Characterization of In vitro Mineralization of Porous Poly (L-Lactic Acid)/Bioactive Glass Composites by Attenuated Total Reflectance-Fourier Transform Infrared Mapping

Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) mapping was used to characterize the mineralization of porous poly (L-lactic acid)/bioactive glass (PLLA/BG) composite in PBS solution. FTIR images were generated on the basis of the ratio of the absorbance of the band at 1044 cm−1 to the one at 1755 cm−1 (A1044/A1755) at a resolution of 8 cm−1 with 8-coadded scans. The imaging results showed that the amount of hydroxyapatite (HA) on the surface of the composites increased with soaking time and most of the surface area was covered by HA after being mineralized for 84 d. However, the heterogeneous mineralization increased with time lasted. The mineralization curve from the average spectra further suggested that there were four stages during mineralization. At the initial one (less than 21 d), the amounts of HA were small; at the growth one (21–70 d), BG was gradually converted to HA; at the rapid growth one (70–91 d), the mineralization was accelerated and reached up to the maximum at 91 d; and at the late stage (over 91 d), the curve became steady at first and then declined after 105 d. The results suggested that ATR-FTIR mapping was promised to be an important tool for study of the scaffold in bone tissue engineering.

ATR-FTIR images of PLLA/BG composite were produced on the basis of A1755 directly and of the absorbance ratio of A1044 to A1755. The latter can eliminate the effects of the variations of contact pressure on the absorbance.Figure optionsDownload as PowerPoint slide