Chapter 16: Bioactive Glasses as Carriers of Therapeutic Ions and the Biological Implications

In the last few decades bioactive glasses (BGs) have been widely considered for bone tissue engineering applications due to their bioactivity and their osteogenic effects. The available scientific evidence suggests that ionic dissolution products (at a critical concentration) released during the degradation of the BG matrix induce osteogenic gene expression hence stimulating the bone regeneration process. Moreover, adding bioactive metallic ions (e.g. boron, copper, cobalt, lithium silver, zinc and strontium) to silicate as well as to phosphate and borate glasses has emerged as a promising route to develop novel BG formulations with specific therapeutic functionalities, including antibacterial, angiogenic, osteogenic and wound healing. The degradation behaviour of BGs can be tailored by adjusting the glass chemistry, making these biomaterials suitable carrier systems for controlled therapeutic ion release. This book chapter summarizes the fundamental aspects of the effect of ionic dissolution products released from BGs on osteogenesis and angiogenesis, also discussing novel BG compositions containing inorganic therapeutic agents. In vitro cellular as well as in vivo responses to specific therapeutic ions are discussed.