In-vitro evaluation of bioactive and biodegradation properties of mesoporous ZnO architectures

Currently there is strong interest in the development of smart piezoelectric biomaterials for tissue engineering, where piezoelectricity may actively promote the growth, proliferation and differentiation of cells. [1] Piezoelectric Zinc Oxide (ZnO) materials may be easily prepared in high-surface area structures by several techniques, and captured considerable attention due to their biocompatibility and antibacterial properties. [2] Despite being widely investigated for sensors and energy harvesting applications, [3] the study of ZnO-based materials for tissue engineering is still in its infancy. Herein, we propose a preliminary investigation on the in-vitro bioactive and biodegradation behavior of high-surface area mesoporous ZnO layers, after soaking in Simulated Body Fluid (SBF) solution for different times. The ZnO samples were obtained by thermal oxidation of Zn layers sputtered on silicon substrates. The morphology, crystal structure, and chemical composition of the ZnO samples were studied before and after in-vitro tests. Our results show the rapid formation of CaP structures after soaking in SBF for few hours, then resulting into the formation of a CaP-rich layer onto the whole ZnO surface for prolonged soaking times. The mesoporous ZnO architecture was preserved during the overall in-vitro experimental analyses, with negligible release of biodegradation products from the ZnO structure. [1] C. Ribeiro, V. Sencadas, D.M. Correia, and S. Lanceros-Méndez, Colloids. Surf. B, 136 (2015) 46-55. [2] Y. Zhang, T. R. Nayak, H. Hong, and W. Cai, Curr. Mol. Med. 13 (2013) 1633–1645. [3] M. Laurenti, G. Canavese, A. Sacco, M. Fontana, K. Bejtka, M. Castellino, C.F. Pirri, and V. Cauda, Adv. Mater. 27 (2015) 4218–4223.