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Micro and Nanosystems


ISSN (Print): 1876-4029
ISSN (Online): 1876-4037

Opinion Article

Is it Necessary to Calculate Young’s Modulus in AFM Nanoindentation Experiments Regarding Biological Samples?

Author(s): Stylianos-Vasileios Kontomaris*, Anna Malamou and Andreas Stylianou

Volume 13, Issue 1, 2021

Published on: 14 February, 2020

Page: [3 - 8] Pages: 6

DOI: 10.2174/1876402912666200214123734

Price: $65


Background: The determination of the mechanical properties of biological samples using Atomic Force Microscopy (AFM) at the nanoscale is usually performed using basic models arising from the contact mechanics theory. In particular, the Hertz model is the most frequently used theoretical tool for data processing. However, the Hertz model requires several assumptions, such as homogeneous and isotropic samples and indenters with perfectly spherical or conical shapes. As it is widely known, none of these requirements are 100 % fulfilled for the case of indentation experiments at the nanoscale. As a result, significant errors arise in the Young’s modulus calculation. At the same time, an analytical model that could account complexities of soft biomaterials, such as nonlinear behavior, anisotropy, and heterogeneity, may be far-reaching. In addition, this hypothetical model would be ‘too difficult’ to be applied in real clinical activities since it would require a very heavy workload and highly specialized personnel.

Objective: In this paper, a simple solution is provided to the aforementioned dead-end. A new approach is introduced in order to provide a simple and accurate method for mechanical characterization at the nanoscale.

Methods: The ratio of the work done by the indenter on the sample of interest to the work done by the indenter on a reference sample is introduced as a new physical quantity that does not require homogeneous, isotropic samples or perfect indenters.

Results: The proposed approach provides an accurate solution from not only a physical perspective but also a simpler solution which does not require activities such as the determination of the cantilever’s spring constant and the dimensions of the AFM tip.

Conclusion: It has been observed from this opinion paper that the solution aims to provide a significant opportunity to overcome the existing limitations provided by Hertzian mechanics and apply AFM techniques in real clinical activities.

Keywords: Mechanical properties, non-homogeneous samples, anisotropic samples, young's modulus, indentation work, nanoscale.

