Table 1.

Phase, chemical composition and surface charge of the samples.

Sample	CaP	CaP–HS
HA (wt.%) a	42.8 ± 1.7	42.6 ± 1.3
β-TCP (wt.%)a	57.1 ± 1.7	57.4 ± 1.2
CI (a.u.) a	61.4 ± 0.5	61.2 ± 0.5
Ca (wt.%) b	34.0 ± 0.3	33.5 ± 0.6
P (wt.%)b	18.7 ± 0.2	18.3 ± 0.4
K (wt.%) b	1.64 ± 0.02	1.11 ± 0.01
Mg (wt.%) b	0.69 ± 0.01	0.67 ± 0.01
Na (wt.%) b	1.80 ± 0.34	1.26 ± 0.03
Ca/P molar ratio b	1.41 ± 0.01	1.41 ± 0.01
Humic acid (wt.%) c	-	0.4
ζ-potential d	−23.0 ± 1.0	−29.5 ± 0.2

^a Determined by XRD, ^b Determined by ICP-OES, ^c Determined by TGA, ^d Determined by DLS.