The barks of M. elengi were collected from the campus of
SGB Amravati University, Amravati. Later, these were
washed with distilled water and air-dried for about
3–4 days. The dried bark was then ground to fine powder.
The powder was then added to the distilled water and
centrifuged. The supernatant was collected and used for
synthesis. The protocol for chemical synthesis of calcium
phosphate nanoparticles suggested by Chen et al. (2010)
was modified for biological synthesis. Calcium phosphate
nanoparticles were prepared by mixing 7.5 ml of 12.5 mM
calcium chloride; 7.5 ml of 12.5 mM dibasic sodium
phosphate solution into 1.5 ml of M. elengi bark extract
solution (supernatant) by continuous stirring for
10–15 min. The mixture was sonicated (frequency 22 kHz,
power 120 W) for 30 min, dispersion was then filtered.