Graphical Abstract
Franz, C.M.; Puech, P.H. Atomic force microscopy – a versatile tool for studying cell morphology, adhesion and mechanics. Cell. Mol. Bioeng., 2008, 1(4), 289-300.
Webb, H.K.; Truong, V.K.; Hasan, J.; Crawford, R.J.; Ivanova, E.P. Physico-mechanical characterisation of cells using atomic force microscopy - Current research and methodologies. J. Microbiol. Methods, 2011, 86(2), 131-139.
Thomas, G.; Burnham, N.A.; Camesano, T.A.; Wen, Q. Measuring the mechanical properties of living cells using atomic force microscopy. J. Vis. Exp., 2013, 2013(76)e50497
Kurland, N.E.; Drira, Z.; Yadavalli, V.K. Measurement of nanomechanical properties of biomolecules using atomic force microscopy. Micron, 2012, 43(2-3), 116-128.
Stylianou, A.; Kontomaris, S.V.; Grant, C.; Alexandratou, E. Atomic force microscopy on biological materials related to pathological conditions. Scanning, 2019, 20198452851
Kuznetsova, T.G.; Starodubtseva, M.N.; Yegorenkov, N.I.; Chizhik, S.A.; Zhdanov, R.I. Atomic force microscopy probing of cell elasticity. Micron, 2007, 38(8), 824-833.
Kontomaris, S.V. The hertz model in AFM nanoindentation experiments: Applications in biological samples and biomaterials. Micro Nanosyst., 2018, 10(1), 11-22.
Efremov, Y.M.; Cartagena-Rivera, A.X.; Athamneh, A.I.M.; Suter, D.M.; Raman, A. Mapping heterogeneity of cellular mechanics by multi-harmonic atomic force microscopy. Nat. Protoc., 2018, 13(10), 2200-2216.
Kontomaris, S.V.; Stylianou, A.; Malamou, A.; Nikita, K.S. An alternative approach for the Young’s modulus determination of biological samples regarding AFM indentation experiments. Mater. Res. Express, 2018, 6025407
Kontomaris, S.V.; Stylianou, A. Atomic force microscopy for university students: Applications in biomaterials. Eur. J. Phys., 2017, 38(3)033003
Krieg, M.; Fläschner, G.; Alsteens, D. Atomic force microscopy-based mechanobiology. Nat. Rev. Phys., 2018, 1, 41-47.
Stylianou, A.; Lekka, M.; Stylianopoulos, T. AFM assessing of nanomechanical fingerprints for cancer early diagnosis and classification: from single cell to tissue level. Nanoscale, 2018, 10(45), 20930-20945.
Fuhrmann, A.; Staunton, J.R.; Nandakumar, V.; Banyai, N.; Davies, P.C.W.; Ros, R. AFM stiffness nanotomography of normal, metaplastic and dysplastic human esophageal cells. Phys. Biol., 2011, 8(1)015007
Bastatas, L.; Martinez-Marin, D.; Matthews, J.; Hashem, J.; Lee, Y.J.; Sennoune, S.; Filleur, S.; Martinez-Zaguilan, R.; Park, S. AFM nano-mechanics and calcium dynamics of prostate cancer cells with distinct metastatic potential. Biochim. Biophys. Acta, 2012, 1820(7), 1111-1120.
Cross, S.E.; Jin, Y.S.; Lu, Q.Y.; Rao, J.; Gimzewski, J.K. Green tea extract selectively targets nanomechanics of live metastatic cancer cells. Nanotechnology, 2011, 22(21)215101
Lekka, M.; Wiltowska-Zuber, J. Biomedical applications of AFM. J. Phys. Conf. Ser., 2009, 146(1)012023
Darling, E.M.; Zauscher, S.; Block, J.A.; Guilak, F. A thin-layer model for viscoelastic, stress-relaxation testing of cells using atomic force microscopy: do cell properties reflect metastatic potential? Biophys. J., 2007, 92(5), 1784-1791.
Faria, E.C.; Ma, N.; Gazi, E.; Gardner, P.; Brown, M.; Clarke, N.W.; Snook, R.D. Measurement of elastic properties of prostate cancer cells using AFM. Analyst (Lond.), 2008, 133(11), 1498-1500.
Lekka, M.; Laidler, P.; Gil, D.; Lekki, J.; Stachura, Z.; Hrynkiewicz, A.Z. Elasticity of normal and cancerous human bladder cells studied by scanning force microscopy. Eur. Biophys. J., 1999, 28(4), 312-316.
Li, Q.S.; Lee, G.Y.H.; Ong, C.N.; Lim, C.T. AFM indentation study of breast cancer cells. Biochem. Biophys. Res. Commun., 2008, 374(4), 609-613.
Zhou, Z.L.; Ngan, A.H.W.; Tang, B.; Wang, A.X. Reliable measurement of elastic modulus of cells by nanoindentation in an atomic force microscope. J. Mech. Behav. Biomed. Mater., 2012, 8, 134-142.
Lekka, M.; Gil, D.; Pogoda, K.; Dulińska-Litewka, J.; Jach, R.; Gostek, J.; Klymenko, O.; Prauzner-Bechcicki, S.; Stachura, Z.; Wiltowska-Zuber, J.; Okoń, K.; Laidler, P. Cancer cell detection in tissue sections using AFM. Arch. Biochem. Biophys., 2012, 518(2), 151-156.
Lekka, M. Discrimination between normal and cancerous cells using AFM. Bionanoscience, 2016, 6, 65-80.
Cross, S.E.; Jin, Y.S.; Rao, J.; Gimzewski, J.K. Nanomechanical analysis of cells from cancer patients. Nat. Nanotechnol., 2007, 2(12), 780-783.
Guck, J.; Schinkinger, S.; Lincoln, B.; Wottawah, F.; Ebert, S.; Romeyke, M.; Lenz, D.; Erickson, H.M.; Ananthakrishnan, R.; Mitchell, D.; Käs, J.; Ulvick, S.; Bilby, C. Optical deformability as an inherent cell marker for testing malignant transformation and metastatic competence. Biophys. J., 2005, 88(5), 3689-3698.
