Caracterização físico-química e efeito biológico de scaffolds 3D-nanofibrilares de alumina produzidos por fiação por sopro em solução.

Abstract

Bone substitute biomaterials with the potential to improve cell-material interactions are in high demand. The aim of this study was to perform physicochemical characterization and evaluate in vivo the bioactivity of amorphous 3D-nanofibrous alumina scaffolds produced by the SBS (Solution Blow Spinning) technique for bone regeneration. The nanofibers used in this study were obtained from a solution of aluminum nitrate, polyvinylpyrrolidone (PVP), ethanol and distilled water, and spun in the SBS apparatus under defined pressure and temperature. The fibers had a macro and microscopic cotton-like 3D structure and were calcined at 500°C. The morphological characterization of the nanofibers was performed using scanning electron microscopy (SEM), and the mineralogical characterization by X-ray diffraction (XRD). To evaluate the biological effect, bone defects were created in the femur of 20 male Wistar rats. The defects were filled with blood or alumina nanofibers. The animals were euthanized at 14 or 28 days. Femurs were collected and processed to obtain histological slides. Descriptive histological analysis of the bone repair process associated with the biomaterial was performed. Also, bone neoformation and the particles of the remaining graft were quantified for histomorphometry analysis. In the morphological analysis, the nanofibers had a circular cross section with mean diameters of 287 nm; the XRD pattern did not present diffraction reflections, characterizing an amorphous alumina. Histomorphometry revealed a greater amount of bone neoformation in the Alumina groups when compared to the control in the two experimental periods (p<0.05) and the percentage of Alumina graft particles remaining at 14 and 28 days was similar. In conclusion, the tested 3D alumina scaffolds allowed bone deposition and favored bone defect filling with new bone.