Fabrication and in-vitro evaluation of copper doped bioactive glass/polymer composite scaffolds for bone tissue engineering

Composites developed by combining bioactive glasses and biopolymers are attractive materials for use in bone tissue engineering scaffolds due to their bioactivity, biocompatibility, osteoconductivity and mechanical properties. From this point of view, in this study, three-dimensional polymer/bioactive composite scaffolds were fabricated by using polymer foam replication method. To be able to achieve this goal, in the first stage new bioactive glass composition in the system SiO2-CaO-Na2O-P2O5 were developed with the incorporation of copper which have antibacterial and angiogenic properties. Scaffolds that mimic the structure of the foams were obtained after the heat treatment process. Then, the scaffolds were coated with gelatine at different percentages (1 and 3 weight%) in order to improve mechanical properties of the scaffolds. Microstructural, physical, chemical and mechanical properties of the composite scaffolds were investigated by using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), compressive strength test and porosity measurements. Furthermore, bioactivity and biodegradability behavior of the samples were determined by in vitro simulated body fluid (SBF) studies. The results showed that all scaffolds favored precipitation of calcium phosphate layer when they were soaked in SBF; they can also deliver controlled doses of copper toward the SBF medium. It was concluded that scaffolds coated with gelatine may be promising candidates for bone tissue engineering applications due to their porosity, bioactivity and appropriate biodegradation rate.