Rosenbluth, M.J.; Lam, W.A.; Fletcher, D.A. Force microscopy of nonadherent cells: A comparison of leukemia cell deformability. Biophys. J., 2006, 90(8), 2994-3003.
Ward, K.A.; Li, W.I.; Zimmer, S.; Davis, T. Viscoelastic properties of transformed cells: role in tumor cell progression and metastasis formation. Biorheology, 1991, 28(3-4), 301-313.
Lam, W.A.; Rosenbluth, M.J.; Fletcher, D.A. Chemotherapy exposure increases leukemia cell stiffness. Blood, 2007, 109(8), 3505-3508.
Plodinec, M.; Loparic, M.; Monnier, C.A.; Obermann, E.C.; Zanetti-Dallenbach, R.; Oertle, P.; Hyotyla, J.T.; Aebi, U.; Bentires-Alj, M.; Lim, R.Y.; Schoenenberger, C.A. The nanomechanical signature of breast cancer. Nat. Nanotechnol., 2012, 7(11), 757-765.
Tian, M.; Li, Y.; Liu, W.; Jin, L.; Jiang, X.; Wang, X.; Ding, Z.; Peng, Y.; Zhou, J.; Fan, J.; Cao, Y.; Wang, W.; Shi, Y. The nanomechanical signature of liver cancer tissues and its molecular origin. Nanoscale, 2015, 7(30), 12998-13010.
Stolz, M.; Gottardi, R.; Raiteri, R.; Miot, S.; Martin, I.; Imer, R.; Staufer, U.; Raducanu, A.; Düggelin, M.; Baschong, W.; Daniels, A.U.; Friederich, N.F.; Aszodi, A.; Aebi, U. Early detection of aging cartilage and osteoarthritis in mice and patient samples using atomic force microscopy. Nat. Nanotechnol., 2009, 4(3), 186-192.
Stolz, M.; Raiteri, R.; Daniels, A.U.; VanLandingham, M.R.; Baschong, W.; Aebi, U. Dynamic elastic modulus of porcine articular cartilage determined at two different levels of tissue organization by indentation-type atomic force microscopy. Biophys. J., 2004, 86(5), 3269-3283.
Fratzl, P. Collagen Structure and Mechanics; Springer: New York, NY, USA, 2008.
Hulmes, D.J.S. 2008 Collagen diversity, synthesis and assembly.Collagen; Springer: Boston, MA, USA, 2008, pp. 15-47.
Kadler, K.E.; Baldock, C.; Bella, J.; Boot-Handford, R.P. Collagens at a glance. J. Cell Sci., 2007, 120(Pt 12), 1955-1958.
Hasirci, V.; Vrana, E.; Zorlutuna, P.; Ndreu, A.; Yilgor, P.; Basmanav, F.B.; Aydin, E. Nanobiomaterials: a review of the existing science and technology, and new approaches. J. Biomater. Sci. Polym. Ed., 2006, 17(11), 1241-1268.
Minary-Jolandan, M.; Yu, M.F. Nanomechanical heterogeneity in the gap and overlap regions of type I collagen fibrils with implications for bone heterogeneity. Biomacromolecules, 2009, 10(9), 2565-2570.
Choi, S.; Cheong, Y.; Shin, J.H.; Lee, H.J.; Lee, G.J.; Choi, S.K.; Jin, K.H.; Park, H.K. Short-term nanostructural effects of high radiofrequency treatment on the skin tissues of rabbits. Lasers Med. Sci., 2012, 27(5), 923-933.
Sionkowska, A.; Wess, T. Mechanical properties of UV irradiated rat tail tendon (RTT) collagen. Int. J. Biol. Macromol., 2004, 34(1-2), 9-12.
Kontomaris, S.V.; Stylianou, A.; Yova, D. Investigation of the mechanical properties of collagen fibrils under the influence of low power red laser irradiation. Biomed. Phys. Eng. Express, 2016, 2(6)064002
Kontomaris, S.V.; Yova, D.; Stylianou, A.; Balogiannis, G. The effects of UV irradiation on collagen D-band revealed by atomic force microscopy. Scanning, 2015, 37(2), 101-111.
Moreno-Madrid, F.; Martín-González, N.; Llauró, A.; Ortega-Esteban, A.; Hernando-Pérez, M.; Douglas, T.; Schaap, I.A.; de Pablo, P.J. Atomic force microscopy of virus shells. Biochem. Soc. Trans., 2017, 45(2), 499-511.
Mateu, M.G. Mechanical properties of viruses analyzed by atomic force microscopy: a virological perspective. Virus Res., 2012, 168(1-2), 1-22.
Kontomaris, S.V.; Stylianou, A.; Nikita, K.S.; Malamou, A.; Stylianopoulos, T. A simplified approach for the determination of fitting constants in Oliver-Pharr method regarding biological samples. Phys. Biol., 2019, 16(5)056003
Kontomaris, S.V.; Stylianou, A.; Nikita, K.S.; Malamou, A. Determination of the linear elastic regime in AFM nanoindentation experiments on cells. Mater. Res. Express, 2019, 6(11)115410
Radmacher, M.; Fritz, M.; Hansma, P.K. Imaging soft samples with the atomic force microscope: gelatin in water and propanol. Biophys. J., 1995, 69(1), 264-270.
Suriano, R.; Credi, C.; Levi, M. Turri. S. AFM nanoscale indentation in air of polymeric and hybrid materials with highly different stiffness. Appl. Surf. Sci., 2014, 311(30), 558-566.
Liu, P.; He, J.H. Geometric potential: An explanation of nanofiber’s wettability. Therm. Sci., 2017, 22(00), 146-146.
Li, X.X.; He, J.H. Nanoscale adhesion and attachment oscillation under the geometric potential. Part 1: The formation mechanism of nanofiber membrane in the electrospinning. Results Phys., 2019, 12, 1405-1410.

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