Nanomechanics of Surface Modified Nanohydroxyapatite Particulates Used in Biomaterials
Publication: Journal of Engineering Mechanics
Volume 135, Issue 5
Abstract
Hydroxyapatite is an important constituent of natural bone, and possesses excellent biocompatibility and bioactivity, but its brittle nature limits its use for bone tissue engineering. Nanohydroxyapatite (nanoHAP) has been used in synthesis of biomimetic composites for more than a decade, yet the mechanics of nanoHAP particles is not fully understood. The present work attempts to advance the current understanding of mechanics of hydroxyapatite at nanoscale, by carrying out systematic nanoindentation experiments on nanoHAP and surface modified nanoHAP [prepared by in situ mineralization in presence of polyacrylic acid (PAAc)]. Quantitative nanomodulus maps of both modified and unmodified HAP nanoparticles indicate that various surface features of HAP nanoparticles can be probed. Dips in values of elastic moduli across the nanoparticle surfaces in modified nanohydroxyapatite are indicative of composite responses from both polymer and mineral phases (PAAc-HAP) on the surface. Nanoindentation experiments were performed at 100, 1,000, 3,000, 5,000, and loads, respectively, to obtain the indentation response from both shallow and deep penetration depths. Nanoindentation results at shallow penetration depths are influenced by nanoscale surface roughness of irregular-shaped HAP nanoparticles and nonuniform distribution of PAAc in the microstructure. Significant nonbonded interactions between HAP and PAAc, as well as the mechanical properties of individual constituents (HAP and PAAc) lead to superior nanomechanical properties of surface-modified nanoHAP as compared to unmodified HAP. The overall inelastic nanomechanical response (including damage leading to reduced overall elastic modulus) is strongly influenced by the nature of the interfaces between the nanoparticles, especially when indent size is much larger than the particle size.
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Acknowledgments
The writers acknowledge National Science Foundation (NSF) support for the research conducted. This research was supported by NSF CAREER Award No. NSF0132768 (K.K.), and NSF IMR Award No. NSF0315513 for the nanoindentation equipment. The writer R. K. would like to acknowledge support from NDSU Graduate School.
References
Alivisatos, A. P. (1996). “Semiconductor clusters, nanocrystals, and quantum dots.” Science, 271, 933–937.
Asif, S. A. S., Wahl, K. J., and Colton, R. J. (1999). “Nanoindentation and contact stiffness measurement using force modulation with a capacitive load-displacement transducer.” Rev. Sci. Instrum., 70, 2408–2413.
Asif, S. A. S., Wahl, K. J., Colton, R. J., and Warren, O. L. (2001). “Quantitative imaging of nanoscale mechanical properties using hybrid nanoindentation and force modulation.” J. Appl. Phys., 90, 1192–1200.
Balooch, G., Marshall, G. W., Marshall, S. J., Warren, O. L., Asif, S. A. S., and Balooch, M. (2004). “Evaluation of a new modulus mapping technique to investigate microstructural features of human teeth.” J. Biomech., 37, 1223–1232.
Bhowmik, R., Katti, K. S., and Katti, D. (2007a). “Molecular dynamics simulation of hydroxyapatite-polyacrylic acid interfaces.” Polymer, 48, 664–674.
Bhowmik, R., Katti, K. S., Verma, D., and Katti, D. R. (2007b). “Probing molecular interactions in bone biomaterials: Through molecular dynamics and Fourier transform infrared spectroscopy.” Mater. Sci. Eng., C, 27, 352–371.
Bobji, M. S., and Biswas, S. K. (1998). “Estimation of hardness by nanoindentation of rough surfaces.” J. Mater. Res., 13(11), 3227–3233.
Bonefield, W., and Clark, E. A. (1973). “Elastic deformation of compact bone.” J. Mater. Sci., 8, 1590–1594.
Braiman, Y., Barhen, J., and Protopopescu, V. (2003). “Control of friction at the nanoscale.” Phys. Rev. Lett., 90(9), 094301.
Bushby, A. J., and Dunstan, D. J. (2004). “Plasticity size effects in nanoindentation.” J. Mater. Res., 19, 137.
Ciprari, D., Jacob, K., and Tannenbaum, R. (2006). “Characterization of polymer nanocomposite interphase and its impact on mechanical properties.” Macromolecules, 39, 6565–6573.
Dickinson, M. E., and Mann, A. B. (2006). “Nanomechanics and morphology of salivary pellicle.” J. Mater. Res., 21(8), 1996–2002.
Discher, D. E., Janmey, P., and Wang, Y.-L. (2005). “Tissue cells feel and respond to the stiffness of their substrate.” Science, 310(5751), 1139–1143.
Dormieux, L., Kondo, D., and Ulm, F.-J. (2006). “A micromechanical analysis of damage propagation in fluid-saturated cracked media.” C. R. Mec., 334, 440–446.
