Nanomechanical Characterization of Living Mammary Tissues by Atomic Force Microscopy
The mechanical properties of living cells and tissues are important for a variety of functional processes in vivo, including cell adhesion, migration, proliferation and differentiation. Changes in mechano-cellular phenotype, for instance, are associated with cancer progression. Atomic force microscopy (AFM) is an enabling technique that topographically maps and quantifies the mechanical properties of complex biological matter in physiological aqueous environments at the nanometer length scale. Recently we applied AFM to spatially resolve the distribution of nanomechanical stiffness across human breast cancer biopsies in comparison to healthy tissue and benign tumors. This led to the finding that AFM provides quantitative mechano-markers that may have translational significance for the clinical diagnosis of cancer. Here, we provide a comprehensive description of sample preparation methodology, instrumentation, data acquisition and analysis that allows for the quantitative nanomechanical profiling of unadulterated tissue at submicron spatial resolution and nano-Newton (nN) force sensitivity in physiological conditions.
Key wordsAtomic Force Microscopy Sensitivity Spatial resolution Mechanobiology Cells Extracellular matrix Living mammary tissues Human breast biopsies Diagnosis Disease
This work is funded by the Commission for Technology and Innovation (CTI) Project 11977.2 PFNM-NM; ARTIDIS ‘Automated and Reliable Tissue Diagnostics’ awarded to R.Y.H.L. in partnership with Nanosurf AG.
The authors thank Christian Räz, Christophe A. Monnier and Philipp Oertle for their contributions to this manuscript.
Competing financial interests: The University of Basel has filed patents on the technology and intellectual property related to this work based on the inventions of M.P. and R.Y.H.L.
- 10.Fuhrmann A, Staunton JR, Nandakumar V, Banyai N, Davies PCW, Ros R (2011) AFM stiffness nanotomography of normal, metaplastic and dysplastic human esophageal cells. Phys Biol 8Google Scholar
- 21.Loparic M, Wirz D, Daniels AU, Raiteri R, VanLandingham MR, Guex G, Martin I, Aebi U, Stolz M (2010) Micro- and nanomechanical analysis of articular cartilage by indentation-type atomic force microscopy: validation with a gel-microfiber composite. Biophys J 98: 2731–2740PubMedCentralPubMedCrossRefGoogle Scholar
- 24.Hay JL, Oliver WC, Bolshakov A, Pharr GM (1998) Using the ratio of loading slope and elastic stiffness to predict pile-up and constraint factor during indentation. Fundamentals of nanoindentation and nanotribology vol. 522. pp. 101–106Google Scholar