Then, to mimic the mineral and organic component of natural bone, the PCL-Gelatin-HAp nanocomposites were prepared via layer solvent casting combined with freeze-drying and lamination techniques. Finally, glutardialdehyde selleck bio (GA) was used as a cross-linking agent. The increasing of the PCL weight through the scaffold samples caused the improvement of mechanical properties. Eventually, the cellular responses of the scaffolds were examined. The proliferation of the MSCs in direct contact with the scaffolds was qualitatively determined by Scanning Electron Microscope (SEM) analysis and quantitatively with MTT assay. Results and Discussion HAp powder The XRD data of the nanocrystalline HAp powder is presented in Figure 2A. The XRD analysis was performed using an X-ray diffractometer.
The straight base line and the sharp peaks of the diffractogram confirmed that the product was well crystallized. The XRD patterns indicated that HAp was formed in this sample, and traces of other calcium phosphate impurities were not detected by this technique. The XRD pattern of sintered samples can be completely indexed with HAp in the standard card (JCPDS No. 09�C0432), the only phase found present. No processing residue or secondary phases were found in the materials. Figure 2. (A) The XRD pattern of the synthesized nanocrystalline HAp powder. (B) The FTIR spectrum of the synthesized HAp powder. Figure 2B shows the FTIR spectrum in the 500�C4,000 cm?1 spectral range of the HAp powder. The HAp powder exhibited five important infrared bands located at 560, 605, 622, 1,040 and 3,555 cm?1.
Among these bands, two bonds were observed at 3,555 and 622 cm?1 due to the stretching mode of hydrogen-bonded OH- ions and the liberational mode of hydrogen-bonded OH- ions, respectively. In addition, the band at 1,040 cm?1 arises from ��3 PO4, and the bonds at 605 and 560 cm?1 arise from ��4 PO4.50 The FTIR analysis showed all typical absorption characteristics of the HAp powder, and, according to these explanations, it is obvious that the synthesized powder is certainly HAp. The result of measurement of elemental composition (Ca and P content) and Ca/P molar ratio were chemically analyzed by quantitative chemical analysis via EDTA titration technique and AAS. The Ca and P content and bulk Ca/P molar ratio was determined as 38.63 (wt%), 17.48 (wt%) and 1.71, respectively.
The measured Ca/P ratio for this synthesized powder was higher than the stoichiometric ratio (1.667) expected for a pure HAp phase that can arise from local presence of carbonate apatite in which the Ca/P molar ratio can be as high as 3.33.51 TEM analysis was used to examine and estimate HAp crystallites. TEM micrographs of the HAp powder in low and high magnifications are shown in Figure 3. The crystalline structure of HAp particles has an elliptical shape with a grain size in the range of 8�C12 nm. Figure 3. The TEM micrographs of the Cilengitide HAp powder, (A) low and (B) high magnifications.