Draghi, L., and Cigada, A. (2007). “Nanostructured surfaces for biomedical applications. Part I: Nanotopography.” J. Appl. Biomater. Biomech., 5(2), 61–69.
Durst, K., Göken, M., and Vehoff, H. (2004). “Finite-element study for nanoindentation measurements on two-phase materials.” J. Mater. Res., 19, 85–93.
Ebenstein, D. M., and Pruitt, L. A. (2004). “Nanoindentation of soft hydrated materials for application to vascular tissues.” J. Biomed. Mater. Res., 69A, 222–232.
Gao, H. (2006). “Application of fracture mechanics concepts to hierarchical biomechanics of bone and bone-like materials.” Int. J. Fract., 138, 101–137.
Gilmore, R. S., and Katz, J. L. (1982). “Elastic properties of apatites.” J. Mater. Sci., 17, 1131–1141.
Gouldstone, A., Challacoop, N., Dao, M., Li, J., Minor, A. M., and Shen, Y.-L. (2007). “Indentation across size scales and disciplines: Recent developments in experimentation and modeling.” Acta Mater., 55, 4015–4039.
Grenoble, D. E., Katz, J. L., Dunn, K. L., Gilmore, R. S., and Linga Murthy, K. (1972). “The elastic properties of hard tissues and apatites.” J. Biomed. Mater. Res., 6, 221–33.
Hainsworth, S. V., Chandler, H. W., and Page, T. F. (1996). “Analysis of nanoindentation load-displacement loading curves.” J. Mater. Res., 11(8), 1987–1995.
Hirano, M. (2006). “Atomistics of friction.” Surf. Sci. Rep., 60, 159–201.
Hong, Z., et al. (2005). “Nano-composite of poly(L-lactase) and surface grafted hydroxyapatite: Mechanical properties and biocompatibility.” Biomaterials, 26, 6296–6304.
Huang, J., Best, S. M., Bonefield, W., Brooks, R. A., Rushton, N., and Jayasinghe, S. N. (2004). “In vitro assessment of the biological response to nano-sized hydroxyapatite.” J. Mater. Sci.: Mater. Med., 15, 441–445.
Jacot, J. G., Dianis, S., Schnall, J., and Wong, J. Y. (2006). “A simple microindentation technique for mapping the microscale compliance of soft hydrated materials and tissues.” J. Biomed. Mater. Res., 79A, 485–494.
Johnson, K. L. (1987). Contact mechanics, Cambridge University Press, Cambridge, U.K., 175.
Kato, K., Eika, Y., and Ikada, Y. (1997). “In situ hydroxyapatite crystallization for the formation of hydroxyapatite/polymer composites.” J. Mater. Sci., 32, 5533–5543.
Katti, K. S., Mohanty, B., and Katti, D. R. (2006a). “Nanomechanical properties of nacre.” J. Mater. Res., 21(5), 1237–1242.
Katti, K. S., Sikdar, D., Katti, D. R., Ghosh, P., and Verma, D. (2006c). “Molecular interactions in intercalated organically modified clay and clay-polycaprolactum nanocomposites: Experiments and modeling.” Polymer, 47, 403–414.
Katti, K. S., Turlapati, P., Verma, D., Bhowmik, R., Gujjula, P. K., and Katti, D. R. (2006b). “Static and dynamic mechanical behavior of hydroxyapatite-polyacrylic acid composites under simulated body fluid.” Am. J. Biochem. Biotechnol., 2(2), 73–79.
Katz, J. L., and Meunier, A. (1987). “The elastic anisotropy of bone.” J. Biomech., 20(11/12), 1063–1070.
Katz, J. L., and Ukraincik, K. (1971). “On the anisotropic elastic properties of hydroxyapatite.” J. Biomech., 4, 221–227.
Kaufman, J. D., Song, J., and Klapperich, C. M. (2007). “Nanomechanical analysis of bone tissue engineering scaffolds.” J. Biomed. Mater. Res., 81A, 611–623.
Khanna, R., and Basu, B. (2006). “Low friction and severe wear of alumina in cryogenic environment: A first report.” J. Mater. Res., 21(4), 832–843.
Kim, G.-M., Lee, D.-H., Hoffmann, B., Kressler, J., and StoÈppelmann, G. (2001). “Influence of nanofillers on the deformation process in layered silicate/polyamide-12 nanocomposites.” Polymer, 42, 1095–1100.
Kim, J. Y., Lee, J. J., Lee, Y. H., Jang, J. I., and Kwon, D. (2006a). “Surface roughness effect in instrumented indentation: A simple contact depth model and its verification.” J. Mater. Res., 21, 2975–2978.
