Bioactive materials, specially surface reactive materials such as bioactive glasses (BGs), are being increasingly considered in the tissue engineering (TE) field, expanding from bone TE to soft tissue repair and wound healing. Such TE applications are based on the biochemical reactions occurring at the interface between the material surface and the biological environment, which involve the (controlled) release of biologically active ions as dissolution products that stimulate the cellular environment during new tissue growth [1]. As an example, the effect of specific metallic ions on vascular endothelial growth factor release from stem cells will be shown to demonstrate the angiogenic potential of such biomaterials. In model cell culture studies, the variation of ion concentration in the medium and the time dependent effects on stem cells will be discussed, which is required for the comprehensive assessment of the biological performance of such bioreactive materials with implication for their clinical translation. 

In this context, applications of BGs in the field of 3D bioprinting (biofabrication) have been emerging in the last few years. In the second part of the presentation, the progress in the development and characterization of TE scaffolds made purely from BGs or by combining BGs and biopolymers, including their application in biofabrication (3D bioprinting) approaches will be discussed. Recent results on the development of hydrogel-BG composites as innovative bioinks for cell encapsulation and for 3D bioprinting of cell laden scaffolds will be presented [2], highlighting the properties and applications of bioreactive, multimaterial and colloidal bioinks in the emerging field of biofabrication for generating cell laden 3D structures of increasing complexity and functionality.

References
[1] A. Hoppe, et al., A review of the biological response to ionic dissolution products from bioactive glasses and glass-ceramics, Biomaterials 32 (2011) 2757-2774.
[2] S. Heid, A. R. Boccaccini, Advancing bioinks for 3D bioprinting using reactive fillers: A review, Acta Biomater. 113 (2020) 1-22.