Influence of Boroxide Bioactive Bioglasses (BBB) on osteoblast viability

Abstract

The term bioglass addresses to surface reactive glass biomaterials. Their high bioactivity results in formation of strong bonds with the neighboring bones while the material contacts the bone. Bioactivity performance of bioglasses has been experimentally and clinically demonstrated both in vitro and in vivo, respectively. The first bioglass, named as bioglass 45S5, was invented by Hench with typical formulation of 25.5% Na2O, 24.5% CaO, 45% SiO2 and 6% P2O5. That classical formula melts, however, at around 1450 degrees C. Addition of various amounts of B2O3 causes considerable lowering of glass melting temperature down to 950-1050 degrees C. The significant reduction of glass melting temperature increases the feasibility of glass production processing and reduces the production cost of the resultant glasses. Under the perspective of health care, the primary use of boron in the body aims at absorbing calcium. Hence, boron is essential for healthy bones. In fact, boron is useful for women suffering from postmenopausal osteoporosis. Our study addresses its interest in boron-containing bioglasses, termed as boroxide containing bioactive bioglasses (BBB). In particular, the investigated glasses were based on the 45S5 bioglass having additives of B2O3 as follows: (a) Glass-B2 31.5% B2O3, (b) glass-B3 12.48% B2O3, (c) glass-B4 6.5% B2O3, (d) glass-B5 3.5% B2O3, and (e) glass-B6 2.5% B2O3. Medium, containing fine powders from each BBB glass, was put in contact with osteoblasts that have been plated at 1 x 10(5) cell density. The experiments were performed 72 hours after incubation. Morphological changes were investigated under light microscope. Cells' viability was assayed by MTT. Among the 5 investigated BBB glasses, the glass-B4 and glass-B5 exhibited the best performance and hence they can be qualified for further consideration and experimentation.