Morphological and biomechanical characterization of poly(glycolic acid) scaffolds after in vitro degradation

摘要

Morphology and the biomechanical properties of the fibrous nonwoven poly (glycolic acid) (PGA) scaffolds were studied over 8 weeks of in vitro degradation. Morphology of the PGA scaffold was examined using scanning electron microscopy (SEM). Results showed that at day 3 to day 14, the fibers in the scaffolds became more separated apparently due to the initial swelling effect of medium absorption. However, the samples shrank dimensionally by day 28 and some became disintegrated shortly afterwards. More fiber endings could apparently be found in samples with longer periods of degradation. As degradation time increased, some fiber end surfaces showed signs of further decays. During the degradation period, there were little changes in the chemical structures as determined by Fourier Transform Infrared Spectroscopy. Thermal studies by differential scanning calorimetry (DSC) showed that the melting temperatures of the scaffold material shifted lower, while the degree of crystallinity determined by both DSC and X-ray diffraction increased significantly during the initial degradation period and apparently decreased afterwards. Biomechanical tests of 10% compression and 14% shear were performed to study the structural properties of the scaffolds upon degradation. The results clearly showed that the fibrous non-woven PGA scaffolds lost their structural properties substantially over relatively short period of in-vitro degradation. Whether such a degradation speed is optimal or not should be carefully evaluated for different tissue engineering applications. (C) 2003 Elsevier Science Ltd. All rights reserved. [References: 15]