Growth and phenotypic expression of human endothelial cells cultured on a glass-reinforced hydroxyapatite

Glass-reinforced hydroxyapatite composites (GR-HA) are bone regenerative materials that are characterized by their increased mechanical properties, when compared to synthetic hydroxyapatite. Bonelike(A (R)) is a GR-HA that is a result of the addition of a CaO-P2O5 based glass to a HA matrix. This biomaterial has been successfully applied in clinical bone regenerative applications. This work aims to evaluate the ability of Bonelike(A (R)) to support the adhesion, proliferation and phenotypic expression of human endothelial cells, aiming to establish new bone tissue engineering pre-endothelialization strategies. Bonelike(A (R)) discs, regardless of being submitted to a pre-immersion treatment with culture medium, were seeded with first passage human umbilical vein endothelial cells, and characterized regarding proliferation and differentiation events. Pre-immersed Bonelike(A (R)) allowed the adhesion, proliferation and phenotype expression of endothelial cells. Seeded materials presented positive immunofluorescent staining for PECAM-1 and a tendency for the formation of cord-like arrangements under angiogenesis-stimulating conditions, although, compared to standard culture plates, a slight decreased cell growth was observed. In this way, Bonelike(A (R)) may be a suitable candidate for pre-endothelialization approaches in bone tissue engineering applications.