Borate Bioactive Glass

Abstract

Borate-based bioactive glasses, including borate glasses and borosilicate glasses, react with the surrounding biological solution so as to convert to apatite and/or an apatite-like phase and directly bond to bone as in the case of silica-based bioactive glasses. It is easier to match the degradation rate of the borate-based bioactive glasses with that of the target tissue than to the faster degradation rate. On the other hand, there are some concerns regarding the cytotoxity of borate bioactive glasses as they tend to release large amounts of borate ions. In this chapter, the biological reaction of boron and the capacity of the borate bioactive glass for both hard and soft tissue regeneration are described. Although borate bioactive glasses with the higher B 2 O 3 content resulted in greater inhibition in cell proliferation under a static cell culture condition, no cytotoxicity was observed under dynamic culture conditions mimicking the body environment. Recent studies have accumulated the results that little or no cytotoxicity has occurred in vivo and enhancement of hard and soft tissue regeneration. The application of borate bioactive glasses to wound healing was remarkably advanced by the introduction of the cotton-like glass pad into the 13-93B3 glass, although further study is still required to fully understand the mechanism of wound healing process induced by the borate microfibers.