The biomechanics toolbox: experimental approaches for living cells and biomolecules

The mechanical behavior of biological materials has been studied extensively at the tissue, organ and systems levels. Emerging experimental tools, however, enable quantitative studies of deformation of individual cells and biomolecules. These approaches also facilitate the exploration of biological processes mediated by mechanical signals, with force and displacement resolutions of 0.1 pN and 0.1 nm, respectively. As a result of these capabilities, it is now possible to establish the structure-function relationships among the various components of a living cell. In order to fully realize this potential, it is necessary to critically assess the capabilities of current experimental methods in elucidating whether and how the mechanics of living cells and biomolecules, under physiological and pathological conditions, plays a major role in health and disease. Here, we review the operating principles, advantages and limitations, and illustrative examples of micro- and nano-scale mechanical testing techniques developed across many research communities to manipulate cell populations, single cells, and single biomolecules. Further, we discuss key opportunities for improved analysis of such experiments, as well as future directions and applications. (C) 2003 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.