Kim, S. S., Park, M. S., Jeon, O., Choi, C. Y., and Kim, B. S. (2006b). “Poly(lactase-co-glycolide)/hydroxyapatite composite scaffolds for bone tissue engineering.” Biomaterials, 27, 1399–1409.
Kingery, W. D., Bowen, H. K., and Uhlmann, D. R. (2004). “Introduction to ceramics.” Elasticity, anelasticity and strength, 2nd Ed., Wiley Interscience, New York, 797.
Kumar, R. R., and Wang, M. (2002). “Functionally graded bioactive coatings of hydroxyapatite/titanium oxide composite system.” Mater. Lett., 55, 133–137.
Li, X., An, Y. H., Wu, Y.-D., Song, Y. C., Chao, Y. J., and Chien, C.-H. (2007). “Microindentation test for assessing he mechanical properties of cartilaginous tissues.” J. Biomed. Mater. Res., Part B: Appl. Biomater., 80B, 25–31.
Lim, J. Y., Hansen, J. C., Siedlecki, C. A., Hengstebeck, R. W., Cheng, J., and Winograd, N. (2005). “Osteoblast adhesion on poly(L-lactic acid)/polystyrene demixed thin film blends: Effect of nanotopography, surface chemistry, and wettability.” Biomacromolecules, 6(6), 3319–3327.
Liu, Y., and Ngan, A. H. W. (2001). “Depth dependence of hardness in copper single crystals measured by nanoindentation.” Scr. Mater., 44(2), 237–241.
Lopes, M. A., Silva, R. F., Monteiro, F. J., and Santos, J. D. (2000). “Biaxial residual stress states of plasma-sprayed hydroxyapatite coatings on titanium alloy substrate.” Biomaterials, 21(13), 1327–1337.
Lowenstam, H. A., and Weiner, S. (1989). On biomineralization, Oxford University Press, New York.
McConnell, D. (1962). “The crystal structure of bone.” Clin. Orthop., 23, 253–268.
McElhaney, K. W., Vlassak, J. J., and Nix, W. D. (1998). “Determination of indenter tip geometry and indentation contact area for depth-sensing indentation experiments.” J. Mater. Res., 13(5), 1300–1306.
Misra, S. K., Valappil, S. P., Roy, I., and Boccaccini, A. R. (2007). “Polyhydroxyalkanoate (PHA)/inorganic phase composites for tissue engineering applications.” Biomacromolecules, 7(8), 2249–2258.
Mohanty, B., Katti, K. S., Katti, D. R., and Verma, D. (2006). “Dynamic nanomechanical response of nacre.” J. Mater. Res., 21(8), 2045–2051.
Mook, W. M., et al. (2007). “Compressive stress effects on nanoparticle modulus and fracture.” Phys. Rev. B, 75, 214112.
Nix, W. D., and Gao, H. (1998). “Indentation size effects in crystalline materials: A law for strain gradient plasticity.” J. Mech. Phys. Solids, 46, 411–425.
Olivas, E. R., Swadener, J. G., and Shen, Y.-L. (2006). “Nanoindentation measurement of surface residual stresses in particle-reinforced metal matrix composites.” Scr. Mater., 54, 263–268.
Oliver, W. C., and Pharr, G. M. (1992). “An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments.” J. Mater. Res., 7, 1564–1583.
Oyen, M. L. (2006). “Nanoindentation hardness of mineralized tissues.” J. Biomech., 39, 2699–2702.
Park, K., Mishra, S., Lewis, G., Losby, J., Fan, Z., and Park, J. B. (2004). “Quasistatic and dynamic nanoindentation studies on highly cross-linked ultrahigh-molecular-weight polyethylene.” Biomaterials, 25, 2427–2436.
Pelham, R. J., and Wang, Y. L. (1997). “Cell locomotion and focal adhesions are regulated by substrate flexibility.” Proc. Natl. Acad. Sci. U.S.A., 94(25), 13661–13665.
Pensée, V., Kondo, D., and Dormieux, L. (2002). “Micromechanical analysis of anisotropic damage in brittle materials.” J. Eng. Mech., 128(8), 889–897.
Pichler, B., Hellmich, C., and Mang, H. A. (2007). “A combined fracture-micromechanics model for tensile strain-softening in brittle materials, based on propagation of interacting microcracks.” Int. J. Numer. Analyt. Meth. Geomech., 31, 111–132.
Puleo, D. A., Holleran, L. A., Doremus, R. H., and Bizios, R. (1991). “Osteoblast responses to orthopedic implant materials in vitro.” J. Biomed. Mater. Res., 25, 711–723.
Qing, M., and Clarke, D. R. (1995). “Size dependent hardness of silver single crystals.” J. Mater. Res., 10, 853–863.
Ratner, B. D., Hoffman, A. S., Schoen, F. J., and Lemons, J. E. (2004). An introduction to materials in medicine, Elsevier, New York.
