Feasibility of alumina and alumina-silica nanoparticles to fabricate strengthened betatricalcium phosphate scaffold with improved biological responses

摘要

Betatricalcium phosphate (beta-TCP), nano-alumina- and nano-aluminaano-silica added beta-TCP scaffolds were prepared by the foam replication method followed by sintering at 1200-1300 degrees C. The rheological properties of beta-TCP and the nano-additive-containing beta-TCP slurries were investigated using a computerized rheometer. The phase composition, mechanical strength, microstructure and rat-calvarium-derived osteoblast responses of the scaffolds were also studied. The results showed that nano-alumina decreased viscosity of beta-TCP slurry and receded its thixotropy whereas a reverse result was obtained for the nano-silica additive. The phase composition of the scaffolds was whitlockite regardless of sintering temperature. The nano-alumina-added beta-TCP scaffolds were 2-4 times stronger than pure beta-TCP and their compressive strength values were in the range of 0.1-0.5 MPa, depending on the additive content and temperature. However, when nano-alumina and nano-silica were simultaneously used, the compressive strength was dramatically improved to 5 MPa for temperature 1250 degrees C and 15 MPa for temperature 1300 degrees C. Adding nano-alumina and nano-aluminaano-silica to pure beta-TCP resulted in a more compacted microstructure with reduced grain size. All scaffolds exhibited adequate cell attachment, but the proliferation and alkaline phosphatase activity of the cells increased when nano-alumina and nano-silica were simultaneously used. Overall, tissue engineering scaffolds with interconnected macropores and improved mechanical and biological properties can be fabricated using a small quantity of nano-alumina and nano-silica additives. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.