Ionic Dissolution Products from a Lithium-doped 45S5 Bioactive Glass Promotes Angiogenesis.

L.A. HARO DURAND, GE. VARGAS, RV MESONES, M.A FANOVICH, A BALDI, A GORUSTOVICH

Amsterdam

Congreso; 5th International Meeting on Angiogenesis; 2014

5th International Meeting on Angiogenesis

One of the main limitations to vascularized tissue regenerative medicine is the difficulty in achieving the rapid neovascularization needed for the transportation and exchange of oxygen, nutrients, growth factors and cells that take part in the process of tissue repair and/or regeneration. As it has been established that lithium (Li) may perform functions in  angiogenesis, the controlled and localized release of Li ions from biomaterials could be expected to provide a promising therapeutic alternative for repairing and regenerating tissues that require a high degree of vascularization, e.g. bone tissue.        The aim of this study was to assess the angiogenic effects of the ionic dissolution products from bioactive glasses in the SiO2-CaO-Na2O-P2O5 (45S5) system and 45S5 modified with 5% Li2O (45S5.5Li). The ionic dissolution products were obtained by incubating 1% w/v bioactive glass particles (<5 µm) in embryo medium at 37ºC in an orbital shaker for 72 h. Soluble ions (Li, Si, P, Ca and Na) leached from the bioactive glasses were determined by inductively coupled plasma optical emission spectrometry (ICP-OES). The in vivo pro-angiogenic capacity was assessed by using the embryonic quail (Coturnix coturnix japonica) chorioallantoic membrane (CAM) assay.         The results show for the first time that ionic dissolution products from 45S5.5Li bioactive glass particles increased the in vivo angiogenesis, shown quantitatively by the higher (21%) vascular density in the quail embryo CAMs. The positive effects can be attributed to the release of 0.20 mM Li from 45S5.5Li microparticles. It is important to note that the response observed at 5 days post-treatment was equivalent to that achieved by applying 10 µg/mL of the growth factor bFGF. These findings are relevant to vascularized tissue engineering because the ionic dissolution products from 45S5.5Li bioactive glass may act as an inorganic angiogenic agent and could serve as an alternative to expensive and potentially risky growth factors.