A method for analyzing AFM force mapping data obtained from soft tissue cryosections

Cydney A Wong; Nina Sara Fraticelli Guzmán; A Thomas Read; Adam Hedberg-Buenz; Michael G Anderson; Andrew J Feola; Todd Sulchek; C Ross Ethier

doi:10.1016/j.jbiomech.2024.112113

A method for analyzing AFM force mapping data obtained from soft tissue cryosections

J Biomech. 2024 Apr 19:168:112113. doi: 10.1016/j.jbiomech.2024.112113. Online ahead of print.

Authors

Cydney A Wong¹, Nina Sara Fraticelli Guzmán², A Thomas Read¹, Adam Hedberg-Buenz³, Michael G Anderson³, Andrew J Feola⁴, Todd Sulchek⁵, C Ross Ethier⁶

Affiliations

¹ Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA.
² Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA.
³ Department of Molecular Physiology & Biophysics, University of Iowa, Iowa City, IA.
⁴ Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA; Department of Ophthalmology, Emory University, Atlanta, GA; Center for Visual & Neurocognitive Rehabilitation, Atlanta Veterans Affairs Medical Center, Decatur, GA.
⁵ Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA; Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA.
⁶ Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA; Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA; Department of Ophthalmology, Emory University, Atlanta, GA. Electronic address: ross.ethier@bme.gatech.edu.

PMID: 38648717
DOI: 10.1016/j.jbiomech.2024.112113

Abstract

Atomic force microscopy (AFM) is a valuable tool for assessing mechanical properties of biological samples, but interpretations of measurements on whole tissues can be difficult due to the tissue's highly heterogeneous nature. To overcome such difficulties and obtain more robust estimates of tissue mechanical properties, we describe an AFM force mapping and data analysis pipeline to characterize the mechanical properties of cryosectioned soft tissues. We assessed this approach on mouse optic nerve head and rat trabecular meshwork, cornea, and sclera. Our data show that the use of repeated measurements, outlier exclusion, and log-normal data transformation increases confidence in AFM mechanical measurements, and we propose that this methodology can be broadly applied to measuring soft tissue properties from cryosections.

Abstract

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