A low-cost approach to develop silica doped Tricalcium Phosphate (TCP) scaffold by valorizing animal bone waste and rice husk for tissue engineering applications

Abstract

In the present study Hydroxyapatite (HAp) derived Tricalcium Phosphate (TCP) and Silica (SiO2) based scaffold was successfully fabricated for the first time by effective utilizing various waste such as animal waste bone (AWB) and rice husk (RH) as a source of HAp and SiO2 respectively. Scaffold development involved simple steps comprising of segregation of waste materials followed by sample preparation through die compaction and sintering (1000 °C and 1300 °C). Advanced characterization techniques like XRD, SEM, TEM, and FTIR were employed to study the properties of the waste materials as well as the developed composite scaffold. The presence of silica from RH combines with the HAp during high temperature sintering and initiates the phenomenon of phase transformation of HAp to TCP along with the formation of a glassy phase. The extent of phase transformation increases as the wt% of RH increases. XRD analysis revealed the development of different phases. SEM microstructure shows that the addition of silica restricts the grain growth and supports the formation of crystalline glassy phase termed as Si-TCP. FTIR results confirmed the presence of phosphate, carbonate, and hydroxyl groups in the sintered samples. The porosity of the scaffold was in the range of 34–61% and the compressive strength was up to 4.1 MPa. The SEM images of scaffold dipped in simulated body fluid (SBF) shows formation of apatite layer throughout the surface. The bioactivity of the scaffold was highly influenced by the addition of silica in the HAp matrix. The apatite forming ability of the developed porous was much greater than that of pure HAp for the same incubation period. The obtained properties of the developed scaffold are comparable to that of natural bone. Thus the present work creates an opportunity to use AWB for the development of composite for tissue engineering applications.