Compressive Strength Enhancement of Carbon Nanotube Reinforced 13-93B1 Bioactive Glass Scaffolds.

Abstract

45S5 Bioglass® has been used quite extensively in the form of particulate as synthetic bone graft. However, 45S5 glass has certain limitations such as difficulty in sintering and slow and partial conversion to hydroxy carbonated apatite. In pursuit of overcoming these limitations, bioactive glasses (13-93B1) containing increased amount of B₂O₃ by partial replacement of SiO₂ have been prepared using sol-gel technique in this study. Since bioactive glasses are brittle in nature, therefore, they are unsuitable for load bearing sites. Consequently, 3D porous scaffolds by reinforcement with varying weight percent of carbon nanotubes (CNTs) have been fabricated in this work by physical mixing and polymer foam replication technique. Compared with pure 13-93B1 bioactive glasses, addition of 0.2 weight percent of CNT resulted in maximum increase in compressive strength from 1.80 MPa to 5.84 MPa (a 224% increase) and elastic modulus from 102 MPa to 269.4 MPa (a 164% increase), respectively. Bioactivity of these scaffolds was confirmed in vitro using simulated body fluid test for 28 days. The compressive strength post-SBF studies were within the range of compressive strength of trabecular bone. These results show potential of fabricating a 3D porous scaffold with sufficient strength and biocompatibility using CNT-1393B1 bioactive glasses.