Therapeutic cobalt ion incorporated in poly(vinyl alcohol)/bioactive glass scaffolds for tissue engineering

Hybrid scaffolds appear as a promising strategy to accelerate bone tissue repair due to their biocompatibility and to combine physical, mechanical and biological characteristics similar to those of human bone tissue. However, there are no studies in hybrid scaffolds using the sol–gel method and a foaming system, with the direct incorporation of cobalt therapeutic ion. In this work, novel porous polyvinyl alcohol polymer (PVA)/bioactive glasses (BG) hybrids scaffolds containing cobalt were obtained, combining the PVA non-toxicity, non-carcinogenicity and processability to the BG bioactivity and osteogenic properties and Co angiogenic effect by the sol–gel and foaming processing method, in order to obtain a new scaffold with angiogenic properties. The effects of Co incorporation on scaffold structure, bioactivity and ion release were evaluated. Cell viability and cell growth assay were performed on human umbilical vein endothelial cells, demonstrating excellent mitochondrial activity without cytotoxicity and cell-friendly environment. Hybrid scaffolds supported fast ion release and an elastic modulus of 20.19 MPa. The presence of cobalt was confirmed by SEM and EDS. Co-incorporated samples showed high porosity and favorable pore size. PVA–BG hybrid scaffolds containing Co showed ionic release rate in the therapeutic range and are promising for angiogenesis in tissue engineering applications.