Angiogenic potential of bioactive glasses

Abstract

Enhancement of the angiogenic potential of implantable tissue scaffolds is the focus of considerable research efforts in tissue engineering (TE) strategies. 1–3 Angiogenesis, the formation of new blood vessels from the endothelium of the existing vasculature, plays a pivotal role in TE and wound healing. During wound repair, microvascular endothelial cells migrate into the blood clot; they proliferate and form new blood vessels. This complex process is regulated at the molecular level by growth factors, ECM proteins, membrane receptors and signalling molecules that tightly modulate the formation of new blood vessels (Fig. 5.1).4 This process, called neovascularisation, contributes to the success of regenerating and growing new tissue, because blood vessels bring oxygen, nutrients and growth factors as well as serve as a route for inflammatory cells and precursor cells to reach to the highly metabolically active regenerating tissue. If TE scaffolds have the ability to induce neovascularisation, the viability of native or transplanted cells within scaffolds will be increased, which will enhance the possibility of engineering larger volumes of new tissues. Several approaches are being proposed to induce rapid vascular in-growth, such as gene and/or protein delivery of angiogenic growth factors and ex vivo culturing of scaffolds with endothelial cells alone or in combination with other cell types.3,5.