Fabrication and characterization of bioactive glass (45S5)/titania biocomposites Hanan H. Beherei, Khaled R. Mohamed * , Gehan T. El-Bassyouni National Research Centre, Biomaterials Department, Behoos Street, Dokki, Giza, Egypt Received 21 August 2007; received in revised form 27 September 2008; accepted 28 October 2008 Abstract Bioactive glass (BG) (45S5) has been used successfully as bone-filling material in orthopedic and dental surgery but its lean mechanical strength limits its applications in load-bearing positions. Approaches to strengthen these materials decreased their bioactivity. In order to realize the optimal matching between mechanical and bioactivity properties, bioactive glass (45S5) was reinforced by introducing titania (TiO 2 ) in anatase form and treated at 1000 8C to form new bioactive glass/titania biocomposites. The prepared biocomposites were assessed by XRD, FT-IR, mechanical properties and SEM. The results verified that the increase of titania percentage to BG powder enhanced gradually the mechanical data of the prepared biocomposites. SEM and FT-IRRS confirmed the presence of a rich bone-like apatite layer post-immersion on the composite surface. It has been found that the new BG/titania biocomposite materials especially those containing high content of titania have high bioactivity properties and compressive strength values comparable to cortical bone. Therefore, these biocomposite materials are promising for medical applications such as bone substitutes especially in load-bearing sites. # 2008 Elsevier Ltd and Techna Group S.r.l. All rights reserved. Keywords: Titania; Bioactive glass; Biocomposites; Bone implants; SBF; SEM 1. Introduction Artificial implants, such as the total hip replacement, are successful for a limited time, but all orthopedic implants lack three of the most critical characteristics of living tissues: (a) the ability to self-repair; (b) the ability to maintain a blood supply; and (c) the ability to modify their structure and properties in response to environmental factors such as mechanical load. A recent study showed that 24% of charnley hip operations required revision surgery [1]. Since the discovery of ‘‘Bioglass’’ by Hench in the late sixties [2], many bioactive materials (e.g. glasses, sintered HA, glass–ceramics, compo- sites), which exhibit the ability to bond to living bone through a hydroxyapaptite (HA) layer formed onto their surfaces, have been synthesized and developed for medical applications [3]. The mechanism of HA formation is widely accepted that involves dissolution of calcium ions from the surface of bioactive materials, which increases the super-saturation in the surrounding fluid, with respect to HA components. The simultaneous dissolution of silicates results in the formation of silanol groups on material’s surface, which are essential for nucleation sites leading to HA formation [4]. However, bioglass implants present critical drawbacks in their low mechanical properties and this causes great limitations to their use for load- bearing sites. For this reason, bioglass parts often coupled with tougher material, providing thus their excellent surface properties without a great loss in the bioactivity of the bioglass [5,6]. The apatite can be formed biomimetically on bioactive materials even in simulated body fluid with ion concentra- tions. TiO 2 has a tendency to adsorb water at the surface, resulting in the formation of titanium hydroxide groups. The basic Ti–OH groups were reported to induce apatite nucleation and crystallization in SBF [7]. The production of composite materials has proven to be suitable solutions for improving the mechanical properties of weaker materials. Ceramic matrix biocomposites were reinforced by introdu- cing another tough phase [8] Al 2 O 3 , ZrO 2 , and other. The choice or the design of the best materials for a specific application plays an important role in the feasibility of high www.elsevier.com/locate/ceramint Available online at www.sciencedirect.com Ceramics International xxx (2008) xxx–xxx * Corresponding author. Fax: +2 02 33370931. E-mail address: kh_rezk@yahoo.com (K.R. Mohamed). + Models CERI-3155; No of Pages 7 Please cite this article in press as: H.H. Beherei, et al., Fabrication and characterization of bioactive glass (45S5)/titania biocomposites, Ceram. Int. (2008), doi:10.1016/j.ceramint.2008.10.014 0272-8842/$34.00 # 2008 Elsevier Ltd and Techna Group S.r.l. All rights reserved. doi:10.1016/j.ceramint.2008.10.014