Fig 1.
The initial microstructure of the biomaterials.
Scanning electron microscopy analysis of (a) hydroxyapatite (HA); (b); β-tricalcium phosphate (β-TCP); (c) biphasic calcium phosphate (BCP); (d) β-TCP/MgO nanocomposite; (e) β-TCP/SiO2 nanocomposite.
Fig 2.
Morphology of precipitated drug onto calcium phosphate surface.
Backscattered electron microscopy analysis of the biomaterials-carboplatin loading in the 70 mg/g concentration showing the micrometric carboplatin precipitate in (a) hydroxyapatite (HA), (b) β-tricalcium phosphate (β-TCP) and (c) biphasic calcium phosphate (BCP); mannitol precipitate in (d) β-TCP/MgO nanocomposite; amorphous precipitate in (e) β-TCP/SiO2 nanocomposite.
Fig 3.
Morphology and composition of carboplatin precipitates on the calcium phosphate surface.
Scanning electron microscopy analysis of the biomaterials-carboplatin loading: (a) well-defined micrometric carboplatin precipitated in HA-carboplatin 60 mg/g surface; (b) carboplatin precipitate and superposed calcium phosphate biomaterial in BCP-carboplatin 50 mg/g; (c) not well-defined boundary of carboplatin in β-TCP/SiO2 nanocomposite 70 mg/g; energy dispersive spectroscopy (EDS) analysis detected peaks of marked regions: (d) the EDS analysis of point 1 in HA-carboplatin; (e) the EDS analysis of point 2 and (f) of point 1 in BCP-carboplatin; (g) the EDS analysis of the β-TCP/SiO2 nanocomposite.
Table 1.
The initial surface area of the calcium phosphate (CaP) biomaterials.
Fig 4.
X-ray diffraction analysis of the biomaterials before and after drug loading.
(a) detected characteristics hydroxyapatite (H) and β-TCP (T) peaks in the calcium phosphates (CaPs) before drug loading; (b) carboplatin (C) peaks in biomaterials after drug loading process in the 70 mg/g concentration, compared with the drug that presented carboplatin (C) and mannitol peaks (M).
Table 2.
X-ray fluorescence spectroscopy of calcium phosphate (CaP)-carboplatin (wt%).
Fig 5.
Fourier transform infrared analysis of the biomaterials after the drug loading.
FTIR analysis of the 70 mg/g carboplatin-biomaterials compared with carboplatin drug alone (carboplatin and mannitol).
Fig 6.
Raman spectroscopy of the granulated calcium phosphate-carboplatin biomaterials and carboplatin drug alone (carboplatin and mannitol).
(a) High-intensity phosphate peaks of calcium phosphate biomaterials and carboplatin-drug detected peaks in the 70 mg/g concentration biomaterials; (b) 700–150 cm-1 graphs with calcium phosphate peaks and characteristics platinum vibrational modes of carboplatin in 50 mg/g (black line), 60 mg/g (blue line) and 70 mg/g (red line) biomaterials.
Fig 7.
Ultraviolet-visible (UV-Vis) spectroscopy analysis of release medium and blank tests.
(a) UV-Vis spectra of 60 minutes-release solution; 50 μg/mL carboplatin-drug (carboplatin and mannitol) solution (blue line), and 50 μg/mL mannitol solution alone (red line); (b) UV-Vis spectra of blank analysis with only biomaterials and blue line at 232 nm. Absorbance scales in Fig 7A and 7B are not the same.
Table 3.
Remaining weight of the CaP-carboplatin biomaterials after the load process by the high-vacuum method.
Fig 8.
Cumulative carboplatin release from biomaterials carboplatin-load in three different initial concentration.
(a) 50 mg/g; (b) 60 mg/g; (c) 70 mg/g.