Rho, J.-Y., Roy, M. E., II, Tsui, T. Y., and Pharr, G. M. (1999). “Elastic properties of microstructural components of human bone tissue as measured by nanoindentation.” J. Biomed. Mater. Res., 45(1), 48–54.
Ribeiro, R., Ganguly, P., Darensbourg, D., Usta, M., Ucisik, A. H., and Liang, H. (2007). “Biomimetic study of a polymeric composite material for joint repair applications.” J. Mater. Res., 22(6), 1632–1639.
Sikdar, D., Katti, D. R., Katti, K. S., and Bhowmik, R. (2006). “Insight into molecular interactions between constituents in polymer clay nanocomposites.” Polymer, 47, 5196–5205.
Sikdar, D., Pradhan, S., Katti, D. R., Katti, K. S., and Mohanty, B. (2008). “Altered phase model for polymer clay nanocomposites.” Langmuir, 24(10), 5599–5607.
Swadener, J. G., George, E. P., and Pharr, G. M. (2002). “The correlation of the indentation size effect measured with indenters of various shapes.” J. Mech. Phys. Solids, 50(4), 681–694.
Swadener, J. G., Taljat, B., and Pharr, G. M. (2001). “Measurement of residual stress by load and depth sensing indentation with spherical indenters.” J. Mater. Res., 16(7), 2091–2102.
Synders, R., Music, D., Sigumonrong, D., Schelnberger, B., Jensen, J., and Schneider, J. M. (2007). “Experimental and ab initio study of the mechanical properties of hydroxyapatite.” Appl. Phys. Lett., 90, 193902–1.
Tabor, D. (1951). The hardness of metal, Clarendon, Oxford U.K., 51.
Tai, K., Ulm, F.-J., and Ortiz, C. (2006). “Nanogranular origins of the strength of bone.” Nano Lett., 6(11), 2520–2525.
Tymiak, N. I., Kramer, D. E., Bahr, D. F., Wyrobek, T. J., and Gerberich, W. W. (2001). “Plastic strain and strain gradients at very small indentation depths.” Acta Mater., 49, 1021–1034.
Urbakh, M., Klafter, J., Gourdon, D., and Israelachvili, J. (2004). “The nonlinear nature of friction.” Nature (London), 430, 525–528.
Uskokovic, P. S., Tang, C. Y., Tsui, C. P., Ignjatovic, N., and Uskokovic, D. P. (2007). “Micromechanical properties of a hydroxyapatite/poly-L-lactase biocomposite using nanoindentation and modulus mapping.” J. Eur. Ceram. Soc., 27, 1559–1564.
Verma, D., Katti, K., and Katti, D. (2006). “Experimental investigation of interfaces in hydroxyapatite/polyacrylic acid/polycaprolactone composites using photoacoustic FTIR spectroscopy.” J. Biomed. Mater. Res., 77A, 59–66.
Verma, D., Katti, K. S., Katti, D. R., and Mohanty, B. (2007). “Mechanical response and multilevel structure of biomimetic hydroxyapatite/polygalacturonic/chitosan nanocomposites.” Mater. Sci. Eng., C, 28(3), 399–405.
Viswanath, B., Raghavan, R., Ramamurty, U., and Ravishankar, N. (2007). “Mechanical properties and anisotropy in hydroxyapatite single crystals.” Scr. Mater., 57, 361–364.
Wang, R. Z., Suo, Z., Evans, A. G., Yao, N., and Aksay, I. A. (2001). “Deformation mechanisms in nacre.” J. Mater. Res., 16(9), 2485–2493.
Wei, Y., Wang, X., and Zhao, M. (2004). “Size effect measurement and characterization in nanoindentation test.” J. Mater. Res., 19, 208–217.
Yoon, Y. S., and Katz, J. L. (1976a). “Ultrasonic wave propagation in human cortical bone: I: Theoretical considerations for hexagonal symmetry.” J. Biomech., 9, 407–412.
Yoon, Y. S., and Katz, J. L. (1976b). “Ultrasonic wave propagation in human cortical bone. II: Measurements of elastic properties and microhardness.” J. Biomech., 9, 459–464.
Young, R. J., and Eichhorn, S. J. (2007). “Deformation mechanisms in polymer fibres and nanocomposites.” Polymer, 48, 2–18.
Zysset, P. K., Guo, X. E., Hoffler, C. E., Moore, K. E., and Goldstein, S. A. (1999). “Elastic modulus and hardness of cortical and trabecular bone lamellae measured by nanoindentation in the human femur.” J. Biomech., 32(10), 1005–1012.
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Published In
Journal of Engineering Mechanics
Volume 135 • Issue 5 • May 2009
Pages: 468 - 478
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© 2009 ASCE.
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Received: Mar 27, 2008
Accepted: Nov 12, 2008
Published online: May 1, 2009
Published in print: May 2009
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