Preparation and Degradability of Poly(lactic acid)-Poly(ethylene glycol)-Poly(lactic acid)/SiO2 Hybrid Material

Poly(lactic acid)-poly(ethylene glycol)-poly (lactic acid) (PLA-PEG-PLA)/SiO2 hybrid material is prepared by sol-gel method using tetraethoxysilane (TEOS) and PLA-PEG-PLA as raw material. From Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) spectra, the hydroxyl groups of the silica sol derived from partially hydrolysis of TEOS and the unhydrolyzed ethoxy groups of TEOS can react with PLA-PEG-PLA. Differential scanning calorimetry (DSC) curves imply that the glass transition temperature (T-g) of PLA-PEG-PLA/SiO2 hybrid material is higher than that of PLA-PEG-PLA and increases with the increase of silica content. X-ray diffraction (XRD) analysis results show that PLA-PEG-PLA and PLA-PEG-PLA/SiO2 hybrid material are both amorphous. Field scanning electron microscope (FSEM) photographs show that when PLA-PEG-PLA/SiO2 hybrid material has been degraded for 1.2 weeks in normal saline at 37 degrees C, a three-dimensional porous scaffold is obtained, which is available for cell growth and metabolism. Moreover, the hydroxyl (-OH) groups on SiO2 of PLA-PEG-PLA/SiO2 hybrid material could buffer the acidity resulted from the degradation of PLA, which is beneficial to proliferation of cell in tissue repairing. (C) 2008 Wiley Periodicals, Inc. J Appl Polym Sci 110: 3985-3989, 2008