Short Poster Lecture
Lightweight, Mechanically Robust and Dual-Porous Silsesquioxane/Silk-based Composite Aerogel Scaffolds for Bone Tissue Engineering
Hajar Maleki,* Nicola Hüsing
Chemistry and Physics of Materials, Paris-Lodron-University Salzburg, Jakob-Haringer-Strasse 2a, 5020, Salzburg, Austria, E-mail: email@example.com
The lack of suitable mechanical functionality and macroporosity in RSiO1,5-based aerogels (with R being an organofunctional group) are considered as the two most important challenges that need to be overcome prior to use them as a scaffold in bone tissue engineering applications . In this work, we address the challenge of the mechanical functionality by simultaneously processing silk fibroin proteins with organically substituted organosilanes in an aqueous-based sol-gel approach to yield homogeneous composite aerogel monoliths for the first time . In order to develop micron size porosity (~100-500 μm), a temporary scaffold of fused paraffin wax spheres (porogens) was used to generate an interconnected, dual macro-/ mesoporosity during the gelation process of both, the silk and silsesquioxane phases. The development of the macroporosity in the obtained aerogels is associated with a loss of initial mechanical robustness (e.g., ~ 100-times lower initial compressive strength) as well as the elastic modulus. Therefore, an extra mechanical reinforcement of the gels has been conducted by forming an interpenetrating polymethylmethacrylate (PMMA) network within the fragile gel. Moreover, the influence of different sizes of porogens on the macroporosity and the mechanical performance of developed composites have also been investigated. In this work, we succeeded to develop a novel class of durable, light-weight, hierarchically organized meso-/macroporous silk-silsesquioxane based composite aerogels for cell scaffolding applications by carefully controlling the sol-gel parameters at a molecular level.
 aJ. Stergar, U. Maver, J. Sol-Gel Sci. Technol 2016, 77, 738–752; bH. Maleki, L. Durães, C. A. García-González, P. del Gaudio, A. Portugal, M. Mahmoudi, Adv. Col. Interf. Sci. 2016, 36, 1-27.
 H. Maleki, N. Hüsing, 2017, submitted.