The effect of mesoporous bioactive glass on the physiochemical, biological and drug-release properties of poly(DL-lactide-co-glycolide) films Chengtie Wu a, b , Yogambha Ramaswamy a, b , Yufang Zhu c , Rongkun Zheng d , Richard Appleyard e , Andrew Howard a, b , Hala Zreiqat a, b, * a Biomaterials and Tissue Engineering Research Unit, School of AMME, The University of Sydney, Sydney 2006, Australia b Bosch Institute, The University of Sydney, Sydney 2006, Australia c ICYS-Sengen, National Institute for Materials Science, 1-2-1 Segen, Tsukuba, Ibaraki 305-0047, Japan d EMU, The University of Sydney, Sydney, 2006 NSW, Australia e Murray Maxwell Biomechanics Laboratory, Kolling Institute (University of Sydney), Royal North Shore Hospital, Sydney, 2065 NSW, Australia article info Article history: Received 7 January 2009 Accepted 19 January 2009 Available online 8 February 2009 Keywords: Mesoporous bioactive glass PLGA Osteoblasts Dexamethazone Drug release abstract Poly(lactide-co-glycolide) (PLGA) has been widely used for bone tissue regeneration. However, it lacks hydrophilicity, bioactivity and sufficient mechanical strength and its acidic degradation by-products can lead to pH decrease in the vicinity of the implants. Mesoporous bioactive glass (MBG) with highly ordered structure (pore size 2–50 nm) possesses higher bioactivity than non-mesoporous bioactive glass (BG). The aim of this study is to investigate the effect of MBG on the mechanical strength, in vitro degradation, bioactivity, cellular response and drug release of PLGA films and optimize their physico- chemical, biological and drug-delivery properties for bone tissue engineering application. The surface and inner microstructure, mechanical strength and surface hydrophilicity of MBG/PLGA and BG/PLGA films were tested. Results indicated that MBG or BG was uniformly dispersed in the PLGA films. The incorporation of MBG into PLGA films significantly improved their tensile strength, modulus and surface hydrophilicity. MBG/PLGA resulted in an enhanced mechanical strength, in vitro degradation (water absorbance, weight loss and ions release), apatite-formation ability and pH stability in simulated body fluids (SBF), compared to BG/PLGA. MBG/PLGA and BG/PLGA films enhanced human osteoblastic-like cells (HOBs) attachment, spreading and proliferation compared to PLGA. HOBs differentiation was significantly upregulated when cells were cultured on 30 MBG/PLGA for 14 days, compared to 30 BG/PLGA. MBG/PLGA enhanced the accumulative release of dexamethazone (DEX) at early stages (0–200 h) compared to BG/PLGA, however, after 200 h, DEX-release rates for MBG/PLGA was slower than that of BG/PLGA. The contents of MBG in PLGA films can control the amount of DEX released. Taken together, MBG/PLGA films possessed excellent physicochemical, biological and drug-release properties, indicating their potential application for bone tissue engineering by designing 3D scaffolds according to their corresponding compositions. Ó 2009 Elsevier Ltd. All rights reserved. 1. Introduction Synthetic biodegradable polyesters like polyglycolide (PGA), polylactide (PLA) and their copolysters poly(lactide-co-glycolide) (PLGA) have been widely used for bone tissue regeneration [1,2]. These materials are biodegradable with generally good biocom- patibility and can be easily processed. However, a number of problems have been encountered regarding the use of these poly- mers in tissue engineering applications. For example the main problems associated with PLGA are that they lack hydrophilicity and bioactivity, their mechanical strength is compromised and the release of acidic degradation by-products can lead to a decreased pH value in the vicinity of the implants which may lead to inflammatory response [3–7]. To solve these problems, inorganic materials, such as hydroxyaptite (HAp), b-tricalcium phosphate (b-TCP) and bioactive glass, have been incorporated into PLGA to develop inorganic/organic composites [8–10]. It is found that bioactive glass can improve the bioactivity of the composites and is more effective in stabling the pH, compared to HAp. Bioactive glass can release Ca and Si ionic products, which will neutralize the acidic degradation by-products of the PLGA and stabilizes the pH value of the surrounding environments [8,11]. * Corresponding author. Tel.: þ61 2 93512392; fax: þ61 2 93517060. E-mail address: hzreiqat@usyd.edu.au (H. Zreiqat). Contents lists available at ScienceDirect Biomaterials journal homepage: www.elsevier.com/locate/biomaterials 0142-9612/$ – see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.biomaterials.2009.01.029 Biomaterials 30 (2009) 2199–2208