Preparation and bioactive characteristics of a porous 13-93 glass, and fabrication into the articulating surface of a proximal tibia

Abstract

The silicate-based 45S5 bioactive glass, typically in particulate form, has been widely investigated for bone repair. However, its application as a scaffold for bone tissue engineering is limited due to the difficulty of forming porous three-dimensional constructs with complex shapes. In this study, the use of another silicate-based bioactive glass, referred to as 13-93, was investigated for the preparation of porous constructs. Particles of 13-93 glass (255-325 microm) were consolidated and sintered to form cylindrical constructs. Characterization of these constructs was performed using mercury porosimetry, scanning electron microscopy (SEM), and mechanical testing. Constructs with porosities of 40-45% and pore sizes in the range 100-300 microm were found to have a compressive strength of 22 +/- 1 MPa. The bioactivity of the 13-93 glass was studied by immersing disks in a simulated body fluid at 37 degrees C and characterizing the reaction products. X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, and SEM showed the formation of a crystalline hydroxyapatite layer on the glass surface after approximately 7 days. The ability to fabricate the complex geometrical shape of the articulating surface of a human tibia from 13-93 glass particles was demonstrated.