Nano-beta-tricalcium phosphates synthesis and biodegradation: 2. Biodegradation and apatite layer formation on nano-β-TCP synthesized via microwave treatment

The degradation and/or apatite layer precipitation ability of porous beta-tricalcium phosphate (beta-TCP) samples treated and untreated with microwave radiation during synthesis is investigated. Microwave heating was used to accelerate the formation of CDHA with the Ca/P ratio 1.5 in a shorter processing time which later forms beta-TCP at around 650 degrees C. Soaking in simulated body fluid (SBF) for several periods (4, 8, 12, 24, 36, 48, 60 and 72 h) is performed in a cumulative manner. The deposition of an apatite layer is followed through diffuse reflected FT-IR, SEM and EDS. A microwave-treated sample having a smaller particle size than its parent induces the formation of a homogeneous carbonated apatite layer on its surface. On the other hand, the parent beta-TCP sample exhibited less ability to induce Ca-P formation after being soaked in SBF. The formation of an apatite layer is attributed to the increase in surface area consequent to reduced particle and grain sizes besides the presence of a minor amount of hydroxyapatite phase in the microwave-treated beta-TCP sample. The results prove that it is possible to control the biodegradation and apatite layer formation on sintered beta-TCP porous disks through controlling the particle size.