Fabrication and characterization of polyvinyl alcohol/TiO2 membrane immersed in simulated body fluid for biomedical application

Abstract

In this study, we synthesized hydroxyapatite (HA) on polyvinyl alcohol/TiO2 (PVA/TiO2) in which TiO2 was prepared by the sol-gel method. HA was formed by immersing the membrane in the simulated body fluid (SBF) solution. We improved the mechanical strength of the membranes by adding glutaraldehyde (GA) combining with heat treatment to cross-link the polymer network. In addition, the composition of TiO2 crystalline phase, TiO2 content in each membrane, and the duration of membrane immersion in SBF solution were investigated. The morphological structures of hydroxyapatite/polyvinyl alcohol/TiO2 (HA/PVA/TiO2) membranes were characterized by IR, SEM, and XRD. We confirmed that the HA formation depended on the TiO2 content and phase composition (rutile or anatase). Membranes containing TiO2 rutile-phase showed more pronounced HA formation than membranes containing TiO2 anatase-phase. The appearance of HA also depended on SBF immersion duration. Membranes soaked for 3 weeks showed significantly more HA formation than membranes soaked for 1 and 2 weeks. Furthermore, the number of cells in membranes soaked for 3 weeks was clearly higher than in other membranes. Finally, HA/PVA/TiO2 membranes containing 25 wt.% of TiO2 rutile-phase are biocompatible based on the number of viable cells and thus have the potential for biomedical application.