Rhological Behavior of Injectable Bioactive Glass/Gelatin Pastes Used for Bone Replacement

Injectable pastes are bioactive materials which are used in various forms in the living organism. The bioactivity of these materials are derived from calcium phosphate powder and/or a bio-glass composition. These materials are not individually injectable; however, they will be when suitable polymers such as chitosan, gelatin, sodium alginate, hyaluronic acid, etc. added to the paste. In this research, the authors have tried to prepare a bioactive injectable glass/polymer paste via mixing a sol-gel derived glass powder, based on the SiO2-CaO-P2O5 system, with polymer’s solution of gelatin. The rheological behavior and the injectability of the pastes were also investigated. The results showed that the paste was well-injected; however, it showed an undefined rheological behavior. The maximum viscosity of the paste was 8.88 × 10 Pa.s and it was washed out during it’s immersion in a simulated body fluid with time and reached to approximately 60wt.% of its initial weight after 48h. According to microstructural analysis, mineralogical phase analysis and Fourier Transform IR spectrometry analysis, the paste showed bioactivity after 14 days immersion in SBF solution.