Application of Low Cost Polyurethane (PU) Foam for Fabricating Porous Tri-Calcium Phosphate (TCP) A.R. Fariza a , A. Zuraida b and I.Sopyan c Department of Manufacturing and Materials Engineering, Faculty of Engineering, International Islamic University Malaysia, P.O. Box 10, 50728 Kuala Lumpur, Malaysia a fariza_iiu@yahoo.com, b zuraidaa@iiu.edu.my, c sopyan@iiu.edu.my Keywords: Porous tri-calcium phosphate, low-cost polyurethane, porosity Abstract: Porous tri-calcium phosphate, well-known for its use as artificial bone, was prepared via sponge polymeric method by the application of low cost polyurethane (PU) foam as a structural guide. In this experiment, fractions of tri-calcium phosphate (TCP) are controlled at 12, 13, 14, 15 and 16 grams and mixed with distilled water (fixed at 25 grams) to produce slurries. Subsequently, rectangular shaped PU foam was immersed in the slurry and dried for three days. Samples were then sintered at 1100°C to obtain porous tri-calcium phosphate. This method produces porous tri- calcium phosphate with porosity between 31-44% and the compressive strength in the range of 0.17-1.02 MPa. The macroporosity of the tri-calcium phosphate, observed through SEM, was in the range of 100 μm to 900 μm. Introduction There are a lot of concerns for researchers to consider when responding to the demand for biomaterial products, since there are a lot of shortcomings derived from allograft and autograft as bone substitutes. Researchers have tried to discover an ‘as simple as possible’ preparation method whilst considering cost implications. Substitutes must meet several criteria in order to be an ideal artificial bone including being biocompatible, bioactive, resorbable, an osteoconductor, an osteoinductor, possessing good mechanical properties and availability in unlimited quantities [1]. These are the major challenges for researchers in order to develop porous artificial bone with desired porosity and acceptable mechanical strength. For synthetic bone applications, bioceramics from the calcium phosphate family are often used due to the properties that mimic the natural human bone. However, hydroxyapatite (HA) and tri-calcium phosphate (TCP) are the most favoured because of their good biocompatibility and osteointegrative properties [2]. When comparison is made between these two bioceramics, TCP has more advantages as it dissolves and resorbs more quickly than HA. Moreover, HA shows almost no absorption and remains in the body for a long time as a foreign substance [3]. In order for the artificial bone to be accommodated by the host tissues, it must exhibit porosity to encourage cell growth within the three dimensional structure. Yet the pores must be connected to each other in order to mimic the architecture of the mineral phase of living bone. There are many inspired ways of producing porous artificial bones such as by polymeric sponge method, conversion of marine coral skeleton, salt leaching, gas forming, phase separation, freeze-drying and sintering [4]. Since the porosity of the artificial bone needs to be controlled, researchers nowadays are using pore creating agents, either organic or inorganic materials to achieve the desired result. Examples of the prominent pore creating agents are polymethylmethacrylate micro beads (PMMA) [5], carbon beads [6], naphthalene [7] etc. The key idea is that these pore creating agents will be removed from the prepared samples during sintering, creating the pores [8]. The use of polyurethane (PU) foam in producing porous ceramics has been widely studied. Due to the ability to control the porosity of the foam, PU offers benefits as a template for porous ceramics [9]. This is because the structure of PU foam consists of struts and voids. The elasticity of the struts allows the foam to recover to its original shape when a force is removed. On the other Journal of Biomimetics, Biomaterials and Tissue Engineering Vol.8 (2010) pp 1-7 Online available since 2010/Nov/17 at www.scientific.net © (2010) Trans Tech Publications, Switzerland doi:10.4028/www.scientific.net/JBBTE.8.1 All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of TTP, www.ttp.net. (ID: 210.48.222.9, International Islamic University Malaysia, Kuala Lumpur, Malaysia-02/01/14,04:51:04)