3D Printed Bone-Like Biopolymer Composites Inspired By Nacre

REFERENCES[1] A. R. Costa-Pinto, R. L. Reis, N. M. Neves, Tissue Engineering Part B: Reviews 2011, 17, 331-347.[2] aG. Atlan, O. Delattre, S. Berland, A. LeFaou, G. Nabias, D. Cot, E. Lopez, Biomaterials 1999, 20, 1017-1022; bJ. Sun, B. Bhushan, Rsc Advances 2012, 2, 7617-7632.[3] J. D. Currey, P. Zioupos, D. Peter, A. Casinos, Proceedings of the Royal Society of London B: Biological Sciences 2001, 268, 107-111.[4] L. Addadi, D. Joester, F. Nudelman, S. Weiner, Chemistry–A European Journal 2006, 12, 980-987.[5] S. Zhang, K. Gonsalves, Journal of applied polymer science 1995, 56, 687-695.[6] R. O. Ritchie, Nature materials 2011, 10, 817-822.[7] G. De Stasio, M. A. Schmitt, S. H. Gellman, American Journal of Science 2005, 305, 673-686[8] Medical, S. (2015). XtremeCT. Tibia segmentation. Retrieved 28/07/2016, from http://www.scanco.ch/en/docs/images/xtremect.html

CONCLUSIONS Structurally stable 3D scaffolds based on chitosan

hydrogel was fabricated successfully using our custom-designed 3D printer.

The McGrath mineralization method was successfully used to mineralize the 3D scaffolds, SEM and EDS results suggests good mineralization though out the scaffold.

3D printing is advantageous over bulk gelation based scaffold fabrication in terms of achievable structural precision and increased area of exposure to the mineralization media thus, enhanced diffusion.

Matrix induced mineralization results in the growth of minerals in association with the organic matrix hence inducing small scale hierarchy in the organization of the nanocomposite similar to that in nacre and bone.

INTRODUCTIONArtificial bone grafts have received considerable attention over the years as bone replacement materials due to persistent issues associated with the use of autografts, allografts and xenografts[1]. In this work we are evaluating the applicability of a biopolymer composite based on chitosan hydrogels and calcium carbonate, inspired by Nacre (mother of pearl), as a biocompatible bone graft material. The mechanical strength of nacre is comparable to that of bone but lacks the necessary porosity requirements of a prospective bone graft, however this has been successfully used as bone graft material[2,3]. In this work, 3D printed scaffolds are fabricated using chitosan hydrogel as the ink. These scaffolds are then mineralized via the McGrath Method- a Matrix induced biomineralization strategy devised by our lab to mimic nacre at laboratory conditions. The fabricated scaffolds have printer introduced macropores which fulfills the porosity aspect of a prospective bone graft as well

3D PRINTING VS BULK GELATION FOR HYDROGEL BASED SCAFFOLD FABRICATION

Figure 2: Shows the EDS images of McGrath mineralized scaffolds fabricated via bulk gelation and 3D printing:

(A) Top view of 3D printed scaffold, effect is similar in the case of bulk gelation as well.(B) Transverse cross section of scaffold fabricated via bulk gelation(C) Cross section of 3D printed scaffold

Figure 1: A schematic representation of our project. This work is inspired by the nanostructure of nacre and micro architecture of bone, which is mimicked at laboratory conditions though a combination of 3D printing technology and in-vitro matrix induced biomineralization which has been successfully replicated on a 2D template. Adapted from[4-8]

(A)

(B) (C)

Mima Kurian, Kathryn M McGrath

School of Chemical and Physical SciencesVictoria University of Wellington, New Zealand