Since lithium (Li+) plays a role in angiogenesis, the localized and controlled release of Li+ ions from bioactive glasses (BGs) represents a promising alternative therapy for tissue engineering and repair of vascularized tissues. This presentation will review recent advances in the development of Li-containing bioactive glass-ceramic scaffolds derived from the 45S5 BG and their in vitro angiogenic potential. It has been demonstrated that ion release from Li-substituted BG can be tailored to induce an appropriate biological response, for example, the partial replacement of Na2O by up to 5 wt% of Li2O in the 45S5 BG ensures the release of Li+ within the therapeutic range for humans (0.5-1.2 mmol). Recent experimental results have shown that human umbilical vein endothelial cells (HUVECs) treated with ion dissolution products (IDPs) of glass-ceramic scaffolds containing 5 wt% of Li2O (45S5.5Li) exhibit a proliferative and migratory response and have the capacity to form tubules in vitro. In addition, the activation of the Wnt/β-catenin canonical pathway was observed. At 24 h post-stimulation, the expression of β-catenin in HUVECs treated with IDPs of the bioactive glass-ceramic scaffolds 45S5.5Li showed a statistically significant increase in comparison to the control, with an equivalent response to that obtained with the use of 0.60 mmol LiCl and M199 medium supplemented with VEGF.
Moreover Li+ ions also promote osteogenesis and bone repair. In this context, new Li-delivering bioactive glass-ceramic scaffolds could further represent a promising biomaterial-based strategy to initiate angiogenesis and to induce desirable bone regeneration.