title: Fabrication of poly-DL-lactide/polyethylene glycol scaffolds using the gas foaming technique.
abstract: The aim of this study was to prepare poly-DL-lactide/polyethylene glycol (PDLLA/PEG) blends to improve medium absorption and cell proliferation in the three-dimensional (3-D) structure of their scaffolds. Carbon dioxide (CO2) was used as a foaming agent to create porosity in these blends. The results of Fourier transform infrared (FTIR) spectroscopy demonstrated that the blends were homogeneous mixtures of PDLLA and PEG. The peak shifts at 1092 and 1744 cm(-1) confirmed the presence of molecular interactions between these two compounds. Increasing the PEG weight ratio enhanced the relative crystallinity and hydrophilicity. The PDLLA/PEG blends (especially 80/20 and 70/30 weight ratios) exhibited linear degradation profiles over an incubation time of 8 weeks. The mechanical properties of PDLLA/PEG blends having less than 30 wt.% PEG were suitable for the fabrication of porous scaffolds. Increasing the concentration of PEG to above 50% resulted in blends that were brittle and had low mechanical integrity. Highly porous scaffolds with controllable pore size were produced for 30 wt.% PEG samples using the gas foaming technique at temperatures between 25 and 55 °C and pressures between 60 and 160 bar. The average pore diameters achieved by gas foaming process were between 15 and 150 μm, and had an average porosity of 84%. The medium uptake and degradation rate of fabricated PDLLA/PEG scaffolds were increased compared with neat PDLLA film due to the presence of PEG and porosity. The porous scaffolds also demonstrated a lower modulus of elasticity and a higher elongation at break compared to the non-porous film. The fabricated PDLLA/PEG scaffolds have high potential for various tissue-engineering applications.
authors: School of Chemical and Biomolecular Engineering, University of Sydney, Sydney 2006, Australia.
authors: Chengdong
authors: C
authors: Ji
authors: Nasim
authors: N
authors: Annabi
authors: Maryam
authors: M
authors: Hosseinkhani
authors: Sobana
authors: S
authors: Sivaloganathan
authors: Fariba
authors: F
authors: Dehghani
mesh_terms: D002152:Calorimetry, Differential Scanning; D002245:Carbon Dioxide / Q000737:chemistry*; D003460:Crystallization; D057927:Hydrophobic and Hydrophilic Interactions; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D011091:Polyesters / Q000138:chemical synthesis* / Q000737:chemistry; D011092:Polyethylene Glycols / Q000138:chemical synthesis* / Q000737:chemistry; D016062:Porosity; D012997:Solvents / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D013718:Tensile Strength; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D011091:Polyesters; D012997:Solvents; D002245:Carbon Dioxide; D011092:Polyethylene Glycols; C033616:poly(lactide)