PSI - Issue 28

Shirsha Bose et al. / Procedia Structural Integrity 28 (2020) 843–849 S. Bose et. al/ Structural Integrity Procedia 00 (2019) 000–000

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Fig. 4b. Deformation of collagen film in - aqua conditions

4. Conclusions The results obtained for collagen films tested in-aqua exhibited a drop in tensile strength and fracture energy by more than 90% and 40%, respectively, while increasing the ductility by about 1600% as opposed to in-air specimens. In-air deformation demonstrated a sudden, unstable crack propagation in collagen films leading to a catastrophic failure, while under the influence of water the collagen film showed slow crack-tip opening followed by crack blunting and failure. The brittle failure for in-air samples was accompanied by crack deflection, micro cracking and crack bridging while in-aqua the fibrillar alignment, straightening and relative sliding might lead to a ductile crack propagation. References Bose, S., Li, S., Mele, E. and Silberschmidt, V. V (2020a) ‘Dry vs. wet: Properties and performance of collagen films. Part I. mechanical behaviour and strain-rate effect’, Journal of the Mechanical Behavior of Biomedical Materials , p. 103983. doi: 10.1016/j.jmbbm.2020.103983. Bose, S., Li, S., Mele, E. and Silberschmidt, V. V. (2020b) ‘Dry vs. wet: Properties and performance of collagen films. Part II. Cyclic and time dependent behaviours’, Journal of Mechanical Behaviour of Biomedical Materials , in review. Collins, R. L. L., Christiansen, D., Zazanis, G. A. and Silver, F. H. (1991) ‘Use of collagen film as a dural substitute: Preliminary animal studies’, Journal of Biomedical Materials Research , 25, pp. 267–276. doi: 10.1002/jbm.820250212. Fratzl, P. (2008) ‘Collagen: structure and mechanics, an introduction.’, In: Collagen: Structure and Mechanics. P. Fratzl (ed.) Springer, Boston., pp. 1–13. Gautieri, A., Vesentini, S., Redaelli, A. and Buehler, M. J. (2011) ‘Hierarchical structure and nanomechanics of collagen microfibrils from the atomistic scale up’, Nano Letters , 11(2), pp. 757–766. doi: 10.1021/nl103943u. Kadler, K. E., Baldock, C., Bella, J. and Boot-Handford, R. P. (2007) ‘Collagens at a glance’, Journal of Cell Science , 120(12), pp. 1955–1958. doi: 10.1242/jcs.03453. Liu, Y., Ren, L., Yao, H. and Wang, Y. (2012) ‘Collagen films with suitable physical properties and biocompatibility for corneal tissue engineering prepared by ion leaching technique’, Materials Letters , 87, pp. 1–4. doi: 10.1016/j.matlet.2012.07.091. Moreno, S., Baniasadi, M., Mohammed, S., Mejia, I., Chen, Y., Quevedo-Lopez, M. A., Kumar, N., Dimitrijevich, S. and Minary-Jolandan, M. (2015) ‘Biocompatible collagen films as substrates for flexible implantable electronics’, Advanced Electronic Materials , 1(9), p. 1500154. doi: Ber, S., Torun Köse, G. and Hasirci, V. (2005) ‘Bone tissue engineering on patterned collagen films: An in vitro study’, Biomaterials , 26(14), pp. 1977–1986. doi: 10.1016/j.biomaterials.2004.07.007.