During the correction process, replacements were provided for tables 2 and 3 which were incorrectly included in the final published article. The correct tables 2 and 3 have been provided below; accordingly, some corrections in the discussion were performed. We sincerely apologise for any inconvenience caused by this oversight.

Table 2. Chemical constitution of prepared powders showing the calculated and measured molar ratios.

Sample symbolCalculated (Ca+x)/PMeasured (Ca+x)/PCalculated Ca/(P+Si)Measured Ca/(P+Si)Calculated (Ca+x)/(P+Si)Measured (Ca+x)/(P+Si)Calculated Ca/PMeasured Ca/PHA——————1.671.41NaHA1.671.57————1.58581.56Si.CHA1.961.6541.741.621.851.6451.84671.63Si.NaHA1.7621.4981.561.481.671.4961.6481.48TiHA12.7921.57————1.671.57TiHA21.831.53————1.671.52TiHA31.8751.5————1.671.50LiHA11.671.51————1.6621.51LiHA21.671.56————1.6581.53LiHA31.671.6————1.6541.59

X = Na, Ti or Li.

Table 3. Chemical constitution of prepared powders, showing the calculated and measured molar ratios of X/Ca and Si/P with X = Na, Ti or Li.

Sample symbolCalculated X/CaMeasured X/CaCalculated Si/PMeasured Si/PHA————NaHA0.05310.00872——Si.CHA0.0640.015130.0610.00537Si.NaHA0.06930.111170.0570.00098TiHA10.0750.00026——TiHA20.10.0032——TiHA30.1250.001——LiHA10.00250.00219——LiHA20.005020.01463——LiHA30.007560.00469——

X = Na, Ti or Li.

In Discussion section:

- Paragraphs 2nd and 3rd: replace the sentences from 'From ICP results (table 1), Ca/P in all samples, pure and ion substituted HA, increased after preparation...' to the sentence '... competing with ions into site.' by the following:

From ICP results (table 2), Ca/P in all samples, pure and ion substituted HA, decreased slightly after preparation that is maybe due to the deficiency of Ca or incorporation of some substituted ions in the site of Ca in quantities larger than the calculated ones. Feki et al [31] found that to balance the total net charge, when the percentage of sodium substituting the calcium grew, an equal quantity of carbonate ions were incorporated into the phosphate sites. The calculated and measured molar ratio of Na/Ca is ascending as follows: NaHA < Si.CHA < Si.NaHA. This is manifested in the increase in the degree of sharpness of FTIR of B-type carbonate bands, indirectly confirming the substitution of sodium for calcium in HA lattice.

Synthesis of Si.NaHA was accomplished by calculating the respective proportion of precursors, assuming that the starting (Ca+Na)/(P+Si) molar ratio = 1.67, resembling that present in the pure HA phase. The measured contents of P and Na in the Si.Na-HA prepared powders were higher than the calculated values as reflected on the Si/P and Na/Ca ratios (table 3). A high drop was recorded in the Si/P (from 0.057 to 0.00098) while an increase was recorded in Na/Ca (from 0.0693 to 0.11117) in the measured values than the calculated ones, (table 3), i.e., the tendency for Na+ to substitute Ca2+ ions is higher than that of to substitute ions competing with ions into site.

- Paragraph 8th: replace the sentence 'The measured Ca/P molar ratios of LiHA1, LiHA2, and LiHA3 (1.951, 1.986, and 2.06, respectively) were higher than calculated ones (table 2), indicating that the B-type carbonate substitution into the HA lattice is possible, as indicated by the FTIR observations (figure 2).' by the following:

The measured Ca/P molar ratios of LiHA1, LiHA2, and LiHA3 (1.51, 1.53, and 1.59, respectively) were slightly lower than the calculated ones (table 2), and in ascending manner respectively as the calculated values, confirming the incorporation of Li+ in the HA as expected with increasing amounts from LiHA1, LiHA2, to LiHA3. The B-type carbonate substitution into the HA lattice is possible as indicated by the FTIR observations (figure 2).