Development of Porous Bioactive SiO2-Na2O-CaO-P2O5 Glass Ceramic Scaffold

Abstract

Bioactive glasses of chemical composition 48.4SiO2 -23.8Na2O- 23.8CaO- 4.0P2O5 wt% was prepared through Sol-Gel route. It was then crystallized through thermal treatment. Porous samples of the mentioned composition using Naphthalene (0, 30, and 50 weight percentage) as pore former were made and tested for Bulk Density, Apparent porosity, Linear Shrinkage, Cold Crushing Strength, and Bi-axial flexural strength. Maximum porosity of 50% was obtained by this process. The maximum value of CCS obtained was 7.8MPa without any pore former and a minimum of 2.3 MPa for 50% Naphthalene. The Bi-axial flexural strength varied between the extremes of 16.3 MPa and 5.6 MPa. Their pore size distribution was also studied to ensure the presence of pores with size greater than 100 µm, which happens to be the critical lower limit for Angiogenesis. Samples were also prepared with a radial porosity gradient similar to the structure of the cancellous part of the Bone structure. The samples contained a central core of higher porosity and a outer concentric ring of lower porosity. These samples were also tested for the above mentioned mechanical properties. The Bioactivity of the samples was also studied by immersing them in a SBF solution for a period of 1, 3, and 7 days. These samples were then studied using XRD, SEM, EDX, and FTIR and showed significant formation of HCA ensuring their Bioactivity.