. While this study focuses on infant monkey eyes, further testing across different age and sex groups is needed to refine these observations.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"169 ","pages":"Article 107047"},"PeriodicalIF":3.3000,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of the Mechanical Behavior of Biomedical Materials","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1751616125001638","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, BIOMEDICAL","Score":null,"Total":0}

引用次数: 0

Abstract

This study investigated the spatial variations of mechanical properties and microstructure in the cornea using atomic force microscopy (AFM) indentation tests and histological analysis. Corneal samples were collected from three infant African green monkeys, approximately 6 months old. Hematoxylin and eosin (H&E) staining was performed on corneal cross-sections to examine microstructure and quantify staining intensity. AFM indentations were conducted to quantify stiffness variations through pathline scanning and 16 × 16 stiffness mappings. Results showed that the corneal microstructure transitions from thinner, denser lamellae in the anterior layer to thicker, looser lamellae in the posterior layer. Stiffness variations along pathlines in the central, paracentral, peripheral, and limbus regions correlate positively with the corresponding staining intensities. The average stiffness across all samples was highest at the central anterior cornea (392.6 ± 118.4 kPa) and anterior limbus (645.4 ± 158.1 kPa). Additionally, both the anterior and posterior layers showed higher stiffness than the middle layer, except in the central region. AFM stiffness maps further revealed the layered structure of the lamellae. The stiffness variations between layers may result from different orientations of collagen fibrils in each lamellae. These observations were expected to provide valuable insights into corneal microstructure and mechanical properties variations during the progression of corneal diseases, aiding in the design of optimal artificial corneas. While this study focuses on infant monkey eyes, further testing across different age and sex groups is needed to refine these observations.

查看原文本刊更多论文

组织学染色强度和角膜硬度变化的空间关系：来自非洲绿猴婴儿AFM压痕的见解

本研究采用原子力显微镜（AFM）压痕试验和组织学分析研究了角膜力学性能和微观结构的空间变化。角膜样本取自3只大约6个月大的非洲绿猴幼猴。对角膜横切面进行苏木精和伊红（H&；E）染色，观察微观结构并定量染色强度。通过路径扫描和16 × 16刚度映射，进行AFM压痕来量化刚度变化。结果表明，角膜微观结构由前层薄而致密的片层向后层厚而松散的片层转变。中央、中央旁、外周和边缘区域沿路径的硬度变化与相应的染色强度呈正相关。所有样本的平均刚度在中央前角膜（392.6±118.4 kPa）和前角膜缘（645.4±158.1 kPa）处最高。此外，除中心区域外，前后两层均表现出比中间层更高的刚度。AFM刚度图进一步揭示了薄片的层状结构。层间硬度的变化可能是由于每层胶原原纤维的取向不同所致。这些观察结果有望为角膜疾病进展过程中角膜微观结构和力学性能的变化提供有价值的见解，有助于设计最佳人工角膜。虽然这项研究的重点是婴儿猴子的眼睛，但需要对不同年龄和性别群体进行进一步的测试来完善这些观察结果。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Journal of the Mechanical Behavior of Biomedical Materials 工程技术-材料科学：生物材料

CiteScore

7.20

自引率

7.70%

发文量

505

审稿时长

46 days

期刊介绍： The Journal of the Mechanical Behavior of Biomedical Materials is concerned with the mechanical deformation, damage and failure under applied forces, of biological material (at the tissue, cellular and molecular levels) and of biomaterials, i.e. those materials which are designed to mimic or replace biological materials. The primary focus of the journal is the synthesis of materials science, biology, and medical and dental science. Reports of fundamental scientific investigations are welcome, as are articles concerned with the practical application of materials in medical devices. Both experimental and theoretical work is of interest; theoretical papers will normally include comparison of predictions with experimental data, though we recognize that this may not always be appropriate. The journal also publishes technical notes concerned with emerging experimental or theoretical techniques, letters to the editor and, by invitation, review articles and papers describing existing techniques for the benefit of an interdisciplinary readership.